PTEN improve renal fibrosis in vitro and in vivo through inhibiting FAK/AKT signaling pathway

Marein Alleviates Doxorubicin-Induced Cardiotoxicity through FAK/AKT Pathway Modulation while Potentiating its Anticancer Activity

Doxorubicin (DOX) is an effective anticancer agent, yet its clinical utility is hampered by dose-dependent cardiotoxicity. This study explores the cardioprotective potential of Marein (Mar) against DOX-induced cardiac injury and elucidates underlying molecular mechanisms. Neonatal rat cardiomyocytes (NRCMs) and murine models were employed to assess the impact of Mar on DOX-induced cardiotoxicity (DIC). In vitro, cell viability, oxidative stress were evaluated. In vivo, a chronic injection method was employed to induce a DIC mouse model, followed by eight weeks of Mar treatment. Cardiac function, histopathology, and markers of cardiotoxicity were assessed. In vitro, Mar treatment demonstrated significant cardioprotective effects in vivo, as evidenced by improved cardiac function and reduced indicators of cardiac damage. Mechanistically, Mar reduced inflammation, oxidative stress, and apoptosis in cardiomyocytes, potentially via activation of the Focal Adhesion Kinase (FAK)/AKT pathway. Mar also exhibited an anti-ferroptosis effect. Interestingly, Mar did not compromise DOX's efficacy in cancer cells, suggesting a dual benefit in onco-cardiology. Molecular docking studies suggested a potential interaction between Mar and FAK. This study demonstrates Mar's potential as a mitigator of DOX-induced cardiotoxicity, offering a translational perspective on its clinical application. By activating the FAK/AKT pathway, Mar exerts protective effects against DOX-induced cardiomyocyte damage, highlighting its promise in onco-cardiology. Further research is warranted to validate these findings and advance Mar as a potential adjunctive therapy in cancer treatment.

DPP8/9 inhibition attenuates the TGF-β1-induced excessive deposition of extracellular matrix (ECM) in human mesangial cells via Smad and Akt signaling pathways

The pathogenesis of glomerular diseases is strongly influenced by abnormal extracellular matrix (ECM) deposition in mesangial cells. Dipeptidyl peptidase IV (DPPIV) enzyme family contains DPP8 and DPP9, which are involved in multiple diseases. However, the pathogenic roles of DPP8 and DPP9 in mesangial cells ECM deposition remain unclear. In this study, we observed that DPP8 and DPP9 were significantly increased in glomerular mesangial cells and podocytes in CKD patients compared with healthy individuals, and DPP9 levels were higher in the urine of IgA nephropathy (IgAN) patients than in control urine. Therefore, we further explored the mechanism of DPP8 and DPP9 in mesangial cells and revealed a significant increase in the expression of DPP8 and DPP9 in human mesangial cells (HMCs) following TGF-β1 stimulation. Silencing DPP8 and DPP9 by siRNAs alleviated the expression of ECM-related proteins including collagen Ⅲ, collagen Ⅳ, fibronectin, MMP2, in TGF-β1-treated HMCs. Furthermore, DPP8 siRNA and DPP9 siRNA inhibited TGF-β1-induced phosphorylation of Smad2 and Smad3, as well as the phosphorylation of Akt in HMCs. The findings suggested the inhibition of DPP8/9 may alleviate HMCs ECM deposition induced by TGF-β1 via suppressing TGF-β1/Smad and AKT signaling pathways.

Modulation of miR-29a and miR-29b Expression and Their Target Genes Related to Inflammation and Renal Fibrosis by an Oral Nutritional Supplement with Probiotics in Malnourished Hemodialysis Patients

