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Background: Ubiquitin-specific protease 7 (USP7) has been found to be associated with motor function recovery after spinal cord injury (SCI). Therefore, its role and mechanism in SCI process need further exploration. Methods: SCI rat models were established via performing laminectomy at the T9-T11 spinal vertebrae and cutting spinal cord tissues. SCI cell models were constructed by inducing PC12 cells with lipopolysaccharide (LPS). The protein levels of USP7, nuclear respiratory factor 1 (NRF1), Krüppel-like factor 7 (KLF7) and apoptosis-related markers were detected by western blot. Cell viability and apoptosis were tested by cell counting kit-8 assay and flow cytometry. The contents of inflammatory factors were examined using ELISA. The interaction between NRF1 and USP7 or KLF7 was analyzed by co-immunoprecipitation assay, chromatin immunoprecipitation assay and dual-luciferase reporter assay, respectively. Results: USP7 was downregulated in SCI rat models and LPS-induced PC12 cells. Overexpressed USP7 promoted viability, while repressed apoptosis and inflammation in LPS-induced PC12 cells. USP7 could stabilize NRF1 protein expression via deubiquitination, and NRF1 knockdown reversed the protective effect of USP7 against LPS-induced PC12 cell injury. NRF1 is bound to KLF7 promoter to enhance its transcription. NRF1 overexpression inhibited LPS-induced PC12 cell inflammation and apoptosis via increasing KLF7 expression. Conclusion: USP7 alleviated inflammation and apoptosis in LPS-induced PC12 cells via NRF1/KLF7 axis, indicating that targeting of USP7/NRF1/KLF7 axis might be a promising treatment strategy for SCI. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) play an important role in the progression of atherosclerosis (AS). This study aimed to explore the exact role and mechanism of circ_0002984 in oxidized low-density lipoprotein (ox-LDL)-mediated human vascular smooth muscle cells (HVSMCs). The model of smooth muscle cell phenotype switching was constructed by treating HVSMCs with ox-LDL. The levels of circ_0002984, let-7a-5p, and kruppel-like factor 5 (KLF5) were measured by quantitative real-time PCR or western blot assay. Cell proliferation, migration, and apoptosis were detected by Cell Counting Kit-8 (CCK-8), EdU staining, wound healing assay, transwell assay, and flow cytometry. The expression of cleaved-caspase-3 and KLF5 was examined by western blot. The relationship between let-7a-5p and circ_0002984 or KLF5 was verified by dual-luciferase reporter assay or RIP assay. The results showed that circ_0002984 and KLF5 were up-regulated, while let-7a-5p was down-regulated in AS patients and ox-LDL-disposed HVSMCs. Silence of circ_0002984 suppressed proliferation and migration, and promoted apoptosis in ox-LDL-stimulated HVSMCs. Moreover, circ_0002984 sponged let-7a-5p to regulate the proliferation, migration, and apoptosis in ox-LDL-resulted HVSMCs. In addition, KLF5 was a target of let-7a-5p and its overexpression reversed the effect of let-7a-5p on the proliferation, migration, and apoptosis in ox-LDL-treated HVSMCs. Also, circ_0002984 positively regulated KLF5 expression by absorbing let-7a-5p. The promotion effect of circ_0002984 on the proliferation and migration of ox-LDL-treated HVSMCs was reversed by KLF5 silencing. Taken together, depletion of circ_0002984 inhibited the proliferation and migration of ox-LDL-stimulated HVSMCs, which might be achieved by modulating the let-7a-5p/KLF5 axis. [ABSTRACT FROM AUTHOR]

Oral submucous fibrosis (OSF) is a condition characterized by inflammation and excessive collagen deposition, which has been identified as a potentially malignant disorder. Recently, several microRNAs (miRNAs) have been shown to be implicated in various disorders associated with fibrosis. However, how these miRNAs modulate OSF development is poorly understood. Therefore, the study aimed to identify the specific miRNAs that contribute to the progression of OSF and to investigate their molecular mechanisms in promoting fibrosis. The expression and clinical significance of potential pro-fibrosis miRNA in the OSF cohort and primary buccal mucosal fibroblasts were confirmed through RNA sequencing and qRT–PCR. Luciferase reporter activity assay, miRNA mimic or inhibitor, and short-hairpin RNA silencing were used to elucidate the molecular mechanism of miRNA. Transwell migration, collagen contraction, and reactive oxygen species (ROS) generation detection were used to investigate the effects of this mechanism on the myofibroblast phenotype and cellular pro-fibrosis capacity. This study demonstrated that miR-190a was overexpressed in fibrotic buccal mucosal fibroblasts (fBMFs). Transfecting fBMFs with miR-190a inhibitor resulted in reduced cell migration, collagen gel contraction, ROS generation, and expression of fibrotic markers. Furthermore, miR-190a exerted this pro-fibrosis property by direct binding to its target, Krüppel-like factor 15 (KLF15). The results also indicated that the aberrant upregulation of miR-190a, in turn, downregulated the expression of KLF15, which resulted in the activation of myofibroblast. Our findings demonstrated that miR-190a was involved in myofibroblast activation, suggesting that targeting the miR-190a/KLF15 axis may be a feasible approach in the therapy of OSF. [ABSTRACT FROM AUTHOR]

Cell-cell junctions, and specifically desmosomes, are crucial for robust intercellular adhesion. Desmosomal function is compromised in the autoimmune blistering skin disease pemphigus vulgaris. We combine whole-genome knockout screening and a promotor screen of the desmosomal gene desmoglein 3 in human keratinocytes to identify novel regulators of intercellular adhesion. Kruppel-like-factor 5 (KLF5) directly binds to the desmoglein 3 regulatory region and promotes adhesion. Reduced levels of KLF5 in patient tissue indicate a role in pemphigus vulgaris. Autoantibody fractions from patients impair intercellular adhesion and reduce KLF5 levels in in vitro and in vivo disease models. These effects were dependent on increased activity of histone deacetylase 3, leading to transcriptional repression of KLF5. Inhibiting histone deacetylase 3 increases KLF5 levels and protects against the deleterious effects of autoantibodies in murine and human pemphigus vulgaris models. Together, KLF5 and histone deacetylase 3 are regulators of desmoglein 3 gene expression and intercellular adhesion and represent potential therapeutic targets in pemphigus vulgaris. Cell-cell adhesion by desmosomes is weakened in the blistering skin disease pemphigus vulgaris. Here, authors found that the transcription factor Kruppel-like factor 5 is essential for the expression of the desmosomal gene desmoglein 3 and suggest a novel treatment approach. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to investigate the function of RAD51AP1 in the self-renewal and chemosensitivity of CD133 positive (CD133+) ovarian cancer (OC) stem-like cells. Methods: CD133+ (CD133 positive) OVCAR4 and CD133 negative (CD133−) OVCAR4 cells were separated from OVCAR4 by flow cytometry. Then, the separated CD133+OVCAR4 cells were divided into the following groups: Vector group; RAD51AP1 group; siNC group; si-RAD51AP1 group. Next, sphere-formation assay and colony forming assay were used to evaluate the self-renewal and proliferation ability of cells; western blot to detect the expression of RAD51AP1, transforming growth factor beta 1 (TGF-β1) and SMAD4 proteins in tissues and cells; qRT-PCR to assess the mRNA levels of sex-determining region Y-box 2 (SOX2), octamer-binding transcription factor 4 (OCT4), NANOG and Kruppel-like factor 4 (KLF4). Results: The performance of CD133+OVCAR4 cells was much better than that of CD133−OVCAR4 cells in sphere-formation assay and colony forming assay. Besides, compared with adjacent group and CD133−OVCAR4 cells, the expression level of RAD51AP1 increased significantly in OC group and CD133+OVCAR4 cells. Moreover, the over-expression of RAD51AP1 promoted the self-renewal and proliferation of CD133+OVCAR4 cells. On the contrary, knocking down the expression level of RAD51AP1 could inhibit the self-renewal and proliferation of CD133+OVCAR4 cells and improve the sensitivity of cells to chemotherapy drugs. Conclusion: The findings of this study showed that RAD51AP1 was highly expressed in OC tissue and CD133+OVCAR4 cells, and regulated the self-renewal and chemosensitivity of tumor cells through the TGF-β1/SMAD4 signaling pathway. [ABSTRACT FROM AUTHOR]

Lung adenocarcinoma (LUAD) is the most important subtype of lung cancer. It is well known that the gut microbiome plays an important role in the pathophysiology of various diseases, including cancer, but little research has been done on the intestinal microbiome associated with LUAD. Utilizing bioinformatics tools and data analysis, we identified novel potential prognostic biomarkers for LUAD. To integrate differentially expressed genes and clinical significance modules, we used a weighted correlation network analysis system. According to the Peryton database and the gutMGene database, the composition and structure of gut microbiota in LUAD patients differed from those in healthy individuals. LUAD was associated with 150 gut microbiota and 767 gut microbiota targets, with Krüppel-like factor 5 (KLF5) being the most closely related. KLF5 was associated with immune status and correlated well with the prognosis of LUAD patients. The identification of KLF5 as a potential prognostic biomarker suggests its utility in improving risk stratification and guiding personalized treatment strategies for LUAD patients. Altogether, KLF5 could be a potential prognostic biomarker in LUAD. [ABSTRACT FROM AUTHOR]

