Α-smooth Muscle Actin Expression Research Articles

CTRP6 alleviates endometrial fibrosis by regulating Smad3 pathway in intrauterine adhesion†.

Intrauterine adhesion (IUA) is manifestations of endometrial fibrosis and excessive extracellular matrix deposition. C1q/tumor necrosis factor-related protein-6 (CTRP6) is a newly identified adiponectin paralog which has been reported to modulate the fibrosis process of several diseases; however, the endometrial fibrosis function of CTRP6 remains unknown. Our study aimed to assess the role of CTRP6 in endometrial fibrosis and further explore the underlying mechanism. Here, we found that the expression of CTRP6 was downregulated in the endometrial tissues of IUA. In vitro experiments demonstrated the reduced level of CTRP6 in facilitated transforming growth factor-β1 (TGF-β1)-induced human endometrial stromal cells (HESCs). In addition, CTRP6 inhibited the expression of α-smooth muscle actin (α-SMA) and collagen I in TGF-β1-treated HESCs. Mechanistically, CTRP6 activated the AMP-activated protein kinase (AMPK) and protein kinase B (AKT) pathway in HESCs, and AMPK inhibitor (AraA) or PI3K inhibitor (LY294002) pretreatment abolished the protective effect of CTRP6 on TGF-β1-induced fibrosis. CTRP6 markedly decreased TGF-β1-induced Smad3 phosphorylation and nuclear translocation, and AMPK or AKT inhibition reversed these effects. Notably, CTRP6-overexpressing treatment alleviated the fibrosis of endometrium in vivo. Therefore, CTRP6 ameliorates endometrial fibrosis, among which AMPK and AKT are essential for the anti-fibrotic effect of CTRP6 via the Smad3 pathway. Taken together, CTRP6 may be a potential therapeutic target for the treatment of intrauterine adhesion.

CTRP6 alleviates endometrial fibrosis by regulating Smad3 pathway in intrauterine adhesion†.

Intrauterine adhesion (IUA) is manifestations of endometrial fibrosis and excessive extracellular matrix deposition. C1q/tumor necrosis factor-related protein-6 (CTRP6) is a newly identified adiponectin paralog which has been reported to modulate the fibrosis process of several diseases; however, the endometrial fibrosis function of CTRP6 remains unknown. Our study aimed to assess the role of CTRP6 in endometrial fibrosis and further explore the underlying mechanism. Here, we found that the expression of CTRP6 was downregulated in the endometrial tissues of IUA. In vitro experiments demonstrated the reduced level of CTRP6 in facilitated transforming growth factor-β1 (TGF-β1)-induced human endometrial stromal cells (HESCs). In addition, CTRP6 inhibited the expression of α-smooth muscle actin (α-SMA) and collagen I in TGF-β1-treated HESCs. Mechanistically, CTRP6 activated the AMP-activated protein kinase (AMPK) and protein kinase B (AKT) pathway in HESCs, and AMPK inhibitor (AraA) or PI3K inhibitor (LY294002) pretreatment abolished the protective effect of CTRP6 on TGF-β1-induced fibrosis. CTRP6 markedly decreased TGF-β1-induced Smad3 phosphorylation and nuclear translocation, and AMPK or AKT inhibition reversed these effects. Notably, CTRP6-overexpressing treatment alleviated the fibrosis of endometrium in vivo. Therefore, CTRP6 ameliorates endometrial fibrosis, among which AMPK and AKT are essential for the anti-fibrotic effect of CTRP6 via the Smad3 pathway. Taken together, CTRP6 may be a potential therapeutic target for the treatment of intrauterine adhesion.

Exploring Fibrosis Pathophysiology in Lean and Obese Metabolic-Associated Fatty Liver Disease: An In-Depth Comparison.

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-β, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.

Effects of Bulleyaconitine A on Extracellular Matrix Secretion and Expression of Related Proteins in Acetaldehyde-Activated Hepatic Stellate Cells.