Malnutrition is prevalent in patients with chronic kidney disease (CKD), especially those on hemodialysis. Recently, our group described that a new oral nutritional supplement (ONS), specifically designed for malnourished (or at risk) hemodialysis patients with a "similar to the Mediterranean diet" pattern, improved caloric-protein intake, nutritional status and biomarkers of inflammation and oxidation. Our aim in this study was to evaluate whether the new ONS, associated with probiotics or not, may produce changes in miRNA's expression and its target genes in malnourished hemodialysis patients, compared to individualized diet recommendations. We performed a randomized, multicenter, parallel-group trial in malnourished hemodialysis patients with three groups (1: control (C) individualized diet (n = 11); 2: oral nutritional supplement (ONS) + placebo (ONS-PL) (n = 10); and 3: ONS + probiotics (ONS-PR) (n = 10)); the trial was open regarding the intake of ONS or individualized diet recommendations but double-blinded for the intake of probiotics. MiRNAs and gene expression levels were analyzed by RT-qPCR at baseline and after 3 and 6 months. We observed that the expression of miR-29a and miR-29b increased significantly in patients with ONS-PR at 3 months in comparison with baseline, stabilizing at the sixth month. Moreover, we observed differences between studied groups, where miR-29b expression levels were elevated in patients receiving ONS-PR compared to the control group in the third month. Regarding the gene expression levels, we observed a decrease in the ONS-PR group compared to the control group in the third month for RUNX2 and TNFα. TGFB1 expression was decreased in the ONS-PR group compared to baseline in the third month. PTEN gene expression was significantly elevated in the ONS-PR group at 3 months in comparison with baseline. LEPTIN expression was significantly increased in the ONS-PL group at the 3-month intervention compared to baseline. The new oral nutritional supplement associated with probiotics increases the expression levels of miR-29a and miR-29b after 3 months of intervention, modifying the expression of target genes with anti-inflammatory and anti-fibrotic actions. This study highlights the potential benefit of this oral nutritional supplement, especially associated with probiotics, in malnourished patients with chronic renal disease on hemodialysis.

Fibulin7 Mediated Pathological Cardiac Remodeling through EGFR Binding and EGFR-Dependent FAK/AKT Signaling Activation

Adverse remodeling after myocardial infarction (MI) result in heart failure and sudden cardiac death. Fibulin7 (FBLN7) is an adhesion protein excreted into the extracellular matrix that functions in multiple biological processes. However, whether and how FBLN7 affects post-MI cardiac remodeling remains unclear. Here, the authors identify FBLN7 as a critical profibrotic regulator of adverse cardiac remodeling. They observe significantly upregulated serum FBLN7 levels in MI patients with left ventricular remodeling compared to those without MI. Microarray dataset analysis reveal FBLN7 is upregulated in human heart samples from patients with dilated and hypertrophic cardiomyopathy compared with non-failing hearts. The authors demonstrate that FBLN7 deletion attenuated post-MI cardiac remodeling, leading to better cardiac function and reduced myocardial fibrosis, whereas overexpression of FBLN7 results in the opposite effects. Mechanistically, FBLN7 binds to the epidermal growth factor receptor (EGFR) through its EGF-like domain, together with the EGF-like calcium-binding domain, and induces EGFR autophosphorylation at tyrosine (Y) 1068 and Y1173, which activates downstream focal adhesion kinase/AKT signaling, thereby leading to fibroblast-to-myofibroblast transdifferentiation. In addition, FBLN7-EGFR mediates this signal transduction, and the fibrotic response is effectively suppressed by the inhibition of EGFR activity. Taken together, FBLN7 plays an important role in cardiac remodeling and fibrosis after MI.

Long non-coding RNA FABP5P3/miR-22 axis improves TGFβ1-induced fatty acid oxidation deregulation and fibrotic changes in proximal tubular epithelial cells of renal fibrosis

Severe hydronephrosis increases the risk of urinary tract infection and irretrievable renal fibrosis. While TGFβ1-mediated fibrotic changes in proximal tubular epithelial cells and fatty acid oxidation (FAO) deregulation contribute to renal fibrosis and hydronephrosis. Firstly, a few elements were analyzed in this paper, including differentially-expressed long non-coding RNAs (lncRNAs), and miRNAs correlated to CPT1A, RXRA, and NCOA1. This paper investigated TGFβ1 effects on lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression and fibrotic changes in HK-2 cells and FABP5P3 overexpression effects on TGFβ1-induced changes. Moreover, this paper predicted and proved that miR-22 binding to lncRNA FABP5P3, 3'UTR of CPT1A, RXRA, and NCOA1 was validated. The dynamic effects of the FABP5P3/miR-22 axis on TGFβ1-induced changes were investigated. A Renal fibrosis model was established in unilateral ureteral obstruction (UUO) mice, and FABP5P3 effects were investigated. Eventually, this paper concluded that TGFβ1 inhibited lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression, induced fibrotic changes in HK-2 cells, and induced metabolic reprogramming within HK-2 cells, especially lower FAO. FABP5P3 overexpression partially reversed TGFβ1-induced changes. miR-22 targeted lncRNA FABP5P3, CPT1A, RXRA, and NCOA1. LncRNA FABP5P3 counteracted miR-22 inhibition of CPT1A, NCOA1, and RXRA through competitive binding. TGFβ1 stimulation induced the activation of TGFβ/SMAD and JAG/Notch signaling pathways; Nocth2 knockdown reversed TGFβ1 suppression on lncRNA FABP5P3. FABP5P3 overexpression attenuated renal fibrosis in unilateral ureteral obstruction mice. The LncRNA FABP5P3/miR-22 axis might be a potent target for improving the FAO deregulation and fibrotic changes in proximal TECs under TGFβ1 stimulation.

