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Contactin-associated protein1 (Caspr1) plays an important role in the formation and stability of myelinated axons. In Caspr1 mutant mice, autophagy-related structures accumulate in neurons, causing axonal degeneration; however, the mechanism by which Caspr1 regulates autophagy remains unknown. To illustrate the mechanism of Caspr1 in autophagy process, we demonstrated that Caspr1 knockout in primary neurons from mice along with human cell lines, HEK-293 and HeLa, induced autophagy by downregulating the PI3K/AKT/mTOR signaling pathway to promote the conversion of microtubule-associated protein light chain 3 I (LC3-I) to LC3-II. In contrast, Caspr1 overexpression in cells contributed to the upregulation of this signaling pathway. We also demonstrated that Caspr1 knockout led to increased LC3-I protein expression in mice. In addition, Caspr1 could inhibit the expression of autophagy-related 4B cysteine peptidase (ATG4B) protein by directly binding to ATG4B in overexpressed Caspr1 cells. Intriguingly, we found an accumulation of ATG4B in the Golgi apparatuses of cells overexpressing Caspr1; therefore, we speculate that Caspr1 may restrict ATG4 secretion from the Golgi apparatus to the cytoplasm. Collectively, our results indicate that Caspr1 may regulate autophagy by modulating the PI3K/AKT/mTOR signaling pathway and the levels of ATG4 protein, both in vitro and in vivo. Thus, Caspr1 can be a potential therapeutic target in axonal damage and demyelinating diseases. [ABSTRACT FROM AUTHOR]

Elevated intraocular pressure (IOP) is the primary risk factor for glaucoma, a leading cause of irreversible blindness worldwide. IOP homeostasis is maintained through a balance between aqueous humor production and its drainage through the trabecular meshwork (TM)/Schlemm's Canal (SC) outflow pathway. Prior studies by our laboratory reported a key role of mechanical forces and primary cilia (PC)-dependent stretch-induced autophagy in IOP homeostasis. However, the precise mechanism regulating this process remains elusive. In this study, we investigated the upstream signaling pathway orchestrating autophagy activation during cyclic mechanical stretch (CMS) in primary cultured human TM cells, using biochemical and cell biological analyses. Our results indicate that TM cells express catalytic subunits of class IA PI3Ks (PIK3CA, B, and D), and that inhibition of class IA isoforms, but not class II and III, significantly prevent CMS-induced autophagy. Importantly, PIK3CA was found to localize in the PC. Furthermore, we identified a coordinated action of Class IA PI3Ks along INPP4A/B, a 4′ inositol phosphatase, responsible for the formation of PI(3,4)P2 and PI(3)P and stretch-induced autophagy in TM cells. These findings contribute to a deeper understanding of the molecular mechanisms underlying IOP homeostasis. [ABSTRACT FROM AUTHOR]

Background: Colorectal carcinoma ranks as the second most prevalent neoplasm in females and the third most prevalent in males. Methods: In this investigation, we examined the influence of alpha-pinene (ALP), classified as a monoterpene, on the proliferation of HT-29 human colorectal carcinoma cells via the PI3K/AKT signaling cascade. HT-29 cells were exposed to a range of ALP concentrations. The survival rate of the cells was assessed through the MTT assay; while, apoptotic events were evaluated using flow cytometry in conjunction with Annexin V/PI staining. Additionally, cell cycle dynamics were scrutinized through fluorescence-activated cell sorting. The expression levels of Bax, Bcl-2, Caspase-3, PI3K, and AKT at both the gene and protein levels were quantified employing real-time PCR and western blot techniques. Results: ALP treatment led to a significant, dose-dependent decrease in cell viability, with prolonged exposure exacerbating cytotoxic effects. Apoptosis analysis showed that ALP significantly increased apoptotic cells after 24 h of treatment. Cell cycle analysis showed that ALP induces G2/M phase arrest and inhibits cell proliferation and DNA synthesis. Gene expression analysis revealed upregulation of pro-apoptotic genes Bax and caspase-3 and decreased anti-apoptotic gene Bcl-2. Furthermore, the administration of ALP led to a notable reduction in both the gene and protein expression levels of PI3K and Akt, suggesting a suppression of the PI3K/Akt signaling cascade. Conclusion: ALP inhibits HT-29 colon cancer cell growth by reducing cell viability, inducing apoptosis, and blocking the PI3K/AKT pathway. These findings highlight ALP's potential as a therapeutic candidate for colorectal cancer. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma is considered to be the fifth most rampant type of cancer in the whole world and has a high death rate. The hypoxic microenvironment is one of the typical features of tumor tissues and has an important impact on the activity of multiple signaling pathways. It is of great significance to study the effects of hypoxia on the pathophysiological processes and molecular mechanisms of HCC. Signalling pathways associated with SHP2 were analysed using bioinformatics. Detection of relevant protein expression using Western blotting. Tube formation assay was used in evalution of the angiogenic potential. The concentrations of MDA and SOD were measured by ELISA. The cell migration and invasion ability were measured with a scratch wound assay and transwell assay in SMMC-7721, HepG2 and Huh-7 cells. The effect of hypoxia on the growth of hepatocellular carcinoma was examined using subcutaneous graft tumors and HE staining experiments in nude mice. Bioinformatics analysis of SHP2 negatively correlates with the PI3K signalling pathway. Hypoxia promotes the concentration of MDA and inhibited the concentration of SOD. Hypoxia may up-regulate NOX2, NOX4 and p-PI3K and down-regulate the treatment of p-SHP2. Compared with NC group, the expression of SHP2 and p-SHP2 was inhibited in SHP2 KD group and the expression of p-PI3K, HIF1α, COX2, FOXM1, β-catenin and MMP9 was promoted. However, the differences of the expression of p-PI3K, HIF1α, COX2, FOXM1, β-catenin and MMP9 between the two groups were abolished after the addition of PI3K inhibitor. The angiogenesis, migration and invasion abilities were significantly increased in SHP2 KD group compared with NC group. Similarly, after the addition of PI3K inhibitor, the difference of these abilities between the two groups was eliminated. Hypoxia can promote the growth of hepatocellular carcinoma. Hypoxia can activate the oxidative stress-mediated SHP2/PI3K signaling pathway to promote angiogenesis, migration, and invasion in hepatocellular carcinoma, thus advancing the development of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Objective: To investigate the mechanism of Xiaohan Liqi granules (XHLQ) on obstructive sleep apnea-hypopnea syndrome (OSAHS) using network pharmacology and animal validation. Methods: Network pharmacology was used to demonstrate the mechanism of XHLQ in OSAHS with the use of databases and software such as The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), GeneCards, Cytoscape 3.7.2, etcetera. The intermittent hypoxia (IH)-induced rat model was established by placing the rats in an IH chamber and adjusting the oxygen concentration. Hematoxylin and Eosin (H&E) staining was performed to observe the pathological changes in the lung tissues of the rats. Immunohistochemistry (IHC) was used to determine the average optical density values of PI3K and Akt. Quantitative real-time PCR (RT-qPCR) was performed to compare the relative mRNA expression levels of PI3K and Akt in each group. And Enzyme-Linked ImmunoSorbent Assay (ELISA) was used to measure serum IL-6 and TNF-α in rats. Results: The core ingredients of XHLQ for OSAHS were β-sitosterol, palmitoleic acid, α-linolenic acid (ALA), kaempferol and linoleic acid, and the core targets were ALB, IL6, CXCL8, HIF1A, IGF1, MMP9, TLR4, NOS3 and PPARG. Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the common targets of XHLQ and OSAHS were mainly involved PI3K/Akt, HIF-1, TNF-α, NF-κB and other signaling pathways. H&E staining demonstrated that XHLQ can alleviate inflammatory infiltration in the lung tissues. ELISA indicated that XHLQ decreases the expression of IL-6 and TNF-α. IHC staining and RT-qPCR confirmed that XHLQ can reduce the activation of PI3K and Akt. Conclusion: XHLQ may exert therapeutic effects in OSAHS through multiple targets and pathways. Animal experiments verified that XHLQ attenuated airway inflammation and down-regulated PI3K and Akt expression in an IH rat model. Thus, XHLQ shows potential as an adjunctive treatment for OSAHS. [ABSTRACT FROM AUTHOR]

Lipid emulsion has recently emerged as an effective agent for improving the cardiotoxicity of highly lipophilic drugs. However, its effect on cardiotoxicity induced by labetalol, a nonselective beta-blocker, remains unknown. In this study, we investigated the effects of lipid emulsion on the cardiotoxicity of labetalol in rat cardiomyoblasts and tried to decipher the underlying mechanisms. The effects of lipid emulsion on labetalol-induced changes in cell viability, expression of Bax/Bcl-2, cleaved caspase-3, and cleaved caspase-9, and phosphorylation of GSK-3β, Akt, and PI3K were examined. Lipid emulsion inhibited labetalol-induced decrease in cell viability, whereas LY294002, MK2206, and SB216763, the inhibitors of phosphoinositide 3-kinase (PI3K), Akt, glycogen synthase kinase-3β (GSK-3β), respectively, partially attenuated this restoration of cell viability. Lipid emulsion reversed the increase in expression of cleaved caspase-3, cleaved caspase-9, and Bax/Bcl-2 and decrease in the phosphorylation of GSK-3β, Akt, and PI3K by labetalol. Lipid emulsion and cyclosporin, a mitochondrial permeability transition pore (MPTP) inhibitor, reduced the labetalol-induced increase in the number of TUNEL-positive cells and promoted late-stage apoptosis. Overall, lipid emulsion inhibited apoptotic cell death caused by labetalol toxicity via the inhibition of intrinsic apoptotic pathway and MPTP in rat cardiomyoblasts, which appears to involve PI3K, Akt, and GSK-3β signaling pathways. [ABSTRACT FROM AUTHOR]

Recent findings have brought our understanding of diseases at the molecular level, highlighting upstream intracellular pathways as potential therapeutic targets. The PI3K/AKT pathway, a key regulator of cellular responses to environmental changes, is frequently altered in various diseases, making it a promising target for intervention. Metformin is the most known anti-diabetic agent that is known due to its effects on cancer, inflammatory-related diseases, oxidative stress, and other human diseases. It is clearly understood that metformin modulates the activity of the PI3K/AKT pathway leading to a wide variety of outcomes. This interaction has been well-studied in various diseases. Therefore, this review aims to examine PI3K/AKT-modulating properties of metformin in cancer, cardiovascular, and central nervous system diseases. Our findings indicate that metformin is effective in treating cancer and CNS diseases, and plays a role in both the prevention and treatment of cardiovascular diseases. These insights support the potential of metformin in comprehensive strategies for disease management. [ABSTRACT FROM AUTHOR]

PIK3CA variants are known to cause vascular malformations. We were interested in studying the phenotypic spectrum, the location within the PIK3CA gene, and the variant allele frequency (VAF) of somatic PI3KCA variants in vascular malformations. Clinical data of consecutive patients with extracranial/extraspinal vascular malformations were collected in the context of the VASCOM cohort (2008–2022, n = 558). Starting October 2020, biopsy samples were tested with the TSO500 gene panel (Illumina). All consenting patients with PIK3CA variants were included in this study. Eighty‐nine patients had available genetic results by June 2022. PIK3CA variants (n = 25) were found in 16 simple/combined (nonsyndromic) vascular malformations and in nine vascular malformations associated with other anomalies (syndromic). Four hotspot variants in exons 9 and 20 (c.1624G>A, c.1633G>A, c.3140A>G, c.3140A>T) were identified in 16/25 patients (VAF 0.9%–9.7%). Six non‐hotspot variants (c.328_330del, c.323_337del, c.353G>A, c.1258T>C, c.3132T>A, c.3195_3203delinsT) were detected in nine patients (VAF 3.6%–31.7%). Non‐hotspot variants were more frequent in syndromic than nonsyndromic vascular malformations (p = 0.0034) and exhibited a higher VAF than hotspot variants (p = 0.0253). Our study contributes to the growing body of knowledge of the genetic background in vascular malformations. Further studies will enrich the ever‐growing list of pathogenic PIK3CA variants associated with vascular malformations. [ABSTRACT FROM AUTHOR]

Simple Summary: Phosphoinositide 3-kinase (PI3K) activation may occur via different mechanisms that involve defects in PIK3R1 encoding the PI3K regulatory subunit (p85α). We aimed to evaluate PIK3R1 alterations in ovarian cancers in the context of their clinicopathological characteristics, other molecular changes, and patient prognoses. PIK3R1 aberrations were present in the majority of tumors with underexpression as the most frequent event. We found that PIK3R1 mutations mainly contribute to the development of low-stage endometrioid and clear-cell carcinomas with coexisting PTEN mutations. In contrast, PIK3R1 gene deletion and mRNA underexpression are features of aggressive high-grade cancers of different histological types with PIK3CA amplifications and TP53 mutations. We also identified low PIK3R1 mRNA expression as an unfavorable predictive factor for platinum-based therapy. Our data indicate the role of PIK3R1 in ovarian cancer development and define a significant group of patients with different PIK3R1 alterations that may potentially benefit from treatment with PI3K inhibitors. Background: The phosphoinositide 3-kinase (PI3K) pathway is activated in multiple cancers. However, the significance of PIK3R1 encoding the PI3K regulatory subunit, an inhibitor of the PI3K catalytic subunit encoded by PIK3CA, in ovarian cancer development is largely unknown. Methods: Here, we investigated PIK3R1 genomic alterations and gene expression by direct sequencing and qPCR methods in 197 ovarian cancers. The results were correlated with clinicopathological and molecular variables and patient outcomes. Results: In addition to mutations (3.5%) and allelic losses (28.4%), we observed a very high frequency of decreased PIK3R1 mRNA levels in ovarian carcinomas (95.8%). Tumors with PIK3R1 mutations mostly represented low-stage cancers of endometrioid and clear-cell type. Tumors with PIK3R1 deletion and underexpression shared similar phenotypes of high-grade carcinomas (p = 0.003 and p = 0.025, respectively). Allelic loss was also associated with advanced stages (p = 0.003) and high-grade serous histotypes (p = 0.004). The PIK3R1 copy number correlated with mRNA levels (p = 0.009). PIK3R1 mutations coexisted with PTEN mutations (p = 0.041), whereas PIK3R1 deletion and underexpression were linked to PIK3CA amplification (p = 0.038 and p = 0.033, respectively). Low PIK3R1 expression diminished the probability of a complete response (OR 0.07, p = 0.03) in patients treated with platinum-based regimens. Conclusions: PIK3R1 alterations may contribute to the development of ovarian cancers with different malignant potential and molecular changes. The high frequency of PIK3R1 aberrations suggests their importance in PI3K pathway deregulation, and they may potentially serve as an alternative to PIK3CA markers for therapy with these pathway inhibitors. [ABSTRACT FROM AUTHOR]

Objective(s): Plinabulin, a marine-derived anticancer drug targeting microtubules, exhibits anticancer effects on glioblastoma cells. However, its therapeutic potential, specifically for glioblastoma treatment, remains underexplored. This study aims to elucidate the mechanisms by which plinabulin exerts its effects on glioblastoma cells. Materials and Methods: Using the SRB and colony formation assay to observe the effect of plinabulin on glioblastoma cell viability. Wound healing and transwell migration assay were used to test the effect of plinabulin on glioblastoma cell metastatic potential. Crucial target genes were identified through RNA sequencing and bioinformatics analysis. Protein levels were evaluated in a concentrationdependent manner using western blot analysis. Results: Plinabulin suppressed glioblastoma cell proliferation by causing cell cycle G2/M phase arrest and inhibited migration. The IC50 values were 22.20 nM in A172 cells and 20.55 nM in T98G cells. Plinabulin reduced AKT and mTOR phosphorylation. Combined with the AKT/mTOR inhibitors LY294002 and rapamycin, plinabulin decreased p-mTOR and EGFR protein levels and increased cleaved-PARP levels. Plinabulin induces autophagy, and using an autophagy inhibitor enhances plinabulin-induced cell apoptosis. This suggests that plinabulin might trigger cytoprotective autophagy in glioblastoma cells. These findings indicate that plinabulin hinders glioblastoma growth and induces protective autophagy via the PI3K/AKT/mTOR pathway. Additionally, plinabulin combined with erlotinib showed greater cytotoxic efficacy than either drug alone in glioblastoma cells in vitro. Conclusion: Our study provides new insights into the efficacy of plinabulin against glioblastoma and highlights the potential clinical utility of combining plinabulin with EGFR inhibitors as a chemotherapy strategy. [ABSTRACT FROM AUTHOR]