Activated hepatic stellate cells differentiate into myofibroblasts, which synthesize and secrete extracellular matrix (ECM) leading to liver fibrosis. It was previously demonstrated that bulleyaconitine A (BLA), an alkaloid from Aconitum bulleyanum, inhibits proliferation and promotes apoptosis of human hepatic Lieming Xu-2 (LX-2) cells. In this study, we analyzed the effect of BLA on the production of ECM and related proteins by LX-2 cells activated with acetaldehyde (AA). The cells were randomized into the control group, AA group (cells activated with 400 μM AA), and BLA+AA group (cells cultured in the presence of 400 μM AA and 18.75 μg/ml BLA). In the BLA+AA group, the contents of collagens I and III and the expression of α-smooth muscle actin and transforming growth factor-β1 (TGF-β1) were statistically significantly higher than in the control, but lower than in the AA group. Expression of MMP-1 in the BLA+AA group was also significantly higher than in the AA group, but lower than in the control. Expression of TIMP-1 in the BLA+AA group was significantly higher than in the control, but lower than in the AA group. Thus, BLA suppressed activation and proliferation of LX-2 cells by inhibiting TGF-β1 signaling pathway and decreasing the content of collagens I and III by reducing the MMP-1/TIMP-1 ratio.

Myogenic Anti-Nucleolin Aptamer iSN04 Inhibits Proliferation and Promotes Differentiation of Vascular Smooth Muscle Cells.

De-differentiation and subsequent increased proliferation and inflammation of vascular smooth muscle cells (VSMCs) is one of the mechanisms of atherogenesis. Maintaining VSMCs in a contractile differentiated state is therefore a promising therapeutic strategy for atherosclerosis. We have reported the 18-base myogenetic oligodeoxynucleotide, iSN04, which serves as an anti-nucleolin aptamer and promotes skeletal and myocardial differentiation. The present study investigated the effect of iSN04 on VSMCs because nucleolin has been reported to contribute to VSMC de-differentiation under pathophysiological conditions. Nucleolin is localized in the nucleoplasm and nucleoli of both rat and human VSMCs. iSN04 without a carrier was spontaneously incorporated into VSMCs, indicating that iSN04 would serve as an anti-nucleolin aptamer. iSN04 treatment decreased the ratio of 5-ethynyl-2'-deoxyuridine (EdU)-positive proliferating VSMCs and increased the expression of α-smooth muscle actin, a contractile marker of VSMCs. iSN04 also suppressed angiogenesis of mouse aortic rings ex vivo, which is a model of pathological angiogenesis involved in plaque formation, growth, and rupture. These results demonstrate that antagonizing nucleolin with iSN04 preserves VSMC differentiation, providing a nucleic acid drug candidate for the treatment of vascular disease.

Senescent Fibroblasts Potentiate Peritoneal Metastasis of Diffuse-type Gastric Cancer Cells via IL-8-mediated Crosstalk.

Diffuse-type gastric cancer (DGC) often forms peritoneal metastases, leading to poor prognosis. However, the underlying mechanism of DGC-mediated peritoneal metastasis is poorly understood. DGC is characterized by desmoplastic stroma, in which heterogeneous cancer-associated fibroblasts (CAFs), including myofibroblastic CAFs (myCAFs) and senescent CAFs (sCAFs), play a crucial role during tumor progression. This study investigated the CAF subtypes induced by GC cells and the role of sCAFs in peritoneal metastasis of DGC cells. Conditioned medium of human DGC cells (KATOIII, NUGC-4) and human intestinal-type GC (IGC) cells (MKN-7, N87) was used to induce CAFs. CAF subtypes were evaluated by analyzing the expression of α-smooth muscle actin (α-SMA), senescence-associated β-galactosidase (SA-β-gal), and p16 in human normal fibroblasts (GF, FEF-3). A cytokine array was used to explore the underlying mechanism of GC-induced CAF subtype development. The role of sCAFs in peritoneal metastasis of DGC cells was analyzed using a peritoneally metastatic DGC tumor model. The relationships between GC subtypes and CAF-related markers were evaluated using publicly available datasets. IGC cells significantly induced α-SMA+ myCAFs by secreting transforming growth factor-β, whereas DGC cells induced SA-β-gal+/p16+ sCAFs by secreting interleukin (IL)-8. sCAFs further secreted IL-8 to promote DGC cell migration. In vivo experiments demonstrated that co-inoculation of sCAFs significantly enhanced peritoneal metastasis of NUGC-4 cells, which was attenuated by administration of the IL-8 receptor antagonist navarixin. p16 and IL-8 expression was significantly associated with poor prognosis of DGC patients. sCAFs promote peritoneal metastasis of DGC via IL-8-mediated crosstalk.