The inhibition of centromere protein K causes anticancer effects in breast carcinoma via effects on the FAK/PI3K/AKT/mTOR pathway

The overexpression of centromere protein K (CENPK) is a major contributor to the malignant progression of numerous cancers. To date, the detailed functions and mechanisms of CENPK in breast carcinoma are not fully elucidated. The goals of this project were to comprehensively address the relevance of CENPK in breast carcinoma. The initial investigation by TCGA analysis revealed a high expression level of CENPK in breast carcinoma. Subsequently, an immunoblotting assay confirmed that CENPK is highly expressed in the clinical samples of breast carcinoma. In vitro experiments elucidated that the inhibition of CENPK produced substantial anticancer effects, including a reduction of proliferation, the inhibition of epithelial-mesenchymal transition, the induction of cell cycle arrest and chemosensitivity. Mechanism research unveiled a role for CENPK in mediating the focal adhesion kinase (FAK1)/PI3K/AKT/mTOR pathway. Inhibiting the FAK/PI3K/AKT/mTOR pathway was able to reverse CENPK-elicited cancer-promoting effects. Additionally, CENPK-silenced breast carcinoma cells exhibited low tumorigenicity in vivo. In summary, our data demonstrated that CENPK inhibition provided an excellent anticancer effect for breast carcinoma by regulating FAK/PI3K/AKT/mTOR pathway. This work illustrates a novel molecular mechanism for CENPK in breast carcinoma and suggests CENPK inhibition as a promising targeted therapy for breast carcinoma.

Nintedanib Inhibits Endothelial Mesenchymal Transition in Bleomycin-Induced Pulmonary Fibrosis via Focal Adhesion Kinase Activity Reduction

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease (ILD). Pulmonary fibroblasts play an important role in the development of IPF. Emerging evidence indicates that pulmonary endothelial cells could be the source of pulmonary fibroblasts through endothelial mesenchymal transition (EndoMT), which contributes to pulmonary fibrosis. EndoMT is a complex process in which endothelial cells lose their expression of endothelial markers and give rise to the characteristics of mesenchymal cells, including morphological fibroblast-like change and the expression of mesenchymal markers, which result in cardiac, renal, and dermal fibroses. Furthermore, EndoMT inhibition attenuates pulmonary fibrosis. Herein, we demonstrate that nintedanib, a tyrosine kinase receptor inhibitor, ameliorated murine bleomycin (BLM)-induced pulmonary fibrosis and suppressed the in vivo and in vitro models of EndoMT. We demonstrated that the activity of focal adhesion kinase (FAK), a key EndoMT regulator, increased in murine lung tissues and human pulmonary microvascular endothelial cells after BLM stimulation. Nintedanib treatment inhibited BLM-induced FAK activation and thus suppressed both in vivo and in vitro BLM-induced EndoMT. Importantly, we found that the VEGF/FAK signaling pathway was involved in nintedanib regulating EndoMT. These novel findings help us understand the mechanism and signaling pathway of EndoMT to further develop more efficacious drugs for IPF treatment.

DNMT3a negatively regulates PTEN to activate the PI3K/AKT pathway to aggravate renal fibrosis

BACKGROUND

Renal fibrosis has become one of the major diseases threatening global public health and harming human life and health. PTEN methylation plays an important role in fibrotic diseases of many organs. However, the relationship between PTEN methylation and renal fibrosis is still elusive.

