MicroRNA-10a/b inhibit TGF-β/Smad-induced renal fibrosis by targeting TGF-β receptor 1 in diabetic kidney disease

TGF-β: elusive target in diabetic kidney disease

Transforming growth factor-beta (TGF-β), a cytokine with near omnipresence, is an integral part of many vital cellular processes across the human body. The family includes three isoforms: Transforming growth factor-beta 1, 2, and 3. These cytokines play a significant role in the fibrosis cascade. Diabetic kidney disease (DKD), a major complication of diabetes, is increasing in prevalence daily, and the classical diagnosis of diabetes is based on the presence of albuminuria. The occurrence of nonalbuminuric DKD has provided new insight into the pathogenesis of this disease. The emphasis on multifactorial pathways involved in developing DKD has highlighted some markers associated with tissue fibrosis. In diabetic nephropathy, TGF-β is significantly involved in its pathology. Its presence in serum and urine means that it could be a diagnostic tool while its regulation provides potential therapeutic targets. Completely blocking TGF-β signaling could reach untargeted regions and cause unanticipated effects. This paper reviews the basic details of TGF-β as a cytokine, its role in DKD, and updates on research carried out to validate its candidacy.

microRNAs in Type 1 Diabetes: Roles, Pathological Mechanisms, and Therapeutic Potential

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the progressive destruction of pancreatic β-cells, leading to insulin deficiency. The primary drivers of β-cell destruction in T1D involve autoimmune-mediated processes that trigger chronic inflammation and ultimately β-cell loss. Regulatory microRNAs (miRNAs) play a crucial role in modulating these processes by regulating gene expression through post-transcriptional suppression of target mRNAs. Dysregulated miRNAs have been implicated in T1D pathogenesis, serving as both potential diagnostic biomarkers and therapeutic targets. This review explores the role of miRNAs in T1D, highlighting their involvement in disease mechanisms across both rodent models and human patients. While current antidiabetic therapies manage T1D symptoms, they do not prevent β-cell destruction, leaving patients reliant on lifelong insulin therapy. By summarizing key miRNA expression profiles in diabetic animal models and patients, this review explores the potential of miRNA-based therapies to restore β-cell function and halt or slow the progression of the disease.

miR-16-5p Regulates Proliferation and Apoptosis in High Glucose-Treated Human Retinal Microvascular Endothelial Cells by Targeting VEGFA and TGFBR1

Diabetic retinopathy (DR) is a common complication of diabetes and the main cause of vision loss in the middle-aged and elderly people. miRNAs play vital roles in the development of DR. This study aimed to explore the effects of miR-16-5p on high glucose (HG)-stimulated human retinal microvascular endothelial cells (HRECs) by modulating vascular endothelial growth factor A (VEGFA) and transforming growth factor beta receptor 1 (TGFBR1). HRECs were treated with 5 mM, 10 mM, 20 mM, and 30 mM of HG to induce the DR cell model. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of miR-16-5p and mRNAs of VEGFA and TGFBR1. Western blot was used to examine VEGFA and TGFBR1 protein levels. The 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide assay was conducted to test cell proliferation. Flow cytometry with Annexin V-FITC/PI double staining was carried out to assess cell apoptosis ratio. Dual-luciferase assay was used to identify the target relationship between miR-16-5p and VEGFA and TGFBR1. Results found that the expression of miR-16-5p in HG-treated HRECs was reduced, and VEGFA and TGFBR1 expressions were upregulated. Knockdown of miR-16-5p increased VEGFA and TGFBR1 mRNA and protein levels, promoted cell proliferation, and inhibited apoptosis in HG-treated HRECs. VEGFA and TGFBR1 inhibition reversed the effect of knocking down miR-16-5p on HRECs. Dual-luciferase reporter assay revealed that VEGFA and TGFBR1 were the target of miR-16-5p. Overall, knockdown of miR-16-5p enhances proliferation and inhibits apoptosis of HRECs by upregulating VEGFA and TGFBR1 expression.

FOSL2 activates TGF-β1-mediated GLUT1/mTOR signaling to promote diabetic kidney disease

AIMS/INTRODUCTION

Diabetic kidney disease (DKD) is a major cause of kidney failure. FOS-like antigen 2 (FOSL2) has been revealed to be increased in kidney biopsies of patients with lupus nephritis, while its association with DKD remains unsolved. This study aimed to characterize the role of FOSL2 in DKD and its mechanism.

METHOD

The kidney tissues of DKD mice induced by STZ and a high-fat diet were subjected to PAS and Masson's staining. Glomerular mesangial cells (MCs) were treated with high glucose (HG) or normal glucose (NG). CCK-8 and EdU assays were performed to detect cell proliferation, and immunoblotting was conducted to analyze ECM deposition. ChIP-qPCR was performed on MCs to detect the binding of FOSL2 on the TGF-β1 promoter and a dual-luciferase assay to detect the impact of FOSL2 on the transcription of the TGF-β1 promoter.

