TGF-β1/Smads and miR-21 in Renal Fibrosis and Inflammation

Leucine-rich alpha-2-glycoprotein 1 deficiency suppresses ischemia-reperfusion injury-induced renal fibrosis

Ischemia reperfusion injury (IRI) is a major cause of acute kidney injury (AKI) and ultimately leads to renal fibrosis, primarily via the transforming growth factor-β (TGF-β) pathway. Leucine-rich alpha-2-glycoprotein 1 (LRG1), a novel modulator of the TGF-β pathway, has been implicated in the modulation of renal fibrosis by affecting the TGF-β/Smad3 signaling axis. However, the role of LRG1 in the transition from AKI to chronic kidney disease (CKD) remains unclear. This study aimed to investigate the functional role of LRG1 during the remodeling phase post-IRI. Unilateral IRI was induced in C57BL/6J wild-type (WT) mice and systemic LRG1 knockout (KO) mice. In C57BL/6J WT mice, renal LRG1 mRNA expression was significantly elevated on the ischemia/reperfusion side compared to the sham side over a 28-day period. In contrast, LRG1 KO mice demonstrated significantly reduced renal fibrosis compared to WT mice on postoperative day 28. Additionally, renal mRNA expression of TGF-β and associated pro-fibrotic genes was diminished in LRG1 KO mice compared to WT mice. Consequently, LRG1 KO mice exhibited attenuated IRI-induced chronic fibrosis. These findings indicate that LRG1 is involved in the pathogenesis of the transition from AKI to CKD and may be a potential therapeutic target.

Emerging technologies in regenerative medicine: The future of wound care and therapy

Wound healing, an intricate biological process, comprises orderly phases of simple biological processed including hemostasis, inflammation, angiogenesis, cell proliferation, and ECM remodeling. The regulation of the shift in these phases can be influenced by systemic or environmental conditions. Any untimely transitions between these phases can lead to chronic wounds and scarring, imposing a significant socio-economic burden on patients. Current treatment modalities are largely supportive in nature and primarily involve the prevention of infection and controlling inflammation. This often results in delayed healing and wound complications. Recent strides in regenerative medicine and tissue engineering offer innovative and patient-specific solutions. Mesenchymal stem cells (MSCs) and their secretome have gained specific prominence in this regard. Additionally, technologies like tissue nano-transfection enable in situ gene editing, a need-specific approach without the requirement of complex laboratory procedures. Innovating approaches like 3D bioprinting and ECM bioscaffolds also hold the potential to address wounds at the molecular and cellular levels. These regenerative approaches target common healing obstacles, such as hyper-inflammation thereby promoting self-recovery through crucial signaling pathway stimulation. The rationale of this review is to examine the benefits and limitations of both current and emerging technologies in wound care and to offer insights into potential advancements in the field. The shift towards such patient-centric therapies reflects a paradigmatic change in wound care strategies.

MiR-126 accelerates renal injury induced by UUO via inhibition PI3K/ IRS-1/ FAK signaling induced M2 polarization and endocytosis in macrophages

To investigate the role and molecular mechanism of miR-126 in unilateral ureteral occlusion (UUO). We used bioinformatics to analyse miRNAs specifically expressed in UUO. The mouse model of UUO was established using RAW264.7 cells cultured in vitro and in vivo. The mice were divided into control group, miR-126-NC (negative control) group and miR-126-KD (knockdown) group. Then the relative expression of miR-126 was detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), the renal fibrosis was detected by Masson staining, and the protein expression of CD68, collagen I and collagen III in the kidney was detected by immunofluorescence assay. Immunohistochemistry detects α-SMA expression. Moreover, Western blotting was performed to measure the expressions of p-PI3K, CD163, CD206, CD86, iNOS, IL-1β, p-FAK, p-Rac-1, p-IRS-1 and MMP9. The relative fluorescence intensity of F-actin and p-FAK was detected by immunofluorescence assay, and the phagocytosis ability of macrophages was determined by phagocytosis assay with fluorescent microspheres. Bioinformatics analysis reveals miR-126-specific overexpression in UUO. Successful transfection of miR-126-NC and miR-126-KD was confirmed by RT-PCR. The selective reduction of miR-126 was validated by Masson, immunohistochemistry and immunofluorescence staining to decrease the area of UUO-induced renal fibrosis and to lower the expression of CD68, α-SMA, collagen I, and collagen III. The reduction of iNOS expression may also be achieved with selective knockdown of miR-126, as verified by cell tests. enhances the phagocytic ability of macrophages and the expression of p-PI3K, CD206, p-FAK, F-actin, p-Rac-1, p-IRS-1 and MMP9. MiR-126 can inhibit the PI3K signaling pathway, promote M1 macrophage polarization, and suppress the activation of FAK and Rac-1, thus accelerating the progression of UUO.

Small non-coding RNAs and pancreatic ductal adenocarcinoma: Linking diagnosis, pathogenesis, drug resistance, and therapeutic potential

This review comprehensively investigates the intricate interplay between small non-coding RNAs (sncRNAs) and pancreatic ductal adenocarcinoma (PDAC), a devastating malignancy with limited therapeutic options. Our analysis reveals the pivotal roles of sncRNAs in various facets of PDAC biology, spanning diagnosis, pathogenesis, drug resistance, and therapeutic strategies. sncRNAs have emerged as promising biomarkers for PDAC, demonstrating distinct expression profiles in diseased tissues. sncRNA differential expression patterns, often detectable in bodily fluids, hold potential for early and minimally invasive diagnostic approaches. Furthermore, sncRNAs exhibit intricate involvement in PDAC pathogenesis, regulating critical cellular processes such as proliferation, apoptosis, and metastasis. Additionally, mechanistic insights into sncRNA-mediated pathogenic pathways illuminate novel therapeutic targets and interventions. A significant focus of this review is dedicated to unraveling sncRNA mechanisms underlying drug resistance in PDAC. Understanding these mechanisms at the molecular level is imperative for devising strategies to overcome drug resistance. Exploring the therapeutic landscape, we discuss the potential of sncRNAs as therapeutic agents themselves as their ability to modulate gene expression with high specificity renders them attractive candidates for targeted therapy. In summary, this review integrates current knowledge on sncRNAs in PDAC, offering a holistic perspective on their diagnostic, pathogenic, and therapeutic relevance. By elucidating the roles of sncRNAs in PDAC biology, this review provides valuable insights for the development of novel diagnostic tools and targeted therapeutic approaches, crucial for improving the prognosis of PDAC patients.

miR-21 attenuated inflammation targeting MyD88 in human chondrocytes stimulated with Hyaluronan oligosaccharides

Inflammation is the body's response to injuries, which depends on numerous regulatory factors. Among them, miRNAs have gained much attention for their role in regulating inflammatory gene expression at multiple levels. In particular, miR-21 is up-regulated during the inflammatory response and reported to be involved in the resolution of inflammation by down-regulating pro-inflammatory mediators, including MyD88. Herein, we evaluated the regulatory effects of miR-21 on the TLR-4/MyD88 pathway in an in vitro model of 6-mer HA oligosaccharides-induced inflammation in human chondrocytes. The exposition of chondrocytes to 6-mer HA induced the activation of the TLR4/MyD88 pathway, which culminates in NF-kB activation. Changes in miR-21, TLR-4, MyD88, NLRP3 inflammasome, IL-29, Caspase1, MMP-9, iNOS, and COX-2 mRNA expression of 6-mer HA-stimulated chondrocytes were examined by qRT-PCR. Protein amounts of TLR-4, MyD88, NLRP3 inflammasome, p-ERK1/2, p-AKT, IL-29, caspase1, MMP-9, p-NK-kB p65 subunit, and IKB-a have been evaluated by ELISA kits. NO and PGE2 levels have been assayed by colorimetric and ELISA kits, respectively. HA oligosaccharides induced a significant increase in the expression of the above parameters, including NF-kB activity. The use of a miR-21 mimic attenuated MyD88 expression levels and the downstream effectors. On the contrary, treatment with a miR-21 inhibitor induced opposite effects. Interestingly, the use of a MyD88 siRNA confirmed MyD88 as the target of miR-21 action. Our results suggest that miR-21 expression could increase in an attempt to reduce the inflammatory response, targeting MyD88.

Epigenetic Mechanisms in Sepsis-Associated Acute Kidney Injury

Sepsis, the dysregulated immune response of the host to infections, leads to numerous complications, including multiple organ dysfunction with sepsis-associated acute kidney injury (SA-AKI) being a frequent complication associated with increased risk of mortality and the progression toward chronic kidney disease (CKD). Several mechanisms have been widely investigated in understanding the complex pathophysiology of SA-AKI, including hemodynamic alterations, inflammation, oxidative stress, and direct cellular injury driven by pathogens or cell-derived products (pathogen-associated molecular patterns and damage-associated molecular patterns). Despite advancements in the management of septic patients, the prognosis of SA-AKI patients remains significantly poor and is associated with high in-hospital mortality and adverse long-term outcomes. Therefore, recent research has focused on the early identification of specific SA-AKI endotypes and subphenotypes through epigenetic analysis and the use of potential biomarkers, either alone or in combination with clinical data, to improve prognosis. Epigenetic regulation, such as DNA methylation, histone modifications, and noncoding RNA modulation, is crucial in modulating gene expression in response to stress and renal injury in SA-AKI. At the same time, these modifications are dynamic and reversible processes that can alter gene expression in several pathways implicated in the context of SA-AKI, including inflammation, immune response, and tolerance status. In addition, specific epigenetic modifications may exacerbate renal damage by causing persistent inflammation or cellular metabolic reprogramming, leading to progression toward CKD. This review aims to provide a comprehensive understanding of the epigenetic characteristics that define SA-AKI, also exploring targeted therapies that can improve patient outcomes and limit the chronic progression of this syndrome.