METHODS

In the present study, we established a unilateral ureteral obstruction (UUO) mouse model in vivo and a transforming growth factor β1 (TGF-β1)-stimulated renal tubular epithelial cell (HK-2) model in vitro. The degree of renal interstitial fibrosis was detected by haematoxylin-eosin (HE) staining and Masson's trichrome staining. Western blot (WB), qRT-PCR, immunohistochemistry (IHC) and methylation-specific PCR (MSP) analyses were used to determine the mechanism by which PTEN methylation regulates renal fibrosis. The α-SMA fibrosis marker was detected by immunofluorescence (IF). Additionally, the relationship of PTEN and DNMT3a in UUO was determined by ChIP-qRT-PCR.

RESULTS

Our results showed that the promoter region of PTEN was methylated in UUO. Compared to the sham group, the expression of PTEN was significantly reduced in the UUO group. However, the demethylation reagent significantly inhibited epithelial-mesenchymal transition (EMT), which showed increased expression of E-cadherin and decreased expression of α-SMA and fibronectin. Moreover, treatment of HK-2 cells with 5-aza-dc reversed the activation of the TGF-β1-induced PI3K/AKT signalling pathway, which inhibited renal fibrosis. WB analysis demonstrated that TGF-β1 inhibited the PTEN protein expression level and DNMT3a knockdown reversed the inhibitory effect of TGF-β1 on PTEN expression. Furthermore, ChIP-qRT-PCR showed that DNMT3a interacted with PTEN. Finally, we found that DNMT3a negatively regulated PTEN to activate the PI3K/AKT signalling pathway and aggravate renal fibrosis in vitro and in vivo.

CONCLUSION

In summary, these results indicated that renal fibrosis is related to the downregulation of PTEN. Additionally, DNMT3a negatively regulates PTEN to activate the PI3K/AKT signalling pathway and induce EMT in renal tubular epithelial cells, thereby aggravating renal fibrosis.

OTUD7B (Cezanne) ameliorates fibrosis after myocardial infarction via FAK-ERK/P38 MAPK signaling pathway

Fibrosis is one of the crucial reasons for cardiac dysfunction after myocardial infarction (MI). Understanding the underlying molecular mechanism that causes fibrosis is crucial to developing effective therapy. Recently, OUT domain-containing 7B (OTUD7B), also called Cezanne, a multifunctional deubiquitylate, has been found to play various roles in cancer and vascular diseases and control many important signaling pathways, including inflammation, proliferation, and so on. However, whether OTUD7B plays a role in fibrosis caused by MI remains unclear. Our study aimed to explore the function of OTUD7B in cardiac fibrosis and investigate the underlying mechanism. We found that the expression of OTUD7B was downregulated in the MI rat model and cultured cardiac fibroblasts (CFs) in hypoxic conditions and after TGF-β1 treatment. In vitro, silencing OTUD7B using small interfering RNA (siRNA) increased α-SMA (smooth muscle actin α) and collagen Ⅰ levels in CFs, whereas the overexpression of OTUD7B using adenovirus decreased their expression. Mechanistically, OTUD7B could regulate the phosphorylation of focal adhesion kinase (FAK), a non-receptor tyrosine kinase that has been proved to act as a potential mediator of fibrosis, and ERK/P38 MAPK was involved in this regulation process. In vitro, overexpression of OTUD7B downregulated the phosphorylation level of FAK and then inhibited ERK/P38 phosphorylation, thus leading to decreased α-SMA and collagen Ⅰ expressions, while OTUD7B knockdown showed an opposite result. These findings suggest that OTUD7B could become a potentially effective therapeutic strategy against fibrosis after MI.

Effect of Fushengong Decoction on PTEN/PI3K/AKT/NF-κB Pathway in Rats With Chronic Renal Failure via Dual-Dimension Network Pharmacology Strategy

Overview: The treatment of chronic renal failure (CRF) with traditional Chinese medicine has attracted much attention, but its mechanism is not clear. Network pharmacology is an effective strategy for exploring the interaction mechanisms between Chinese herbs and diseases, however, it still needs to be validated in cell and/or animal experiments due to its virtual screening characteristics. Herein, the anti-CRF mechanism of the Fushengong decoction (FSGD) was investigated using a dual-dimension network pharmacological strategy combined with in vivo experiment.