RESULTS

FOSL2 was elevated in the kidney tissues of DKD mice. Knockdown of FOSL2 reduced the mRNA expression of TGF-β1 to decrease the protein expression of GLUT1 and mTOR in the kidney tissues of DKD mice, and TGF-β1 reversed the effects caused by knockdown of FOSL2. The mTOR inhibitor Rapamycin alleviated kidney injury in the presence of FOSL2. Knockdown of FOSL2 inhibited the proliferation and improved ECM deposition of MCs, which were reversed by TGF-β1. Rapamycin and GLUT1 inhibitor BAY-876 reversed the promotion effect of FOSL2 on the proliferation of NG-MCs/HG-MCs and improved ECM deposition of MCs.

CONCLUSIONS

Our data demonstrated that FOSL2 accentuates DKD in mice by increasing TGF-β1-induced GLUT1/mTOR signaling.

Exploring Liraglutide's mechanism in reducing renal fibrosis: the Fsp1-CoQ10-NAD(P)H pathway

Studies have confirmed that elevated glucose levels could lead to renal fibrosis through the process of ferroptosis. Liraglutide, a human glucagon-like peptide-1 (GLP-1) analogue, is a potential treatment option for diabetes. This study aimed to examine the potential of liraglutide (LIRA) in inhibiting ferroptosis and reducing high glucose-induced renal fibrotic injury in mice, and whether the Fsp1-CoQ10-NAD(P)H signal pathway is a mechanism for this effect. In our study, we used db/db mice to simulate Type 2 diabetes mellitus (T2DM). The mice were intraperitoneally injected with LIRA (200 µg/kg/d) daily for 6 weeks. Renal function, pathologic changes, lipid peroxidation levels, iron levels, and ferroptosis were assessed. First, LIRA ameliorated renal dysfunction and fibrosis in db/db mice. Second, LIRA inhibited lipid peroxidation by up-regulating T-SOD, GSH-Px, and GSH activities as well as down-regulating the levels of 8-OHDG, MDA, LPO, 4-HNE, 12-Lox, and NOX4 in db/db mice. In addition, LIRA attenuated iron deposition by decreasing the expression of TfR1 and increasing the expression of FPN1. Meanwhile, LIRA reduced high levels of high glucose-induced cell viability decline and intracellular lipid peroxidation. Furthermore, LIRA inhibited ferroptosis by adjusting the Fsp1-CoQ10-NAD(P)H pathway in vivo and in vitro. These findings suggested that LIRA attenuated kidney fibrosis injury in db/db mice by inhibiting ferroptosis through the Fsp1-CoQ10-NAD(P)H pathway.

GS-4997 halts the progression of tubulointerstitial injury in lupus nephritis

Tubulointerstitial injury has been increasingly recognized as an important component in lupus nephritis (LN) pathology over the last decades. However, current clinical treatment options for this process remain limited. In this study, we aimed to investigate the potential benefits of GS-4997, a selective inhibitor of ASK1, in tubulointerstitial injury of LN. Female MRL/lpr mice were used as a classical lupus-prone murine model. Development of nephritis was assessed by monitoring of proteinuria, renal function, and histologic analysis. GS-4997 (50 mg/kg) or vehicle were treated orally. In vitro study, human kidney-2 (HK-2) cells were stimulated with 1 μg/mL lipopolysaccharide (LPS) to mimic the response of renal tubular epithelial cells undergoing inflammatory responses during LN. GS-4997 could inhibit the activation of the ASK1 in renal tubulointerstitium in MRL/lpr mice and LPS-induced HK-2 cells. GS-4997 treatment improved renal function, proteinuria, and attenuated tubular injury, renal interstitial fibrosis, and inflammation both in vivo and in vitro. Additionally, we found that in MRL/lpr mice, GS-4997 reduced deposition of IgG and C3 in the kidneys, antibody levels in the serum, splenic enlargement, and inflammatory cell infiltration in the spleen. Mechanistically, GS-4997 inhibited the activation of downstream signaling molecules, p38 and JNK, in the ASK1 signaling pathway. Pharmacological inhibition of ASK1 may prevent the progression of tubulointerstitial injury via inhibiting the ASK1/MAPK pathway in LN. Therefore, our findings demonstrate the potential use of GS-4997 for LN treatment.

Sodium tungstate (NaW) decreases inflammation and renal fibrosis in diabetic nephropathy

BACKGROUND

Diabetic Nephropathy is one of the most severe complications of Diabetes Mellitus and the main cause of end-stage kidney disease worldwide. Despite the therapies available to control blood glucose and blood pressure, many patients continue to suffer from progressive kidney damage. Chronic hyperglycemia is the main driver of changes observed in diabetes; however, it was recently discovered that inflammation and oxidative stress contribute to the development and progression of kidney damage. Therefore, it is important to search for new pharmacological therapies that stop the progression of DN. Sodium tungstate (NaW) is an effective short and long-term antidiabetic agent in both type 1 and type 2 diabetes models.