The mechanical mechanism of angiotensin II induced activation of hepatic stellate cells promoting portal hypertension

In the development of chronic liver disease, the hepatic stellate cell (HSC) plays a pivotal role in increasing intrahepatic vascular resistance (IHVR) and inducing portal hypertension (PH) in cirrhosis. Our research demonstrated that HSC contraction, prompted by angiotensin II (Ang II), significantly contributed to the elevation of type I collagen (COL1A1) expression. This increase was intimately associated with enhanced cell tension and YAP nuclear translocation, mediated through α-smooth muscle actin (α-SMA) expression, microfilaments (MF) polymerization, and stress fibers (SF) assembly. Further investigation revealed that the Rho/ROCK signaling pathway regulated MF polymerization and SF assembly by facilitating the phosphorylation of cofilin and MLC, while Ca2+ chiefly governed SF assembly via MLC. Inhibiting α-SMA-MF-SF assembly changed Ang II-induced cell contraction, YAP nuclear translocation, and COL1A1 expression, findings corroborated in cirrhotic mice models. Overall, our study offers insights into mitigating IHVR and PH through cell mechanics, heralding potential breakthroughs.

Comparative analysis of endometrium after using levonorgestrel-releasing intrauterine system and copper intrauterine device

BACKGROUND: To date, the risks of pelvic inflammatory diseases, including chronic endometritis, associated with the use of various intrauterine contraceptives, have remained debatable. AIM: The aim of this study was to conduct a comparative analysis of the endometrial status in women of reproductive age after the use of copper- or levonorgestrel-releasing intrauterine device. MATERIALS AND METHODS: Morphological and immunohistochemical studies of endometrial biopsies obtained by aspiration Pipelle biopsy were performed after intrauterine device extraction in 18 patients who used a copper-containing intrauterine device and in 12 women who used the levonorgestrel-releasing intrauterine device Mirena. Monoclonal mouse antibodies to CD20, CD138, and α-smooth muscle actin (DAKO, Denmark) were used. Criteria for inclusion of patients in the study are reproductive age, use of an intrauterine device for five years, absence of complications associated with the intrauterine device during its use. Exclusion criteria are a history of pelvic inflammatory diseases, sexually transmitted infections, habitual miscarriage, two or more intrauterine interventions. RESULTS: After using a copper-containing intrauterine device, signs of chronic inflammation were found in the endometrium such as cytogenic stroma fibrosis with pronounced infiltration by inflammatory cells, positive expression of CD138 (33.3% of observations), CD20 (88.9% of observations with an average number of 27.4 ± 5.7), α-smooth muscle actin (up to 70% of the cytogenic stroma area), and the presence of lymphatic follicles consisting of B lymphocytes (33.3% of observations). During the use of the levonorgestrel-releasing intrauterine device, decidual transformation of cytogenic stroma cells, as well as secretion and atrophy of the glandular epithelium, were found in the endometrium. CD20-positive cells were detected in five out of 12 cases (41.6% of observations with an average number of 12.8 ± 4.6). Expression of CD138 and α-smooth muscle actin was not detected in any of the cases. CONCLUSIONS: The use of a copper-containing intrauterine device is associated with a high risk of developing chronic endometritis. The absence of signs of chronic inflammation in the endometrium after the use of a levonorgestrel-releasing intrauterine device is probably due to the protective effect of levonorgestrel on the uterine mucosa. Thus, levonorgestrel-releasing intrauterine devices, in comparison with copper-containing intrauterine devices, have a favorable safety profile relative to the endometrium and can be recommended for women of reproductive age, including those who have not given birth.

#2036 Mitochondrial copper overload promotes renal fibrosis via inhibiting pyruvate dehydrogenase activity

Abstract Background and Aims Copper is a trace element essential for numerous biological activities, whereas the mitochondria serve as both major sites of intracellular copper utilization and copper reservoir. Pyruvate dehydrogenase complex (PDHC) is a rate-limiting enzyme of glucose oxidation in mitochondrial matrix, converting pyruvate into acetyl-CoA and linking glycolysis to tricarboxylic acid (TCA) cycle. Dihydrolipoamide acetyltransferase (DLAT), the E2 component of the PDHC, requires lipoylation for enzymatic function and exhibits a high affinity for copper within its lipoyl moiety. Here, we investigated the impact of mitochondrial copper overload on the tricarboxylic acid cycle and renal senescence and fibrosis. Method Molecular dynamics simulation was used to explore the effect of copper ions on lipoylated DLAT protein. ICP-MS was used to detect copper content in mitochondria. Western blotting was used to detect the level of lipoylated DLAT dimer. Enzyme biopsy test kit, electron microscopy, mitoSOX Red staining and ATP content detection were used to evaluate mitochondrial function. Detect Collagen I, α-smooth muscle actin (α-SMA) expression levels and Masson staining to explore renal fibrosis. To reduce mitochondrial copper level, we used lentivirus to downregulate CRT1 expression or copper chelator tetrathiomolybdate in renal tubular epithelial cells (NRK-52E), and used CTR1 knockdown transgenic mice or tetrathiomolybdate in vivo. Results We found that copper ion levels are significantly elevated in the mitochondria in fibrotic kidney tissues, which are accompanied by reduced pyruvate dehydrogenase (PDH) activity, mitochondrial dysfunction, cellular senescence and renal fibrosis. Conversely, lowering mitochondrial copper levels through knocking-down of copper transporter 1 or treatment with the copper chelator tetrathiomolybdate effectively restore PDH enzyme activity, improve mitochondrial function, and mitigate cellular senescence and renal fibrosis. Mechanically, we found mitochondrial copper binds directly to lipoylated dihydrolipoamide acetyltransferase (DLAT), thereby changing the interaction between protein subunits, inducing lipoylated DLAT protein dimerization, and ultimately inhibiting PDH enzyme activity. Conclusion Our study indicates that mitochondrial copper overload could inhibit PDH activity, subsequently leading to mitochondrial dysfunction, cellular senescence and renal fibrosis. Reducing mitochondrial copper overload might therefore serve as a strategy to rescue renal fibrosis.

P35 Adaptation of a phenotypic screening assay to incorporate 384-well plates: opening the door to high-throughput screening

Abstract Introduction and aims High-throughput screening has significantly impacted drug discovery by increasing speed of experiments and reducing reagent and sample costs. We have previously developed several screening assays to measure myofibroblast inhibition via quantification of α-smooth muscle actin (α-SMA) expression, in a 96-well format. Currently, there are no drugs for the treatment of hypertrophic scarring, a major side-effect of burn injuries that occurs by myofibroblast transformation, leaving a huge gap in this sector. The aim for this project was to adapt our current assay for use in 384-well microplates. Methods Human primary dermal fibroblasts were transformed to myofibroblasts using 10 ng mL−1 transforming growth factor (TGF)-β1. α-SMA expression was measured using the In-Cell enzyme-linked immunosorbent assay method, with cell viability measured using DRAQ5 nuclear staining. Assay accuracy and reliability was determined by calculating the robust z-factor, with guidelines set to an average score over 0.5, with a minimum score per plate above 0.4. To further validate the assay, concentration-response curves (CRCs) for the drug vehicle [dimethyl sulfoxide (DMSO)] and our tool compound (SB-505124) were constructed at varying concentrations, in coincubation with TGF-β1. Results Optimization of well metrics was performed, producing an average robust z-factor of 0.52, confirming the assay Results are reliable and reproducible. The DMSO CRC produced no significant drop in cell viability at concentrations that are expected to be used in the screening of compounds. Our tool compound (SB-505124) produced a concentration-dependant curve for the inhibition of myofibroblast transformation. Conclusions A 384-well assay has been designed, tested and validated for the determination of myofibroblast transformation in human primary dermal fibroblasts. The assay has been shown to deliver an average robust z-factor of above 0.5, it contains a positive control and is compatible with compounds stored in up to 100% DMSO.

P06 A novel drug combination produces a synergistic effect when inhibiting myofibroblast transformation in an in vitro model of hypertrophic scarring

Abstract Introduction and aims Hypertrophic scars affect 91% of patients with burns and yet, there is currently no effective treatment for their prevention. Myofibroblasts are key cells in the pathogenesis of hypertrophic scars, with the inhibition of myofibroblast transformation having been suggested as an effective therapeutic strategy. We have previously screened 1954 drugs approved by the Food and Drug Administration to identify any that could inhibit myofibroblast transformation. Using this data, the aim of this study was to investigate the individual and combined antimyofibroblast effect of two drug classes. Methods Primary human fibroblasts were isolated from the scars of patients with burns, with myofibroblast transformation induced using transforming growth factor (TGF)-β1. Concentration-response curves for drug-class A and drug-class B were constructed at a range of concentrations (0.03–300 µmol L–1), with the In-Cell enzyme-linked immunosorbent assay method used to measure α-smooth muscle actin (α-SMA) expression. Combination experiments were carried out through construction of a concentration-response curve for drug-class A (0.03–100 µmol L–1) in the presence of 3 µmol L–1 of drug-class B. Results Both drug classes showed a concentration-dependent antimyofibroblast effect with an IC50 range of 12.2–120.1 µmol L–1 for drug-class A and 1.4–16.7 µmol L–1 for drug-class B. When given in combination the two classes of drugs produced a synergistic effect at all concentrations up to 10 µmol L–1. For example, an 18% reduction α-SMA expression was expected with 1 µmol L–1 of drug-class A and 3 µmol L–1 of drug-class B; however, a 24% reduction in α-SMA expression was observed instead. Conclusions This is the first study to identify this synergistic effect between these two drug classes, and therefore this novel drug combination could be developed for the prevention of hypertrophic scar formation.