Methods: The traditional Chinese medicine systems pharmacology (TCMSP) database (https://tcmspw.com) and UHPLC-MS/MS technology were used to identify the effective compounds of FSGD in theory and practice, such as quercetin, formononetin, and pachymic acid. The putative targets of FSGD and CRF were obtained from the Swisstarget prediction platform and the Genecards database, respectively. The common target pathways between FSGD and CRF were got from the dual-dimension network pharmacology analysis, which integrated the cross-common targets from the TCMSP components-Swisstarget-Genecards-Venn platform analysis in theory, and the UHPLC-MS/MS identified effective ingredients-Swisstarget screening, such as TNF and PI3K/AKT. Furthermore, system molecular determinations were used to prove the dual-dimension network pharmacology study through CRF rat models, which were constructed using adenine and treated with FSGD for 4 weeks.

Results: A total of 121 and 9 effective compounds were obtained from the TCMSP database and UHPLC-MS/MS, respectively. After dual-dimension network pharmacology analysis, the possible mechanism of PTEN/PI3K/AKT/NF-κB pathway was found for FSGD in CRF. In vivo experiments indicated that FSGD can play a role in protecting renal function and reducing fibrosis by regulating the PTEN/PI3K/AKT/NF-κB pathway. These findings provide a reference for FSGD in CRF.

Conclusion: Based on the theoretical and practical dual-dimension network pharmacology analysis for FSGD in CRF, the possible molecular mechanism of PTEN/PI3K/AKT/NF-κB was successfully predicted, and these results were verified by in vivo experiments. In this study, the dual-dimension network pharmacology was used to interpret the key signal pathway for FSGD in CRF, which also proved to be a smart strategy for the study of effective substances and pharmacology in FSGD.

Focusing on Mechanoregulation Axis in Fibrosis: Sensing, Transduction and Effecting

Fibrosis, a pathologic process featured by the excessive deposition of connective tissue components, can affect virtually every organ and has no satisfactory therapy yet. Fibrotic diseases are often associated with organ dysfunction which leads to high morbidity and mortality. Biomechanical stmuli and the corresponding cellular response havebeen identified in fibrogenesis, as the fibrotic remodeling could be seen as the incapacity to reestablish mechanical homeostasis: along with extracellular matrix accumulating, the physical property became more “stiff” and could in turn induce fibrosis. In this review, we provide a comprehensive overview of mechanoregulation in fibrosis, from initialing cellular mechanosensing to intracellular mechanotransduction and processing, and ends up in mechanoeffecting. Our contents are not limited to the cellular mechanism, but further expand to the disorders involved and current clinical trials, providing an insight into the disease and hopefully inspiring new approaches for the treatment of tissue fibrosis.

Integrin αvβ6 contributes to the development of intestinal fibrosis via the FAK/AKT signaling pathway

Intestinal fibrosis is one of the most severe complications of inflammatory bowel disease (IBD) and frequently requires surgery due to intestinal obstruction. Integrin αvβ6, which is mainly regulated by the integrin β6 subunit gene (ITGB6), is a special integrin subtype expressed only in epithelial cells. In our previous study, we found integrin αvβ6 can promote the development of IBD, but the role of integrin αvβ6 in intestinal fibrosis remains unclear. In this study, we observed a gradual increase of ITGB6 mRNA expression from normal region to stenotic region of IBD patients' intestinal specimens. Next, we established a dextran sulfate sodium (DSS)-induced intestinal fibrosis model and a heterotopic intestinal transplant model, and found intestinal fibrosis was decreased in ITGB6-deficient mice compared to wild-type (WT) mice. Furthermore, we performed RNA-sequencing and KEGG pathway analysis on intestinal tissues from ITGB6-overexpressing transgenic mice and WT mice, and found multiple pathways containing ITGB6, are related to the activation of focal adhesion kinase (FAK); finding was confirmed by Western blot. At last, we generated a heterotopic intestinal transplant model found the FAK/AKT pathway was inhibited in ITGB6-deficient mice. In conclusion, our data demonstrate that integrin αvβ6 promotes the pathogenesis of intestinal fibrosis by FAK/AKT pathway, making integrin αvβ6 a potential therapeutic target to prevent this condition.