Background: Streptococcus pneumoniae (Spn) is a major causative agent of pneumonia, which can disseminate to the bloodstream and brain. Pneumonia remains a leading cause of death among children aged 1–59 months worldwide. This study aims to investigate the role of Kruppel-like factor 2 (KLF2) in lung injury caused by Spn in young mice. Methods: Young mice were infected with Spn to induce pneumonia, and the bacterial load in the bronchoalveolar lavage fluid was quantified. KLF2 expression in lung tissues was analyzed using real-time quantitative polymerase chain reaction and Western blotting assays. Following KLF2 overexpression, lung tissues were assessed for lung wet-to-dry weight ratio and Myeloperoxidase activity. The effects of KLF2 on lung injury and inflammation were evaluated through hematoxylin and eosin staining and enzyme-linked immunosorbent assay. Chromatin immunoprecipitation and dual-luciferase assay were conducted to examine the binding of KLF2 to the promoter of microRNA (miR)-222-3p and cyclin-dependent kinase inhibitor 1B (CDKN1B), as well as the binding of miR-222-3p to CDKN1B. Levels of miR-222-3p and CDKN1B in lung tissues were also determined. Results: In young mice with pneumonia, KLF2 and CDKN1B were downregulated, while miR-222-3p was upregulated in lung tissues. Overexpression of KLF2 reduced lung injury and inflammation, evidenced by decreased bacterial load, reduced lung injury, and lower levels of proinflammatory factors. Co-transfection of miR-222-3p-WT and oe-KLF2 significantly reduced luciferase activity, suggesting that KLF2 binds to the promoter of miR-222-3p and suppresses its expression. Transfection of CDKN1B-WT with miR-222-3p mimics significantly reduced luciferase activity, indicating that miR-222-3p binds to CDKN1B and downregulates its expression. Overexpression of miR-222-3p or downregulation of CDKN1B increased bacterial load in BALF, lung wet/dry weight ratio, MPO activity, and inflammation, thereby reversing the protective effect of KLF2 overexpression on lung injury in young mice with pneumonia. Conclusions: KLF2 alleviates lung injury in young mice with Spn-induced pneumonia by transcriptional regulation of the miR-222-3p/CDKN1B axis. [ABSTRACT FROM AUTHOR]

Simple Summary: Krüppel-like factors (KLFs) are essential transcription factors found in many eukaryotes. In this study, the focus is on identifying and analyzing the KLF gene family members in chickens using bioinformatic tools, and comparing them with representative classes such as fish, amphibians, birds, and mammals. The analysis includes the structural characterization, evolutionary relationship assessment, and functional predictions. Additionally, in this study, the impact of miRNA-22 is explored, associated with lipid metabolism, on the expression of KLF genes in the liver, heart, and muscle tissues of Qingyuan partridge chickens. The results indicate that the avian KLF gene family is evolutionarily closer to that of mammals, and all chicken KLFs are non-transmembrane proteins. Moreover, the effect of miRNA-22 on KLF expression varies across different tissues. These findings provide a scientific basis for further research into the functions of KLFs in chickens. Krüppel-like factors (KLFs) are a class of fundamental transcription factors that are widely present in various eukaryotes from nematodes to humans, named after their DNA binding domain which is highly homologous to the Krüppel factor in fruit flies. To investigate the composition, organization, and evolutionary trajectory of KLF gene family members in chickens, in our study, we leveraged conserved sequences of KLF genes from representative classes across fish, amphibians, birds, and mammals as foundational sequences. Bioinformatic tools were employed to perform homology alignment on the chicken genome database, ultimately identifying the KLF family members present in chickens. The gene structure, phylogenetic analysis, conserved base sequences, physicochemical properties, collinearity analysis, and protein structure were then analyzed using bioinformatic tools. Additionally, the impact of miRNA-22, related to poultry lipid metabolism, on the expression of the KLF gene family in the liver, heart, and muscle of Qingyuan partridge chickens was explored. The results showed that: (1) compared to fish, the KLF family in birds is more closely related to mammals and amphibians; (2) KLFs within the same subgroups are likely to be derived from a common ancestral gene duplication; (3) KLF3/8/12 in the same subgroup may have some similar or overlapping functions; (4) the motif 4 of KLF5 was most likely lost during evolution; (5) KLF9 may perform a similar function in chickens and pigs; (6) there are collinear relationships between certain KLF genes, indicating that there are related biomolecular functions between these KLF genes; (7) all members of the KLF family in chickens are non-transmembrane proteins; and (8) interference and overexpression of miRNA-22 in Qingyuan partridge chickens can affect the expression levels of KLF genes in liver, heart, and muscle. [ABSTRACT FROM AUTHOR]

Krüppel‐like factors (KLFs) are a family of basic transcription factors with three conserved Cys2/His2 zinc finger domains located in their C‐terminal regions. It is acknowledged that KLFs exert complicated effects on cell proliferation, differentiation, survival, and responses to stimuli. Dysregulation of KLFs is associated with a range of diseases including cardiovascular disorders, metabolic diseases, autoimmune conditions, cancer, and neurodegenerative diseases. Their multidimensional roles in modulating critical pathways underscore the significance in both physiological and pathological contexts. Recent research also emphasizes their crucial involvement and complex interplay in the skeletal system. Despite the substantial progress in understanding KLFs and their roles in various cellular processes, several research gaps remain. Here, we elucidated the multifaceted capabilities of KLFs on body health and diseases via various compliable signaling pathways. The associations between KLFs and cellular energy metabolism and epigenetic modification during bone reconstruction have also been summarized. This review helps us better understand the coupling effects and their pivotal functions in multiple systems and detailed mechanisms of bone remodeling and develop potential therapeutic strategies for the clinical treatment of pathological diseases by targeting the KLF family. [ABSTRACT FROM AUTHOR]

To determine the sensitivity of vascular endothelial cells to long durations of low-intensity pulsed ultrasound (LIPUS) compared to normal flow and identify the duration that maximizes expression of two mechanosensitive genes related to healthy endothelial function, endothelial nitric oxide synthase (eNOS) and Krüppel-like factor 2 (KLF2). Custom ultrasound exposure tanks were developed and the acoustic field was characterized. Human umbilical vein endothelial cells were seeded into culture plates and exposed to LIPUS at a frequency of 1 MHz and acoustic pressure of 217 kPa for 20 min, 1 h, 6 h, 9 h, or 24 h. As a comparator, other cells were exposed to normal flow. RT-qPCR was used to assess mRNA expression of eNOS and KLF2. Maximum eNOS and KLF2 expression occurred at 6 h and was localized to the beam path. Both genes exhibited qualitatively similar patterns of expression under LIPUS compared to normal flow. LIPUS induced a more rapid beneficial response compared to normal flow, but flow induced higher expression of both genes. eNOS expression after 6 h of LIPUS was dependent on RNA yield and culture duration prior to experiments. Endothelial cells exposed to longer durations of LIPUS than typically employed exhibited greater expression of beneficial genes. The temporal gene expression patterns resulting from LIPUS and normal flow suggest activation of similar signaling pathways. However, LIPUS also caused increased RNA yield that may be linked to proliferation, which would suggest more of a wound healing than atheroprotective phenotype. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) can progress to renal fibrosis and chronic kidney disease (CKD), which reduces quality of life and increases the economic burden on patients. However, the molecular mechanisms underlying renal fibrosis following AKI remain unclear. This study tested the hypothesis that the Krüppel-like factor 4 (KLF4)/miR-101/Collagen alpha-1X (COL10A1) axis could inhibit epithelial-mesenchymal transition (EMT) and renal fibrosis after AKI in a mouse model of ischemia-reperfusion (I/R)-induced renal fibrosis and HK-2 cells by gene silencing, overexpression, immunofluorescence, immunohistochemistry, real-time quantitative PCR, Western blotting, dual-luciferase reporter assay, fluorescence in situ hybridization (FISH) and ELISA. Compared with the Sham group, I/R induced renal tubular and glomerular injury and fibrosis, and increased the levels of BUN, serum Scr and neutrophil gelatinase-associated lipocalin (NGAL), Col10a1 and Vimentin expression, but decreased E-cadherin expression in the kidney tissues of mice at 42 days post-I/R. Similarly, hypoxia promoted fibroblastic morphological changes in HK-2 cells and enhanced NGAL, COL10A1, Vimentin, and α-SMA expression, but reduced E-cadherin expression in HK-2 cells. These pathological changes were significantly mitigated in COL10A1-silenced renal tissues and HK-2 cells. KLF4 induces miR-101 transcription. More importantly, hypoxia upregulated Vimentin and COL10A1 expression, but decreased miR-101, KLF4, and E-cadherin expression in HK-2 cells. These hypoxic effects were significantly mitigated or abrogated by KLF4 over-expression in the HK-2 cells. Our data indicate that KLF4 up-regulates miR-101 expression, leading to the downregulation of COL10A1 expression, inhibition of EMT and renal fibrosis during the pathogenic process of I/R-related renal fibrosis. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-attributed mortality and the primary liver malignancy in the world. Echinacoside is a phenylethanoid glycoside derived from traditional Chinese medicinal herbs which possessed multiple health benefits on humans, including anti-tumor effects. This study aimed to demonstrate the function of echinacoside in HCC progression and the involvement of miR-30c-5p/FOXD1/KLF12 axis. The HepG2 cells were treated by different dose of echinacoside, miR-30c-5p mimic, miR-30c-5p inhibitor, and FOXD1 overexpression lentiviruses or siRNA individually or simultaneously. The cell invasion and migration were measured by transwell assay. RNA and protein levels were tested by RT-PCR and western blot, respectively. The regulatory function of miR-30c-5p on Forkhead box D1 (FOXD1), FOXD1 on Krüppel-like factor 12 (KLF12) was tested by luciferase reporter assay or/and ChIP assay. Meanwhile, a liver cancer lung metastasis mice model was used to examine the functions of echinacoside and miR-30c-5p on HCC metastasis in vivo. Moreover, the correlations among miR-30c-5p, FOXD1, KLF12, and HCC prognosis was analyzed using clinical sample and TCGA database. Based on both in vitro and in vivo investigations, we found that echinacoside could inhibit HCC cell migration, invasiveness, and tumor metastasis, and associated with the enhanced miR-30c-5p/FOXD1/KLF12 axis. Furthermore, through analyzing the interactions among intermediate molecules, we revealed that miR-30c-5p, FOXD1, and KLF12üere clinically relevant with each other in HCC patients, correlated with HCC prognosis, and regulated by echinacoside to contribute in the inhibition of HCC progression. These findings suggest that echinacoside could inhibit HCC progression, and the mechanism related to the enhanced miR-30c-5p/FOXD1/KLF12 axis. Moreover, the abovementioned intermediate molecules might serve as prospective biomarkers for HCC prognosis. [ABSTRACT FROM AUTHOR]