Membrane Receptor-Mediated Disruption of Cellular Homeostasis: Changes in Intracellular Signaling Pathways Increase the Toxicity of Ochratoxin A

Organisms maintain their cellular homeostatic balance by interacting with their environment through the use of their cell surface receptors. Membrane based receptors such as the transforming growth factor β receptor (TGFR), the prolactin receptor (PRLR), and hepatocyte growth factor receptor (HGFR), along with their associated signaling cascade, play significant roles in retaining cellular homeostasis. While these receptors and related signaling pathways are essential for health of cell and organism, their dysregulation can lead to imbalance in cell function with severe pathological conditions such as cell death or cancer. Ochratoxin A (OTA) can disrupt cellular homeostasis by altering expression levels of these receptors and/or receptor-associated intracellular downstream signaling modulators and/or pattern and levels of their phosphorylation/dephosphorylation. Recent studies have shown that the activity of the TGFR, the PRLR, and HGFR and their associated signaling cascades change upon OTA exposure. A critical evaluation of these findings suggests that while increased activity of the HGFR and TGFR signaling pathways leads to an increase in cell survival and fibrosis, decreased activity of the PRLR signaling pathway leads to tissue damage. This review explores the roles of these receptors in OTA-related pathologies and effects on cellular homeostasis.

Saponin monomers: Potential candidates for the treatment of type 2 diabetes mellitus and its complications

Type 2 diabetes mellitus (T2DM), a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR), has become one of the most serious health challenges of the 21st century, with considerable economic and societal implications worldwide. Considering the inevitable side effects of conventional antidiabetic drugs, natural ingredients exhibit promising therapeutic efficacy and can serve as safer and more cost-effective alternatives for the management of T2DM. Saponins are a structurally diverse class of amphiphilic compounds widely distributed in many popular herbal medicinal plants, some animals, and marine organisms. There are many saponin monomers, such as ginsenoside compound K, ginsenoside Rb1, ginsenoside Rg1, astragaloside IV, glycyrrhizin, and diosgenin, showing great efficacy in the treatment of T2DM and its complications in vivo and in vitro. However, although the mechanisms of action of saponin monomers at the animal and cell levels have been gradually elucidated, there is a lack of clinical data, which hinders the development of saponin-based antidiabetic drugs. Herein, the main factors/pathways associated with T2DM and the comprehensive underlying mechanisms and potential applications of these saponin monomers in the management of T2DM and its complications are reviewed and discussed, aiming to provide fundamental data for future high-quality clinical studies and trials.

Research Progress on Micro (Nano)Plastics Exposure-Induced miRNA-Mediated Biotoxicity

Micro- and nano-plastics (MNPs) are ubiquitously distributed in the environment, infiltrate organisms through multiple pathways, and accumulate, thus posing potential threats to human health. MNP exposure elicits changes in microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), thereby precipitating immune, neurological, and other toxic effects. The investigation of MNP exposure and its effect on miRNA expression has garnered increasing attention. Following MNP exposure, circRNAs serve as miRNA sponges by modulating gene expression, while lncRNAs function as competing endogenous RNAs (ceRNAs) by fine-tuning target gene expression and consequently impacting protein translation and physiological processes in cells. Dysregulated miRNA expression mediates mitochondrial dysfunction, inflammation, and oxidative stress, thereby increasing the risk of neurodegenerative diseases, cardiovascular diseases, and cancer. This tract, blood, urine, feces, placenta, and review delves into the biotoxicity arising from dysregulated miRNA expression due to MNP exposure and addresses the challenges encountered in this field. This study provides novel insights into the connections between MNPs and disease risk.

Osthole ameliorates early diabetic kidney damage by suppressing oxidative stress, inflammation and inhibiting TGF-β1/Smads signaling pathway

BACKGROUND

Osthole is a natural active ingredient extracted from the traditional Chinese medicine Cnidium monnieri. It has been demonstrated to have anti-inflammatory, anti-fibrotic, and anti-hyperglycemic properties. However, its effect on diabetic kidney disease (DKD) remains uncertain. This study aims to assess the preventive and therapeutic effects of osthole on DKD and investigate its underlying mechanisms.

METHODS

A streptozotocin/high-fat and high-sucrose diet induced Type 2 diabetic rat model was established. Metformin served as the positive drug control. Diabetic rats were treated with metformin or three different doses of osthole for 8 weeks. Throughout the treatment period, the progression of DKD was assessed by monitoring increases in urinary protein, serum creatinine, urea nitrogen, and uric acid, along with scrutinizing kidney pathology. Enzyme-linked immunosorbent assay (ELISA) was employed to detect inflammatory factors and oxidative stress levels. At the same time, immunohistochemical staining was utilized to evaluate changes in alpha-smooth muscle actin, fibronectin, E-cadherin, and apoptosis. The alterations in TGF-β1/Smads signaling pathway were ascertained through western blot and immunofluorescence. Furthermore, we constructed a high glucose-stimulated HBZY-1 cells model to uncover its molecular protective mechanism.

RESULTS

Osthole significantly reduced fasting blood glucose, insulin resistance, serum creatinine, uric acid, blood urea nitrogen, urinary protein excretion, and glomerular mesangial matrix deposition in diabetic rats. Additionally, significant improvements were observed in inflammation, oxidative stress, apoptosis, and fibrosis levels. The increase of ROS, apoptosis and hypertrophy in HBZY-1 cells induced by high glucose was reduced by osthole. Immunofluorescence and western blot results demonstrated that osthole down-regulated the TGF-β1/Smads signaling pathway and related protein expression.

CONCLUSION

Our findings indicate that osthole exhibits potential preventive and therapeutic effects on DKD. It deserves further investigation as a promising drug for preventing and treating DKD.

MiR-150-5p Alleviates Renal Tubule Epithelial Cell Fibrosis via the Inhibition of Epithelial-Mesenchymal Transition by Targeting ZEB1

INTRODUCTION

Although microRNA (miR)-150-5p participates in the progression of renal fibrosis, its mechanism of action remains elusive.

METHODS

A mouse model of unilateral ureteral obstruction was used. The in vitro renal fibrosis model was established by stimulating human kidney 2 (HK-2) cells with transforming growth factor beta 1 (TGF-β1). The expression profiles of miR-150-5p, zinc finger E-box binding homeobox 1 (ZEB1), and other fibrosis- and epithelial-mesenchymal transition (EMT)-linked proteins were determined using Western blot and quantitative reverse transcription polymerase chain reaction. The relationship between miR-150-5p and ZEB1 in HK-2 cells was confirmed by a dual-luciferase reporter assay.

RESULTS

Both in vivo and in vitro renal fibrosis models revealed reduced miR-150-5p expression and elevated ZEB1 level. A significant decrease in E-cadherin levels, as well as increases in alpha smooth muscle actin (α-SMA) and collagen type I (Col-I) levels, was seen in TGF-β1-treated HK-2 cells. The overexpression of miR-150-5p ameliorated TGF-β1-mediated fibrosis and EMT. Notably, miR-150-5p acts by directly targeting ZEB1. A significant reversal of the inhibitory impact of miR-150-5p on TGF-β1-mediated fibrosis and EMT in HK-2 cells was observed upon ZEB1 overexpression.

CONCLUSION

MiR-150-5p suppresses TGF-β1-induced fibrosis and EMT by targeting ZEB1 in HK-2 cells, providing helpful insights into the therapeutic intervention of renal fibrosis.

Sirtuins in kidney health and disease

Sirtuins (SIRTs) are putative regulators of lifespan in model organisms. Since the initial discovery that SIRTs could promote longevity in nematodes and flies, the identification of additional properties of these proteins has led to understanding of their roles as exquisite sensors that link metabolic activity to oxidative states. SIRTs have major roles in biological processes that are important in kidney development and physiological functions, including mitochondrial metabolism, oxidative stress, autophagy, DNA repair and inflammation. Furthermore, altered SIRT activity has been implicated in the pathophysiology and progression of acute and chronic kidney diseases, including acute kidney injury, diabetic kidney disease, chronic kidney disease, polycystic kidney disease, autoimmune diseases and renal ageing. The renoprotective roles of SIRTs in these diseases make them attractive therapeutic targets. A number of SIRT-activating compounds have shown beneficial effects in kidney disease models; however, further research is needed to identify novel SIRT-targeting strategies with the potential to treat and/or prevent the progression of kidney diseases and increase the average human healthspan.