Elevation of LncRNA ENST00000453774.1 Prevents Renal Fibrosis by Upregulating FBN1, IGF1R, and KLF7

INTRODUCTION

Transforming growth factor-β (TGF-β), a common outcome of various progressive chronic kidney diseases, can regulate and induce fibrosis.

OBJECTIVE

The study aimed to identify downstream targets of lncRNA ENST00000453774.1 (lnc453774.1) and outline their functions on the development of renal fibrosis.

METHODS

HK-2 cells were induced with 5 ng/mL TGF-β1 for 24 h to construct a renal fibrosis cell model. Differentially expressed genes (DEGs) targeted by lnc453774.1 in TGF-β1-induced renal fibrosis were identified using RNA sequencing. The dataset GSE23338 was employed to identify DEGs in 48-h TGF-β1-stimulated human kidney epithelial cells, and these DEGs were intersected with genes in the key module using weighted gene co-expression network analysis to generate key genes associated with renal fibrosis. MicroRNAs (miRs) that had targeting relationship with keys genes and lnc453774.1 were predicted by using Miranda software, and important genes were intersected with key genes that had targeting relationship with these miRs. Key target genes by lnc453774.1 were identified in a protein-protein interaction network among lnc453774.1, important genes, and reported genes related to autophagy, oxidative stress, and cell adhesion.

RESULTS

Key genes in the key module (turquoise) were intersected with DEGs in the dataset GSE23338 and yielded 20 key genes regulated by lnc453774.1 involved in renal fibrosis. Fourteen miRs had targeting relationship with lnc453774.1 and key genes, and 8 important genes targeted by these 14 miRs were identified. Fibrillin-1 (FBN1), insulin-like growth factor 1 receptor (IGF1R), and Kruppel-like factor 7 (KLF7) were identified to be involved in autophagy, oxidative stress, and cell adhesion and were elevated in the lnc453774.1-overexpressing TGF-β1-induced cells.

CONCLUSION

These results show FBN1, IGF1R, and KLF7 serve as downstream targets of lnc453774.1, and that lnc453774.1 may protect against renal fibrosis through competing endogenous miRs which target FBN1, IGF1R, and KLF7 mRNAs.

Interplay between extracellular matrix components and cellular and molecular mechanisms in kidney fibrosis

Chronic kidney disease (CKD) is characterized by pathological accumulation of extracellular matrix (ECM) proteins in renal structures. Tubulointerstitial fibrosis is observed in glomerular diseases as well as in the regeneration failure of acute kidney injury (AKI). Therefore, finding antifibrotic therapies comprises an intensive research field in Nephrology. Nowadays, ECM is not only considered as a cellular scaffold, but also exerts important cellular functions. In this review, we describe the cellular and molecular mechanisms involved in kidney fibrosis, paying particular attention to ECM components, profibrotic factors and cell-matrix interactions. In response to kidney damage, activation of glomerular and/or tubular cells may induce aberrant phenotypes characterized by overproduction of proinflammatory and profibrotic factors, and thus contribute to CKD progression. Among ECM components, matricellular proteins can regulate cell-ECM interactions, as well as cellular phenotype changes. Regarding kidney fibrosis, one of the most studied matricellular proteins is cellular communication network-2 (CCN2), also called connective tissue growth factor (CTGF), currently considered as a fibrotic marker and a potential therapeutic target. Integrins connect the ECM proteins to the actin cytoskeleton and several downstream signaling pathways that enable cells to respond to external stimuli in a coordinated manner and maintain optimal tissue stiffness. In kidney fibrosis, there is an increase in ECM deposition, lower ECM degradation and ECM proteins cross-linking, leading to an alteration in the tissue mechanical properties and their responses to injurious stimuli. A better understanding of these complex cellular and molecular events could help us to improve the antifibrotic therapies for CKD.

