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Ca2+ overload and mitochondrial dysfunction play crucial roles in myocardial ischemia-reperfusion (I/R) injury. Piezo1, a mechanosensitive cation channel, is essential for intracellular Ca2+ homeostasis. The objective of this research was to explore the effects of Piezo1 on mitochondrial function during myocardial I/R injury. We showed that the expression of myocardial Piezo1 was elevated in the infracted area of I/R and cardiomyocyte-specific Piezo1 deficiency (Piezo1△Myh6) mice attenuated I/R by decreasing infarct size and cardiac dysfunction. Piezo1△Myh6 regulated mitochondrial fusion and fission to improve mitochondrial function and decrease inflammation and oxidative stress in vivo and in vitro. Mechanistically, myocardial Piezo1 knockout alleviated intracellular calcium overload to normalize calpain-associated mitochondrial homeostasis. Our findings indicated that Piezo1 depletion in cardiomyocytes partially restored mitochondrial homeostasis during cardiac ischemia/reperfusion (I/R) injury. This study suggests an innovative therapeutic strategy to alleviate cardiac I/R injury.

Background Heart failure with preserved ejection fraction (HFpEF) is linked to prolonged endoplasmic reticulum (ER) stress. P21‐activated kinase 2 (Pak2) facilitates a protective ER stress response. This study explores the mechanism and role of Pak2 in HFpEF pathology. Methods and Results The HFpEF mouse model was established using a high‐fat diet combined with the nitric oxide synthase inhibitor Nω‐Nitro‐l‐arginine methyl ester (high‐fat diet+Nω‐Nitro‐l‐arginine methyl ester). The model exhibited the typical characteristics of HFpEF (cardiac hypertrophy, diastolic dysfunction with preserved systolic function, and lung edema) as determined by echocardiography and hemodynamic analysis. Terminal deoxynucleotidyl transferase dUTP nick end labeling and dihydroethidium staining results showed that cell death and reactive oxygen species generation were higher in the high‐fat diet+Nω‐Nitro‐l‐arginine methyl ester–treated group. Transmission electron microscopy revealed disruption of the ER subcellular structures in the HFpEF mouse model, while western blot analysis confirmed reduced Pak2 phosphorylation and impaired inositol‐requiring enzyme 1/X‐box binding protein 1 splicing ER stress response signaling. Furthermore, H9c2 cells subjected to the palmitic acid–mediated metabolic stress developed temporal changes in unfolded protein response proteins and Pak2 activity. The inositol requiring enzyme 1/X‐box binding protein 1 splicing branch of unfolded protein response was impaired earlier than other branches. Overexpression of Pak2 by adenovirus in H9c2 cells sustained the activation of inositol requiring enzyme 1/X‐box binding protein 1 splicing. Pak2 deficiency in the mouse heart accelerated the HFpEF progression, and this phenomenon occurred as early as 10 weeks in Pak2 cardiomyocyte‐specific knockout mice. Conversely, adeno‐associated virus serotype 9–mediated Pak2 overexpression mitigated HFpEF symptoms, underscoring its protective role against HFpEF progression. Conclusions Pak2 prevents HFpEF progression, exerting cardioprotective effects against ER stress. These insights underscore the therapeutic value of Pak2 in HFpEF.

Background: Myocardial fibrosis post-myocardial infarction (MI) can induce maladaptive cardiac remodeling as well as heart failure. Although 20(S)-ginsenoside Rg3 (Rg3) has been applied to cardiovascular diseases, its efficacy and specific molecular mechanism in myocardial fibrosis are largely unknown. Herein, we aimed to explore whether TGFBR1 signaling was involved in Rg3's anti-fibrotic effect post-MI. Methods: Left anterior descending (LAD) coronary artery ligation-induced MI mice and TGF-β1-stimulated primary cardiac fibroblasts (CFs) were adopted. Echocardiography, hematoxlin-eosin and Masson staining, Western-blot and immunohistochemistry, CCK8 and Edu were used to study the effects of Rg3 on myocardial fibrosis and TGFBR1 signaling. The combination mechanism of Rg3 and TGFBR1 was explored by surface plasmon resonance imaging (SPRi). Moreover, myocardial Tgfbr1-deficient mice and TGFBR1 adenovirus were adopted to confirm the pharmacological mechanism of Rg3. Results: In vivo experiments, Rg3 ameliorated myocardial fibrosis and hypertrophy and enhanced cardiac function. Rg3-TGFBR1 had the 1.78 × 10−7 M equilibrium dissociation constant based on SPRi analysis, and Rg3 inhibited the activation of TGFBR1/Smads signaling dose-dependently. Cardiac-specific Tgfbr1 knockdown abolished Rg3's protection against myocardial fibrosis post-MI. In addition, Rg3 down-regulated the TGF-β1-mediated CFs growth together with collagen production in vitro through TGFBR1 signaling. Moreover, TGFBR1 adenovirus partially blocked the inhibitory effect of Rg3. Conclusion: Rg3 improves myocardial fibrosis and cardiac function through suppressing CFs proliferation along with collagen deposition by inactivation of TGFBR1 pathway.