Objective: Krüppel-like factor 4 (KLF4) has been demonstrated to exert a pro-carcinogenic effect in solid tissues. However, the precise biological function and underlying mechanisms in colorectal cancer (CRC) remains elucidated. Aims: To investigate whether KLF4 participates in the proliferation and invasion of CRC. Methods: The expression of KLF4 was investigated using immunohistochemistry and immunoblotting. The clinical significance of KLF4 was evaluated. Furthermore, the effect of inhibiting or overexpressing KLF4 on tumor was examined. Immunoblotting and qPCR were used to detect Epithelial–mesenchymal transition-related proteins levels. Additionally, the molecular function of KLF4 is related to the STAT3 signaling pathway and was determined through JASPAR, GSEA analysis, and in vitro experiments. Results: KLF4 exhibits down-regulated expression in CRC and is part of the vessel invasion, TNM stage, and worse prognosis. In vitro studies have shown that KLF4 promotes cellular proliferation and invasion, as well as EMT processes. Xenograft tumor models confirmed the oncogenic role of KLF4 in nude mice. Furthermore, GSEA and JASPAR databases analysis reveal that the binding of KLF4 to the signal transducer and activator of transcription 3 (STAT3) promoter site induces activation of p-STAT3 signaling. Subsequent targeting of STAT3 confirmed its pivotal role in mediating the oncogenic effects exerted by KLF4. Conclusion: The study suggests that KLF4 activates STAT3 signaling, inducing epithelial–mesenchymal transition, thereby promoting CRC progression. [ABSTRACT FROM AUTHOR]

The Krüppel-like factor (KLF) family represents a group of transcription factors (TFs) performing different biological processes that are crucial for proper neuronal function, including neuronal development, synaptic plasticity, and neuronal survival. As reported, genetic variants within the KLF family have been associated with a wide spectrum of neurodevelopmental and psychiatric symptoms. In a patient exhibiting attention deficit hyperactivity disorder (ADHD) combined with both neurodevelopmental and psychiatric symptoms, whole-exome sequencing (WES) analysis revealed a de novo heterozygous variant within the Krüppel-like factor 13 (KLF13) gene, which belongs to the KLF family and regulates axonal growth, development, and regeneration in mice. Moreover, in silico analyses pertaining to the likely pathogenic significance of the variant and the impact of the mutation on the KLF13 protein structure suggested a potential deleterious effect. In fact, the variant was localized in correspondence to the starting residue of the N-terminal domain of KLF13, essential for protein–protein interactions, DNA binding, and transcriptional activation or repression. This study aims to highlight the potential involvement of the KLF13 gene in neurodevelopmental and psychiatric disorders. Nevertheless, we cannot rule out that excluded variants, those undetectable by WES, or the polygenic risk may have contributed to the patient's phenotype given ADHD's high polygenic risk. However, further functional studies are required to validate its potential contribution to these disorders. [ABSTRACT FROM AUTHOR]

Diabetic kidney disease (DKD) is a microvascular complication of diabetes, and glomerular endothelial cell (GEC) dysfunction is a key driver of DKD pathogenesis. Krüppel-like factor 2 (KLF2), a shear stress-induced transcription factor, is among the highly regulated genes in early DKD. In the kidney, KLF2 expression is mostly restricted to endothelial cells, but its expression is also found in immune cell subsets. KLF2 expression is upregulated in response to increased shear stress by the activation of mechanosensory receptors but suppressed by inflammatory cytokines, both of which characterize the early diabetic kidney milieu. KLF2 expression is reduced in progressive DKD and hypertensive nephropathy in humans and mice, likely due to high glucose and inflammatory cytokines such as TNF-α. However, KLF2 expression is increased in glomerular hyperfiltration-induced shear stress without metabolic dysregulation, such as in settings of unilateral nephrectomy. Lower KLF2 expression is associated with CKD progression in patients with unilateral nephrectomy, consistent with its endoprotective role. KLF2 confers endoprotection by inhibition of inflammation, thrombotic activation, and angiogenesis, and thus KLF2 is considered a protective factor for cardiovascular disease (CVD). Based on similar mechanisms, KLF2 also exhibits renoprotection, and its reduced expression in endothelial cells worsens glomerular injury and albuminuria in settings of diabetes or unilateral nephrectomy. Thus KLF2 confers endoprotective effects in both CVD and DKD, and its activators could potentially be developed as a novel class of drugs for cardiorenal protection in diabetic patients. [ABSTRACT FROM AUTHOR]

Background: Krüppel-like 11 factor (KLF11) gene mutation has been implicated in the pathogenesis of maturity onset diabetes of the young type 7 (MODY7). Recently, this potential correlation has been questioned, suggesting the need for more comprehensive diagnostic approaches. Methods: The proband is a 30-years-old male who underwent next-generation sequencing (NGS). This was followed by whole-exon sequencing of the proband and his parents to screen for KLF11 variants. Results: A heterozygous KLF11 mutation c.793G>A (p.Glu265Lys) was identified in the proband and his non-diabetic mother. Conclusions: The novel KLF11 mutation documented in this study might exhibit incomplete penetrance in relation to impaired glucose tolerance, which could also contribute to the argument against the necessity of including KLF11 genetic testing for MODY diagnosis. [ABSTRACT FROM AUTHOR]

Acute environmental changes cause stress during conventional deep‐sea biological sampling without in situ fixation and affect gene expressions of samples collected. However, the degree of influence and underlying mechanisms are hardly investigated. Here, we conducted comparative transcriptomic analyses between in situ and onboard fixed gills and between in situ and onboard fixed mantles of deep‐sea mussel Gigantidas haimaensis to assess the effects of incidental sampling stress. Results showed that transcription, translation, and energy metabolism were upregulated in onboard fixed gills and mantles, thereby mobilizing rapid gene expression to tackle the stress. Autophagy and phagocytosis that related to symbiotic interactions between the host and endosymbiont were downregulated in the onboard fixed gills. These findings demonstrated that symbiotic gill and nonsymbiotic mantle responded differently to sampling stress, and symbiosis in the gill was perturbed. Further comparative metatranscriptomic analysis between in situ and onboard fixed gills revealed that stress response genes, peptidoglycan biosynthesis, and methane fixation were upregulated in the onboard fixed endosymbiotic Gammaproteobacteria inside the gills, implying that energy metabolism of the endosymbiont was increased to cope with sampling stress. Furthermore, comparative analysis between the mussel G. haimaensis and the limpet Bathyacmaea lactea transcriptomes resultedidentified six transcription factor orthologs upregulated in both onboard fixed mussel mantles and limpets, including sharply increased early growth response protein 1 and Kruppel‐like factor 5. They potentially play key roles in initiating the response of sampled deep‐sea macrobenthos to sampling stress. Our results clearly show that in situ fixed biological samples are vital for studying deep‐sea environmental adaptation. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion Chemoresistance is a common event after chemotherapy, including oral squamous cell carcinoma (OSCC). Accumulated evidence suggests that the cancer stemness significantly contributes to therapy resistance. An unresolved question remains regarding how to effectively overcome OSCC chemoresistance by targeting stemness. This study aims to investigate the antitumor effect of metformin and clarify the potential molecular mechanisms.Cellular models resistant to chemotherapy were established, and their viability and sphere‐forming ability were assessed using CCK‐8 and soft agar formation assays, respectively. RNA‐seq and Western blotting analyses were employed to delve into the molecular pathways. Furthermore, to corroborate the inhibitory effects of metformin and cisplatin at an animal level, a subcutaneous tumor transplantation model was instituted.Metformin as a monotherapy exhibited inhibition of stemness traits via Krüppel‐like factor 4 (KLF4). Metformin and cisplatin can synergically inhibit cell proliferation and induce cell apoptosis. Animal experiments confirmed the inhibitory effect of cisplatin and metformin on tumor in mice.Our study proposes a potential therapeutic approach of combining chemotherapy with metformin to overcome chemoresistance in OSCC. [ABSTRACT FROM AUTHOR]