Negative regulators of TGF-β1 signaling in renal fibrosis; pathological mechanisms and novel therapeutic opportunities

Elevated expression of the multifunctional cytokine transforming growth factor β1 (TGF-β1) is causatively linked to kidney fibrosis progression initiated by diabetic, hypertensive, obstructive, ischemic and toxin-induced injury. Therapeutically relevant approaches to directly target the TGF-β1 pathway (e.g., neutralizing antibodies against TGF-β1), however, remain elusive in humans. TGF-β1 signaling is subjected to extensive negative control at the level of TGF-β1 receptor, SMAD2/3 activation, complex assembly and promoter engagement due to its critical role in tissue homeostasis and numerous pathologies. Progressive kidney injury is accompanied by the deregulation (loss or gain of expression) of several negative regulators of the TGF-β1 signaling cascade by mechanisms involving protein and mRNA stability or epigenetic silencing, further amplifying TGF-β1/SMAD3 signaling and fibrosis. Expression of bone morphogenetic proteins 6 and 7 (BMP6/7), SMAD7, Sloan-Kettering Institute proto-oncogene (Ski) and Ski-related novel gene (SnoN), phosphate tensin homolog on chromosome 10 (PTEN), protein phosphatase magnesium/manganese dependent 1A (PPM1A) and Klotho are dramatically decreased in various nephropathies in animals and humans albeit with different kinetics while the expression of Smurf1/2 E3 ligases are increased. Such deregulations frequently initiate maladaptive renal repair including renal epithelial cell dedifferentiation and growth arrest, fibrotic factor (connective tissue growth factor (CTGF/CCN2), plasminogen activator inhibitor type-1 (PAI-1), TGF-β1) synthesis/secretion, fibroproliferative responses and inflammation. This review addresses how loss of these negative regulators of TGF-β1 pathway exacerbates renal lesion formation and discusses the therapeutic value in restoring the expression of these molecules in ameliorating fibrosis, thus, presenting novel approaches to suppress TGF-β1 hyperactivation during chronic kidney disease (CKD) progression.

Redox signaling pathways in unilateral ureteral obstruction (UUO)-induced renal fibrosis

Unilateral ureteral obstruction (UUO) is an experimental rodent model that mimics renal fibrosis associated with obstructive nephropathy in an accelerated manner. After UUO, the activation of the renin-angiotensin system (RAS), nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) and mitochondrial dysfunction lead to reactive oxygen species (ROS) overproduction in the kidney. ROS are secondary messengers able to induce post-translational modifications (PTMs) in redox-sensitive proteins, which activate or deactivate signaling pathways. Therefore, in UUO, it has been proposed that ROS overproduction causes changes in said pathways promoting inflammation, oxidative stress, and apoptosis that contribute to fibrosis development. Furthermore, mitochondrial metabolism impairment has been associated with UUO, contributing to renal damage in this model. Although ROS production and oxidative stress have been studied in UUO, the development of renal fibrosis associated with redox signaling pathways has not been addressed. This review focuses on the current information about the activation and deactivation of signaling pathways sensitive to a redox state and their effect on mitochondrial metabolism in the fibrosis development in the UUO model.

Antioxidation, anti-inflammation and anti-fibrosis effect of phosphorylated polysaccharides from Pleurotus djamor mycelia on adenine-induced chronic renal failure mice

The mycelia polysaccharides (MPS) from Pleurotus djamor were prepared and purified by anion exchange column chromatography, and the phosphate content of phosphorylated MPS (PMPS) was 15.22 ± 0.37%. FT-IR spectra, HPLC and ¹H and ¹³C-NMR results showed the PMPS contained α-pyranose structure and the peak area percentage composition of galacturonic acid and glucose were 13.01% and 85.82%, respectively. Animal experiment investigated the antioxidant, anti-inflammation, anti-fibrosis effects of PMPS on kidney in adenine-induced chronic renal failure (CRF) mice. All results including serum biochemical indices, histopathological observation, qRT-PCR, western blotting, immunohistochemical staining manifested the kidney injury could be remitted by PMPS interventions. This experiment suggested that PMPS could remit CRF and other kidney injury related diseases as one kind of dietary supplements and functional foods without toxic side effects.

Exaggerated renal fibrosis in lncRNA Gas5-deficient mice after unilateral ureteric obstruction

AIMS

Abnormal expression of long non-coding RNAs (lncRNAs) occurs in several diseases including renal fibrosis. Notably, growth arrest-specific 5 (Gas5) is a lncRNA, which functions as an essential modulator of cell proliferation and growth. However, the role and expression of lncRNA Gas5 associated with renal fibrosis remains controversial. