Reduced Collagen Deposition Research Articles

Extracellular matrix-mimicking cryogels composed of methacrylated fucoidan enhance vascularized skeletal muscle regeneration following volumetric muscle loss

Volumetric muscle loss (VML) significantly impairs the inherent regenerative ability of skeletal muscle and results in chronic functional impairment. Polysaccharides in the muscle extracellular matrix are crucial for regulating cell proliferation and differentiation. Recent studies indicate that fucoidan has beneficial effects on musculoskeletal conditions. However, the impact of fucoidan on skeletal muscle regeneration remains poorly understood. In this study, methacrylated fucoidan (FuMA) was synthesized through chemical grafting of the methacryloyl group onto fucoidan. In vitro experiments demonstrated that treatment with FuMA significantly up-regulated the expression of myogenic markers and promoted the formation of myotubes in C2C12 myoblast cells. Importantly, FuMA treatment led to a significant enhancement in mitochondrial energy metabolism of myoblasts via activation of the NRF2 antioxidant signaling pathway. To further investigate the regenerative properties in repairing skeletal muscle defects, we fabricated a dual crosslinked cryogel consisting of FuMA and methacrylated gelatin (GelMA) with a porous and interconnected structure. In a rat tibialis anterior muscle VML model, implantation of the FuMA/GelMA cryogel effectively promoted the regeneration of muscle fibers, reduced collagen deposition, and facilitated the formation of new blood vessels. Hence, polysaccharide-based cryogels represent a promising implantable biomimetic scaffold for facilitating skeletal muscle regeneration following severe injuries.

STAP2 promotes the progression of renal fibrosis via HSP27

BackgroundRenal fibrosis is a key process in the progression from acute kidney injury (AKI) to chronic kidney disease (CKD), while the intricate mechanisms of renal fibrosis remain obscure. While the signal-transducing adaptor protein 2 (STAP2) was well-studied for its notable function in inflammation and immune-related disorders, its specific implication in renal fibrosis remains unclear. This study assessed the mechanism by which STAP2 could promote the progression of renal fibrosis.MethodsThe expression level of STAP2 in fibrotic human samples, murine fibrosis models, and cellular fibrosis models was measured, respectively. Subsequently, immunoprecipitation (IP), mass spectrometry, and RNA sequencing (RNA-seq) were employed to identify HSP27 as an interacting protein and the PI3K-AKT signaling pathway. STAP2 was thereafter knocked down or overexpressed in both in vivo and in vitro models to assess the expression levels of pathway-related and fibrosis-related proteins. Finally, the important role of STAP2 in the fibrosis process in animal models induced by ischemia-reperfusion injury (IRI) and cisplatin was validated.ResultsFunctionally, in vivo assays demonstrated that the genetic knockout of STAP2 could remarkably mitigate epithelial-mesenchymal transition (EMT), diminish inflammatory cell infiltration, and reduce collagen deposition in mice with renal fibrosis. Conversely, in vitro assays employing STAP2-overexpressing cell models exacerbated the expression levels of fibrosis markers. The outcomes uncovered a potential mechanism by which STAP2 could modulate renal fibrosis through its impact on the expression level of phosphorylated HSP27, as well as modulating the PI3K/AKT signaling pathway.ConclusionsThis comprehensive investigation delineated the noticeable function of STAP2 in the advancement of renal fibrosis, and the outcomes might contribute to the development of targeted therapies concentrated on STAP2 to mitigate renal fibrosis.

Abstract 4136116: Metformin Therapy for Reperfusion Injury Consolidates Cardioprotection in the High-Risk Elderly Heart