Abstract Background The pathogenesis of immunoglobulin G4-related disease (IgG4-RD) remains unclear. IgG4-RD often mimics other diseases, including pancreatic cancer (PC) and Sjogren’s syndrome (SS), which may easily lead to misdiagnosis. This study was performed to explore the metabolite changes and potential biomarkers of IgG4-RD and other misdiagnosed diseases. Methods Untargeted liquid chromatography–tandem mass spectrometry metabolomics profiling of plasma samples from a cohort comprising healthy controls (HCs) and patients with IgG4-RD (n = 87), PC (n = 33), and SS (n = 31) was performed. A random forest machine learning model was used to verify the relevance of the identified metabolites in the diagnosis of different diseases and the prediction of disease prognosis. Results The ATP-binding cassette transporter pathway was found to be most closely related to IgG4-RD, which was significantly up-regulated in the IgG4-RD group than in all the matched groups. Five metabolites were proved to be valuable biomarkers for IgG4-RD. Caftaric acid, maltotetraose, d-glutamic acid, 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphoserine, and hydroxyproline were useful in distinguishing between IgG4-RD, PC, SS, and HC [area under the curve (AUC) = 1]. A combination of phenylalanine betaine, 1-(1z-hexadecenyl)-sn-glycero-3-phosphocholine, Pi 40:8, uracil, and N1-methyl-2-pyridone-5-carboxamide showed a moderate value in predicting relapse in patients with IgG4-RD (AUC = 0.8). Conclusions Our findings revealed the metabolite changes of IgG4-RD and provide new insights for deepening our understanding of IgG4-RD despite the lack of validation in external cohorts. Metabolomic biomarkers have significance in the clinical diagnosis and disease prognosis of IgG4-RD.

Aim of the study: This study aims to identify the effects of Nuanxinkang (NXK) on inflammation and pyroptosis post-MI and understand the underlying mechanisms. Materials and methods: Left Anterior Descending (LAD) coronary artery ligation was used to induce MI in mice. NXK or Captopril were orally administered 3 days after surgery for 4 weeks. Cardiac function, as well as infarct size, was detected by echocardiography, 2,3,5-triphenyl-tetrazolium chloride (TTC) staining and Hematoxylin and Eosin (H&E) staining. Inflammatory mediators were measured by flow cytometry, real-time polymerase chain reaction (RT-PCR) and immunofluorescence (IF). Pyroptosis-related protein expressions were determined through Western blot (WB). Intracellular Ca2+ measurements were conducted in bone marrow derived macrophages (BMDM) to detect calcium influx. Molecular docking (MD) was applied to define the candidate ingredients in NXK that regulate Piezo1. Results: NXK increased the ratio of heart or lung and body weight in mice post-MI. TTC and H&E staining infarct size and myocardial damage. The results obtained through echocardiography suggest that NXK remarkably enhanced heart function. Immunofluorescence of F4/80 and flow cytometry results demonstrated that NXK suppressed inflammatory infiltration. Molecular docking showed that Piezo1 had correlation with NXK. Intracellular Ca2+ measurements suggest that NXK inhibit Yoda1-evoked Piezo1 activation. Furthermore, NXK treatment significantly suppressed Piezo1-mediated pyroptosis in vivo and in vitro. Conclusions: The present study indicates that NXK may prevent ventricular remodeling post-MI through regulation of the Piezo1-mediated pyroptosis. Furthermore, the study provides a potential strategy for attenuating NLRP3-inflmmasome activation in the context of ventricular remodeling post-MI using NXK.

BackgroundAn essential fact underlying the severity of Staphylococcus aureus (S. aureus) infection is the bicomponent leukocidins released by the pathogen to target and lyse host phagocytes through specific binding cell membrane receptors. However, little is known about the impact of post-transcriptional modification of receptors on the leukocidin binding.MethodIn this study, we used small interfering RNA library (Horizon/Dharmacon) to screen potential genes that affect leukocidin binding on receptors. The cell permeability was investigated through flow cytometry measuring the internalization of 4′,6-diamidino-2-phenylindole. Expression of C5a anaphylatoxin chemotactic receptor 1 (C5aR1), sulfated C5aR1 in, and binding of 6x-His–tagged Hemolysin C (HlgC) and Panton-Valentine leukocidin (PVL) slow-component to THP-1 cell lines was detected and analyzed via flow cytometry. Bacterial burden and Survival analysis experiment was conducted in WT and myeloid TPST-cko C57BL/6N mice.ResultsAfter short hairpin RNA (shRNA) knockdown of TPST2 gene in THP-1, HL-60, and RAW264.7, the cytotoxicity of HlgAB, HlgCB, and Panton–Valentine leukocidin on THP-1 or HL-60 cells was decreased significantly, and the cytotoxicity of HlgAB on RAW264.7 cells was also decreased significantly. Knockdown of TPST2 did not affect the C5aR1 expression but downregulated cell surface C5aR1 tyrosine sulfation on THP-1. In addition, we found that the binding of HlgC and LukS-PV on cell surface receptor C5aR1 was impaired in C5aR1+TPST2− and C5aR1−TPST2− cells. Phagocyte knockout of TPST2 protects mice from S. aureus infection and improves the survival of mice infected with S. aureus.ConclusionThese results indicate that phagocyte TPST2 mediates the bicomponent leukocidin cytotoxicity by promoting cell membrane receptor sulfation modification that facilitates its binding to leukocidin S component.

Tetramethylpyrazine (TMP) is the main component of functional quality in vinegar. According to recent studies, TMP has a wide range of pharmacological effects, including a positive influence on the cardiovascular system, neurological system, tumors, and other disorders. This review compiled all of the most recent data on the pharmacological effects and probable mechanisms of TMP. TMP has been shown to inhibit platelet aggregation, dilate blood vessels, improve microcirculation, protect vascular endothelium, improve metabolism, be anti-inflammatory, anti-apoptosis, anti-oxidant, anti-cancer, anti-fibrosis, and have other beneficial effects. TMP is nontoxic, chemically stable, and can cross the blood-brain barrier. It is beneficial in treating cardiovascular, nervous, digestive, respiratory, and urinary system disorders. Several signaling pathways, including MAPK, PGC-1α/Nrf2/HO-1, PI3K/AKT, VEGF/VEGFR2, MMP/TIMP, TGF-β1, Bcl-2/Bax, and others, contribute to TMP's extensive pharmacological effects. TMP is a natural compound with promising research and development potential. This study provides a theoretical foundation for TMP's clinical application and references for future research.

BackgroundsObservational studies have identified associations between smoking, alcohol use, body mass index (BMI), and the levels of vitamin D with primary biliary cholangitis (PBC). However, there was a lack of randomization control studies to estimate the causal relationship. This study was to investigate the causal estimates for the effects of those risk factors on PBC.MethodsThe genetic instrument variants were extracted from genome-wide association studies in European ancestry. Two-sample mendelian randomization (MR) and multivariable mendelian randomization were used to determine genetically causal estimates. Primary analyses consisted of random-effects and fix-mode inverse-variance-weighted methods, followed by secondary sensitivity analyses to verify the results.ResultsOur study showed that BMI was a causal factor for PBC (OR 1.35; 95% CI=1.03-1.77; p=0.029). In addition, we found that serum vitamin D levels had a protective effect on PBC after adjusting for BMI (OR 0.51; 95% CI=0.32-0.84; p=0.007). However, we failed to identify evidence supporting that genetic causal effect of smoking and alcohol intake were associated with PBC in European countries.ConclusionOur results enriched findings from previous epidemiology studies and provided evidence from MR that serum vitamin D concentrations and BMI were independent causal factors for PBC, suggesting that ensuing vitamin D sufficiency and healthy lifestyles might be a cost-effective measure for early intervention for PBC.

The NAC (NAM, ATAF1/2 and CUC2) transcription factors are ubiquitously distributed in plants and play critical roles in the construction of plant organs and abiotic stress response. In this study, we described the cloning of a Suaeda liaotungensis K. NAC transcription factor gene SlNAC4, which contained 1450 bp, coding a 331 amino acid. We found that SlNAC4 was highly expressed in stems of S. liaotungensis, and the expression of SlNAC4 was considerably up-regulated after salt, drought, and ABA treatments. Transcription analysis and subcellular localization demonstrated that the SlNAC4 protein was located both in the nucleus and cytoplasm, and contained a C-terminal transcriptional activator. The SlNAC4 overexpression Arabidopsis lines significantly enhanced the tolerance to salt and drought treatment and displayed obviously increased activity of antioxidant enzymes under salt and drought stress. Additionally, transgenic plants overexpressing SlNAC4 had a significantly higher level of physiological indices. Interestingly, SlNAC4 promoted the expression of ABA metabolism-related genes including AtABA1, AtABA3, AtNCED3, AtAAO3, but inhibited the expression of AtCYP707A3 in overexpression lines. Using a yeast one-hybrid (Y1H) assay, we identified that the SlNAC4 transcription factor could bind to the promoters of those ABA metabolism-related genes. These results indicate that overexpression of SlNAC4 in plants enhances the tolerance to salt and drought stress by regulating ABA metabolism.

Panax ginseng has therapeutic effects on various inflammation-related diseases. Ginsenoside Rb3 (GRb3), a natural compound with anti-inflammatory and immunomodulatory properties, is one of the main active panaxadiol extracted from Panax ginseng. We explored whether GRb3 inhibited LPS-mediated inflammation through TLR4/NF-κB/MAPK signaling in macrophages. GRb3 attenuated NO and PGE2 production by attenuating iNOS and COX2 expression. GRb3 also suppressed pro-inflammatory cytokines levels, including IL-1β, IL-6, and TNF-α. Moreover, GRb3 administration significantly suppressed NF-κB (p65) nuclear translocation and the phosphorylation levels of p65, IκBα, JNK, p38, and ERK dose-dependently. Molecular docking demonstrated that GRb3 could dock onto the hydrophobic binding site of TLR4/MD2 complex, with a binding energy of −8.79 kcal/mol. Molecular dynamics (MD) displayed stable TLR4-MD2-GRb3 modeling. GRb3 dose-dependently inhibited LPS binding to cell membranes and blocked TLR4 expression. Surface plasmon resonance imaging (SPRi) revealed that GRb3 had an excellent binding affinity to TLR4/MD2 complex. Notably, resatorvid (TAK242), a selective TLR4 inhibitor, did not increase the repressive influence of GRb3 in RAW264.7 macrophages. Moreover, TLR4 overexpression partially reversed the repressive roles of GRb3 on the NF-κB/MAPK pathway and inflammatory mediators. Collectively, our study strongly indicated that GRb3 attenuated LPS-mediated inflammation through direct inhibition of TLR4 signaling. A novel insight into the underlying mechanism of anti-inflammatory effects of GRb3 in macrophages was confirmed.

Here we reported two anti-Mi-2 autoantibody-positive dermatomyositis (DM) patients with a characteristic antinuclear antibody (ANA) immunofluorescence pattern. Autoantibodes were screened by indirect immunofluorescence (IIF) on HEp-2 cells (Euroimmun, Lübeck, Germany) and confirmed by line immunoblot (ANA Profile 3—Euroimmun, Germany). These two patients were positive for ANA (speckled, titer 1:320), followed by confirmation of positive anti-Mi-2α and anti-Mi-2β positive and negative for all other antibodies. We found a characteristic ANA pattern of the anti-Mi-2 antibody that differed from the AC-4 pattern, especially in the morphology of mitotic cells (metaphase, anaphase, and telophase). Thus, we would like to suggest reporting this characteristic antinuclear antibody pattern as a new AC type, as AC-X.

Dendritic cells instruct different types of T cell responses depending on the types of microbial ligands sensed. Here the authors show that dendritic cells stimulated via Dectin-1 receptor upregulate TNFSF15 and OX40L and induce T helper 9 response and efficient antitumour immunity in mouse models.

The use of polymer gel for water control and oil addition is a common technical method in oilfield development. The polymer and hydrated bentonite react under the action of an organic crosslinking agent to form a composite gel. The particle-size change and microstructure of the composite gel were analyzed via shear thinning, thixotropic, viscoelastic, and start-up stress rheology experiments. The experimental results show that the polyacrylamide/bentonite organic crosslinked composite gel was a gel system with bentonite as the core aggregate structure, and the large particle-size distribution was mostly increased with increasing crosslinker content. The composite gel presented shear thinning characteristics, the content of bentonite or crosslinking agent was increased, and the shear resistance was stronger at a high shear rate. The composite gel exhibited positive thixotropic properties, and the thixotropy increased with increasing bentonite content. The composite gel had good viscoelastic characteristics, the elastic characteristics of the composite gel showed more significantly with bentonite increases, and the viscosity of the composite gel showed its characteristics more significantly with the crosslinking agent increased. After loading at a rate on the composite gel, the shear stress increased significantly with time and reached its maximum value, and then the shear stress decreased and gradually stabilized.

Macrophages play a vital role in the inflammation and repair processes of ischemia/reperfusion-induced acute kidney injury (IR-AKI). The mechanosensitive ion channel Piezo1 is significant in these inflammatory processes. However, the exact role of macrophage Piezo1 in IR-AKI is unknown. The main purpose of this study was to determine the role of macrophage Piezo1 in the injury and repair process in IR-AKI. Genetically modified mice with targeted knockout of Piezo1 in myeloid cells were established, and acute kidney injury was induced by bilateral renal vascular clamping surgery. Additionally, hypoxia treatment was performed on bone marrow-derived macrophages in vitro. Our data indicate that Piezo1 is upregulated in renal macrophages in mice with IR-AKI. Myeloid Piezo1 knockout provided protective effects in mice with IR-AKI. Mechanistically, the regulatory effects of Piezo1 on macrophages are at least partially linked to calpain signaling. Piezo1 activates Ca2+-dependent calpain signaling, which critically upregulates HIF-1α signaling. This key pathway subsequently influences the Notch and CCL2/CCR2 pathways, driving the polarization of M1 macrophages. In conclusion, our findings elucidate the biological functions of Piezo1 in renal macrophages, underscoring its role as a crucial mediator of acute kidney injury. Consequently, the genetic or pharmacological inhibition of Piezo1 presents a promising strategy for treating IR-AKI.

The significant decreased wellbore temperature and increased casing pressure during fracturing fluid injection present a big challenge for the mechanical integrity of cement sheath in fracturing wells. Based on the theories of elastic mechanics, thermodynamics, and a multi-layer composed thick-wall cylinder, this paper proposed a new mechanical model of cement sheath for fracturing wells, coupling pressure, and thermal loads, which consider the failure modes of de-bonding, radial cracking, disking, and shear failure. The radial nonuniform temperature change and the continuous radial stress and radial displacement at two interfaces have been considered. With the proposed model, the radial distributions of failure stress and the corresponding safety factor for cement sheath during fracturing fluid injection have been analyzed and compared under four failure modes. Results show that the decreased wellbore temperature will produce significant tri-axial tensile stress and induce cement failure of de-bonding, radial cracking, and disking. The increased casing pressure will significantly lower the risk of de-bonding but also aggravate radial cracking and shear failure. For integrity protection of cement sheath, increasing the injected fluid temperature, maintaining higher circulation pumping pressures, and adopting cement sheath with a low elasticity modulus have been suggested for fracturing wells.

Geothermal energy development has increasingly been studied in recently decades because of its renewable and sustainable features. It can be divided into two categories: traditional geothermal (hydrothermal) systems and enhanced geothermal systems (EGS) based on the type of exploitation. The hot dry rock (HDR) in the EGS incorporates about 80% of all thermal energy, and its value is about 100–1000 times that of fossil energy. It is pivotal for geothermal wells to improve the flow conductivity of the HDR mass, enhance the communication area of natural fractures, and constitute the fracture network between injection and production wells by hydraulic treatments. While the wellbore temperature significantly decreases because of fracturing, fluid injection will induce additional thermal stresses in the cement sheath, which will aggravate its failure. Considering the radial nonuniform temperature change, this paper proposes a new thermal stress model for a casing-cement sheath-formation combined system for geothermal wells during fracturing based on elastic mechanics and thermodynamics theory. This model is solved by the Gaussian main elimination method. Based on the analytical model, the thermal stresses of cement sheath have been analyzed. The effects of the main influencing parameters on thermal stresses have also been investigated. Results show that the radial and axial tensile thermal stresses are both obviously larger than tangential tensile thermal stress. The maximum radial and axial thermal stresses always occur at the casing interface while the location of the maximum tangential thermal stress varies. Generally, thermal stresses are more likely to induce radial and axial micro cracks in the cement sheath, and the cement sheath will fail more easily at the casing interface in fracturing geothermal wells. For integrity protection of the cement sheath, a proper decrease of casing wall thickness, casing linear thermal expansion coefficient, cement sheath elasticity modulus, and an increase of the fracturing fluid temperature has been suggested.

NMB0315 is an outer membrane protein of Neisseria meningitidis serogroup B (NMB) and a potential candidate for a broad-spectrum vaccine against meningococcal disease. The crystal structure of NMB0315 was solved by single-wavelength anomalous dispersion (SAD) at a resolution of 2.4 Å and revealed to be a lysostaphin-type peptidase of the M23 metallopeptidase family. The overall structure consists of three well-separated domains and has no similarity to any previously published structure. However, only the topology of the carboxyl-terminal domain is highly conserved among members of this family, and this domain is a zinc-dependent catalytic unit. The amino-terminal domain of the structure blocks the substrate binding pocket in the carboxyl-terminal domain, indicating that the wild-type full-length protein is in an inactive conformational state. Our studies improve the understanding of the catalytic mechanism of M23 metallopeptidases.

Microtubules are vital components of the cytoskeleton. Their plus ends are dynamic and respond to changes in cell morphology, whereas the minus ends are stable and serve a crucial role in microtubule seeding and maintaining spatial organization. In mammalian cells, the calmodulin-regulated spectrin-associated proteins (CAMSAPs), play a key role in directly regulating the dynamics of non-centrosomal microtubules minus ends. However, the molecular mechanisms are not yet fully understood. Our study reveals that CAMSAP3 forms dimers through its C-terminal a-helix; this dimerization not only enhances the microtubule-binding affinity of the CKK domain but also enables the CKK domain to regulate the dynamics of microtubules. Furthermore, CAMSAP3 also specializes in decorating at the minus end of microtubules through the combined action of the microtubule-binding domain (MBD) and the C-terminal a-helix, thereby achieving dynamic regulation of the minus ends of microtubules. These findings are crucial for advancing our understanding and treatment of diseases associated with noncentrosomal microtubules. [ABSTRACT FROM AUTHOR]

The manchette is a crucial transient structure involved in sperm development, with its composition and regulation still not fully understood. This study focused on investigating the roles of CAMSAP1 and CAMSAP2, microtubule (MT) minus-end binding proteins, in regulating manchette MTs, spermiogenesis, and male fertility. The loss of CAMSAP1, but not CAMSAP2, disrupts the well-orchestrated process of spermiogenesis, leading to abnormal manchette elongation and delayed removal, resulting in deformed sperm nuclei and tails resembling oligoasthenozoospermia symptoms. We investigated the underlying molecular mechanisms by purifying manchette assemblies and comparing them through proteomic analysis, and results showed that the absence of CAMSAP1 disrupted the proper localization of key proteins (CEP170 and KIF2A) at the manchette minus end, compromising its structural integrity and hindering MT depolymerization. These findings highlight the significance of maintaining homeostasis in manchette MT minus-ends for shaping manchette morphology during late spermiogenesis, offering insights into the molecular mechanisms underlying infertility and sperm abnormalities. [ABSTRACT FROM AUTHOR]