Transcoronary Gradients of Mechanosensitive MicroRNAs as Predictors of Collateral Development in Chronic Total Occlusion

Background and Objectives: In this present study, we investigated the impact of mechanosensitive microRNAs (mechano-miRs) on the collateral development in 126 chronic total occlusion (CTO) patients, selected from 810 undergoing angiography. Materials and Methods: We quantified the collateral blood supply using the collateral flow index (CFI) and assessed the transcoronary mechano-miR gradients. Results: The patients with favorable collaterals had higher CFI values (0.45 ± 0.02) than those with poor collaterals (0.38 ± 0.03, p < 0.001). Significant differences in transcoronary gradients were found for miR-10a, miR-19a, miR-21, miR-23b, miR-26a, miR-92a, miR-126, miR-130a, miR-663, and let7d (p < 0.05). miR-26a and miR-21 showed strong positive correlations with the CFI (r = 0.715 and r = 0.663, respectively), while let7d and miR-663 were negatively correlated (r = -0.684 and r = -0.604, respectively). The correlations between cytokine gradients and mechano-miR gradients were also significant, including Transforming Growth Factor Beta with miR-126 (r = 0.673, p < 0.001) and Vascular Endothelial Growth Factor with miR-10a (r = 0.602, p = 0.002). A regression analysis highlighted the hemoglobin level, smoking, beta-blocker use, miR-26a, and miR-663 as significant CFI determinants, indicating their roles in modulating the collateral vessel development. Conclusions: These findings suggest mechanosensitive microRNAs as predictive biomarkers for collateral circulation, offering new therapeutic perspectives for CTO patients.

Wistar rat as an animal model to study high-fat induced kidney damage: a systematic review

The effects of high-fat-associated kidney damage in humans are not completely elucidated. Animal experiments are essential to understanding the mechanisms underlying human diseases. This systematic review aimed to compile evidence of the role of a high-fat diet during the development of renal lipotoxicity and fibrosis of Wistar rats to understand whether this is a satisfactory model for the study of high fat-induced kidney damage. We conducted systematic searches in PUBMED, EMBASE, Lilacs, and Web of Science databases from inception until May 2021. The risk of bias was assessed using SYRCLE toll. Two reviewers independently screened abstracts and reviewed full-text articles. A total of 11 studies were included. The damage varied depending on the age and sex of the animals, time of protocol, and amount of fat in the diet. In conclusion, the Wistar rat is an adequate animal model to assess the effects of a high-fat diet on the kidneys.HighlightsA high-fat diet may promote kidney damage in Wistar rats.Wistar rat is efficient as an animal model to study high-fat-induced kidney damage.The effect of the diet depends on the fat amount, consumption time, and animal age.

Remimazolam attenuates inflammation and kidney fibrosis following folic acid injury

The transition of acute kidney injury (AKI) to chronic kidney disease (CKD) is characterized by intense inflammation and progressive fibrosis. Remimazolam is widely used for procedural sedation in intensive care units, such as AKI patients. Remimazolam has been shown to possess anti-inflammatory and organ-protective properties. However, the role of remimazolam in inflammation and renal fibrosis following AKI remains unclear. Here, we explored the effects of remimazolam on the inflammatory response and kidney fibrogenesis of mice subjected to folic acid (FA) injury. Our results showed that remimazolam treatment alleviated kidney damage and dysfunction. Mice treated with remimazolam presented less collagen deposition in FA-injured kidneys compared with FA controls, which was accompanied by a reduction of extracellular matrix proteins accumulation and fibroblasts activation. Furthermore, remimazolam treatment reduced inflammatory cells infiltration into the kidneys of mice with FA injury and inhibited proinflammatory or profibrotic molecules expression. Finally, remimazolam treatment impaired the activation of bone marrow-derived fibroblasts and blunted the transformation of macrophages to myofibroblasts in FA nephropathy. Additionally, the benzodiazepine receptor antagonist PK-11195 partially reversed the protective effect of remimazolam on the FA-injured kidneys. Overall, remimazolam attenuates the inflammatory response and renal fibrosis development following FA-induced AKI, which may be related to the peripheral benzodiazepine receptor pathway.

2-Dodecyl-6-Methoxycyclohexa-2, 5-Diene-1, 4-Dione isolated from Averrhoa carambola L. root inhibits high glucose-induced EMT in HK-2 cells through targeting the regulation of miR-21-5p/Smad7 signaling pathway

OBJECTIVE

2-Dodecyl-6-Methoxycyclohexa-2, 5-Diene-1, 4-Dione (DMDD) isolated from Averrhoa carambola L. root, has been proven therapeutic effects on diabetic kidney disease (DKD). This research aims to assess DMDD's effects on DKD and to investigate its underlying mechanisms, to establish DMDD as a novel pharmaceutical agent for DKD treatment.

METHODS

The human renal tubular epithelial (HK-2) cells were induced by high glucose (HG) to mimic DKD and followed by DMDD treatment. The cytotoxicity of DMDD was assessed using the Cell Counting Kit-8 (CCK-8) assay. The migratory capacity of HK-2 cells was evaluated through transwell and scratch-wound assays. To investigate the effect of Smad7 and miR-21-5p, lentiviral transfection was employed in HK-2 cells. Additionally, the expression of proteins related to epithelial-mesenchymal transition (EMT) and TGFβ1/Smad2/3 pathway was checked by QRT-PCR, Western blot, and immunofluorescence techniques.

RESULTS

This study has shown that DMDD significantly suppresses cell migration and the expression of Vimentin, α-SMA, TGFβ1, and p-Smad2/3 in HK-2 cells under HG conditions. Concurrently, DMDD enhances the protein expression of E-cadherin and Smad7. Intriguingly, the therapeutic effect of DMDD was abrogated upon Smad7 silencing. Further investigations revealed that DMDD effectively inhibits miR-21-5p expression, which is upregulated by HG. Downregulation of miR-21-5p inhibits the activation of the TGFβ1/Smad2/3 pathway and EMT induced by HG. In contrast, overexpression of miR-21-5p negates DMDD's therapeutic benefits.

CONCLUSION

DMDD mitigates EMT in HG-induced HK-2 cells by modulating the miR-21-5p/Smad7 pathway, thereby inhibiting renal fibrosis in DKD. These findings suggest that DMDD holds promise as a potential therapeutic agent for DKD.

The role of matrix metalloproteinase 9 in fibrosis diseases and its molecular mechanisms

Fibrosis is a process of tissue repair that results in the slow creation of scar tissue to replace healthy tissue and can affect any tissue or organ. Its primary feature is the massive deposition of extracellular matrix (mainly collagen), eventually leading to tissue dysfunction and organ failure. The progression of fibrotic diseases has put a significant strain on global health and the economy, and as a result, there is an urgent need to find some new therapies. Previous studies have identified that inflammation, oxidative stress, some cytokines, and remodeling play a crucial role in fibrotic diseases and are essential avenues for treating fibrotic diseases. Among them, matrix metalloproteinases (MMPs) are considered the main targets for the treatment of fibrotic diseases since they are the primary driver involved in ECM degradation, and tissue inhibitors of metalloproteinases (TIMPs) are natural endogenous inhibitors of MMPs. Through previous studies, we found that MMP-9 is an essential target for treating fibrotic diseases. However, it is worth noting that MMP-9 plays a bidirectional regulatory role in different fibrotic diseases or different stages of the same fibrotic disease. Previously identified MMP-9 inhibitors, such as pirfenidone and nintedanib, suffer from some rather pronounced side effects, and therefore, there is an urgent need to investigate new drugs. In this review, we explore the mechanism of action and signaling pathways of MMP-9 in different tissues and organs, hoping to provide some ideas for developing safer and more effective biologics.

Study on effects and relevant mechanisms of Mudan granules on renal fibrosis in streptozotocin-induced diabetes rats

AIMS

The effects and relevant mechanisms of Mudan granules in the renal fibrosis of diabetic rats were explored through in vivo experiments, which provided a scientific basis for expanding their clinical indications.

METHODS

Male SD rats were given a single intraperitoneal injection of STZ (65 mg/kg) to induce diabetes rat models. After treatment with Mudan granules, the general condition of rats was recorded. Blood glucose, blood lipids, and renal function-related indicators were detected, renal tissue morphological changes and fibrosis-related indicators were observed, and the expression of pathway-related proteins were examined.

RESULTS

The general condition of diabetes rats was improved after the treatment of Mudan granules, the 24-h urinary protein and urinary albumin to creatinine ratio were reduced, and the renal function and lipid results were modified. The tissue damage to the rat kidney has been repaired. Expression of TGF-β1/Smad-related pathway proteins was suppressed in kidney tissues, and the fibrosis factor CO-IV, FN, and LN were reduced in serum.

CONCLUSION

Mudan granules may inhibit of TGF-β1/Smad pathway, inhibit the production of ECM, reduce the levels of fibrosis factors CO-IV, FN, and LN, to have a protective effect on kidney in diabetes rats.

Mitochondrial Signaling, the Mechanisms of AKI-to-CKD Transition and Potential Treatment Targets

Acute kidney injury (AKI) is increasing in prevalence and causes a global health burden. AKI is associated with significant mortality and can subsequently develop into chronic kidney disease (CKD). The kidney is one of the most energy-demanding organs in the human body and has a role in active solute transport, maintenance of electrochemical gradients, and regulation of fluid balance. Renal proximal tubular cells (PTCs) are the primary segment to reabsorb and secrete various solutes and take part in AKI initiation. Mitochondria, which are enriched in PTCs, are the main source of adenosine triphosphate (ATP) in cells as generated through oxidative phosphorylation. Mitochondrial dysfunction may result in reactive oxygen species (ROS) production, impaired biogenesis, oxidative stress multiplication, and ultimately leading to cell death. Even though mitochondrial damage and malfunction have been observed in both human kidney disease and animal models of AKI and CKD, the mechanism of mitochondrial signaling in PTC for AKI-to-CKD transition remains unknown. We review the recent findings of the development of AKI-to-CKD transition with a focus on mitochondrial disorders in PTCs. We propose that mitochondrial signaling is a key mechanism of the progression of AKI to CKD and potential targeting for treatment.

Expression of miR-21 &IL-4 in endometriosis

BACKGROUND

Endometriosis characterized with existence of endometrial-like tissue outside the uterus. Fibrosis of ectopic lesions is an important feature of endometriosis. IL-4 induces fibrosis via fibroblast proliferation, collagen production and myofibroblast differentiation. Increasing of miR-21 expression promotes fibroblast activation and fibrosis expansion. The aim of study was to evaluate the expression of miR-21 and its relationship with IL-4 gene expression in endometrial ectopic and eutopic tissues of endometriosis patients.

METHODS AND RESULTS

Ectopic and eutopic tissue samples were taken from 20 women with endometriosis, and control samples were taken from the endometrium of 20 endometriosis-free women. The relative expression of IL-4 and miR-21 evaluated by Real Time PCR. IL-4 relative gene expression was significantly increased in ectopic tissue compared to eutopic (p = 0.025) and control tissue (p = 0.021). The relative expression of miR-21 gene in ectopic tissue was increased compared to eutopic (p = 0.850) and control tissue (p = 0.978) but these differences were not significant. Also, the correlation between IL-4 and miR-21 relative gene expression was not significant (p = 0.083).

CONCLUSION

The increased expression of miR-21 in endometrium of women with endometriosis may upregulate the IL-4 gene expression and lead to fibrosis. Further studies may suggest miR-21 and IL-4 as candidates for diagnosis of endometriosis.

Prolonged Antibiotic Use in a Preclinical Model of Gulf War Chronic Multisymptom-Illness Causes Renal Fibrosis-like Pathology via Increased micro-RNA 21-Induced PTEN Inhibition That Is Correlated with Low Host Lachnospiraceae Abundance

Gulf War (GW) veterans show gastrointestinal disturbances and gut dysbiosis. Prolonged antibiotic treatments commonly employed in veterans, especially the use of fluoroquinolones and aminoglycosides, have also been associated with dysbiosis. This study investigates the effect of prolonged antibiotic exposure on risks of adverse renal pathology and its association with gut bacterial species abundance in underlying GWI and aims to uncover the molecular mechanisms leading to possible renal dysfunction with aging. Using a GWI mouse model, administration of a prolonged antibiotic regimen involving neomycin and enrofloxacin treatment for 5 months showed an exacerbated renal inflammation with increased NF-κB activation and pro-inflammatory cytokines levels. Involvement of the high mobility group 1 (HMGB1)-mediated receptor for advanced glycation end products (RAGE) activation triggered an inflammatory phenotype and increased transforming growth factor-β (TGF-β) production. Mechanistically, TGF-β- induced microRNA-21 upregulation in the renal tissue leads to decreased phosphatase and tensin homolog (PTEN) expression. The above event led to the activation of protein kinase-B (AKT) signaling, resulting in increased fibronectin production and fibrosis-like pathology. Importantly, the increased miR-21 was associated with low levels of Lachnospiraceae in the host gut which is also a key to heightened HMGB1-mediated inflammation. Overall, though correlative, the study highlights the complex interplay between GWI, host gut dysbiosis, prolonged antibiotics usage, and renal pathology via miR-21/PTEN/AKT signaling.

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

MicroRNA-122-5p alleviates endometrial fibrosis via inhibiting the TGF-β/SMAD pathway in Asherman's syndrome

RESEARCH QUESTION

What is the effect of miR-122 on the progression and recovery of fibrosis in Asherman's syndrome?

DESIGN

Endometrial tissue was collected from 21 patients, 11 with intrauterine adhesion (IUA) and 10 without IUA. Quantitative real-time polymerase chain reaction, immunofluorescence and Western blot were applied to observe the expression of mRNAs/miRNAs and protein, respectively. The endometrial physical injury was carried out in C57BL/6 mice to create an endometrial fibrosis model, with intrauterine injection of adenovirus to compare the antifibrosis and repair function of miR-122 on endometrium. The morphology of the uterus was observed using haematoxylin and eosin staining, and fibrosis markers were detected by immunohistochemistry.

RESULTS

miR-122 expression was reduced in patients with IUAs, accompanied by fibrosis. MiR-122 overexpression reduced the degree of fibrosis in endometrial stromal cells. Further molecular analyses demonstrated that miR-122 inhibited fibrosis through the TGF-β/SMAD pathway by directly targeting the 3' untranslated region of SMAD family member 3, suppressing its expression. Notably, miR-122 promoted endometrial regeneration and recovery of pregnancy capacity in a mouse endometrial injury model.

CONCLUSIONS

miR-122 is a critical regulator for repair of endometrial fibrosis and provided new insight for the clinical treatment of intrauterine adhesions.

A single administration of FGF2 after renal ischemia-reperfusion injury alleviates post-injury interstitial fibrosis

BACKGROUND

Despite lack of clinical therapy in acute kidney injury (AKI) or its progression to chronic kidney disease (CKD), administration of growth factors shows great potential in the treatment of renal repair and further fibrosis. At an early phase of AKI, administration of exogenous fibroblast growth factor 2 (FGF2) protects against renal injury by inhibition of mitochondrial damage and inflammatory response. Here, we investigated whether this treatment attenuates the long-term renal interstitial fibrosis induced by ischemia-reperfusion (I/R) injury.

METHODS

Unilateral renal I/R with contralateral nephrectomy was utilized as an in vivo model for AKI and subsequent CKD. Rats were randomly divided into four groups: Sham-operation group, I/R group, I/R-FGF2 group and FGF2-3D group. These groups were monitored for up to 2 months. Serum creatinine, inflammatory response and renal histopathology changes were detected to evaluate the role of FGF2 in AKI and followed renal interstitial fibrosis. Moreover, the expression of vimentin, α-SMA, CD31 and CD34 were examined.

RESULTS

Two months after I/R injury, the severity of renal interstitial fibrosis was significantly attenuated in both of I/R-FGF2 group and FGF2-3D group, compared with the I/R group. The protective effects of FGF2 administration were associated with the reduction of high-mobility group box 1 (HMGB1)-mediated inflammatory response, the inhibition of transforming growth factor beta (TGF-β1)/Smads signaling-induced epithelial-mesenchymal transition and the maintenance of peritubular capillary structure.

CONCLUSIONS

A single dose of exogenous FGF2 administration 1 h or 3 days after reperfusion inhibited renal fibrogenesis and thus blocked the transition of AKI to CKD. Our findings provided novel insight into the role of FGF signaling in AKI-to-CKD progression and underscored the potential of FGF-based therapy for this devastating disease.

Effect of X-ray irradiation combined with PD-1 inhibitor treatment on lung tissue injury in mice

PURPOSE

To determine the effect of X-ray irradiation combined with PD-1 immune checkpoint inhibitor administration on lung tissue injury in a mouse model and its potential mechanism.

METHODS

In all, 20 C57BL/6J mice were randomly divided into four groups with five mice in each group: control group, PD-1 inhibitor group, irradiation group, and irradiation combined with PD-1 inhibitor group. Hematoxylin-eosin staining of the lung tissue was performed 30 days after the end of irradiation to evaluate the morphological and pathological changes in the tissue. Masson staining and analysis of hydroxyproline were used to evaluate the degree of pulmonary fibrosis. The levels of transforming growth factor-β1 (TGF-β1) and tumor necrosis factor α(TNF-α) were evaluated by Enzyme-Linked immunosorbent assay (ELISA). CD3+, CD4+, and CD8+ T lymphocytes in the lung tissue were detected by immunohistochemistry. The expression levels of TGF-β1, Smad3, cGAS, and STING in the lung tissue were evaluated by Western blotting.

RESULTS

The lung injury scores and pulmonary fibrosis indices in the irradiation group were higher than those in the control group. Meanwhile, lung pneumonia score, pulmonary fibrosis index, percentage of CD4 cells and expression of TGF-β1, p-Smad3, and STING in the lung tissue of mice in irradiation combined with PD-1 inhibitor group were higher than those in the other three groups.

CONCLUSION

Lung injury and pulmonary fibrosis were induced by whole chest X-ray irradiation in mice, and PD-1 inhibitor could aggravate lung injury and pulmonary fibrosis in mice. Thus, radiotherapy combined with PD-1 inhibitors may affect the immune inflammatory microenvironment in the lung tissues of mice by activating TGF-β1/Samd3 and cGAS/STING signaling pathways, thus aggravating lung tissue damage induced by radiation.

Inhibition of PRMT1 alleviates sepsis-induced acute kidney injury in mice by blocking the TGF-β1 and IL-6 trans-signaling pathways

Sepsis-induced acute kidney injury (SI-AKI) causes renal dysfunction and has a high mortality rate. Protein arginine methyltransferase-1 (PRMT1) is a key regulator of renal insufficiency. In the present study, we explored the potential involvement of PRMT1 in SI-AKI. A murine model of SI-AKI was induced by cecal ligation and perforation. The expression and localization of PRMT1 and molecules involved in the transforming growth factor (TGF)-β1/Smad3 and interleukin (IL)-6/signal transducer and activator of transcription 3 (STAT3) signaling pathways were detected in mouse kidney tissues by western blot analysis, immunofluorescence, and immunohistochemistry. The association of PRMT1 with downstream molecules of the TGF-β1/Smad3 and IL-6/STAT3 signaling pathways was further verified in vitro in mouse renal tubular epithelial cells. Cecal ligation and perforation caused epithelial-mesenchymal transition, apoptosis, and inflammation in renal tissues, and this was alleviated by inhibition of PRMT1. Inhibition of PRMT1 in SI-AKI mice decreased the expression of TGF-β1 and phosphorylation of Smad3 in the renal cortex, and downregulated the expression of soluble IL-6R and phosphorylation of STAT3 in the medulla. Knockdown of PRMT1 in mouse renal tubular epithelial cells restricted the expression of Cox-2, E-cadherin, Pro-caspase3, and phosphorylated Smad3 (involved in the TGF-β1-mediated signaling pathway), and also blocked IL-6/soluble IL-6R, inducing the expression of Cox-2 and phosphorylated-STAT3. In conclusion, our findings suggest that inhibition of PRMT1 mitigates SI-AKI by inactivating the TGF-β1/Smad3 pathway in the cortex and the IL-6/STAT3 pathway in the medulla. Our findings may aid in the identification of potential therapeutic target molecules for SI-AKI.

Exosomes from human adipose-derived mesenchymal stem cells attenuate localized scleroderma fibrosis by the let-7a-5p/TGF-βR1/Smad axis

BACKGROUND

Inflammation and fibrosis of the skin are characteristics of localized scleroderma (LS). Emerging evidence has demonstrated that exosomes from human adipose tissue-derived mesenchymal stem cells (ADSC-Exo) could alleviate skin fibrosis.

OBJECTIVE

The impact and potential mechanism of ADSC-Exo on LS fibrosis was examined.

METHODS

ADSC-Exo was isolated and identified. The effects of ADSC-Exo on the abilities of proliferation and migration of LS-derived fibroblasts (LSFs) were assessed by CCK-8 and scratch assays, respectively. qRT-PCR, western blot, and immunofluorescence were conducted to detect LSFs stimulated with ADSC-Exo, ADSC-ExoAnti-let-7a-5p, let-7a-5p mimic/TGF-βR1 shRNA virus, and negative controls. The impact of ADSC-Exo on C57BL/6j LS mice was evaluated by photographic morphology, hematoxylin-eosin (H&E), Masson's trichrome, and immunohistochemical staining.

RESULTS

The verified ADSC-Exo limited the proliferation and migration of LSFs and reduced the expression of COL1, COL3, α-SMA, TGF-βR1, and p-Smad2/ 3 in vitro and in vivo. TGF-βR1 knockdown and let-7a-5p mimic in LSFs reduced the expression of COL1, COL3, α-SMA, and p-Smad2/3. However, compared with the ADSC-ExoNC group, the dermal thickness was increased, collagen arrangement was disordered, and α-SMA and TGF-βR1 levels were increased after exposure to ADSC-ExoAnti-let-7a-5p.

CONCLUSIONS

In this study, it might show that ADSC-Exo may successfully prevent LSF bioactivity, collagen deposition, and myofibroblast trans-differentiation. Additionally, we confirmed that let-7a-5p in ADSC-Exo could directly target TGF-R1 to control the Smad pathway and reduce fibrosis in LSFs. Our work offered a brand-new therapeutic approach and clarified the unique mechanism for the clinical management of LS.

Acute Kidney Injury in Kidney Transplant Patients in Intensive Care Unit: From Pathogenesis to Clinical Management

Kidney transplantation is the first-choice treatment for end-stage renal disease (ESRD). Kidney transplant recipients (KTRs) are at higher risk of experiencing a life-threatening event requiring intensive care unit (ICU) admission, mainly in the late post-transplant period (more than 6 months after transplantation). Urosepsis and bloodstream infections account for almost half of ICU admissions in this population; in addition, potential side effects related to immunosuppressive treatment should be accounted for cytotoxic and ischemic changes induced by calcineurin inhibitor (CNI), sirolimus/CNI-induced thrombotic microangiopathy and posterior reversible encephalopathy syndrome. Throughout the ICU stay, Acute Kidney Injury (AKI) incidence is common and ranges from 10% to 80%, and up to 40% will require renal replacement therapy. In-hospital mortality can reach 30% and correlates with acute illness severity and admission diagnosis. Graft survival is subordinated to baseline estimated glomerular filtration rate (eGFR), clinical presentation, disease severity and potential drug nephrotoxicity. The present review aims to define the impact of AKI events on short- and long-term outcomes in KTRs, focusing on the epidemiologic data regarding AKI incidence in this subpopulation; the pathophysiological mechanisms underlying AKI development and potential AKI biomarkers in kidney transplantation, graft and patients' outcomes; the current diagnostic work up and management of AKI; and the modulation of immunosuppression in ICU-admitted KTRs.

Piperlonguminine attenuates renal fibrosis by inhibiting TRPC6

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang (LWDH) is a classic prescription that has been used to the treatment of "Kidney-Yin" deficiency syndrome for more than 1000 years in China. Recent studies have confirmed that LWDH can prevent the progression of renal fibrosis. Numerous studies have demonstrated the critical role that TRPC6 plays in the development of renal fibrosis. Due to the complex composition of LWDH and its remarkable therapeutic effect on renal fibrosis, it is possible to discover new active ingredients targeting TRPC6 for the treatment of renal fibrosis.

AIM OF STUDY

This study aimed to identify selective TRPC6 inhibitors from LWDH and evaluate their therapeutical effects on renal fibrosis.

MATERIALS AND METHODS

Computer-aided drug design was used to screen the biologically active ingredients of LWDH, and their affinities to human TRPC6 protein were detected by microcalorimetry. TRPC6, TRPC3, and TRPC7 over-expressed HEK293 cells were constructed, and the selective activities of the compounds on TRPC6 were determined by measuring [Ca²⁺]_i in these cells. To establish an in vitro model of renal fibrosis, human renal proximal tubular epithelial HK-2 cells were stimulated with TGF-β1. The therapeutic effects of LWDH compounds on renal fibrosis were then tested by detecting the related proteins. TRPC6 was knocked-down in HK-2 cells to investigate the effects of LWDH active ingredients on TRPC6. Finally, a unilateral ureteral obstruction model of renal fibrosis was established to test the therapeutic effect.

RESULTS

From hundreds of LWDH ingredients, 64 active components with oral bioavailability ≥30% and drug-likeness index ≥0.18 were acquired. A total of 10 active components were obtained by molecular docking with TRPC6 protein. Among them, 4 components had an affinity with TRPC6. Piperlonguminine (PLG) had the most potent affinity with TRPC6 and blocking effect on TRPC6-mediated Ca²⁺ entry. A 100 μM of PLG showed no detectable inhibition on TRPC1, TRPC3, TRPC4, TRPC5, or TRPC7-mediated Ca²⁺ influx into cells. In vitro results indicated that PLG concentration-dependently inhibited the abnormally high expression of α-smooth muscle actin (α-SMA), collagen I, vimentin, and TRPC6 in TGF-β1-induced HK-2 cells. Consistently, PLG also could not further inhibit TGF-β1-induced expressions of these protein biomarkers in TRPC6 knocked-down HK-2 cells. In vivo, PLG dose-dependently reduced urinary protein, serum creatinine, and blood urea nitrogen levels in renal fibrosis mice and markedly alleviated fibrosis and the expressions of α-SMA, collagen I, vimentin, and TRPC6 in kidney tissues.

CONCLUSION

Our results showed that PLG had anti-renal fibrosis effects by selectively inhibiting TRPC6. PLG might be a promising therapeutic agent for the treatment of renal fibrosis.

SMAD4 Expression in Monocytes as a Potential Biomarker for Atherosclerosis Risk in Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) patients are at special risk of suffering atherosclerosis, leading to major cardiovascular diseases. Notably, the transforming growth factor (TGF-β) plays a crucial role in the development and progression of atherosclerosis. In this context, the central regulator of TGF-β pathway, SMAD4 (small mother against decapentaplegic homolog 4), has been previously reported to be augmented in OSA patients, which levels were even higher in patients with concomitant cardiometabolic diseases. Here, we analyzed soluble and intracellular SMAD4 levels in plasma and monocytes from OSA patients and non-apneic subjects, with or without early subclinical atherosclerosis (eSA). In addition, we used in vitro and ex vivo models to explore the mechanisms underlying SMAD4 upregulation and release. Our study confirmed elevated sSMAD4 levels in OSA patients and identified that its levels were even higher in those OSA patients with eSA. Moreover, we demonstrated that SMAD4 is overexpressed in OSA monocytes and that intermittent hypoxia contributes to SMAD4 upregulation and release in a process mediated by NLRP3. In conclusion, this study highlights the potential role of sSMAD4 as a biomarker for atherosclerosis risk in OSA patients and provides new insights into the mechanisms underlying its upregulation and release to the extracellular space.

Liquid Biopsies Poorly miRror Renal Ischemia-Reperfusion Injury

Acute kidney injury (AKI) is the rapid reduction in renal function. It is often difficult to detect at an early stage. Biofluid microRNAs (miRs) have been proposed as novel biomarkers due to their regulatory role in renal pathophysiology. The goal of this study was to determine the overlap in AKI miRNA profiles in the renal cortex, urine, and plasma samples collected from a rat model of ischemia-reperfusion (IR)-induced AKI. Bilateral renal ischemia was induced by clamping the renal pedicles for 30 min, followed by reperfusion. Urine was then collected over 24 h, followed by terminal blood and tissue collection for small RNA profiling. Differentially expressed (IR vs. sham) miRs within the urine and renal cortex sample types demonstrated a strong correlation in normalized abundance regardless of injury (IR and sham: R2 = 0.8710 and 0.9716, respectively). Relatively few miRs were differentially expressed in multiple samples. Further, there were no differentially expressed miRs with clinically relevant sequence conservation common between renal cortex and urine samples. This project highlights the need for a comprehensive analysis of potential miR biomarkers, including analysis of pathological tissues and biofluids, with the goal of identifying the cellular origin of altered miRs. Analysis at earlier timepoints is needed to further evaluate clinical potential.

Diminazene aceturate exacerbates renal fibrosis after unilateral ureteral obstruction in female mice

Background: Diminazene aceturate (DIZE), an angiotensin-converting enzyme 2 (ACE2) activator, exerts anti-inflammatory and antifibrotic effects in a variety of human chronic diseases. However, the role of DIZE in kidney fibrosis and the underlying mechanism remain unclear. Therefore, we investigated the effects of DIZE on the progression of renal fibrosis after unilateral ureteral obstruction (UUO), a well-established model of chronic kidney disease. Methods: C57BL/6 female or male mice were subjected to right UUO. Mice received 15 mg/kg DIZE or vehicle (saline) daily. On the 7th day after UUO, kidneys were collected for analysis of renal fibrosis (α-smooth muscle actin, phosphorylated SMAD3, transforming growth factor (TGF)-β, Masson’s trichrome, and Sirius red staining), inflammation (macrophage infiltration, proinflammatory cytokines/chemokines), apoptosis/necrotic cell death (TUNEL and periodic acid-Schiff staining), and ACE2 activity and messenger RNA (mRNA) expression.Results: Treatment with DIZE exacerbated renal fibrosis by upregulating the profibrotic TGF-β/SMAD3 pathway, proinflammatory cytokine/chemokines (interleukin [IL]-1β, monocyte chemoattractant protein-1, IL-6, and macrophage inflammatory protein-2) levels, M2 macrophage accumulation (CD206, IL-4, IL-10, and CX3CL1), and apoptotic/necrotic cell death in the obstructed kidneys of female mice but not male mice. However, DIZE treatment had no effect on ACE2 activity or mRNA expression.Conclusion: DIZE exacerbates UUO-induced renal fibrosis by aggravating tubular damage, apoptosis, and inflammation through independent of Ang (1–7), Ang 2 levels, and ACE2 expression/activity, rather than protecting against renal fibrosis after UUO. DIZE also has powerful effects on recruiting macrophages, including the M2-polarized subtype, in female UUO mice.

The Role of Histone Modifications in the Pathogenesis of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease. The pathogenesis of DKD is multifactorial, with several molecular pathways implicated. Recent data suggest that histone modification plays an important role in the development and progression of DKD. Histone modification appears to induce oxidative stress, inflammation and fibrosis in the diabetic kidney. In the present review, we summarize the current knowledge on the association between histone modification and DKD.

The Expression of TGF-β1, SMAD3, ILK and miRNA-21 in the Ectopic and Eutopic Endometrium of Women with Endometriosis

The molecular pathogenesis of endometriosis has been associated with pathological alterations of protein expression via disturbances in homeostatic genes, miRNA expression profiles, and signaling pathways that play an essential role in the epithelial-mesenchymal transition (EMT) process. TGF-β1 has been hypothesized to play a key role in the development and progression of endometriosis, but the activation of a specific mechanism via the TGF-β-SMAD-ILK axis in the formation of endometriotic lesions is poorly understood. The aim of this study was to assess the expression of EMT markers (TGF-β1, SMAD3, ILK) and miR-21 in ectopic endometrium (ECE), in its eutopic (EUE) counterpart, and in the endometrium of healthy women. The expression level of the tested genes and miRNA was also evaluated in peripheral blood mononuclear cells (PBMC) in women with and without endometriosis. Fifty-four patients (n = 54; with endometriosis, n = 29, and without endometriosis, n = 25) were enrolled in the study. The expression levels (RQ) of the studied genes and miRNA were evaluated using qPCR. Endometriosis patients manifested higher TGF-β1, SMAD3, and ILK expression levels in the eutopic endometrium and a decreased expression level in the ectopic lesions in relation to control tissue. Compared to the endometrium of healthy participants, miR-21 expression levels did not change in the eutopic endometrium of women with endometriosis, but the RQ was higher in their endometrial implants. In PBMC, negative correlations were found between the expression level of miR-21 and the studied genes, with the strongest statistically significant correlation observed between miR-21 and TGF-β1. Our results suggest the loss of the endometrial epithelial phenotype defined by the differential expression of the TGF-β1, SMAD3 and ILK genes in the eutopic and ectopic endometrium. We concluded that the TGF-β1-SMAD3-ILK signaling pathway, probably via a mechanism related to the EMT, may be important in the pathogenesis of endometriosis. We also identified miR-21 as a possible inhibitor of this TGF-β1-SMAD3-ILK axis.

The Nephroprotective Effects of Hibiscus sabdariffa Leaf and Ellagic Acid in Vitro and in Vivo Models of Hyperuricemic Nephropathy

Hyperuricemic nephropathy (HN) is caused by urate crystals that get deposited in the kidney and contribute to renal fibrosis. Uric acid (UA) has been proven to directly cause renal mesangial cell oxidative stress and fibrosis in the pathogenesis of HN. Some antioxidants can be used as chemopreventive agents of HN. Hibiscus sabdariffa leaf extracts (HLE), rich in polyphenol, have been shown to possess hypoglycemic, antioxidant, hypolipidemic, antiatherosclerotic, and anticancer effects. The aim of the study is to examine the inhibitory effect of HLE and its main component ellagic acid (EA) on renal fibrosis. In vitro, mouse renal glomerular mesangial SV40MES13 cells pretreated with UA were demonstrated to trigger obvious morphological changes and viability loss, as well as affect matrix metalloproteinases (MMPs) activities. Noncytotoxic doses of HLE and EA abolished the UA-induced cell injury and MMP-2/9 secretion. In addition, HLE and EA exhibited antioxidant and anti-inflammatory effects on the UA-treated cells with a reduction in transforming growth factor-beta (TGF-β) production. Next, the UA-activated pro-fibrotic factors, extracellular matrix (ECM) deposition, and epithelial-mesenchymal-transition (EMT) were inhibited by HLE or EA. Mechanistic assays indicated that antifibrotic effects of HLE might be mediated via TGF-β/Smad signaling, as confirmed by the transfection of Smad7 siRNA. In vivo, HLE and EA supplementations significantly alleviated HN development, which may result from inhibiting adenine-induced TGF-β production accompanying oxidative stress and inflammation, as well as fibrogenesis. Our data imply that EA-enriched HLE regulates the TGF-β/Smad signaling, which in turn led to reduced renal mesangial cell injury and fibrosis in HN and provided a new mechanism for its nephroprotective activity.

Exosomes From Adipose-Derived Stem Cells Suppress the Progression of Chronic Endometritis

Chronic endometritis (CE) is closely linked to the reproductive failure. Exosome (Exo)-based therapy is proposed as an encouraging strategy in inflammation-related disorders; however, little work has been devoted to its usage in CE therapy. An in vitro CE was established by administration of lipopolysaccharide (LPS) in human endometrial stromal cells (HESCs). The cell proliferation, cell apoptosis, and inflammatory cytokine assays were performed in vitro, and the efficacy of Exos derived from adipose tissue-derived stem cells (ADSCs) was evaluated in a mouse model of CE. We found that Exos isolated from ADSCs could be taken up by HESCs. Exos elevated the proliferation and inhibited apoptosis in LPS-treated HESCs. Administration of Exos to HESCs suppressed the content of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). Moreover, Exos exposure repressed the inflammation stimulated by LPS in vivo. Mechanistically, we demonstrated that Exos exerted their ant-inflammatory effect via miR-21/TLR4/NF-kB signaling pathway in endometrial cells. Our findings suggest that ADSC-Exo-based therapy might serve as an attractive strategy for the treatment of CE.

Inhibition of MLL1-menin interaction attenuates renal fibrosis in obstructive nephropathy

Mixed lineage leukemia 1 (MLL1), a histone H3 lysine 4 (H3K4) methyltransferase, exerts its enzymatic activity by interacting with menin and other proteins. It is unclear whether inhibition of the MLL1-menin interaction influences epithelial-mesenchymal transition (EMT), renal fibroblast activation, and renal fibrosis. In this study, we investigated the effect of disrupting MLL1-menin interaction on those events and mechanisms involved in a murine model of renal fibrosis induced by unilateral ureteral obstruction (UUO), in cultured mouse proximal tubular cells and renal interstitial fibroblasts. Injury to the kidney increased the expression of MLL1 and menin and H3K4 monomethylation (H3K4me1); MLL1 and menin were expressed in renal epithelial cells and renal interstitial fibroblasts. Inhibition of the MLL1-menin interaction by MI-503 administration or siRNA-mediated silencing of MLL1 attenuated UUO-induced renal fibrosis, and reduced expression of α-smooth muscle actin (α-SMA) and fibronectin. These treatments also inhibited UUO-induced expression of transcription factors Snail and Twist and transforming growth factor β1 (TGF-β1) while expression of E-cadherin was preserved. Moreover, treatment with MI-503 and transfection with either MLL siRNA or menin siRNA inhibited TGF-β1-induced upregulation of α-SMA, fibronectin and Snail, phosphorylation of Smad3 and AKT, and downregulation of E-cadherin in cultured renal epithelial cells. Finally, MI-503 was effective in abrogating serum or TGFβ1-induced transformation of renal interstitial fibroblasts to myofibroblasts in vitro. Taken together, these results suggest that targeting disruption of the MLL1-menin interaction attenuates renal fibrosis through inhibition of partial EMT and renal fibroblast activation.