Introduction: Metformin (MET), a first-line diabetes therapy, exhibits cardioprotective effects during acute ischemia and reperfusion (I/R). Cardiac injury is enhanced in the aging heart in murine and humans. Acute, high dose MET treatment at the onset of reperfusion (R) markedly reduced infarct size (MI) in the high risk aged heart via modulation of mitochondrial complex I. However, the effect of subsequent chronic, standard dose MET to consolidate and possibly enhance cardioprotection and survival following I/R in the aged heart remains unknown. Hypothesis: Administration of chronic standard dose of MET will ameliorate mortality and morbidity following MI through rescuing an impaired adaptive metabolic remodeling. Methods: Aged (22-24 month) C57BL6/J mice were subjected to sham operations or 45 min of ischemia by LAD ligation followed by R. All mice received acute, high dose MET (2 mM, i.v.) at the onset of R followed by randomization to chronic MET (300 mg/kg/day) in drinking water versus vehicle (VEH) administered for 14 days. Cardiac function was determined by echocardiography weekly. IonOptix Myocyte Calcium and Contractility System measured the contractile functions and transient calcium signaling of isolated cardiomyocytes. Results: The Kaplan-Meier survival analysis showed that chronic MET treatment following acute treatment at the onset of R significantly reduced mortality compared to VEH group. Although chronic MET treatment did not further reduce MI size, echo and histology showed that chronic MET preserved diastolic function, prevented left ventricular hypertrophy and reduced collagen deposition following I/R in aging. Moreover, isolated cardiomyocytes from MET treated hearts showed improvements in contractile function, transit calcium signaling, and the coupling between contractility and calcium levels as compared to the cardiomyocytes from VEH group hearts. Immunoblotting results showed that Sens2/AMPK metabolic signaling was significantly upregulated by chronic MET post-MI, indicating the metabolic homeostasis modulated by MET is a critical factor involved in the beneficial effects of chronic MET on limiting I/R-induced myocardial damage that leads to deleterious remodeling in aging. Conclusions: The mortality and morbidity of MI in the high risk aged heart is attenuated with acute, high dose of MET treatment followed by chronic standard dose MET treatment to consolidate protection via rescuing the impaired adaptive metabolic response in aging.

Daily Subcutaneous injections of Relaxin is a therapy for heart failure with preserved ejection fraction

Abstract Background and Significance: Relaxin (RLX), a hormone of pregnancy has engendered a great deal of excitement as a therapy for cardiovascular diseases. Clinical trials treated patients with acute decompensated Heart Failure (HF) with RLX (i.v. 30µg/kg/day-2 days) and reported a 37% decrease in mortality during a 6-months follow up. This led the FDA to declare RLX a ‘break-through’ therapy. However, a larger trial failed to meet the sought-after end points. Here, we propose that periodic subQ RLX pulses are more effective. We measured the pharmacokinetics of serum RLX following subQ injections of RLX in Sprague Dawley rats. Further, we treated rats with confirmed HFpEF with daily subQ RLX (2-weeks) to reverse the diastolic dysfunction (DD), arrhythmia and fibrotic profile. Methods Sprague-Dawley (250 g, n=20, either sex) received 2-subQ injections 12 hrs apart of RLX (from Relaxera) or the vehicle. Serial blood samples were drawn following each injection to measure [RLX]. ZSF1 rats (9-weeks old, either sex) were placed on a high fat diet (HFD) and serial echos tracked the DD. Once severe DD was established (25-35 weeks of HFD), rats received daily subQ injections of RLX (100µg/kg) or vehicle. After 2-weeks, hearts were perfused to optically map action potentials and Ca2+ transients, and analyze the arrhythmia profile. IF and Westerns were used to measure changes in fibrosis (collagen 1), Nav1.5, connexin 43, Wnt1 and β-catenin. Results After an injection, RLX reached a peak in ~60 min, fell to 50% in 5-6 hours. Injections of 0, 30, 100 or 500 µg/kg yielded peak levels of 0, 11.26±3.52, 58.33±16.10, and 209.42±29.04 ng/ml and residual levels after 24-hrs of 0, 4.9, 45.1 and 156 pg/ml, respectively. The 30µg/kg injections had no effect and 100 µg/kg increased Nav1.5 (25%), Cx43 (30%) and β-catenin (90%). The 500 µg/kg injections increased Nav1.5 and Cx43 but upregulated β-catenin, only slightly. In ZSF1 HFpEF rats that received the vehicle (n=12), a premature stimulus (at 30 ms) elicited arrhythmia in 67% of the hearts. RLX injections reversed DD, suppressed sustained atrial and ventricular arrhythmias (n=0/12) but not self-terminating arrhythmias, lasting < 10sec. RLX improved the conduction velocity (CV), particularly at fast rates (100ms) from 0.74 to 0.9 m/s (p<0.001, n=12). RLX significantly increased Cx43 expression, Nav1.5 and β-catenin at intercalated disks. RLX reduced collagen deposition in HFpEF rats, to normal levels and increased Wnt1 compared to control HFpEF rats. Conclusions The ZSF1 diabetic rat on a HFD recapitulates human HFpEF, high blood pressure, fibrosis, DD, AF and VF. SubQ RLX injections reversed DD i.e. enlarged Left Atrium, E/e’ ratio, fibrosis, and the arrhythmia vulnerability by increasing CV, Cx43, and Nav1.5. Daily subQ RLX injections were highly effective as a therapy for HFpEF.Echo parameterHFpEF + RLX

Biodegradable exosome-engineered hydrogels for the prevention of peritoneal adhesions via anti-oxidation and anti-inflammation

Peritoneal adhesions (PA) are a common and severe complication after abdominal surgery, impacting millions of patients worldwide. The use of anti-adhesion materials as physical barriers is an effective strategy to prevent postoperative adhesions. However, the local inflammatory microenvironment exerts a significant impact on the efficacy of anti-adhesion therapies. In this study, an injectable hydrogel based on oxidized dextran/carboxymethyl chitosan (DCC) is designed and prepared. Furthermore, the DCC hydrogel is specifically engineered to load the adipose mesenchymal stem cells (ADSCs)-derived exosomes (Exos) for the treatment of PA. The prepared DCC hydrogel can act as the physical barrier via covering the irregular wound surface effectively. Moreover, it shows controlled degradation property, enabling the regulated release of Exos. The DCC hydrogel loaded Exos (DCC/Exo) system has high antioxidant capacity, and can effectively modulate the inflammatory microenvironments and diminish apoptosis. Notably, it promotes a polarization shift towards the M2-like phenotype in macrophages. The RNA-seq analysis confirms that the DCC/Exo system exhibits significant anti-inflammatory properties and promotes a reduction in collagen deposition. Consequently, the DCC/Exo system can inhibit peritoneal adhesions significantly in a mouse cecum-abdominal wall injury model. These results demonstrate the DCC/Exo is an ideal material for preventing postoperative adhesions.

Metformin Attenuates Vocal Fold Fibrosis via AMPK Signaling.

Vocal fold fibrosis is a challenging condition with no clear consensus on effective treatment methods. Given the demonstrated efficacy of metformin in treating various fibrotic diseases, we hypothesized that metformin could reduce vocal fold fibrosis via the AMPK signaling pathway. In our study, we induced vocal fold injury in rabbits and administered metformin intraperitoneally at a dose of 250mg/kg two weeks post-injury. Four weeks after the injury, vocal folds were excised and analyzed for fibrosis using Masson's trichrome staining, immunohistochemistry, quantitative real-time polymerase chain reaction (qPCR), and Western blotting. In vitro, vocal fold fibroblasts treated with metformin (10μM) ± TGF-β1 (10ng/mL) were utilized to assess metformin's antifibrotic effects, with Compound C (10μM) employed to inhibit AMPK signaling. Our results demonstrate that metformin significantly improved the structural integrity of the vocal fold lamina, reduced collagen deposition, and decreased the expression levels of COL1A1 and α-SMA. Furthermore, metformin activated the AMPK signaling pathway in vocal fold fibroblasts, resulting in decreased expression of COL1A1, α-SMA, TGF-β, Smad2, and Smad3. These findings suggest that metformin attenuates vocal fold fibrosis by modulating the AMPK signaling pathway, providing a foundation for developing new therapeutic options for vocal fold fibrosis.

Refeeding partially reverses impaired fracture callus in undernourished rats.

Adequate nutritional intake plays a crucial role in maximizing skeletal acquisition. The specific effects of a general food restriction and refeeding on fracture healing are yet to be fully understood. The aim of this study was to assess the impact of general food restriction and refeeding on fracture repair. Fifty-four male Wistar Hannover rats were randomly assigned into three groups: (1) Sham: Sham rats with femoral fracture; (2) FRes: Food-restricted rats with fracture, (3) Fres+Ref: Fres rats with refeeding. Following weaning, the FRes and Fres+Ref groups received 50% of the food amount provided to the Shams. In the sixth week of the experiment, all animals underwent a mid-right femur bone fracture, which was subsequently surgically stabilized. Following the fracture, the Fres+Ref group was refed, while the other groups maintained their pre-fracture diet. Bone calluses were analyzed on the fifth-day post-fracture by gene expression and on the sixth-week post-fracture using dual-energy X-ray absorptiometry, morphometry, histomorphometry, immunohistochemistry, computed microtomography, and torsion mechanical testing. Statistical significance was determined at a probability level of less than 0.05, and comparisons were made using the ANOVA test. Food restriction resulted in significant phenotypic changes in bone calluses when compared to sham rats characterized by deterioration in microstructure (i.e., BV, BV/TV, Tb.N, and Conn.D) reduced collagen deposition, bone mineral density, and mechanical strength (i.e., torque at failure, energy, and stiffness). Moreover, a higher rate of immature bone indicated a decrease in bone callus quality. Refeeding stimulated bone callus collagen formation, reduced local resorption, and effectively restored the microstructural (i.e., SMI, BCa.BV/TV, Tb.Sp, Tb.N, and Conn.D) and mechanical changes (i.e., torque at failure, energy, and angular displacement at failure) caused by food restriction. Despite these positive effects, the density of the bone callus, collagen deposition, and OPG expression remained lower when compared to the shams. Gene expression analysis didn't evidence any significant differences among the groups. Food restriction had detrimental effects on osseous healing, which was partially improved by refeeding. Based on these findings, new research can be developed to create targeted nutritional strategies to treat and improve fracture healing.