LP340, a novel histone deacetylase inhibitor, decreases liver injury and fibrosis in mice: role of oxidative stress and microRNA-23a.

Effective therapy for liver fibrosis is lacking. Here, we examined whether LP340, the lead candidate of a new-generation of hydrazide-based HDAC1,2,3 inhibitors (HDACi), decreases liver fibrosis. Liver fibrosis was induced by CCl4 treatment and bile duct ligation (BDL) in mice. At 6 weeks after CCl4, serum alanine aminotransferase increased, and necrotic cell death and leukocyte infiltration occurred in the liver. Tumor necrosis factor-α and myeloperoxidase markedly increased, indicating inflammation. After 6 weeks, α-smooth muscle actin (αSMA) and collagen-1 expression increased by 80% and 575%, respectively, indicating hepatic stellate cell (HSC) activation and fibrogenesis. Fibrosis detected by trichrome and Sirius-red staining occurred primarily in pericentral regions with some bridging fibrosis in liver sections. 4-Hydroxynonenal adducts (indicator of oxidative stress), profibrotic cytokine transforming growth factor-β (TGFβ), and TGFβ downstream signaling molecules phospho-Smad2/3 also markedly increased. LP340 attenuated indices of liver injury, inflammation, and fibrosis markedly. Moreover, Ski-related novel protein-N (SnoN), an endogenous inhibitor of TGFβ signaling, decreased, whereas SnoN expression suppressor microRNA-23a (miR23a) increased markedly. LP340 (0.05mg/kg, ig., daily during the last 2weeks of CCl4 treatment) decreased 4-hydroxynonenal adducts and miR23a production, blunted SnoN decreases, and inhibited the TGFβ/Smad signaling. By contrast, LP340 had no effect on matrix metalloproteinase-9 expression. LP340 increased histone-3 acetylation but not tubulin acetylation, indicating that LP340 inhibited Class-I but not Class-II HDAC in vivo. After BDL, focal necrosis, inflammation, ductular reactions, and portal and bridging fibrosis occurred at 2 weeks, and αSMA and collagen-1 expression increased by 256% and 560%, respectively. LP340 attenuated liver injury, ductular reactions, inflammation, and liver fibrosis. LP340 also decreased 4-hydroxynonenal adducts and miR23a production, prevented SnoN decreases, and inhibited the TGFβ/Smad signaling after BDL. In vitro, LP340 inhibited immortal human hepatic stellate cells (hTERT-HSC) activation in culture (αSMA and collagen-1 expression) as well as miR23a production, demonstrating its direct inhibitory effects on HSC. In conclusions, LP340 is a promising therapy for both portal and pericentral liver fibrosis, and it works by inhibiting oxidative stress and decreasing miR23a.

Apigenin intervenes in liver fibrosis by regulating PKM2-HIF-1α mediated oxidative stress

Apigenin (API) is a natural flavonoid compound with antioxidant, anti fibrotic, anti-inflammatory and other effects, but there is limited research on the effect of API on liver fibrosis. This study aims to explore the effect and potential mechanism of API on liver fibrosis induced by CCl4 in mice. The results indicate that API reduces oxidative stress levels, inhibits hepatic stellate cell (HSC) activation, and exerts anti liver fibrosis effects by regulating the PKM2-HIF-1α pathway. We observed that API alleviated liver tissue pathological damage and collagen deposition in CCl4 induced mouse liver fibrosis model, promoting the recovery of liver function in mice with liver fibrosis. In addition, the API inhibits the transition of Pyruvate kinase isozyme type M2 (PKM2) from dimer to tetramer formation by regulating the EGFR-MEK1/2-ERK1/2 pathway, thereby preventing dimer from entering the nucleus and blocking PKM2-HIF-1α access. This change leads to a decrease in malondialdehyde (MDA) and Catalase (CAT) levels and an increase in glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) levels, as well as total antioxidant capacity (T-AOC) in the liver of liver fibrosis mice. At the same time, API downregulated the expression of α-smooth muscle actin (α-SMA), Vimentin and Desmin in the liver tissue of mice with liver fibrosis, inhibited the activation of HSC, and reduced collagen deposition. These results indicate that API can inhibit HSC activation and alleviate CCl4 induced liver fibrosis by inhibiting the PKM2-HIF-1α pathway and reducing oxidative stress, laying an important foundation for the development and clinical application of API as a novel drug for treating liver fibrosis.

Ex vivo expansion in a clinical grade medium, containing growth factors from human platelets, enhances migration capacity of adipose stem cells.

Adipose tissue mesenchymal stem/stromal cells (ASC) can be used as advanced therapy medicinal product in regenerative and cancer medicine. We previously demonstrated Supernatant Rich in Growth Factors (SRGF) can replace fetal bovine serum (FBS) to expand ASC by a clinical grade compliant protocol. The therapeutic potential of ASC is based also on their homing capacity toward inflammatory/cancer sites: oriented cell migration is a fundamental process in this scenario. We investigated the impact of SRGF on ASC migration properties. The motility/migration potential of ASC expanded in 5% SRGF was analyzed, in comparison to 10% FBS, by standard wound healing, bidimensional chemotaxis and transwell assays, and by millifluidic transwell tests. Mechanisms involved in the migration process were investigated by transient protein overexpression. In comparison to standard 10% FBS, supplementation of the cell culture medium with 5% SRGF, strongly increased migration properties of ASC along the chemotactic gradient and toward cancer cell derived soluble factors, both in static and millifluidic conditions. We showed that, independently from applied migratory stimulus, SRGF expanded ASC were characterized by far lower expression of α-smooth muscle actin (αSMA), a protein involved in the cell migration machinery. Overexpression of αSMA induced a significant and marked decrease in migration capacity of SRGF expanded ASC. In conclusion, 5% SRGF addition in the cell culture medium increases the migration potential of ASC, reasonably through appropriate downregulation of αSMA. Thus, SRGF could potentially improve the therapeutic impact of ASC, both as modulators of the immune microenviroment or as targeted drug delivery vehicles in oncology.

Nanohydroxyapatite Coating Attenuates Fibrotic and Immune Responses to Promote Keratoprosthesis Biointegration in Advanced Ocular Surface Disorders.

Keratoprosthesis (KPro) implantation is frequently the only recourse for patients with severe corneal disease. However, problems arise due to inadequate biointegration of the KPro, particularly the PMMA optical cylinder, such as tissue detachment, tissue melting, or eye-threatening infection in the interface. Here, using the AuroKPro as a model prosthesis, a surface functionalization approach─coating the optical cylinder with nanohydroxyapatite (nHAp)─was trialed in rabbit eyes with and without a proceeding chemical injury. In chemically injured eyes, which simulated total limbal epithelial stem cell deficiency, clear benefits were conferred by the coating. The total modified Hackett-McDonald score and area of tissue apposition differences 12 weeks after implantation were 5.0 and 22.5%, respectively. Mechanical push-in tests revealed that 31.8% greater work was required to detach the tissues. These differences were less marked in uninjured eyes, which showed total score and tissue apposition differences of 2.5 and 11.5%, respectively, and a work difference of 23.5%. The improved biointegration could be contributed by the attenuated expression of fibronectin (p = 0.036), collagen 3A1 (p = 0.033), and α-smooth muscle actin (p = 0.045)─proteins typically upregulated during nonadherent fibrous capsule envelopment of bioinert material─adjacent to the optical cylinders. The coating also appeared to induce a less immunogenic milieu in the ocular surface tissue, evidenced by the markedly lower expression of tear proteins associated with immune and stimulus responses. Collectively, the level of these tear proteins in eyes with coated prostheses was 1.1 ± 13.0% of naïve eyes: substantially lower than with noncoated KPros (246.5 ± 79.3% of naïve, p = 0.038). Together, our results indicated that nHAp coating may reduce the risk of prosthesis failure in severely injured eyes, which are representative of the cohort of KPro patients.

IQGAP1 Regulates Actin Polymerization and Contributes to Bleomycin-Induced Lung Fibrosis.

We previously found IQ motif containing GTPase activating protein (IQGAP1) to be consistently elevated in lung fibroblasts (LF) isolated from patients with scleroderma (systemic sclerosis, SSc)-associated interstitial lung disease (ILD) and reported that IQGAP1 contributed to SSc by regulating expression and organization of α-smooth muscle actin (SMA) in LF. The aim of this study was to compare the development of ILD in the presence and absence of IQGAP1. Pulmonary fibrosis was induced in IQGAP1 knockout (KO) and wild-type (WT) mice by a single-intratracheal instillation of bleomycin. Two and three weeks later, mice were euthanized and investigated. We observed that the IQGAP1 KO mouse was characterized by a reduced rate of actin polymerization with reduced accumulation of actin in the lung compared to the WT mouse. After exposure to bleomycin, the IQGAP1 KO mouse demonstrated decreased contractile activity of LF, reduced expression of SMA, TGFβ, and collagen, and lowered overall fibrosis scores compared to the WT mouse. The numbers of inflammatory cells and expression of pro-inflammatory cytokines in lung tissue were not significantly different between IQGAP1 KO and WT mice. We conclude that IQGAP1 plays an important role in the development of lung fibrosis induced by bleomycin, and the absence of IQGAP1 reduces the contractile activity of lung fibroblast and bleomycin-induced pulmonary fibrosis. Thus, IQGAP1 may be a potential target for novel anti-fibrotic therapies for lung fibrosis.

Therapeutic potential of vitamin D3 in mitigating high glucose‑induced renal damage: Mechanistic insights into oxidative stress inhibition and TXNIP/NLRP3 signaling pathway blockade.

In the development of diabetic nephropathy, pathological damage such as interstitial fibrosis and cell apoptosis often occur in renal tubules. In the present study, diabetic and control group mice were randomly treated with vitamin D3 or vehicle for 6 months. In addition, human renal tubular epithelial (HK-2) cells were cultured in high-glucose medium and treated with vitamin D3 or the oxidative inhibitor NAC. Immunohistochemistry, western blotting, quantitative PCR), and ELISA showed that vitamin D3 decreased the expression of α-smooth muscle actin and E-cadherin in renal tubular epithelial cells, improving interstitial fibrosis. It also downregulated the ratio of Bax/Bcl2 protein, alleviating apoptosis in renal tubular epithelial cells. Furthermore, vitamin D3 significantly inhibited oxidative stress response in renal tubular epithelial cells and blocked the (Thioredoxin Interacting Protein) TXNIP/NLRP3 inflammatory pathway. Therefore, vitamin D3 can protect renal tubular epithelial cells from fibrosis and apoptosis by inhibiting oxidative stress response and blocking the TXNIP/NLRP3 inflammatory pathway in diabetic nephropathy.

ASK1-mediated Apoptosis in Human Lung Fibroblasts

Idiopathic pulmonary fibrosis (IPF) is a chronic, devastating lung disease characterized by progressive fibrosis and dysregulated wound repair that negatively affect lung function. Although lung fibroblasts are important in repair mechanisms following lung injury, differentiation into myofibroblasts in the presence of TGF-β and resistance to apoptosis can promote the progression of pulmonary fibrosis. Apoptosis signal regulating kinase 1 (ASK1) is a member of the mitogen activated protein (MAP) kinase family that is known to promote apoptosis. The objective of this study was to test the hypothesis that ASK1 is an important mediator of apoptosis in lung fibroblasts. Normal human lung fibroblasts were obtained from five donors and cultured in the presence or absence of TGF-β (1ng/mL) for 72h. Apoptosis was assessed by a Caspase-Glo® 3/7 assay following treatment with a combination of cycloheximide and Fas ligand antibody with or without the ASK1 inhibitor, selonsertib. Expression of α-smooth muscle actin (α-SMA), collagen, ASK1, and survivin (a member of the inhibitor of apoptosis protein family) were determined by western blot. Apoptosis was induced in three of the five donor lines, and selonsertib treatment reduced caspase-3/7 activity. These donor lines expressed lower levels of survivin compared with the non-responding lines. TGF-β did not significantly affect these results. As expected, TGF-β stimulated expression of collagen and α-SMA in all donor lines, but this was reduced by treatment with selonsertib. Interestingly, TGF-β caused a reduction in the expression of ASK1 which is consistent with the idea that myofibroblasts in IPF are resistant to apoptosis. These results suggest that ASK1 can promote apoptosis in normal lung fibroblasts, but this is dependent upon the expression of survivin. Supported by VA Merit Award BX005889 (CMW) and NIH grant HL131526 (CMW). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mechanism of Fuzheng Huayu Tablets against hepatic fibrosis based on transcriptome and single-cell sequencing

This study aimed to investigate the role of macrophage polarization in the treatment of liver fibrosis by Fuzheng Huayu Tablets(FZHY) through single-cell, transcriptome sequencing and in vitro and in vivo experiments. Liver fibrosis-related datasets, transcriptomic datasets, and single-cell sequencing datasets were obtained from the Gene Expression Omnibus(GEO) database to screen differential genes. Liver fibrosis-related genes were obtained from GeneCards, DisGeNET, NCBI, PharmgKB, TTD and OMIM databases. Macrophage polarization-related genes were obtained from the GeneCards database. The above three gene sets were intersected to construct a protein-protein interaction(PPI) network. Cytoscape software was used to screen core proteins, and the expression pattern of core proteins was visualized by single-cell sequencing. A mouse model of liver fibrosis was constructed using carbon tetrachloride(CCl_4). Hematoxylin-eosin(HE) staining and Masson staining were used to observe the pathological morphology of liver tissues. The expressions of α-smooth muscle actin(α-SMA) and transforming growth factor-β1(TGF-β1) were detected by immunohistochemistry. The levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were detected by colorimetry. The le-vels of inflammatory factors in serum were detected by the enzyme-linked immunosorbent assay(ELISA). Furthermore, the expressions of α-SMA, TGF-β1, cluster of differentiation 86(CD86) and thrombospondin 1(THBS1) in liver tissues were detected by Western blot(WB). Lipopolysaccharide(LPS) was used to stimulate RAW264.7 cells to construct the M1 macrophage polarization model. The cell counting kit-8(CCK-8) method was used to detect cell viability. WB was used to detect the protein expressions of CD86 and THBS1 in cells, and the messenger ribonucleic acid(mRNA) expression levels of tumor necrosis factor-α(TNF-α) and interleukin(IL)-1β by real-time fluorescent quantitative reverse transcription polymerase chain reaction(RT-qPCR). The results showed that a total of 26 potential genes related to the polarization of liver fibrosis macrophages were obtained, and 10 core proteins related to the polarization of liver fibrosis macrophages such as THBS1, lumican(LUM) and fibulin-5(FBLN5) were screened. Single-cell data analysis indicated that THBS1, ranking highest, may be expressed by M1 macrophages. Animal experiments demonstrated that FZHY reduced inflammatory cell infiltration and collagen deposition in CCl_4-induced mouse liver, relieved liver injury and inflammation levels, and inhibited the expressions of α-SMA, TGF-β1, CD86, and THBS1 proteins. Cell experiments revealed that FZHY significantly reduced intracellular expression of CD86 and THBS1 proteins and mRNA levels of TNF-α and IL-1β. In conclusion, FZHY may ameliorate liver fibrosis by inhibiting THBS1 protein expression, suppressing M1 macrophage polarization, and reducing inflammation.

Synthesis of amide derivatives containing the imidazole moiety and evaluation of their anti-cardiac fibrosis activity.

Three series of N-{[4-([1,2,4]triazolo[1,5-α]pyridin-6-yl)-5-(6-methylpyridin-2-yl)-1H-imidazol-2-yl]methyl}acetamides (14a-d, 15a-n, and 16a-f) were synthesized and evaluated for activin receptor-like kinase 5 (ALK5) inhibitory activities in an enzymatic assay. The target compounds showed high ALK5 inhibitory activity and selectivity. The half maximal inhibitory concentration (IC50) for phosphorylation of ALK5 of 16f (9.1 nM), the most potent compound, was 2.7 times that of the clinical candidate EW-7197 (vactosertib) and 14 times that of the clinical candidate LY-2157299. The selectivity index of 16f against p38α mitogen-activated protein kinase was >109, which was much higher than that of positive controls (EW-7197: >41, and LY-2157299: 4). Furthermore, a molecular docking study provided the interaction modes between the target compounds and ALK5. Compounds 14c, 14d, and 16f effectively inhibited the protein expression of α-smooth muscle actin (α-SMA), collagen I, and tissue inhibitor of metalloproteinase 1 (TIMP-1)/matrix metalloproteinase 13 (MMP-13) in transforming growth factor-β-induced human umbilical vein endothelial cells. Compounds 14c and 16f showed especially high activity at low concentrations, which suggests that these compounds could inhibit myocardial cell fibrosis. Compounds 14c, 14d, and 16f are potential preclinical candidates for the treatment of cardiac fibrosis.