New mechanisms involved in the development of cardiovascular disease in chronic kidney disease

Chronic kidney disease (CKD) is a pathology with a high worldwide incidence and an upward trend affecting the elderly. When CKD is very advanced, the use of renal replacement therapies is required to prolong its life (dialysis or kidney transplantation). Although dialysis improves many complications of CKD, the disease does not reverse completely. These patients present an increase in oxidative stress, chronic inflammation and the release of extracellular vesicles (EVs), which cause endothelial damage and the development of different cardiovascular diseases (CVD). CKD patients develop premature diseases associated with advanced age, such as CVD. EVs play an essential role in developing CVD in patients with CKD since their number increases in plasma and their content is modified. The EVs of patients with CKD cause endothelial dysfunction, senescence and vascular calcification. In addition, miRNAs free or transported in EVs together with other components carried in these EVs promote endothelial dysfunction, thrombotic and vascular calcification in CKD, among other effects. This review describes the classic factors and focuses on the role of new mechanisms involved in the development of CVD associated with CKD, emphasizing the role of EVs in the development of cardiovascular pathologies in the context of CKD. Moreover, the review summarized the EVs' role as diagnostic and therapeutic tools, acting on EV release or content to avoid the development of CVD in CKD patients.

Up-regulation of the human-specific CHRFAM7A gene protects against renal fibrosis in mice with obstructive nephropathy

Renal fibrosis is a major factor in the progression of chronic kidney diseases. Obstructive nephropathy is a common cause of renal fibrosis, which is also accompanied by inflammation. To explore the effect of human-specific CHRFAM7A expression, an inflammation-related gene, on renal fibrosis during obstructive nephropathy, we studied CHRFAM7A transgenic mice and wild type mice that underwent unilateral ureteral obstruction (UUO) injury. Transgenic overexpression of CHRFAM7A gene inhibited UUO-induced renal fibrosis, which was demonstrated by decreased fibrotic gene expression and collagen deposition. Furthermore, kidneys from transgenic mice had reduced TGF-β1 and Smad2/3 expression following UUO compared with those from wild type mice with UUO. In addition, the overexpression of CHRFAM7A decreased release of inflammatory cytokines in the kidneys of UUO-injured mice. In vitro, the overexpression of CHRFAM7A inhibited TGF-β1-induced increase in expression of fibrosis-related genes in human renal tubular epithelial cells (HK-2 cells). Additionally, up-regulated expression of CHRFAM7A in HK-2 cells decreased TGF-β1-induced epithelial-mesenchymal transition (EMT) and inhibited activation f TGF-β1/Smad2/3 signalling pathways. Collectively, our findings demonstrate that overexpression of the human-specific CHRFAM7A gene can reduce UUO-induced renal fibrosis by inhibiting TGF-β1/Smad2/3 signalling pathway to reduce inflammatory reactions and EMT of renal tubular epithelial cells.

OGG1 in the Kidney: Beyond Base Excision Repair

8-Oxoguanine DNA glycosylase (OGG1) is a repair protein for 8-oxoguanine (8-oxoG) in eukaryotic atopic DNA. Through the initial base excision repair (BER) pathway, 8-oxoG is recognized and excised, and subsequently, other proteins are recruited to complete the repair. OGG1 is primarily located in the cytoplasm and can enter the nucleus and mitochondria to repair damaged DNA or to exert epigenetic regulation of gene transcription. OGG1 is involved in a wide range of physiological processes, such as DNA repair, oxidative stress, inflammation, fibrosis, and autophagy. In recent years, studies have found that OGG1 plays an important role in the progression of kidney diseases through repairing DNA, inducing inflammation, regulating autophagy and other transcriptional regulation, and governing protein interactions and functions during disease and injury. In particular, the epigenetic effects of OGG1 in kidney disease have gradually attracted widespread attention. This study reviews the structure and biological functions of OGG1 and the regulatory mechanism of OGG1 in kidney disease. In addition, the possibility of OGG1 as a potential therapeutic target in kidney disease is discussed.

Role of circulatory miRNA-21 and associated signaling pathways in the pathogenesis of pulmonary fibrosis among individuals recovered after COVID-19 infection

Introduction

Currently pulmonary fibrosis in post-COVID individuals represents a crucial milieu of investigation due to long-term associated complications and worse clinical outcome. Lack of studies in Indian population confers a crucial need for elucidating possible targets and mechanisms to explore better management and outcome. Hence, this study aimed to explore the role of circulating miRNA-21 in patients from South India after COVID-19 recovery, while targeting TGF-β signaling pathway involved in the development of pulmonary fibrosis.

Methods

This prospective, single centre, hospital-based study enrolled a total of 50 participants in the age group of 50 to 60 years including 25 non-infected controls and 25 patients who were recovered after 3–6 months of COVID-19 infection and presented radiological pulmonary abnormalities. Quantification of miRNA-21 and selected gene transcripts (TGF-β, Col1A2, Col3A1, and α-SMA) was performed in plasma samples of both patients and controls.

Results

Significantly increased expression levels of miRNA-21 was observed in patient samples compared to controls (4.50 ± 1.03 vs 12.60 ± 3.52, p < 0.0001) with 72.10% sensitivity and 80.10% specificity. Further, significantly increased levels of central fibrosis regulatory gene transcript TGF-β (0.56 ± 0.27 vs 1.83 ± 0.98), two crucial collagen transcripts Col1A2 (0.62 ± 0.19 vs 1.56 ± 1.00) and Col3A1 (0.61 ± 0.27 vs 1.54 ± 0.89), and α-SMA (0.46 ± 0.17 vs 1.20 ± 0.78) was observed in patients compared to controls. Western-blot analysis also showed almost similar observations at proteins levels.

Conclusion

Circulating miRNA-21 may provide crucial insights for elucidating TGF-β mediated pulmonary remodeling involved in the fibrosis development and achieve better clinical outcome for post-COVID patients after recovery, in real-time with high diagnostic accuracy.

Association between Circulating MicroRNAs (miR-21-5p, miR-20a-5p, miR-29b-3p, miR-126-3p and miR-101-3p) and Chronic Allograft Dysfunction in Renal Transplant Recipients

Chronic allograft dysfunction (CAD) is a major condition affecting long-term kidney graft survival. Serum microRNA (miRNA) has been reported as a biomarker for various conditions of allograft injuries. The upregulation of miR-21 is the best-known miRNA change in graft tissue, urine and plasma. However, the correlation of plasma miR-21 with the severity of CAD remains unclear. In our study, 40 kidney transplantation recipients with late graft survival for more than 10 years were enrolled. The CAD group (n = 20) had either an eGFR between 15 to 60 mL/min or a biopsy-proved chronic allograft nephropathy or rejection. The control group (n = 20) had an eGFR ≥ 60 mL/min without proteinuria and hematuria for a consecutive 3 months before the study. We performed RNA sequencing to profile the miRNAs expression. There were six differentially expressed miRNAs in the CAD group. Among them, miR-21-5p and miR-101-3p were decreased, and miR-20a-5p was increased. We found that miR-21-5p, miR-20a-5p and miR-101-3p all participated in the TGF-beta pathway. We demonstrated that decreased miR-21-5p and miR-101-3p, and increased miR-20a-5p were the novel CAD-associated miRNAs in the TGF-beta pathway. These findings may pave the way for developing early prediction miRNAs biomarkers for CAD, and possibly developing therapeutic tools in the field of kidney transplantation.

MiR-21 regulates epithelial-mesenchymal transition in intestinal fibrosis of Crohn's disease by targeting PTEN/mTOR

BACKGROUND

Previous studies suggested miR-21 regulated epithelial-mesenchymal transition (EMT) and fibrosis in organs. The aim of this study was to explore the role and mechanism of miR-21 in EMT process of CD(Crohn's disease)-associated intestinal fibrosis.

METHODS

Tissue biopsies from fibrotic and nonfibrotic intestine of CD patients, and non-CD patients were obtained; chronic intestinal fibrosis model established by TNBS was treated with antagonist of miR-21; human intestinal epithelial cell, NCM460, were transfected with miR-21 mimics or inhibitor. The expressions of PTEN and mTOR, EMT-related markers and severity of colitis and fibrosis were examined.

RESULTS

Compared to the controls, miR-21 was significantly upregulated in the intestinal tissues from CD patients with fibro stenosis, followed by decreased PTEN expression, increased EMT markers, and mTOR expression, and imbalanced ratio of MMP9(matrix metalloproteinase 9)/TIMP1(tissue inhibitor of metalloproteinase 1). MiR-21 downregulated the expression of PTEN and upregulated mTOR signal in NCM460 cell. Also, knocking miR-21 down reduced EMT in vitro. Inhibiting miR-21 with antagonists reversed TNBS-induced intestinal fibrosis in vivo, through suppressing EMT and balancing MMPs/TIMPs.

CONCLUSION

We identified the involvement of miR-21 in EMT during intestinal fibrosis via targeting PTEN and mTOR, and miR-21 inhibition relieved intestinal fibrosis by regulating extracellular matrix (ECM) remodeling . Our results indicated miR-21 as a potential new target for the treatment of fibrosis complication in CD.

Schwann cells-derived exosomal miR-21 participates in high glucose regulation of neurite outgrowth

As a common complication of diabetes, the pathogenesis of diabetic peripheral neuropathy (DPN) is closely related to high glucose but has not been clarified. Exosomes can mediate crosstalk between Schwann cells (SC) and neurons in the peripheral nerve. Herein, we found that miR-21 in serum exosomes from DPN rats was decreased. SC proliferation was inhibited, cell apoptosis was increased, and the expression of miR-21 in cells and exosomes was downregulated when cultured in high glucose. Increasing miR-21 expression reversed these changes, while knockdown of miR-21 led to the opposite results. When co-cultured with exosomes derived from SC exposed to high glucose, neurite outgrowth was inhibited. On the contrary, neurite outgrowth was accelerated when incubated with exosomes rich in miR-21. We further demonstrated that the SC-derived exosomal miR-21 participates in neurite outgrowth probably through the AKT signaling pathway. Thus, SC-derived exosomal miR-21 contributes to high glucose regulation of neurite outgrowth.

•

The miR-21 was decreased in serum exosomes and sciatic nerve of DPN rats

•

High glucose inhibited SC viability and downregulated the expression of miR-21

•

Exosomes derived from SC cultured in high glucose inhibited the neurite outgrowth

•

SC-derived exosomes rich in miR-21 accelerated the neurite outgrowth of neuron

Fibroblast Growth Factor 21 Attenuates the Progression of Hyperuricemic Nephropathy through Inhibiting Inflammation, Fibrosis and Oxidative stress

Elevated levels of circulating fibroblast growth factor 21 (FGF21) have been reported in patients with hyperuricemia. However, the effect of FGF21 in hyperuricemic nephropathy (HN) remains unexplored. Here, we investigated the effect and mechanism of action of FGF21 on HN. HN model was induced with adenine and potassium oxysalt in wild-type C57BL/6 mice and FGF21^-/- mice. For in vitro studies, human renal tubular epithelial (HK-2) cells were exposed to uric acid with/without FGF21 or β-Klotho-siRNA. Here, we reported aggravated renal dysfunction and structural damage in the FGF21^-/- mice compared to the wild-type mice. These were evident in the upsurge of inflammatory factors IL-1β, TNF-α, IL-6 and IL-18, fibrotic markers Collagen I and α-SMA, and oxidation products ROS and MDA. However, exogenous administration of FGF21 to wild-type HN mice significantly reversed these negative effects. In terms of mechanism, FGF21 significantly inhibited NF-κB/NLRP3 and TGF-β1/Smad3 pathways and promoted nuclear translocation of Nrf2 both in vivo and in vitro. Furthermore, the silencing of β-Klotho was marked by the attenuation of the improved effect of FGF21 on cell damage. In conclusion, our studies revealed that exogenous FGF21 treatment significantly improved HN, which was achieved by the inhibition of inflammation, fibrosis and oxidative stress.

Heidihuangwan alleviates renal fibrosis in rats with 5/6 nephrectomy by inhibiting autophagy

Renal fibrosis is a common pathway for the progression of various chronic kidney diseases (CKD), and the formation and deterioration will eventually lead to end-stage renal failure, which brings a heavy medical burden to the world. HeidihuangWan (HDHW) is a herbal formulation with stable and reliable clinical efficacy in the treatment of renal fibrosis. However, the mechanism of HDHW in treating renal fibrosis is not clear. In this study, we aimed to investigate the mechanism of HDHW to improve renal fibrosis. Wistar rats were randomly divided into the normal control group, 5/6 Nephrectomy group, astragaloside IV (AS-IV) group, HDHW group, and HDHW + IGF-1R inhibitor (JB1) group. Except for the normal control group, the rat renal fibrosis model was established by 5/6 nephrectomy and intervened with drugs for 8 weeks. Blood samples were collected to evaluate renal function. Hematoxylin-Eosin (HE), Periodic Acid-Schiff (PAS), Modified Masson’s Trichrome (Masson) staining were used to evaluate the pathological renal injury, and immunohistochemistry and Western blotting were used to detect the protein expression of renal tissue. The results showed that HDHW was effective in improving renal function and reducing renal pathological damage. HDHW down-regulated the levels of fibrosis marker proteins, including α-smooth muscle actin (α-SMA), vimentin, and transforming growth factors–β(TGF-β), which in turn reduced renal fibrosis. Further studies showed that HDHW down-regulated the expression of autophagy-related proteins Beclin1 and LC3II, indicating that HDHW inhibited autophagy. In addition, we examined the activity of the class I phosphatidylinositol-3 kinase (PI3K)/serine-threonine kinase (Akt)/mTOR pathway, an important signaling pathway regulating autophagy, and the level of insulin-like growth factor 1 (IGF-1), an upstream activator of PI3K/Akt/mTOR. HDHW upregulated the expression of IGF-1 and activated the PI3K/Akt/mTOR pathway, which may be a vital pathway for its inhibition of autophagy. Application of insulin-like growth factor 1 receptor (IGF-1R) inhibitor further confirmed that the regulation of autophagy and renal fibrosis by HDHW was associated with IGF-1-mediated activation of the PI3K/Akt/mTOR pathway. In conclusion, our study showed that HDHW inhibited autophagy by upregulating IGF-1 expression, promoting the binding of IGF-1 to IGF-1R, and activating the PI3K/Akt/mTOR signaling pathway, thereby reducing renal fibrosis and protecting renal function. This study provides support for the application and further study of HDHW.

The progress and prospect of natural components in rhubarb (Rheum ribes L.) in the treatment of renal fibrosis

Background: Renal fibrosis is a key pathological change that occurs in the progression of almost all chronic kidney diseases . CKD has the characteristics of high morbidity and mortality. Its prevalence is increasing each year on a global scale, which seriously affects people’s health and quality of life. Natural products have been used for new drug development and disease treatment for many years. The abundant natural products in R. ribes L. can intervene in the process of renal fibrosis in different ways and have considerable therapeutic prospects.

Purpose: The etiology and pathology of renal fibrosis were analyzed, and the different ways in which the natural components of R. ribes L. can intervene and provide curative effects on the process of renal fibrosis were summarized. Methods: Electronic databases, such as PubMed, Life Science, MEDLINE, and Web of Science, were searched using the keywords ‘R. ribes L.’, ‘kidney fibrosis’, ‘emodin’ and ‘rhein’, and the various ways in which the natural ingredients protect against renal fibrosis were collected and sorted out.

Results: We analyzed several factors that play a leading role in the pathogenesis of renal fibrosis, such as the mechanism of the TGF-β/Smad and Wnt/β-catenin signaling pathways. Additionally, we reviewed the progress of the treatment of renal fibrosis with natural components in R. ribes L. and the intervention mechanism of the crucial therapeutic targets.

Conclusion: The natural components of R. ribes L. have a wide range of intervention effects on renal fibrosis targets, which provides new ideas for the development of new anti-kidney fibrosis drugs.

TGF-β1/Smad3 upregulates UCA1 to promote liver fibrosis through DKK1 and miR18a

TGF-β1 is the strongest cytokine known to promote liver fibrosis. It has been previously demonstrated that the activation of TGF-β1 initiates a temporary collagen accumulation program, which is important for wound repair in several organs. Furthermore, temporary extracellular matrix enhancement often leads to progressive fibrosis, which is accountable for cases of severe morbidity and mortality worldwide. However, its action mechanism has not been fully explored. It was previously reported that UCA1 could promote its occurrence and development in various tumors. Importantly, it was reported that TGF-β1 could activate the expression of UCA1 in liver cancer, gastric cancer, and breast cancer. However, the role of UCA1 in organ fibrosis, including liver fibrosis, remains unreported. The present study reported for the first time that TGF-β1/Smad3 could promote liver fibrosis by upregulating UCA1, which further affected DKK1 and collagen, such as COL1A1, COL1A2, and COL3A1. Meanwhile, UCA1 could competitively bind with miR18a to stabilize Smad3 to constitute a positive feedback pathway, which played a significant role in the promotion of liver fibrosis. Altogether, the present study provides a theoretical basis for devising promising treatment strategies for liver fibrosis. KEY MESSAGES : UCA1 was found to promote the progression of liver fibrosis in vitro. UCA1 is regulated by TGF-β1 and promotes liver fibrosis through the canonical Smad pathway. UCA1 can competitively bind with miR18a, promote liver fibrosis by stabilizing Smad3, and form a UCA1-miR18a/Smad3 positive feedback. UCA1 binds EZH2 to inhibit the DKK1 expression and promote liver fibrosis.

Krill Oil Turns Off TGF-β1 Profibrotic Signaling in the Prevention of Diabetic Nephropathy

Diabetic nephropathy (DN), a severe microvascular complication of diabetes mellitus (DM), results in high mortality due to the lack of effective interventions. The current study investigated the preventive effect of krill oil (KO) on DN using a type 2 DM mouse model induced by streptozotocin and high-fat diet for 24 weeks. The diabetic mice developed albuminuria, mesangial matrix accumulation, glomerular hypertrophy, and fibrosis formation, with an increase in renal proinflammatory, oxidative and profibrotic gene expression. KO significantly prevented these effects but did not improve hyperglycemia and glucose intolerance. In high-glucose-treated mesangial cells (MCs), KO preferably modulated TGF-β1 signaling as revealed by RNA-sequencing. In TGF-β1-treated MCs, KO abolished SMAD2/3 phosphorylation and nuclear translocation and activated Smad7 gene expression. The action of KO on the SMADs was confirmed in the diabetic kidneys. Therefore, KO may prevent DN predominantly by suppressing the TGF-β1 signaling pathway.