Arbutin alleviates Mycoplasma gallinarum-induced damage caused by pulmonary fibrosis via the JAK2/STAT3 pathway

Mycoplasma gallinarum (MG) can cause infectious respiratory diseases in poultry that are chronic. Arbutin (AR) possesses anti-inflammatory, bacteriostatic, antitussive, and expectorant pharmacological effects, but whether it exerts regulatory effects on MG-induced pneumonia and fibrosis remains unclear. The study results unveiled that pulmonary connective tissue hyperplasia, pulmonary capillary congestion, and inflammatory cell infiltration, as well as serum levels of cytokines (i.e., TNF-α, IL-1β, IL-6, and IL-10), were elevated after MG infection. Collagen fibers were significantly deposited in the lung tissue from MG-infected chicks. Furthermore, the expression levels of key factors in the JAK2/STAT3 and TGF-β/Smad pathways markedly increased. AR intervention significantly alleviated MG-induced pneumonic injury, and reduced collagen deposition and the expression of fibrosis markers in the lung tissue. AR reduced the degree of pulmonary fibrosis by regulating key factors of the JAK2/STAT3 signaling pathway in the MG-infected HD11 cells. Thus, AR effectively reduced the expression of inflammatory factors by regulating the JAK2/STAT3 signaling pathway, thereby improving lung inflammation and fibrosis.

Silybin Meglumine Mitigates CCl4-Induced Liver Fibrosis and Bile Acid Metabolism Alterations.

Altered patterns of bile acids (BAs) are frequently present in liver fibrosis, and BAs function as signaling molecules to initiate inflammatory responses. Silybin meglumine (SLB-M) is widely used in treating various liver diseases including liver fibrosis. However, research on its effects on bile acid (BA) metabolism is limited. This study investigated the therapeutic effects of SLB-M on liver fibrosis and BA metabolism in a CCl4-induced murine model. A murine liver fibrosis model was induced by CCl4. Fibrosis was evaluated using HE, picrosirius red, and Masson's trichrome staining. Liver function was assessed by serum and hepatic biochemical markers. Bile acid (BA) metabolism was analyzed using LC-MS/MS. Bioinformatics analyses, including PPI network, GO, and KEGG pathway analyses, were employed to explore molecular mechanisms. Gene expression alterations in liver tissue were examined via qRT-PCR. SLB-M treatment resulted in significant histological improvements in liver tissue, reducing collagen deposition and restoring liver architecture. Biochemically, SLB-M not only normalized serum liver enzyme levels (ALT, AST, TBA, and GGT) but also mitigated disruptions in both systemic and hepatic BA metabolism by increased unconjugated BAs like cholic acid and chenodeoxycholic acid but decreased conjugated BAs including taurocholic acid and taurodeoxycholic acid, compared to that in CCl4-induced murine model. Notably, SLB-M efficiently improved the imbalance of BA homeostasis in liver caused by CCl4 via activating Farnesoid X receptor. These findings underscore SLB-M decreased inflammatory response, reconstructed BA homeostasis possibly by regulating key pathways, and gene expressions in BA metabolism.

Spatiotemporal delivery of multiple components of rhubarb-astragalus formula for the sysnergistic treatment of renal fibrosis.

Rhubarb (Rheum palmatum L.) and astragalus (Radix astragali) find widespread used in clinical formulations for treating chronic kidney disease (CKD). Notably, the key active components, total rhubarb anthraquinone (TRA) and total astragalus saponin (TAS), exhibit superiority over rhubarb and astragalus in terms of their clear composition, stability, quality control, small dosage, and efficacy for disease treatment. Additionally, astragalus polysaccharides (APS) significantly contribute to the treatment of renal fibrosis by modulating the gut microbiota. However, due to differences in the biopharmaceutical properties of these components, achieving synergistic effects remains challenging. This study aims to develop combined pellets (CPs) and evaluate the potential effect on unilateral ureteral obstruction (UUO)-induced renal fibrosis. The CPs pellets were obtained by combining TRA/TAS-loaded SNEDDS pellets and APS-loaded pellets, prepared using the fluidized bed coating process. The prepared pellets underwent evaluation for morphology, bulk density, hardness, and flowing property. Moreover, the in vitro release of the payloads was evaluated with the CHP Type I method. Furthermore, the unilateral ureteral obstruction (UUO) model was utilized to investigate the potential effects of CPs pellets on renal fibrosis and their contribution to gut microbiota modulation. The ex-vivo study demonstrated that the developed CPs pellets not only improved the dissolution of TRA and TAS but also delivered TRA/TAS and APS spatiotemporally to the appropriate site along the gastrointestinal tract. In an animal model of renal fibrosis (UUO rats), oral administration of the CPs ameliorated kidney histological pathology, reduced collagen deposition, and decreased the levels of inflammatory cytokines. The CPs also restored the disturbed gut microbiota induced by UUO surgery and protected the intestinal barrier. The developed CPs pellets represent a promising strategy for efficiently delivering active components in traditional Chinese medicine formulas, offering an effective approach for treating CKD.

Suppression of miR-17 Alleviates Acute Respiratory Distress-associated Lung Fibrosis by Regulating Mfn2.

Acute respiratory distress syndrome (ARDS) patients currently have relatively high mortality, which is associated with early lung fibrosis. This study aimed to investigate whether miR-17 suppression could alleviate ARDS-associated lung fibrosis by regulating Mfn2. A mouse model of ARDS-related lung fibrosis was constructed via intratracheal instillation of bleomycin. The expression level of miR-17 in lung tissues was detected via quantitative real time polymerase chain reaction (qRT-PCR). In the ARDS mouse model of lung fibrosis, the mitigating effects of miR-17 interference were evaluated via tail vein injection of the miR negative control or the miR-17 antagomir. The pathological changes in the lung tissue were examined via HE staining and Masson's trichrome staining, and the underlying molecular mechanism was investigated via ELISA, qRT-PCR and Western blotting. Bleomycin-induced pulmonary fibrosis significantly increased collagen deposition and the levels of hydroxyproline (HYP) and miR-17. Interfering with miR-17 significantly reduced the levels of HYP and miR-17 and upregulated the expression of Mfn2. The intravenous injection of the miR-17 antagomir alleviated lung inflammation and reduced collagen deposition. In addition, interference with miR-17 could upregulate LC3B expression, downregulate p62 expression, and improve mitochondrial structure. Interfering with miR-17 can improve pulmonary fibrosis in mice by promoting mitochondrial autophagy via Mfn2.

Berberine-Loaded PVCL-PVA-PEG Self-Assembled Micelles for the Treatment of Liver Fibrosis.

Liver fibrosis is a necessary pathological process in many chronic liver diseases. Studies have shown that the progression of chronic liver disease can be slowed by rational intervention in hepatic fibrosis. Berberine (BBR), a natural extract of Phellodendron amurense, inhibits the development of liver fibrosis through several mechanisms. However, the clinical application of BBR is limited due to its low solubility. Drug delivery systems have been developed to improve the solubility of hydrophobic drugs and increase their efficacy in treating the liver fibrosis. In this study, a biocompatible nanomicelle was constructed by thin-film dispersion method using polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PVCL-PVA-PEG) as a carrier to encapsulate BBR (PVCL-PVA-PEG/BBR-MCs) to improve the solubility of BBR and reduce the systemic side effects. The ability to inhibit HSC-T6 cell activation of PVCL-PVA-PEG/BBR-MCs was evaluated in vitro. The anti-hepatic fibrosis effects of PVCL-PVA-PEG/BBR-MCs were investigated in vivo. PVCL-PVA-PEG/BBR-MCs have a uniform spherical shape with a mean particle size of 60.04 ± 0.027 nm and a potential of 1.49 ± 0.32 mV. It had an encapsulation efficiency of 98.52% ± 0.70 and drug loading content of 6.16% ± 0.04. Compared to free BBR, PVCL-PVA-PEG/BBR-MCs significantly inhibited HSC-T6 cell activation and TGF-β1-induced HSC-T6 cell migration in vitro. In vivo biodistribution experiments showed significantly improved hepatic distribution of PVCL-PVA-PEG/DiD-MCs compared to free DiD, suggesting that PVCL-PVA-PEG micelles enhance the ability of BBR to enter the liver and improve therapeutic efficacy. After treatment, PVCL-PVA-PEG/BBR-MCs significantly improved fibrotic liver structure and reduced collagen deposition in comparison to the CCl4-treated group; the treatment outcome was more effective than that of the free BBR group. Our results demonstrate the advantages of encapsulating BBR in PVCL-PVA-PEG micelles and highlight the potential of PVCL-PVA-PEG/BBR-MCs as a therapeutic strategy for the treatment of liver fibrosis.

Multiscale drug screening for cardiac fibrosis identifies MD2 as a therapeutic target

Cardiac fibrosis impairs cardiac function, but no effective clinical therapies exist. To address this unmet need, we employed a high-throughput screening for antifibrotic compounds using human induced pluripotent stem cell (iPSC)-derived cardiac fibroblasts (CFs). Counter-screening of the initial candidates using iPSC-derived cardiomyocytes and iPSC-derived endothelial cells excluded hits with cardiotoxicity. This screening process identified artesunate as the lead compound. Following profibrotic stimuli, artesunate inhibited proliferation, migration, and contraction in human primary CFs, reduced collagen deposition, and improved contractile function in 3D-engineered heart tissues. Artesunate also attenuated cardiac fibrosis and improved cardiac function in heart failure mouse models. Mechanistically, artesunate targeted myeloid differentiation factor 2 (MD2) and inhibited MD2/Toll-like receptor 4 (TLR4) signaling pathway, alleviating fibrotic gene expression in CFs. Our study leverages multiscale drug screening that integrates a human iPSC platform, tissue engineering, animal models, in silico simulations, and multiomics to identify MD2 as a therapeutic target for cardiac fibrosis.

Effects of Shaofu Zhuyu decoction on intestinal flora and fibrosis in a mouse model of endometriosis

Shaofu Zhuyu decoction has been widely used to treat gynecological diseases; however, its mechanism of action in endometriosis remains unclear. We analyzed Shaofu Zhuyu decoction's chemical composition using ultra-high performance liquid chromatography-mass spectrometry. In an endometriosis mouse model, ectopic lesions weight measurements and hematoxylin and eosin staining were used to assess the therapeutic efficacy of Shaofu Zhuyu decoction. Effects on intestinal microflora were analyzed using 16S ribosomal ribonucleic acid sequencing, and impacts on focal fibrosis were analyzed using Masson's trichrome staining. Moreover, fibrosis- and metabolism-related proteins were assessed using immunohistochemistry and enzyme-linked immunosorbent assay. The study identified 157 chemical constituents within Shaofu Zhuyu decoction. Shaofu Zhuyu decoction treatment in mice with endometriosis resulted in a reduction in ectopic lesions weight (P < 0.05) and delayed disease progression. Moreover, it improved the diversity and abundance of intestinal flora, and decreased the expression of Lachnospiraceae (P < 0.05), Rikenellaceae (P < 0.01), Ruminococcaceae (P < 0.01), Lachnoclostridium (P < 0.05), and unclassified_f__Ruminococcaceae (P < 0.05). Kyoto Encyclopedia of Genes and Genomes analysis revealed enrichment in carbohydrate, amino acid, and lipid metabolism pathways. Masson's trichrome staining revealed that compared to the untreated group, the Shaofu Zhuyu decoction group exhibited significantly reduced collagen deposition areas (P < 0.001), lower TGF-β1 (P < 0.001), COL1A1 (P < 0.05), and α-SMA (P < 0.01) expression in ectopic lesions, along with increased serum adiponectin (P < 0.05), decreased serum TGF-β1 (P < 0.001), and CTGF (P < 0.05). Shaofu Zhuyu decoction regulates the intestinal flora of mice with endometriosis while also reducing fibrosis at the lesion site. These findings highlight novel mechanisms for its efficacy in alleviating endometriosis.

Sustained linagliptin administration: superior glycemic control and less pancreatic injury in diabetic rats

While linagliptin is the most potent dipeptidyl peptidase 4 inhibitor, its use is limited due to poor bioavailability and the potential risk of pancreatic injury. Here, we investigated whether the sustained weekly administration of linagliptin could provide better effect compared to frequent daily oral administration. Type 2 diabetes was induced by feeding rats a high fructose/fat/salt diet followed by STZ injection. Compared to the partial glycemic control achieved with daily oral linagliptin, a weekly subcutaneous injection containing about one-fourth of the oral dose produced superior glycemic control, as evidenced by the 4-week postprandial glucose follow-up and oral glucose tolerance test. This was confirmed by the significant increase in serum insulin in the case of the sustained linagliptin administration. Higher levels of the anti-inflammatory cytokine adiponectin and lower triglyceride levels were observed after sustained linagliptin administration compared with daily oral linagliptin. In addition, sustained linagliptin displayed a significant increase in β-cells’ insulin immunoreactivity when compared with daily linagliptin. More reduction in collagen deposition and caspase-3 immunoreactivity in pancreatic tissue were observed in sustained linagliptin compared with oral linagliptin. In conclusion, sustained linagliptin administration provided superior glycemic control, which seems to be mediated by more reduction in pancreatic injury.

Abstract B041: Fibroblast STAT3 Signaling in Pancreatic Cancer: Implications for Immunotherapy and Tumor Microenvironment Modulation

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer distinguished by a dense stromal microenvironment. The current investigation delves into the fibroblast-specific STAT3 signaling in the PDAC tumor microenvironment (TME) and its effects on immune cell infiltration and extracellular matrix (ECM) modulation. An association was identified between heightened levels of phosphorylated STAT3 (pSTAT3) in tumor-associated fibroblasts (CAFs) and a more unfavorable prognosis, particularly among male patients. Comparative analysis of gene expression patterns in normal fibroblasts and those deficient in STAT3, extracted from mouse models of pancreatic cancer, unveiled distinct gene expression profiles related to the inflammatory signaling pathway (IL6, ADM, CXCL11, CD80, VEGFA, TGFB1, STC1, STC2). Utilizing ChIP-Seq analysis with an anti-pSTAT3 antibody, it was confirmed that STAT3 binds to the regulatory regions of these genes, supporting its regulatory role in the inflammatory signaling pathway. Moreover, the absence of STAT3 in CAFs resulted in a decline in M2 macrophages and an upsurge in M1 macrophages within the TME, indicating a potential function of STAT3 in influencing macrophage polarization. Noteworthy observations also revealed that STAT3 signaling in CAFs impacts ECM remodeling, as illustrated by reduced collagen deposition. Furthermore, the deficiency of STAT3 in CAFs led to a notable reduction in the quantity of neutrophils within the TME in our mouse model. Additionally, a plausible involvement of STAT3 in neutrophil recruitment and activation through the CXCL1/CXCR2 axis was indicated. Alterations in the infiltration of neutrophils and macrophages due to the absence of STAT3 could profoundly influence the immune response against PDAC. The modified composition of ECM following STAT3 deletion might also impact the infiltration and functioning of immune cells. These outcomes underscore the significance of STAT3 signaling in CAFs as a promising therapeutic target in PDAC, offering potential for modulating the tumor microenvironment, augmenting anti-tumor immunity, and advancing patient outcomes. Citation Format: Samaneh Saberi, Cameron Bumbleburg, Caroline Everett, Julia E Lefler, Victoria Jordan, Lu Han, Sudarshana Sharma, Michael C. Ostrowski. Fibroblast STAT3 Signaling in Pancreatic Cancer: Implications for Immunotherapy and Tumor Microenvironment Modulation [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B041.

Effect of an Autotaxin Inhibitor, 2-(4-Chlorophenyl)-7-methyl-8-pentylimidazo[1,2-a] Pyrimidin-5(8H)-one (CBT-295), on Bile Duct Ligation-Induced Chronic Liver Disease and Associated Hepatic Encephalopathy in Rats.

The role of autotaxin (ATX)-lysophosphatidic acid (LPA) is yet to be explored in the context of liver cirrhosis and associated encephalopathy. Our objective of this study was to evaluate the role of an ATX inhibitor in biliary cirrhosis and associated hepatic encephalopathy in rats. The preliminary investigation revealed significant impairment in liver function, which eventually led to the development of hepatic encephalopathy. Interestingly, LPA levels were significantly increased in the plasma, liver, and brain of rats following bile duct ligation. Subsequently, we tested the efficacy of an ATX inhibitor, CBT-295, in bile duct-induced biliary cirrhosis and neuropsychiatric symptoms associated with hepatic encephalopathy. CBT-295 showed good oral bioavailability and favorable pharmacokinetic properties. CBT-295 exhibited a significant reduction in inflammatory cytokines like TGF-β, TNF-α, and IL-6 levels, also reduced bile duct proliferation marker CK-19, and lowered liver fibrosis, as evident from reduced collagen deposition. The reversal of liver fibrosis with CBT-295 led to a reduction in blood and brain ammonia levels. Furthermore, CBT-295 also reduced neuroinflammation induced by ammonia, which is characterized by a significant reduction in brain cytokine levels. It improved neuropsychiatric symptoms such as locomotor activities, cognitive impairment, and clinical grading scores associated with hepatic encephalopathy. The improvement in hepatic encephalopathy observed with the ATX inhibitor could be the result of its hepatoprotective action and its ability to attenuate neuroinflammation. Therefore, inhibition of ATX-LPA signaling can be a multifactorial approach for the treatment of chronic liver diseases.

Vitamin B1 and calcitriol enhance glibenclamide suppression of diabetic nephropathy: Role of HMGB1/TLR4/NF-κB/TNF-α/Nrf2/α-SMA trajectories

Glibenclamide is one of the most prescribed insulin secretagogues in diabetes due to its low cost, but its efficacy on suppressing diabetic complications is limited. Here, we examine whether addition of either vitamin B1 or calcitriol to glibenclamide could produce more suppression of diabetic nephropathy. Type 2 diabetes was induced by high fructose (10 % in drinking water), high salt (3 % in diet), and high fat diet (25 % in diet) for 3 weeks, followed by single dose of STZ (40 mg/kg, i.p.). Diabetic rats were treated with either glibenclamide (0.6 mg/kg), vitamin B1 (70 mg/kg), glibenclamide/vitamin B1, calcitriol (0.1 μg/kg), or glibenclamide/calcitriol. Addition of either vitamin B1 or calcitriol to glibenclamide therapy enabled more suppression of diabetic nephropathy development as evidenced by more preserved creatinine clearance and less renal damage scores. Combination therapy resulted in mild enhancement in the effect of glibenclamide on glucose tolerance without affecting the area under the curve. Combination therapy was associated with more suppression of inflammatory cascades as evidenced by reducing the expression of high mobility group box-1 (HMGB1), toll-like receptor-4 (TLR4), nuclear factor-kappa B (NF-κB), and tumor necrosis factor-α (TNF-α). In addition, combination therapy enhanced the antioxidant mechanisms as evidenced by increased expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione content and reducing malondialdehyde and nitric oxide levels. Furthermore, combination therapy provided more suppression of fibrotic pathways as appear from reducing collagen deposition and the expression of α- smooth muscle actin (α-SMA). In conclusion, addition of vitamin B1 or calcitriol to glibenclamide therapy can enhance the therapeutic efficiency of glibenclamide in suppressing diabetic nephropathy progression to the same extend, the protective effect is mediated through modulating HMGB1/TLR4/NF-κB/TNF-α/Nrf2/α-SMA trajectories.

Metformin and intermittent fasting mitigate high fat-fructose diet-induced liver and skeletal muscle injury through upregulation of mitophagy genes in rats

BackgroundHigh fat-fructose diet is a proinflammatory diet that increases risk of hepatocytes and myocytes steatosis and fibrosis. Finding anti-inflammatory strategies to fight these harmful effects is paid attention to nowadays. This study compared the effects of two widely anti-inflammatory interventions—metformin and intermittent fasting on myocytes and hepatocyte injury induced by proinflammatory diet and tracking possible underlying mechanisms. In this work, rats fed high fat-fructose diet were subdivided into untreated group, treated by metformin, and/or intermittent fasting.ResultsMetformin (300 mg/kg/day) and intermittent fasting (3 days/week) specially their combination for 4 weeks showed significant improvement in insulin resistance, lipid profile, antioxidants (p < 0.05), as well as enhanced hepatocytes and myocytes repair and reduced collagen deposition through upregulation of mitophagy-related genes: PINK1, PARKIN, LAMP2, and PPAR-α (p < 0.05).ConclusionsIntermittent fasting has beneficial metabolic and molecular therapeutic effects against proinflammatory diet-induced injury. Their results are like those of metformin sparing its adverse effects. Their combination showed additional effects against diet-induced myocytes and hepatocyte injury by upregulation of mitophagy-related genes without the need of increasing the dose of metformin.Graphic abstract

Protective effects of Parkin knockout on asthma-induced changes in juvenile mice: inflammation, airway resistance, and oxidative stress

Objective This study aimed to explore the effects of Parkin (Prkn) knockout in a juvenile mouse model of asthma. Methods Prkn knockout (KO) and wild type (WT) mice were utilized to establish a juvenile mouse asthma model. The asthma model involved exposure to hyperoxia/ovalbumin (OVA), encompassing hyperoxia from postnatal day 1 (P1) to P7, sensitization on P21 and P28, and challenge from P36 to P42. Room air/phosphate-buffered saline (PBS) served as the control condition. Following airway resistance measurement, bronchoalveolar lavage fluid (BALF) was collected for cellular analysis, and lung tissues were subjected to histological examination and oxidative stress assessment. Serum levels of ovalbumin-specific immunoglobulin E (IgE), total IgE, interleukin-4 (IL-4), IL-5, and IL-13 were quantified using enzyme-linked immunosorbent assay (ELISA). Results WT mice exposed to hyperoxia/OVA showed decreased body weight and increased airway resistance compared to those exposed to control condition. Conversely, KO mice exhibited increased body weight under asthma conditions. KO mice with asthma had reduced total cell counts, along with lower levels of lymphocytes, eosinophils, and neutrophils, compared to WT asthma mice. Histological assessment showed attenuated inflammation and reduced collagen deposition in KO mice relative to WT mice, with lower serum levels of inflammatory markers and improved lung oxidative stress profiles. No significant differences were observed between KO and WT mice under room air/PBS conditions. Conclusions Parkin knockout in juvenile mice mitigates asthma-related alterations in airway resistance, histopathological changes, inflammation status, and oxidative stress. These findings highlight a protective role of Parkin deficiency against asthma-associated pathologies.