METHODS

In this study, the effect of NaW on proinflammatory signalling pathways, proinflammatory proteins and fibrosis in the streptozotocin (STZ)-induced type 1 diabetic rat model was analysed using histological analysis, western blotting and immunohistochemistry.

RESULTS

NaW treatment in diabetic rats normalize parameters such as glycemia, glucosuria, albuminuria/creatinuria, glomerular damage, and tubulointerstitial damage. NaW decreased the proinflammatory signaling pathway NF-κB, inflammatory markers (ICAM-1, MCP-1 and OPN), profibrotic pathways (TGFβ1/Smad2/3), reduced epithelial-mesenchymal transition (α -SMA), and decreased renal fibrosis (type IV collagen).

CONCLUSION

NaW could be an effective drug therapy for treating human diabetic nephropathy.

Therapy Targeted to the NLRP3 Inflammasome in Chronic Kidney Disease

Background

The NLRP3 inflammasome is a cytoplasmic polymeric protein complex composed of the cytoplasmic sensor NLRP3, the apoptosis-related spot-like protein ASC, and the inflammatory protease caspase-1. NLRP3 activates and releases IL-1β through classical pathways, and IL-18 mediates inflammation and activates gasdermin-D protein to induce cellular pyroptosis. Numerous studies have also emphasized the non-classical pathway activated by the NLRP3 inflammasome in chronic kidney disease (CKD) and the inflammasome-independent function of NLRP3.

Summary

The NLRP3-targeting inflammasome and its associated pathways have thus been widely studied in models of CKD treatment, but no drug that targets NLRP3 has thus far been approved for the treatment of CKD.

Key Messages

We herein reviewed the current interventional methods for targeting the NLRP3 inflammasome in various CKD models, analyzed their underlying mechanisms of action, classified and compared them, and discussed the advantages and follow-up directions of various interventional methods. This review therefore provides novel ideas and a reference for the development of targeted NLRP3-inflammasome therapy in CKD.

Development of a Lipid-encapsulated TGFβRI-siRNA Drug for Liver Fibrosis Induced by Schistosoma mansoni

Schistosoma mansoni infection leads to chronic schistosomiasis and severe hepatic fibrosis. We designed a liver-targeted lipid nanoparticle (LNP) carrying siRNA against type I TGF-β receptor (TGFβRI) mRNA to treat schistosomiasis-induced liver fibrosis in BALB/c mice. Knockdown of TGFβRI by LNP-siTGFβRI reduced LX-2 cell activation in vitro and alleviated liver fibrosis in S. mansoni-infected mice. αSMA and Col1a1 fibrotic markers in the liver tissues of infected mice were significantly suppressed in the treatment groups. In the serum of the LNP-siTGFβRI-treated groups, cytokines IFNγ, IL-1α, IL-6, IL-12, RANTES (CCL5), and TNFα increased, while GM-CSF, IL-2, IL-4, IL-10, IL-13, and KC (CXCL1) decreased compared to the control. Cell proportions were significantly altered in S. mansoni-infected mice, with increased CD56d NK cells and decreased CD19+ B cells and CD4+ T cells compared to naïve mice. Following LNP-siTGFβRI treatment, CD56d NK cells were downregulated, while B and memory Th cell populations were upregulated. The density of fibrotic regions significantly decreased with LNP-siTGFβRI treatment in a dose-dependent manner, and no systemic toxicity was observed in the major organs. This targeted siRNA delivery strategy effectively reduced granulomatous lesions in schistosomiasis-induced liver fibrosis without detectable side effects.

Plasma MCP-1 and TGF-β1 Levels are Associated with Kidney Injury in Children with Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract (CAKUT) are primarily causal for end-stage renal disease and have significant implications for long-term survival. A total of 39 healthy controls and 94 children with chronic kidney disease (CKD) were enrolled (3-12 years old as children, 13-18 years old as adolescents), who were divided into CAKUT and Non-CAKUT according to the etiology of CKD. CKD group was further classified according to estimating glomerular filtration rate (eGFR). Circulating levels of inflammatory markers such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemokine-1 (MCP-1), and transforming growth factor-β1 (TGF-β1) were analyzed. The relationship between these inflammatory markers with eGFR and the kidney injury parameter (urine protein) was investigated to assess their potential as early markers of disease progression. All circulating levels of these inflammatory cytokines were increased in CKD patients (including CAKUT and Non-CAKUT) compared with healthy subjects. The circulating levels of MCP-1 and TGF-β1 were increased in CAKUT adolescents compared with CAKUT children. In CAKUT children, levels of MCP-1 and TGF-β1 increased as CKD progressed, and MCP-1 and TGF-β1 were negatively and significantly correlated with eGFR and positively with urine protein. MCP-1 and TGF-β1 may contribute to the early detection of CKD and disease stage/progression in CAKUT children.

Upregulation of Metrnl improves diabetic kidney disease by inhibiting the TGF-β1/Smads signaling pathway: A potential therapeutic target

PURPOSE

This study comprises an investigation of the role of meteorin-like (Metrnl) in an experimental model of diabetic kidney disease (DKD).

METHODS

Twenty-four db/db mice were randomly assigned to one of the following groups: DKD, DKD + Metrnl-/-, and DKD + Metrnl+/+. Plasma Metrnl concentrations were measured using ELISA. Kidney tissues were examined via western blotting, qRT-PCR, and immunohistochemistry to determine the expression levels of inflammatory factors. Electron microscopy was employed to observe stained kidney sections.

RESULTS

Compared with the NC group, FBG, BW, and UACR were elevated in the DKD and Metrnl-/- groups, with severe renal pathological injury, decreased serum Metrnl concentration, decreased renal Metrnl expression, and increased expression levels of TNF-α, TGF-β1, TGF-R1, pSmad2, pSmad3, and α-SMA. In contrast, the Metrnl+/+ group showed decreased FBG and UACR, BUN, TC and TG, increased HDL-C and serum Metrnl concentration, increased renal Metrnl expression, and decreased expression of TNF-α, TGF-β1, TGF-R1, pSmad2, pSmad3, and α-SMA, compared to the DKD and Metrnl-/- groups. A Pearson bivariate correlation analysis revealed a negative correlation between UACR and Metrnl, and a positive correlation between UACR and TGF-β1.

CONCLUSION

Upregulation of renal Metrnl expression can improve renal injury by downregulating the expression of molecules in the TGF-β1/Smads signaling pathway in the renal tissues of type 2 diabetic mice; and by reducing the production of fibrotic molecules such as α-SMA.

Role of TGFβ-producing regulatory T cells in scleroderma and end-stage organ failure

Regulatory T cells (Tregs) are crucial immune cells that initiate a tolerable immune response. Transforming growth factor-beta (TGFβ) is a key cytokine produced by Tregs and plays a significant role in stimulating tissue fibrosis. Systemic sclerosis, an autoimmune disease characterized by organ fibrosis, is associated with an overrepresentation of regulatory T cells. This review aims to identify Treg-dominant tolerable host immune reactions and discuss their association with scleroderma and end-stage organ failure. End-stage organ failures, including heart failure, liver cirrhosis, uremia, and pulmonary fibrosis, are frequently linked to tissue fibrosis. This suggests that TGFβ-producing Tregs are involved in the pathogenesis of these conditions. However, the exact significance of TGFβ and the mechanisms through which it induces tolerable immune reactions during end-stage organ failure remain unclear. A deeper understanding of these mechanisms could lead to improved preventive and therapeutic strategies for these severe diseases.

Deciphering the role of MicroRNAs in diabetic nephropathy: Regulatory mechanisms and molecular insights

A serious consequence of diabetes mellitus, diabetic nephropathy (DN) which causes gradual damage to the kidneys. Dietary changes, blood pressure control, glucose control, and hyperlipidemia are all important components of DN management. New research, however, points to microRNAs (miRNAs) as having a pivotal role in DN pathogenesis. Miniature non-coding RNA molecules such as miRNAs control gene expression and impact several biological processes. The canonical and non-canonical routes of miRNA biogenesis are discussed in this article. In addition, several important signaling pathways are examined in the study of miRNA regulation in DN. A deeper knowledge of these regulatory mechanisms would allow for a better understanding of the molecular basis of DN and the development of innovative therapeutic strategies. Finally, miRNAs show tremendous potential as DN diagnostic biomarkers and treatment targets, opening up promising avenues for further study and potential clinical use.

Fibrosis in Chronic Kidney Disease: Pathophysiology and Therapeutic Targets

Chronic kidney disease (CKD) is a slowly progressive condition characterized by decreased kidney function, tubular injury, oxidative stress, and inflammation. CKD is a leading global health burden that is asymptomatic in early stages but can ultimately cause kidney failure. Its etiology is complex and involves dysregulated signaling pathways that lead to fibrosis. Transforming growth factor (TGF)-β is a central mediator in promoting transdifferentiation of polarized renal tubular epithelial cells into mesenchymal cells, resulting in irreversible kidney injury. While current therapies are limited, the search for more effective diagnostic and treatment modalities is intensive. Although biopsy with histology is the most accurate method of diagnosis and staging, imaging techniques such as diffusion-weighted magnetic resonance imaging and shear wave elastography ultrasound are less invasive ways to stage fibrosis. Current therapies such as renin-angiotensin blockers, mineralocorticoid receptor antagonists, and sodium/glucose cotransporter 2 inhibitors aim to delay progression. Newer antifibrotic agents that suppress the downstream inflammatory mediators involved in the fibrotic process are in clinical trials, and potential therapeutic targets that interfere with TGF-β signaling are being explored. Small interfering RNAs and stem cell-based therapeutics are also being evaluated. Further research and clinical studies are necessary in order to avoid dialysis and kidney transplantation.

Integrin β8 prevents pericyte-myofibroblast transition and renal fibrosis through inhibiting the TGF-β1/TGFBR1/Smad3 pathway in diabetic kidney disease

Diabetic kidney disease (DKD) is one of the leading causes to develop end-stage kidney disease worldwide. Pericytes are implicated in the development of tissue fibrosis. However, the underlying mechanisms of pericytes in DKD remain largely unknown. We isolated and cultured primary pericytes and rat mesangial cells (HBZY-1). Western blot and qRT-PCR analysis were used to explore the role and regulatory mechanism of Integrin β8/transforming growth factor beta 1 (TGF-β1) pathway. We also constructed pericyte-specific Integrin β8 knock-in mice as the research objects to determine the role of Integrin β8 in vivo. We discovered that reduced Integrin β8 expression was closely associated with pericyte transition in DKD. Overexpressed Integrin β8 in pericytes dramatically suppressed TGF-β1/TGF beta receptor 1 (TGFBR1)/Smad3 signaling pathway and protected glomerular endothelial cells (GECs) in vitro. In vivo, pericyte-specific Integrin β8 knock-in ameliorated pericyte transition, endothelium injury and renal fibrosis in STZ-induced diabetic mice. Mechanistically, Murine double minute 2 (MDM2) was found to increase the degradation of Integrin β8 and caused TGF-β1 release and activation. Knockdown MDM2 could partly reverse the decline of Integrin β8 and suppress pericytes transition. In conclusion, the present findings suggested that upregulated MDM2 expression contributes to the degradation of Integrin β8 and activation of TGF-β1/TGFBR1/Smad3 signaling pathway, which ultimately leads to pericyte transition during DKD progression. These results indicate MDM2/Integrin β8 might be considered as therapeutic targets for DKD.

MiR-141-3p-Functionalized Exosomes Loaded in Dissolvable Microneedle Arrays for Hypertrophic Scar Treatment

Hypertrophic scar (HS) is a common fibroproliferative disease caused by abnormal wound healing after deep skin injury. However, the existing approaches have unsatisfactory therapeutic effects, which promote the exploration of newer and more effective strategies. MiRNA-modified functional exosomes delivered by dissolvable microneedle arrays (DMNAs) are expected to provide new hope for HS treatment. In this study, a miRNA, miR-141-3p, which is downregulated in skin scar tissues and in hypertrophic scar fibroblasts (HSFs), is identified. MiR-141-3p mimics inhibit the proliferation, migration, and myofibroblast transdifferentiation of HSFs in vitro by targeting TGF-β2 to suppress the TGF-β2/Smad pathway. Subsequently, the engineered exosomes encapsulating miR-141-3p (miR-141-3pOE -Exos) are isolated from adipose-derived mesenchymal stem cells transfected with Lv-miR-141-3p. MiR-141-3pOE -Exos show the same inhibitive effects as miR-141-3p mimics on the pathological behaviors of HSFs in vitro. The DMNAs for sustained release of miR-141-3pOE -Exos are further fabricated in vivo. MiR-141OE -Exos@DMNAs effectively decrease the thickness of HS and improve fibroblast distribution and collagen fiber arrangement, and downregulate the expression of α-SMA, COL-1, FN, TGF-β2, and p-Smad2/3 in the HS tissue. Overall, a promising, effective, and convenient exosome@DMNA-based miRNA delivery strategy for HS treatment is provided.

Functional nucleic acids for the treatment of diabetic complications

In recent decades, diabetes mellitus (DM) has become a major global health problem owing to its high prevalence and increased incidence of diabetes-associated complications, including diabetic wounds (DWs), diabetic nephropathy, metabolic syndrome, diabetic retinopathy, and diabetic neuropathy. In both type 1 and type 2 diabetes, tissue damage is organ-specific, but closely related to the overproduction of reactive oxygen species (ROS) and hyperglycaemia-induced macrovascular system damage. However, existing therapies have limited effects on complete healing of diabetic complications. Fortunately, recent advances in functional nucleic acid materials have provided new opportunities for the treatment and diagnosis of diabetic complications. Functional nucleic acids possess independent structural functions that can replace traditional proteases and antibodies and perform specific biological non-genetic functions. This review summarises the current functional nucleic acid materials reported for the treatment of diabetic complications, including tetrahedral framework nucleic acids (tFNAs), short interfering RNA (siRNA), micorRNA (miRNA), locked nucleic acids, antisense oligonucleotides (ASOs), and DNA origami, which may assist in the development of novel nucleic acids with new functions and capabilities for better healing of diabetic complications.

TGF-β as A Master Regulator of Aging-Associated Tissue Fibrosis

Fibrosis is the abnormal accumulation of extracellular matrix proteins such as collagen and fibronectin. Aging, injury, infections, and inflammation can cause different types of tissue fibrosis. Numerous clinical investigations have shown a correlation between the degree of liver and pulmonary fibrosis in patients and telomere length and mitochondrial DNA content, both of which are signs of aging. Aging involves the gradual loss of tissue function over time, which results in the loss of homeostasis and, ultimately, an organism's fitness. A major feature of aging is the accumulation of senescent cells. Senescent cells abnormally and continuously accumulate in the late stages of life, contributing to age-related fibrosis and tissue deterioration, among other aging characteristics. Furthermore, aging generates chronic inflammation, which results in fibrosis and decreases organ function. This finding suggests that fibrosis and aging are closely related. The transforming growth factor-beta (TGF-β) superfamily plays a crucial role in the physiological and pathological processes of aging, immune regulation, atherosclerosis, and tissue fibrosis. In this review, the functions of TGF-β in normal organs, aging, and fibrotic tissues is discussed: TGF-β signalling is altered with age and is an indicator of pathology associated with tissue fibrosis. In addition, this review discusses the potential targeting of noncoding.

RUNX1 promotes liver fibrosis progression through regulating TGF-β signalling

Liver fibrosis is caused by chronic liver injury. There are limited treatments for it, and the pathogenesis is unclear. Therefore, there is an urgent need to explore the pathogenesis of liver fibrosis, and to try to identify new potential therapeutic targets. For this study we used the carbon tetrachloride abdominal injection induced liver fibrosis animal model in mice. Primary hepatic stellate cell isolation was performed by a density-gradient separation method, and this was followed by immunofluorescence stain analyses. Signal pathway analysis was performed by dual-luciferase reporter assay and western blotting. Our results showed that RUNX1 was upregulated in cirrhotic liver tissues compared with normal liver tissues. Besides, overexpression of RUNX1 caused more severe liver fibrosis lesions than control group under CCl4 -induced conditions. Moreover, α-SMA expression in the RUNX1 overexpression group was significantly higher than in the control group. Interestingly, we found that RUNX1 could promote the activation of TGF-β/Smads in a dual-luciferase reporter assay. Thus we demonstrated that RUNX1 could be considered as a new regulator of hepatic fibrosis by activating TGF-β/Smads signalling. Based on this, we concluded that RUNX1 may be developed as a new therapeutic target in the treatment of liver fibrosis in the future. In addition, this study also provides a new insight about the aetiology of liver fibrosis.

Impact of High Fat Diet and Sex in a Rabbit Model of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is a common musculoskeletal disorder, characterized by fibrosis of the subsynovial connective tissue (SSCT) mediated by transforming growth factor beta (TGF-β). Risk factors for CTS include metabolic dysfunction and age. Additionally, the incidence of CTS is higher in women. In this study we hypothesized that a high-fat diet (HFD), a common driver of metabolic dysfunction, would promote SSCT fibrosis found in CTS and that this response would be sex dependent. To test this, we examined the effects of HFD and sex on SSCT fibrosis using our established rabbit model of CTS. Forty-eight (24 male, 24 female) adult rabbits were divided into four groups including HFD or standard diet with and without CTS induction. SSCT was collected for histological and gene expression analysis. HFD promoted SSCT thickening and upregulated profibrotic genes, including TGF-β. Fibrotic genes were differentially expressed in males and females. Interestingly while the prevalence of CTS is greater in women than in men, the converse is observed in the presence of metabolic dysfunction. This work recapitulates this clinical observation and begins to elucidate the sex-based differences found in SSCT fibrosis. This knowledge should drive further research and may lead to metabolic and sex specific therapeutic strategies for the treatment of patients with CTS.

miR-10a-3p modulates adiposity and suppresses adipose inflammation through TGF-β1/Smad3 signaling pathway

Background

Obesity is a multifactorial disease characterized by an enhanced amount of fat and energy storage in adipose tissue (AT). Obesity appears to promote and maintain low-grade chronic inflammation by activating a subset of inflammatory T cells, macrophages, and other immune cells that infiltrate the AT. Maintenance of AT inflammation during obesity involves regulation by microRNAs (miRs), which also regulate the expression of genes implicated in adipocyte differentiation. This study aims to use ex vivo and in vitro approaches to evaluate the role and mechanism of miR-10a-3p in adipose inflammation and adipogenesis.

Methods

Wild-type BL/6 mice were placed on normal (ND) and high-fat diet (HFD) for 12 weeks and their obesity phenotype, inflammatory genes, and miRs expression were examined in the AT. We also used differentiated 3T3-L1 adipocytes for mechanistic in vitro studies.

Results

Microarray analysis allowed us to identify an altered set of miRs in the AT immune cells and Ingenuity pathway analysis (IPA) prediction demonstrated that miR-10a-3p expression was downregulated in AT immune cells in the HFD group as compared to ND. A molecular mimic of miR-10a-3p reduced expression of inflammatory M1 macrophages, cytokines, and chemokines, including transforming growth factor-beta 1 (TGF-β1), transcription factor Krüppel-like factor 4 (KLF4), and interleukin 17F (IL-17F) and induced expression of forkhead box P3 (FoxP3) in the immune cells isolated from AT of HFD-fed mice as compared to ND. In differentiated 3T3-L1 adipocytes, the miR-10a-3p mimics also reduced expression of proinflammatory genes and lipid accumulation, which plays a role in the dysregulation of AT function. In these cells, overexpression of miR-10a-3p reduced the expression of TGF-β1, Smad3, CHOP-10, and fatty acid synthase (FASN), relative to the control scramble miRs.

Conclusion

Our findings suggest that miR-10a-3p mimic mediates the TGF-β1/Smad3 signaling to improve metabolic markers and adipose inflammation. This study provides a new opportunity for the development of miR-10a-3p as a novel therapeutic for adipose inflammation, and its associated metabolic disorders.

Biochanin A Ameliorates Nephropathy in High-Fat Diet/Streptozotocin-Induced Diabetic Rats: Effects on NF-kB/NLRP3 Axis, Pyroptosis, and Fibrosis

Nephropathy is the most prevalent microvascular disorder in diabetes mellitus. Oxidative stress and inflammatory cascade provoked by the persistent hyperglycemic milieu play integral roles in the aggravation of renal injury and fibrosis. We explored the impact of biochanin A (BCA), an isoflavonoid, on the inflammatory response, nod-like receptor protein 3 (NLRP3) inflammasome activation, oxidative stress, and fibrosis in diabetic kidneys. A high-fat-diet/streptozotocin (HFD/STZ)-induced experimental model of diabetic nephropathy (DN) was established in Sprague Dawley rats, and in vitro studies were performed in high-glucose-induced renal tubular epithelial (NRK-52E) cells. Persistent hyperglycemia in diabetic rats was manifested by perturbation of renal function, marked histological alterations, and oxidative and inflammatory renal damage. Therapeutic intervention of BCA mitigated histological changes, improved renal function and antioxidant capacity, and suppressed phosphorylation of nuclear factor-kappa B (NF-κB) and nuclear factor-kappa B inhibitor alpha (IκBα) proteins. Our in vitro data reveal excessive superoxide generation, apoptosis, and altered mitochondrial membrane potential in NRK-52E cells that were cultured in a high-glucose (HG) environment were subsided by BCA intervention. Meanwhile, the upregulated expressions of NLRP3 and its associated proteins, the pyroptosis-indicative protein gasdermin-D (GSDMD) in the kidneys, and HG-stimulated NRK-52E cells were significantly ameliorated by BCA treatment. Additionally, BCA blunted transforming growth factor (TGF)-β/Smad signaling and production of collagen I, collagen III, fibronectin, and alfa-smooth muscle actin (α-SMA) in diabetic kidneys. Our results indicate the plausible role of BCA in attenuating DN, presumably through modulation of the apoptotic cascade in renal tubular epithelial cells and the NF-κB/NLRP3 axis.

(-)‑Epigallocatechin‑3‑O‑gallate upregulates the expression levels of miR‑6757‑3p, a suppressor of fibrosis‑related gene expression, in extracellular vesicles derived from human umbilical vein endothelial cells

As pulmonary fibrosis (PF), a severe interstitial pulmonary disease, has such a poor prognosis, the development of prevention and treatment methods is imperative. (-)-Epigallocatechin-3-O-gallate (EGCG), one of the major catechins in green tea, exerts an antifibrotic effect, although its mechanism remains unclear. Recently, it has been reported that microRNAs (miRNAs or miRs) transported by extracellular vesicles (EVs) from vascular endothelial cells (VECs) are involved in PF. In the present study, the effects of EGCG on the expression of miRNAs in EVs derived from human umbilical vein endothelial cells (HUVECs) were assessed and miRNAs with antifibrotic activity were identified. miRNA microarray analysis revealed that EGCG modulated the expression levels of 31 miRNAs (a total of 27 miRNAs were upregulated, and 4 miRNAs were downregulated.) in EVs from HUVECs. Furthermore, TargetScan analysis indicated that miR-6757-3p in particular, which exhibited the highest degree of change, may target transforming growth factor-β (TGF-β) receptor 1 (TGFBR1). To evaluate the effects of miR-6757-3p on TGFBR1 expression, human fetal lung fibroblasts (HFL-1) were transfected with an miR-6757-3p mimic. The results demonstrated that the miR-6757-3p mimic downregulated the expression of TGFBR1 as well the expression levels of fibrosis-related genes including fibronectin and α-smooth muscle actin in TGF-β-treated HFL-1 cells. In summary, EGCG upregulated the expression levels of miR-6757-3p, which may target TGFBR1 and downregulate fibrosis-related genes, in EVs derived from VECs.

Noncoding RNAs: Master Regulator of Fibroblast to Myofibroblast Transition in Fibrosis

Myofibroblasts escape apoptosis and proliferate abnormally under pathological conditions, especially fibrosis; they synthesize and secrete a large amount of extracellular matrix (ECM), such as α-SMA and collagen, which leads to the distortion of organ parenchyma structure, an imbalance in collagen deposition and degradation, and the replacement of parenchymal cells by fibrous connective tissues. Fibroblast to myofibroblast transition (FMT) is considered to be the main source of myofibroblasts. Therefore, it is crucial to explore the influencing factors regulating the process of FMT for the prevention, treatment, and diagnosis of FMT-related diseases. In recent years, non-coding RNAs, including microRNA, long non-coding RNAs, and circular RNAs, have attracted extensive attention from scientists due to their powerful regulatory functions, and they have been found to play a vital role in regulating FMT. In this review, we summarized ncRNAs which regulate FMT during fibrosis and found that they mainly regulated signaling pathways, including TGF-β/Smad, MAPK/P38/ERK/JNK, PI3K/AKT, and WNT/β-catenin. Furthermore, the expression of downstream transcription factors can be promoted or inhibited, indicating that ncRNAs have the potential to be a new therapeutic target for FMT-related diseases.

Transforming growth factor-β signaling: From tissue fibrosis to therapeutic opportunities

Fibrosis refers to the excessive deposition of extracellular matrix components in the processes of wound repair or tissue regeneration after tissue damage. Fibrosis occurs in various organs such as lung, heart, liver, and kidney tissues, resulting in the failure of organ structural integrity and its functional impairment. It has long been thought to be relentlessly progressive and irreversible process, but both preclinical models and clinical trials in multiorgans have shown that fibrosis is a highly dynamic process. Transforming growth factor-beta (TGF-β) is a superfamily of related growth factors. Many studies have described that activation of profibrotic TGF-β signaling promotes infiltration and/or proliferation of preexisting fibroblasts, generation of myofibroblasts, extracellular matrix deposition, and inhibition of collagenolysis, which leads to fibrosis in the pathological milieu. This review describes the effect of TGF-β signaling in fibrotic-associate lung, heart, liver, and kidney tissues, followed by a detailed discussion of canonical and non-canonical TGF-β signaling pathway. In addition, this review also discusses therapeutic options by using natural products and chemical agents, for targeting tissue fibrosis via modulating TGF-β signaling to provide a more specific concept-driven therapy strategy for multiorgan fibrosis.

MicroRNA-10 Family Promotes the Epithelial-to-Mesenchymal Transition in Renal Fibrosis by the PTEN/Akt Pathway

Renal fibrosis (RF) is a common reason for renal failure, and epithelial-mesenchymal transition (EMT) is a vital mechanism that promotes the development of RF. It is known that microRNA-10 (miR-10) plays an important role in cancer EMT; however, whether it takes part in the EMT process of RF remains unclear. Therefore, we established an in vivo model of unilateral ureteral obstruction (UUO), and an in vitro model using TGF-β1, to investigate whether and how miR-10a and miR-10b take part in the EMT of RF. In addition, the combinatorial effects of miR-10a and miR-10b were assessed. We discovered that miR-10a and miR-10b are overexpressed in UUO mice, and miR-10a, miR-10b, and miRs-10a/10b knockout attenuated RF and EMT in UUO-treated mouse kidneys. Moreover, miR-10a and miR-10b overexpression combinatorially promoted RF and EMT in TGF-β1-treated HK-2 cells. Inhibiting miR-10a and miR-10b attenuated RF and EMT induced by TGF-β1. Mechanistically, miR-10a and miR-10b suppressed PTEN expression by binding to its mRNA3'-UTR and promoting the Akt pathway. Moreover, PTEN overexpression reduced miR-10a and miR-10b effects on Akt phosphorylation (p-Akt), RF, and EMT in HK-2 cells treated with TGF-β1. Taken together, miR-10a and miR-10b act combinatorially to negatively regulate PTEN, thereby activating the Akt pathway and promoting the EMT process, which exacerbates RF progression.