The objective of this study was to elucidate the protective role of quercetin in atherosclerosis by examining its effect on the phenotypic switch of vascular smooth muscle cells (VSMCs) to macrophage-like cells and the underlying regulatory pathways. Aorta tissues from apolipoprotein E-deficient (ApoE KO) mice fed a high-fat diet (HFD), treated with or without 100 mg/kg/day quercetin, were analyzed for histopathological changes and molecular mechanisms. Quercetin was found to decrease the size of atherosclerotic lesions and mitigate lipid accumulation induced by HFD. Fluorescence co-localization analysis revealed a higher presence of macrophage-like vascular smooth muscle cells (VSMCs) co-localizing with phospho-Janus kinase 2 (p-JAK2), phospho-signal transducer and activator of transcription 3 (p-STAT3), and Krüppel-like factor 4 (KLF4) in regions of foam cell aggregation within aortic plaques. However, this co-localization was reduced following treatment with quercetin. Quercetin treatment effectively inhibited the KLF4-mediated phenotypic switch in oxidized low-density lipoprotein (ox-LDL)-loaded mouse aortic vascular smooth muscle cells (MOVAS), as indicated by decreased expressions of KLF4, LGALS3, CD68, and F4/80, increased expression of alpha smooth muscle actin (α-SMA), reduced intracellular fluorescence Dil-ox-LDL uptake, and decreased lipid accumulation. In contrast, APTO-253, a KLF4 activator, was found to reverse the effects of quercetin. Furthermore, AG490, a JAK2 inhibitor, effectively counteracted the ox-LDL-induced JAK2/STAT3 pathway-dependent switch to a macrophage-like phenotype and lipid accumulation in MOVAS cells. These effects were significantly mitigated by quercetin but exacerbated by coumermycin A1, a JAK2 activator. Our research illustrates that quercetin inhibits the KLF4-mediated phenotypic switch of VSMCs to macrophage-like cells and reduces atherosclerosis by suppressing the JAK2/STAT3 pathway. [ABSTRACT FROM AUTHOR]

Inactivation of phosphatase and tensin homolog (PTEN) is prevalent in human prostate cancer and causes high-grade adenocarcinoma with a long latency. Cancer-associated fibroblasts (CAFs) play a pivotal role in tumor progression, but it remains elusive whether and how PTEN-deficient prostate cancers reprogram CAFs to overcome the barriers for tumor progression. Here, we report that PTEN deficiency induced Krüppel-like factor 5 (KLF5) acetylation and that interruption of KLF5 acetylation orchestrated intricate interactions between cancer cells and CAFs that enhance FGF receptor 1 (FGFR1) signaling and promote tumor growth. Deacetylated KLF5 promoted tumor cells to secrete TNF-α, which stimulated inflammatory CAFs to release FGF9. CX3CR1 inhibition blocked FGFR1 activation triggered by FGF9 and sensitized PTENdeficient prostate cancer to the AKT inhibitor capivasertib. This study reveals the role of KLF5 acetylation in reprogramming CAFs and provides a rationale for combined therapies using inhibitors of AKT and CX3CR1. [ABSTRACT FROM AUTHOR]

Background: Megakaryocytic differentiation is a complicated process regulated by a series of transcription factors in a context- and stage-dependent manner. Recent studies have suggested that krüppel-like transcription factor 2 (KLF2) is involved in the control of embryonic erythroid precursor cell differentiation and maturation. However, the function and mechanism of KLF2 in regulating megakaryocytic differentiation remain unclear. Methods: The expression patterns of krüppel-like transcription factors (KLFs) during megakaryocytic differentiation were identified from public databases. Phorbol 12-myristate 13-acetate (PMA) treatment of the myeloid-erythroid-leukemic cell lines K562 and HEL were used as cellular megakaryocytic differentiation models. A lentiviral transduction system was utilized to achieve the goal of amplifying or reducing KLF2. The expression of KLF2 was examined using real-time PCR and western blot. The impact of KLF2 on the megakaryocytic differentiation of K562 cells was examined by flow cytometry, Giemsa staining, Phalloidin staining and western blot. RNA-sequencing (RNA-seq) and chromatin immunoprecipitation-sequencing (ChIP-seq) technologies were used to identify the KLF2-regulated targets. Results: KLF2 is increased in the maturation process of megakaryocytes. KLF2 overexpression accelerated the PMA-induced megakaryocytic differentiation, as reflected by an increased percentage of CD41/CD61 cells, an increased number of polyploid cells, and an elevated expression of P21 and P27. KLF2 knockdown exhibited the opposite results, indicating that KLF2 knockdown suppressed the megakaryocytic differentiation. Further, combination of the RNA-seq and ChIP-seq results suggested that chimerin 1 (CHN1) and potassium voltage-gated channel subfamily Q member 5 (KCNQ5) may be target genes regulated of KLF2. Both CHN1 and KCNQ5 knockdown could block the megakaryocytic differentiation to some content. Conclusion: This study implicated a regulatory role of KLF2 in megakaryocytic differentiation, which may suggest KLF2 as a target for illness with abnormal megakaryocytic differentiation. [ABSTRACT FROM AUTHOR]

Glioblastomas (GBMs) are characterized by high heterogeneity, involving diverse cell types, including those with stem‐like features contributing to GBM's malignancy. Moreover, metabolic alterations promote growth and therapeutic resistance of GBM. Depending on the metabolic state, antimetabolic treatments could be an effective strategy. Against this background, we investigated temporal and regional expression changes and co‐staining patterns of selected metabolic markers [pyruvate kinase muscle isozyme 1/2 (PKM1/2), glucose transporter 1 (GLUT1), monocarboxylate transporter 1/4 (MCT1/4)] in a rodent model and patient‐derived samples of GBM. To understand the cellular sources of marker expression, we also examined the connection of metabolic markers to markers related to stemness [Nestin, Krüppel‐like factor 4 (KLF4)] in a regional and temporal context. Rat tumour biopsies revealed a temporally increasing expression of GLUT1, higher expression of MCT1/4, Nestin and KLF4, and lower expression of PKM1 compared to the contralateral hemisphere. Patient‐derived tumours showed a higher expression of PKM2 and Nestin in the tumour centre vs. edge. Whereas rare co‐staining of GLUT1/Nestin was found in tumour biopsies, PKM1/2 and MCT1/4 showed a more distinct co‐staining with Nestin in rats and humans. KLF4 was mainly co‐stained with GLUT1, MCT1 and PKM1/2 in rat and human tumours. All metabolic markers yielded individual co‐staining patterns among themselves. Co‐staining mainly occurred later in tumour progression and was more pronounced in tumour centres. Also, positive correlations were found amongst markers that showed co‐staining. Our results highlight a link between metabolic alterations and stemness in GBM progression, with complex distinctions depending on studied markers, time points and regions. [ABSTRACT FROM AUTHOR]

Background: Uveal melanoma (UM), the most common adult intraocular tumor, is characterized by high malignancy and poor prognosis in advanced stages. Angiogenesis is critical for UM development, however, not only the role of vascular endothelial dysfunction in UM remains unknown, but also their analysis at the single-cell level has been lacking. A comprehensive analysis is essential to clarify the role of the endothelium in the development of UM. Methods: By using single-cell RNA transcriptomics data of 11 cases of primary and liver metastasis UM, we analyzed the endothelial cell status. In addition, we analyzed and validated ECs in the in vitro model and collected clinical specimens. Subsequently, we explored the impact of endothelial dysfunction on UM cell migration and explored the mechanisms responsible for the endothelial cell abnormalities and the reasons for their peripheral effects. Results: UM metastasis has a significantly higher percentage of vascular endothelial cells compared to in situ tumors, and endothelial cells in metastasis show significant senescence. Senescent endothelial cells in metastatic tumors showed significant Krüppel-like factor 4 (KLF4) upregulation, overexpression of KLF4 in normal endothelial cells induced senescence, and knockdown of KLF4 in senescent endothelium inhibited senescence, suggesting that KLF4 is a driver gene for endothelial senescence. KLF4-induced endothelial senescence drove tumor cell migration through a senescence-associated secretory phenotype (SASP), of which the most important component of the effector was CXCL12 (C-X-C motif chemokine ligand 12), and participated in the composition of the immunosuppressive microenvironment. Conclusion: This study provides an undesirable insight of senescent endothelial cells in promoting UM metastasis. [ABSTRACT FROM AUTHOR]

Hepatic stellate cells (HSCs) are critical regulator contributing to the onset and progression of liver fibrosis. Chronic liver injury triggers HSCs to undergo vast changes and trans‐differentiation into a myofibroblast HSCs, the mechanism remains to be elucidated. This study investigated that the involvement of hydroxymethylase TET1 (ten–eleven translocation 1) in HSC activation and liver fibrosis. It is revealed that TET1 levels were downregulated in the livers in mouse models of liver fibrosis and patients with cirrhosis, as well as activated HSCs in comparison to quiescent HSCs. In vitro data showed that the inhibition of TET1 promoted the activation HSC, whereas TET1 overexpression inhibited HSC activation. Moreover, TET1 could regulate KLF2 (Kruppel‐like transcription factors) transcription by promoting hydroxymethylation of its promoter, which in turn suppressed the activation of HSCs. In vivo, it is confirmed that liver fibrosis was aggravated in Tet1 knockout mice after CCl4 injection, accompanied by excessive activation of primary stellate cells, in contrast to wild‐type mice. In conclusion, we suggested that TET1 plays a significant role in HSC activation and liver fibrosis, which provides a promising target for anti‐fibrotic therapies. [ABSTRACT FROM AUTHOR]

Previous studies have shown that podocyte injury is involved in the development of proteinuria in rats under hypobaric hypoxia conditions. Prolyl hydroxylase inhibitors (PHIs) may reduce proteinuria. This study aimed to further investigate whether the protective effects of hypoxia‐inducible factor 1α (HIF1α) on podocyte injury induced by hypobaric hypoxia are related to Krüppel‐like factor 4 (KLF4). Rats were housed in a low‐pressure oxygen chamber to simulate a high‐altitude environment (5000 m), and a PHI was intraperitoneally injected. Urinary protein electrophoresis was performed and the morphology of the podocytes was observed by electron microscopy. Rat podocytes were cultured under 1% O2, and siRNA was used to interfere with KLF4 expression. The protein expression levels of HIF1α, KLF4, CD2‐associated protein (CD2AP) and nephrin were determined by western blotting. Compared with those in the experimental group, the rats in the intervention group on day 14 had lower urinary protein levels, increased protein expression levels of CD2AP and nephrin, and reduced podocyte injury. The results of in vitro experiments showed that the protein expression levels of KLF4, CD2AP and nephrin were greater in the PHI intervention group and lower in the HIF1α inhibitors group than in the low‐oxygen group. The protein expression of CD2AP and nephrin in the siKLF4‐transfected podocytes treated with PHI and HIF1α inhibitors did not differ significantly from that in the low‐oxygen group. HIF1α may be involved in reducing progressive high‐altitude proteinuria by regulating KLF4 expression and contributing to the repair of podocyte injury induced by hypobaric hypoxia. What is the central question of this study?Podocyte injury is involved in the development of proteinuria in rats under simulated high‐altitude environments and prolyl‐hydroxylase inhibitors (PHI) may have a potential role in reducing proteinuria: what are the effects of PHIs on podocytes and what are the mechanisms?What is the main finding and its importance?PHIs may have a potential role in reducing proteinuria by upregulating local hypoxia‐inducible factor 1α (HIF1α) expression in the kidney to alleviate podocyte injury. HIF1α plays a potential role in regulating Krüppel‐like factor 4 expression and contributing to the repair of podocyte injury induced by hypobaric hypoxia. [ABSTRACT FROM AUTHOR]

The abnormality of the p53 tumor suppressor is crucial in lung cancer development, because p53 regulates target gene promoters to combat cancer. Recent studies have shown extensive p53 binding to enhancer elements. However, whether p53 exerts a tumor suppressor role by shaping the enhancer landscape remains poorly understood. In the current study, we employed several functional genomics approaches to assess the enhancer activity at p53 binding sites throughout the genome based on our established TP53 knockout (KO) human bronchial epithelial cells (BEAS-2B). A total of 943 active regular enhancers and 370 super-enhancers (SEs) disappeared upon the deletion of p53, indicating that p53 modulates the activity of hundreds of enhancer elements. We found that one p53-dependent SE, located on chromosome 9 and designated as KLF4-SE, regulated the expression of the Krüppel-like factor 4 (KLF4) gene. Furthermore, the deletion of p53 significantly decreased the KLF4-SE enhancer activity and the KLF4 expression, but increased colony formation ability in the nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced cell transformation model. Subsequently, in TP53 KO cells, the overexpression of KLF4 partially reversed the increased clonogenic capacity caused by p53 deficiency. Consistently, KLF4 expression also decreased in lung cancer tissues and cell lines. It appeared that overexpression of KLF4 significantly suppressed the proliferation and migration of lung cancer cells. Collectively, our results suggest that the regulation of enhancer formation and activity by p53 is an integral component of the p53 tumor suppressor function. Therefore, our findings offer some novel insights into the regulation mechanism of p53 in lung oncogenesis and introduce a new strategy for screening therapeutic targets. [ABSTRACT FROM AUTHOR]

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Background and objectives: Colorectal cancer is one of the most significant and deadliest malignant tumors among various types of cancers. Due to its generally low overall survival rate, the development of new treatment strategies for early detection and diagnosis, as well as the identification of prognostic markers, has become exceedingly crucial. The molecular mechanism of colorectal cancer remains uncertain and to address this, the aim is to identify key genes, determine in which pathways these genes are involved, explore their interactions with regulatory molecules, and investigate their overall relationship with survival and immune cell infiltration. Methods: After selecting the databases related to colorectal cancer from the Gene Expression Omnibus database, differentially expressed genes were identified. Gene ontology and pathway analyses were then conducted for these genes, and interaction networks with proteins were constructed. Core genes were identified, and their relationship with regulatory molecules such as miRNAs and transcription factors was examined. Additionally, immune cell infiltration and survival analyses were performed. Results: As a result of the bioinformatic analyses, 71 differentially expressed genes were identified, which were found to overlap in four distinct microarray datasets. Among these differentially expressed genes, Krüppel-like factor 4 (KLF4), CLCA4, GUCA2B, GUCA2A, LGR5, SLC4A4, ZG16, CA7, CA2, and GCG were determined as hub genes. Among the hub genes, CA2, CLCA4, SLC4A4, and KLF4 genes showed a positive correlation with immune cells in immune cell infiltration analyses. The expression levels of these four genes were also confirmed using data from the Human Protein Atlas database. Additionally, only the KLF4 gene was associated with poor prognosis in overall survival analyses. Conclusion: The obtained results suggest that the KLF4 gene may serve as a potential therapeutic agent. [ABSTRACT FROM AUTHOR]

In this in vitro study, for the first time, we evaluate the effects of simvastatin‐loaded liposome nanoparticles (SIM‐LipoNPs) treatment on fibrosis‐induced liver microtissues, as simvastatin (SIM) has shown potential benefits in the non‐alcoholic fatty liver disease process. We developed multicellular liver microtissues composed of hepatic stellate cells, hepatoblastoma cells and human umbilical vein endothelial cells. The microtissues were supplemented with a combination of palmitic acid and oleic acid to develop fibrosis models. Subsequently, various groups of microtissues were exposed to SIM and SIM‐LipoNPs at doses of 5 and 10 mg/mL. The effectiveness of the treatments was evaluated by analysing cell viability, production of reactive oxygen species (ROS) and nitric oxide (NO), the expression of Kruppel‐like factor (KLF) 2, and pro‐inflammatory cytokines (interleukin(IL)‐1 α, IL‐1 β, IL‐6 and tumour necrosis factor‐α), and the expression of collagen I. Our results indicated that SIM‐LipoNPs application showed promising results. SIM‐LipoNPs effectively amplified the SIM‐klf2‐NO pathway at a lower dosage compatible with a high dosage of free SIM, which also led to reduced oxidative stress by decreasing ROS levels. SIM‐LipoNPs administration also resulted in a significant reduction in pro‐inflammatory cytokines and Collagen I mRNA levels, as a marker of fibrosis. In conclusion, our study highlights the considerable therapeutic potential of using SIM‐LipoNPs to prevent liver fibrosis progress, underscoring the remarkable properties of SIM‐LipoNPs in activating the KLF2‐NO pathway and anti‐oxidative and anti‐inflammatory response. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) is characterized by vascular remodeling predominantly driven by a phenotypic switching in pulmonary artery smooth muscle cells (PASMCs). However, the underlying mechanisms for this phenotypic alteration remain incompletely understood. Here, we identified that RNA methyltransferase METTL3 is significantly elevated in the lungs of hypoxic PH (HPH) mice and rats, as well as in the pulmonary arteries (PAs) of HPH rats. Targeted deletion of Mettl3 in smooth muscle cells exacerbated hemodynamic consequences of hypoxia-induced PH and accelerated pulmonary vascular remodeling in vivo. Additionally, the absence of METTL3 markedly induced phenotypic switching in PASMCs in vitro. Mechanistically, METTL3 depletion attenuated m6A modification and hindered the processing of pri-miR-143/145, leading to a downregulation of miR-143-3p and miR-145-5p. Inhibition of hnRNPA2B1, an m6A mediator involved in miRNA maturation, similarly resulted in a significant reduction of miR-143-3p and miR-145-5p. We demonstrated that miR-145-5p targets Krüppel-like factor 4 (KLF4) and miR-143-3p targets fascin actin-bundling protein 1 (FSCN1) in PASMCs. The decrease of miR-145-5p subsequently induced an upregulation of KLF4, which in turn suppressed miR-143/145 transcription, establishing a positive feedback circuit between KLF4 and miR-143/145. This regulatory circuit facilitates the persistent suppression of contractile marker genes, thereby sustaining PASMC phenotypic switch. Collectively, hypoxia-induced upregulation of METTL3, along with m6A mediated regulation of miR-143/145, might serve as a protective mechanism against phenotypic switch of PASMCs. Our results highlight a potential therapeutic strategy targeting m6A modified miR-143/145-KLF4 loop in the treatment of PH. [ABSTRACT FROM AUTHOR]

Asthma is viewed as an airway disease and an inflammatory condition. This study aims to reveal the role of Kruppel-like factor 5 (KLF5)-mediated pyroptosis of airway epithelial cells in airway inflammation in asthma. The asthmatic mouse model was established. The mice were infected with the lentivirus containing sh-KLF5, antagomiR-182–5p, and pc-Toll-like receptor 4 (TLR4). Airway hyperresponsiveness was measured, and the cells in bronchoalveolar lavage fluid (BALF) were sorted and counted. The expression levels of interleukin (IL)-4/IL-13/IL-6/IL-18/IL-1β/NOD-like receptor family pyrin domain containing 3 (NLRP3)/N-gasdermin D (GSDMD-N)/cleaved caspase-1 were detected. The pathological changes in lung tissue were observed. The enrichment of KLF5 in the miR-182–5p promoter region was measured. The binding relationship among KLF5, miR-182–5p, and TLR4 were analyzed. KLF5 was highly expressed in asthmatic mice. Silencing KLF5 improved airway resistance and lung dynamic compliance, reduced the cells in BALF and the expression of IL-4/IL-13/IL-6/NLRP3/GSDMD-N/cleaved caspase-1/IL-18/IL-1β, and alleviated the pathological changes. Mechanistically, KLF5 bonded to the miR-182–5p promoter to inhibit miR-182–5p expression, and miR-182–5p inhibited TLR4. Silencing miR-182–5p or TLR4 overexpression reversed the improvement of silencing KLF5 on airway inflammation and pyroptosis in asthmatic mice. In conclusion, KLF5 inhibited miR-182–5p to promote TLR4 expression, thus aggravating pyroptosis and airway inflammation in asthmatic mice. • KLF5 is highly expressed in the lung tissue of asthmatic mice. • Silencing KLF5 reduces airway inflammation by inhibiting pyroptosis. • KLF5 inhibits the transcription and expression of miR-182–5p. • miR-182–5p targets and inhibits TLR4 expression. • KLF5 rises pyroptosis and airway inflammation via the miR-182–5p/TLR4 axis. [ABSTRACT FROM AUTHOR]

Aim: Pancreatic cancer (PC) has a poor prognosis and high mortality. Kruppel‐like factor 9 (KLF9), a transcription factor, is aberrantly expressed in various neoplasms. The current study sought to analyze the functional role of KLF9 in the proliferation, invasion, and migration of PC cells. Methods: The expression patterns of KLF9 and KIAA1522 in normal pancreatic cells (HPDE‐C7) and PC cells (Panc 03.27, BxPc3, SW1990) were determined by real‐time quantitative polymerase chain reaction and Western blot assay. After treatment of KLF9 overexpression, proliferation, invasion, and migration were evaluated by cell counting kit‐8, 5‐ethynyl‐2′‐deoxyuridine staining, and Transwell assays. The binding of KLF9 to the KIAA1522 promoter was analyzed by dual‐luciferase assay and chromatin immunoprecipitation. The rescue experiment was conducted to analyze the role of KIAA1522. Results: KLF9 was downregulated, while KIAA1522 was upregulated in PC cells. KLF9 overexpression mitigated the proliferation, invasion, and migration of PC cells. Enrichment of KLF9 led to inhibition of the KIAA1522 promoter and repressed KIAA1522 expression. KIAA1522 overexpression neutralized the inhibitory role of KLF9 in PC cell functions. Conclusion: KLF9 is enriched in the KIAA1522 promoter and negatively regulates KIAA1522 expression, thereby mitigating the proliferation, invasion, and migration of PC cells. [ABSTRACT FROM AUTHOR]

Neuroinflammation plays a key role in the progression of secondary brain injury after ischemic stroke, and exosomes have been increasingly recognized to eliminate inflammatory responses through various mechanisms. This study aimed to explore the effect and possible mechanism of human umbilical vein endothelial cells derived exosomes (H-EXOs) on neuroinflammation. We established a transient middle cerebral artery occlusion/reperfusion (tMCAO/R) in male rats and oxygen-glucose-deprivation/reoxygenation (OGD/R) model in cultured neurons to mimic secondary brain injury after ischemic stroke in vivo. H-EXOs were administered at the same time of reperfusion. Results showed that the production of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6, and the transcription factor Krüppel-like factor 14 (KLF14) were significantly increased both in rat brain tissue and cultured neural cells after ischemic-reperfusion (I/R) injury. H-EXOs treatment significantly improved the cultured cell viability, reduced infarct sizes, mitigated neurobehavioral defects, and alleviated the expression of pro-inflammatory cytokines compared with the control group, indicating that H-EXOs exerted anti-inflammatory effect against I/R injury. Further studies revealed that the anti-inflammatory effect of H-EXOs could be weakened by small-interfering RNA (siKLF4) transfection. KLF14 was a protective factor produced during cerebral ischemia-reperfusion injury. In conclusion, H-EXOs protect neurons from inflammation after I/R injury by enhancing KLF14 expression. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) represents a significant global health burden, necessitating an in‐depth exploration of its molecular underpinnings to facilitate the development of effective therapeutic strategies. This investigation delves into the complex role of long non‐coding RNAs (lncRNAs) in the modulation of hypoxia‐induced HCC progression, with a specific emphasis on delineating and functionally characterizing the novel KLF4/Lnc18q22.2/ULBP3 axis. To elucidate the effects of hypoxic conditions on HCC cells, we established in vitro models under both normoxic and hypoxic environments, followed by lncRNA microarray analyses. Among the lncRNAs identified, Lnc18q22.2 was found to be significantly upregulated in HCC cells subjected to hypoxia. Subsequent investigations affirmed the oncogenic role of Lnc18q22.2, highlighting its critical function in augmenting HCC cell proliferation and migration. Further examination disclosed that Kruppel‐like factor 4 (KLF4) transcriptionally governs Lnc18q22.2 expression in HCC cells, particularly under hypoxic stress. KLF4 subsequently enhances the tumorigenic capabilities of HCC cells through the modulation of Lnc18q22.2 expression. Advancing downstream in the molecular cascade, our study elucidates a novel interaction between Lnc18q22.2 and UL16‐binding protein 3 (ULBP3), culminating in the stabilization of ULBP3 protein expression. Notably, ULBP3 was identified as a pivotal element, exerting dual functions by facilitating HCC tumorigenesis and mitigating immune evasion in hypoxia‐exposed HCC cells. The comprehensive insights gained from our research delineate a hitherto unidentified KLF4/Lnc18q22.2/ULBP3 axis integral to the understanding of HCC tumorigenesis and immune escape under hypoxic conditions. This newly unveiled molecular pathway not only enriches our understanding of hypoxia‐induced HCC progression but also presents novel avenues for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Krüppel‐like factor 13 (KLF13), a zinc finger transcription factor, is considered as a potential regulator of cardiomyocyte differentiation and proliferation during heart morphogenesis. However, its precise role in the dedifferentiation of vascular smooth muscle cells (VSMCs) during atherosclerosis and neointimal formation after injury remains poorly understood. In this study, we investigated the relationship between KLF13 and SM22α expression in normal and atherosclerotic plaques by bioanalysis, and observed a significant increase in KLF13 levels in the atherosclerotic plaques of both human patients and ApoE−/− mice. Knockdown of KLF13 was found to ameliorate intimal hyperplasia following carotid artery injury. Furthermore, we discovered that KLF13 directly binds to the SM22α promoter, leading to the phenotypic dedifferentiation of VSMCs. Remarkably, we observed a significant inhibition of platelet‐derived growth factor BB‐induced VSMCs dedifferentiation, proliferation, and migration when knocked down KLF13 in VSMCs. This inhibitory effect of KLF13 knockdown on VCMC function was, at least in part, mediated by the inactivation of p‐AKT signaling in VSMCs. Overall, our findings shed light on a potential therapeutic target for treating atherosclerotic lesions and restenosis after vascular injury. [ABSTRACT FROM AUTHOR]

The impaired endometrial receptivity is a major factor contributing to infertility in patients with endometriosis (EM), but the underlying mechanism remains unclear. Qur study aimed to investigate the role of Kruppel-like factor 15 (KLF15) in endometrial receptivity and its regulation in EM. We observed a significant decrease in KLF15 expression in the mid-secretory epithelial endometrial cells of EM patients compared to normal females without EM. To confirm the role of KLF15 in endometrial receptivity, we found a significantly reduced KLF15 expression and a significant decrease in embryo implantation number in the rat model via uterine horn infection with siRNA. This highlights the importance of KLF15 as a regulator receptivity. Furthermore, through ChIP-qPCR, we discovered that the progesterone receptor (PR) directly binds to KLF15 promoter regions, indicating that progesterone resistance may mediate the decrease in KLF15 expression in EM patients. Additionally, we found that the mid-secretory endometrium of EM patients exhibited impaired epithelial-mesenchymal transition (EMT). Knockdown of KLF15 upregulated E-cadherin and downregulated vimentin expression, leading to inhibited invasiveness and migration of Ishikawa cells. Qverexpression KLF15 promotes EMT, invasiveness, and migration ability, and increases the attachment rate of JAR cells to Ishikawa cells. Through RNA-seq analysis, we identified TWIST2 as a downstream gene of KLF15. We confirmed that KLF15 directly binds to the promoter region of TWIST2 via ChIP-qPCR, promoting epithelial cell EMT during the establishment of endometrial receptivity. Qur study reveals the involvement of KLF15 in the regulation of endometrial receptivity and its downstream effects on EMT. These findings provide valuable insights into potential therapeutic approaches for treating non-receptive endometrium in patients with EM. [ABSTRACT FROM AUTHOR]

Background and Objectives: Despite the fact that biologic drugs have transformed inflammatory bowel disease (IBD) treatment, addressing fibrosis-related strictures remains a research gap. This study explored the roles of cytokines, macrophages, and Krüppel-like factors (KLFs), specifically KLF4, in intestinal fibrosis, as well as the interplay of KLF4 with various gut components. Materials and Methods: This study examined macrophage subtypes, their KLF4 expression, and the effects of KLF4 knockdown on macrophage polarization and cytokine expression using THP-1 monocyte models. Co-culture experiments with stromal myofibroblasts and a conditioned medium from macrophage subtype cultures were conducted to study the role of these cells in intestinal fibrosis. Human-induced pluripotent stem cell-derived small intestinal organoids were used to confirm inflammatory and fibrotic responses in the human small intestinal epithelium. Results: Each macrophage subtype exhibited distinct phenotypes and KLF4 expression. Knockdown of KLF4 induced inflammatory cytokine expression in M0, M2a, and M2c cells. M2b exerted anti-fibrotic effects via interleukin (IL)-10. M0 and M2b cells showed a high migratory capacity toward activated stromal myofibroblasts. M0 cells interacting with activated stromal myofibroblasts transformed into inflammatory macrophages, thereby increasing pro-inflammatory cytokine expression. The expression of IL-36α, linked to fibrosis, was upregulated. Conclusions: This study elucidated the role of KLF4 in macrophage polarization and the intricate interactions between macrophages, stromal myofibroblasts, and cytokines in experimental in vitro models of intestinal fibrosis. The obtained results may suggest the mechanism of fibrosis formation in clinical IBD. [ABSTRACT FROM AUTHOR]

Krüppel‐like factors (KLFs) are crucial in the development of bone disease. They are a family of zinc finger transcription factors that are unusual in containing three highly conserved zinc finger structural domains interacting with DNA. It has been discovered that it engages in various cell functions, including proliferation, apoptosis, autophagy, stemness, invasion and migration, and is crucial for the development of human tissues. In recent years, the role of KLFs in bone physiology and pathology has received adequate attention. In addition to regulating the normal growth and development of the musculoskeletal system, KLFs participate in the pathological process of the bones and joints and are intimately linked to several skeletal illnesses, such as osteoarthritis (OA), rheumatoid arthritis (RA), osteoporosis (OP) and osteosarcoma (OS). Consequently, targeting KLFs has emerged as a promising therapeutic approach for an array of bone disorders. In this review, we summarize the current literature on the importance of KLFs in the emergence and regulation of bone illnesses, with a particular emphasis on the pertinent mechanisms by which KLFs regulate skeletal diseases. We also discuss the need for KLFs‐based medication‐targeted treatment. These endeavours offer new perspectives on the use of KLFs in bone disorders and provide prognostic biomarkers, therapeutic targets and possible drug candidates for bone diseases. [ABSTRACT FROM AUTHOR]

The epidermis is a stratified epithelium that forms the outer layer of the skin. It is composed primarily of keratinocytes and is constantly renewed by the proliferation of stem cells and their progeny that undergo terminal differentiation as they leave the basal layer and migrate to the skin surface. Basal keratinocytes rest on a basement membrane composed of an extracellular matrix that controls their fate via integrin‐mediated focal adhesions and hemidesmosomes which are critical elements of the epidermal barrier and promote its regenerative capabilities. The distribution of basal cells with optimal activity provides the basement membrane with its characteristic undulating shape; this configuration disappears with age, leading to epidermal weakness. In this study, we present an in‐depth imaging analysis of basal keratinocyte anchorage in samples of human skin from participants across the age spectrum. Our findings reveal that skin aging is associated with the depletion of hemidesmosomes that provide crucial support for stem cell maintenance; their depletion correlates with the loss of the characteristic basement membrane structure. Atomic force microscopy studies of skin and in vitro experiments revealed that the increase in tissue stiffness observed with aging triggers mechanical signals that alter the basement membrane structure and reduce the extent of basal keratinocyte anchorage, forcing them to differentiate. Genomic analysis revealed that epidermal aging was associated with mechanical induction of the transcription factor Krüppel‐like factor 4. The altered mechanical properties of tissue being a new hallmark of aging, our work opens new avenues for the development of skin rejuvenation strategies. [ABSTRACT FROM AUTHOR]

Anomalous vascular endothelium significantly contributes to various cardiovascular diseases. VE-cadherin plays a vital role in governing the endothelial barrier. Krüppel-like factor 4(KLF4), as a transcription factor, which binds the VE-cadherin promoter and enhances its transcription. Tumor necrosis factor receptor-associated factor 7 (TRAF7) is an E3 ubiquitin ligase that has been shown to modulate the degradation of KLF4. H 2 S can covalently modify cysteine residues on proteins through S-sulfhydration, thereby influencing the structure and functionality of the target protein. However, the role of S-sulfhydration on endothelial barrier integrity remains to be comprehensively elucidated. This study aims to investigate whether protein S-sulfhydration in the endothelium regulates endothelial integrity and its underlying mechanism. In this study, we observed that protein S-sulfhydration was reduced in the endothelium during diabetes and TRAF7 was the main target. Overexpression of TRAF7-Cys327 mutant could mitigate the endothelial barrier damage by weakening TRAF7 interaction with KLF4 and reducing ubiquitination degradation of KLF4. In conclusion, our research demonstrates that H 2 S plays a pivotal role in regulating S-sulfhydration of TRAF7 at Cys327. This regulation effectively inhibits the ubiquitin-mediated degradation of KLF4, resulting in an upregulation of VE-cadherin levels. This molecular mechanism contributes to the prevention of endothelial barrier damage. [Display omitted] • H 2 S plays a pivotal role in regulating S-sulfhydration of TRAF7 at Cys327. • Transfection with TRAF7-Cys327, the S-sulfhydration level of TRAF7 significantly decreased with NaHS treatment. • S-sulfhydration of TRAF7 at Cys327 prevents KLF4 degradation. • S-sulfhydration of TRAF7 at Cys327 maintains endothelial permeability. [ABSTRACT FROM AUTHOR]

The CACCC-box motif emerges as a pivotal cis-regulatory element implicated in diverse developmental processes and diseases, particularly cardiovascular diseases (CVDs). This study centers on the intricate interplay between the CACCC-box and its binding proteins such as: the Krüppel-Like Family (KLF) of transcription factors as primary effectors in the context of CVDs. Our analysis was through a bioinformatics approach, which revealed significant transcriptional activity among KLF subgroup 2, exhibiting the highest number of interactions focusing on the established roles: pluripotency, cancer, and cardiovascular development and diseases. Our analysis reveals KLF's interactions with GATA4, MEF2C, NKX2.5 and other ~90 potential genes that participate in the regulation of the hypertrophic environment (or CVDs' Environment). Also, the GO analysis showed that genes containing the motif CACCC were enriched for multiple CVDs; in combination with STRING analysis, these results pointed to a link between KLFs and these diseases. The analysis further identifies other potential CACCC-box binding factors, such as SP family members, WT1, VEZF1, and -SALL4, which are implicated in cardiac contraction, remodeling, and inflammation processes. [ABSTRACT FROM AUTHOR]

Halloysite nanotubes (HNTs) are nanomaterials (NMs) derived from natural clays and have been considered as biocompatible NMs for biomedical uses. However, the cardiovascular toxicity of HNTs has not been thoroughly investigated. In this study, we compared the cardiotoxicity of HNTs and multi-walled carbon nanotubes (MWCNTs), focusing on the changes in Kruppel-like factor (KLF)-mediated signaling pathways. Mice were intravenously injected with 50 µg NMs, once a day, for 5 days, and then mouse hearts were removed for experiments. While HNTs or MWCNTs did not induce obvious pathological changes, RNA-sequencing data suggested the alterations of KLF gene expression. We further confirmed an increase of Klf15 positive cells, accompanied by changes in Klf15-related gene ontology (GO) terms. We noticed that most of the changed GO terms are related with the regulation of gene expression, and we confirmed that the NMs increased myoneurin (Mynn) but decreased snail family transcriptional repressor 1 (Snai1), two transcription factors (TFs) related with Klf15. Besides, the changed GO terms also include metal ion binding and positive regulation of glucose import, and we verified an increase of phosphoenolpyruvate carboxykinase 1 (Pck1) and insulin receptor (Insr). However, HNTs and MWCNTs only showed minimal impact on cell death signaling pathways, and no increase in apoptotic sites was observed after NM treatment. We concluded that intravenous administration of HNTs and MWCNTs activated a protective TF, namely Klf15 in mouse aortas, to alter gene expression and signaling pathways related with metal ion binding and glucose import. [ABSTRACT FROM AUTHOR]

Calcitonin gene-related peptide (CGRP) is a neuropeptide that causes anxiety behavior; however, the underlying mechanisms remain unclear. We found that CGRP modulates anxiety behavior by epigenetically regulating the HP1γ-KLF-11-MAOB pathway and depleting dopamine in the dorsal hippocampus. Intracerebroventricular administration of CGRP (0.5 nmol) elicited anxiety-like behaviors in open field, hole-board, and plus-maze tests. Additionally, we observed an increase in monoamine oxidase B (MAOB) levels and a concurrent decrease in dopamine levels in the dorsal hippocampus of mice following CGRP administration. Moreover, CGRP increased abundance the transcriptional regulator of MAOB, Krüppel-like factor 11 (KLF11), and increased levels of phosphorylated heterochromatin protein (p-HP1γ), which is involved in gene silencing, by methylating histone H3 in the dorsal hippocampus. Chromatin immunoprecipitation assay showed that HP1γ was recruited to the Klf11 enhancer by CGRP. Furthermore, infusion of CGRP (1 nmol) into the dorsal hippocampus significantly increased MAOB expression as well as anxiety-like behaviors, which were suppressed by the pharmacological inhibition or knockdown of MAOB. Together, these findings suggest that CGRP reduces dopamine levels and induces anxiety-like behavior through epigenetic regulation in the dorsal hippocampus. Calcitonin gene-related peptide (CGRP) causes anxiety by modulating the HP1γKLF11-MAOB pathway, depleting dopamine in the dorsal hippocampus, and increasing MAOB while reducing dopamine levels, leading to anxiety-like behaviors. [ABSTRACT FROM AUTHOR]

Backgrounds: The overall survival of patients with lower-grade gliomas and glioblastoma varies greatly. No reliable or existing procedures can accurately forecast survival and prognostic biomarkers for early diagnosis in glioma and glioblastoma. However, investigations are progressing in immunotherapy, tumor purity, and tumor microenvironment which may be therapeutic targets for glioma and glioblastoma. Results: This study indicated the possible prognostic signatures that can be used to identify immune-related prognostic biomarkers in the prediction of the survival of low-grade glioma (LGG) patients which may be a possible therapeutic target. In addition, the Kaplan–Meier plot, ESTIMATE algorithm, and TIMER 2.0 analysis indicated that Krüppel-like factor 15 (KLF15) p = 0.030, Aquaporin 7 (AQP7) p = 0.001, and Human 1-acylglycerol-3-phosphate O-acyltransferase 9 (AGPAT9) p = 0.005 are significantly associated in glioma. Hence, they may be possible prognostic biomarkers in glioma. Meanwhile, in the glioblastoma, only KLF15 has a significant association with glioblastoma (p = 0.025). Stromal and immune scores of gliomas were determined from transcriptomic profiles of LGG cohort from TCGA (The Cancer Genome Atlas) using the ESTIMATE (Estimation of Stromal and Immune cells in Malignant Tumours using Expression data algorithm). The immune infiltration of the KLF15, AQP7, and AGPAT9 for low-grade glioma and glioblastoma was determined using TIMER immune 2.0 which indicates correlation with tumor purity for KLF15, AQP7, and AGPAT9, but only KLF15 and AGPAT9 are significantly associated in both glioma and glioblastoma, respectively. Conclusions: These results highlight the significance of microenvironment monitoring, analysis of glioma and glioblastoma prognosis, and targeted immunotherapy. To our knowledge, this is the first time to investigate an analysis that revealed that KLF15, AQP7, and AGPAT9 may be important prognostic biomarkers for patients with glioma and KLF15 for patients with glioblastoma. Meanwhile, KLF15 and AGPAT9 are significantly associated in both glioma and glioblastoma, respectively, for tumor purity. [ABSTRACT FROM AUTHOR]

Background: Krüppel-like factor 1 (KLF1), a crucial erythroid transcription factor, plays a significant role in various erythroid changes and haemolytic diseases. The rare erythrocyte Lutheran inhibitor (In(Lu)) blood group phenotype serves as an effective model for identifying KLF1 hypomorphic and loss-of-function variants. In this study, we aimed to analyse the genetic background of the In(Lu) phenotype in a population-based sample group by high-throughput technologies to find potentially clinically significant KLF1 variants. Results: We included 62 samples with In(Lu) phenotype, screened from over 300,000 Chinese blood donors. Among them, 36 samples were sequenced using targeted Next Generation Sequencing (NGS), whereas 19 samples were sequenced using High Fidelity (HiFi) technology. In addition, seven samples were simply sequenced using Sanger sequencing. A total of 29 hypomorphic or loss-of-function variants of KLF1 were identified, 21 of which were newly discovered. All new variants discovered by targeted NGS or HiFi sequencing were validated through Sanger sequencing, and the obtained results were found to be consistent. The KLF1 haplotypes of all new variants were further confirmed using clone sequencing or HiFi sequencing. The lack of functional KLF1 variants detected in the four samples indicates the presence of additional regulatory mechanisms. In addition, some samples exhibited BCAM polymorphisms, which encodes antigens of the Lutheran (LU) blood group system. However, no BCAM mutations which leads to the absence of LU proteins were detected. Conclusions: High-throughput sequencing methods, particularly HiFi sequencing, were introduced for the first time into genetic analysis of the In(Lu) phenotype. Targeted NGS and HiFi sequencing demonstrated the accuracy of the results, providing additional advantages such as simultaneous analysis of other blood group genes and clarification of haplotypes. Using the In(Lu) phenotype, a powerful model for identifying hypomorphic or loss-of-function KLF1 variants, numerous novel variants have been detected, which have contributed to the comprehensive understanding of KLF1. These clinically significant KLF1 mutations can serve as a valuable reference for the diagnosis of related blood cell diseases. [ABSTRACT FROM AUTHOR]

This article presents a case study of a patient with maturity-onset diabetes of the young (MODY) type 7, caused by a mutation in the KLF11 gene. The patient and other family members were found to have mutations in the same gene, with some displaying diabetes mellitus and others exhibiting hyperinsulinemia. The article emphasizes the importance of molecular diagnosis in effectively treating and providing genetic counseling for individuals with monogenic diabetes. Treatment options for MODY7 patients include oral antidiabetic drugs, insulin injections, and dietary intervention. The article also includes a table with clinical indicators and laboratory examination results for the family members, providing further insight into their conditions and genetic mutations. Another document discusses a case study of a patient with MODY7, who initially received insulin and oral hypoglycemic agents for treatment. After one year, the patient's clinical indicators and laboratory results showed significant improvement. The study highlights the importance of molecular diagnosis in effectively treating and managing monogenic diabetes, but further research is needed to evaluate long-term complications and determine optimal treatment strategies for MODY7. [Extracted from the article]

This article explores the role of Krüppel-like factor 4 (KLF4) in the transcriptional control of Agouti-related peptide (AgRP) isoforms in mice. The study found that KLF4 promotes the transcription of AgRP in lean mice, but this mechanism is altered during diet-induced obesity. The findings suggest that the expression of AgRP isoforms is dependent on cell type and that KLF4 plays a context-dependent role in AgRP control. Further research is needed to investigate the differential regulation of Agrp isoforms by KLF4. The article also provides information about the funding and support received for the research project, as well as a list of references to other scientific articles and databases related to the study of energy homeostasis, gene expression, and neuroendocrinology. [Extracted from the article]

The highly expressed oncogenic factor Krüppel‐like factor 5 (KLF5) promotes various cancerous processes, such as cell growth, survival, anti‐apoptosis, migration and metastasis, particularly in lung cancer. Nevertheless, the modifications to KLF5 after translation are poorly understood. Protein arginine methyltransferase 5 (PRMT5) is considered as an oncogene known to be involved in different types of carcinomas, including lung cancer. Here, we show that the expression levels of PRMT5 and KLF5 are highly expressed lung cancer. Moreover, PRMT5 interacts with KLF5 and facilitates the dimethylation of KLF5 at Arginine 41 in a manner that depends on methyltransferase activity. Downregulation or pharmaceutical suppression of PRMT5 reduces the expression of KLF5 and its downstream targets both in vitro and in vivo. Mechanistically, the dimethylation of KLF5 by PRMT5 promotes the maintenance and proliferation of lung cancer cells at least partially by stabilising KLF5 via regulation of the Akt/GSK3β signalling axis. In summary, PRMT5 methylates KLF5 to prevent its degradation, thereby promoting the maintenance and proliferation of lung cancer cells. These results suggest that targeting PRMT5/KLF5 axis may offer a potential therapeutic strategy for lung cancer. [ABSTRACT FROM AUTHOR]

Diabetic kidney disease (DKD) is a long-term and serious complication of diabetes that affects millions of people worldwide. It is characterized by proteinuria, glomerular damage, and renal fibrosis, leading to end-stage renal disease, and the pathogenesis is complex and involves multiple cellular and molecular mechanisms. Among three kinds of intraglomerular cells including podocytes, glomerular endothelial cells (GECs) and mesangial cells (MCs), the alterations in one cell type can produce changes in the others. The cell-to-cell crosstalk plays a crucial role in maintaining the glomerular filtration barrier (GFB) and homeostasis. In this review, we summarized the recent advances in understanding the pathological changes and interactions of these three types of cells in DKD and then focused on the signaling pathways and factors that mediate the crosstalk, such as angiopoietins, vascular endothelial growth factors, transforming growth factor-β, Krüppel-like factors, retinoic acid receptor response protein 1 and exosomes, etc. Furthermore, we also simply introduce the application of the latest technologies in studying cell interactions within glomerular cells and new promising mediators for cell crosstalk in DKD. In conclusion, this review provides a comprehensive and updated overview of the glomerular crosstalk in DKD and highlights its importance for the development of novel intervention approaches. [ABSTRACT FROM AUTHOR]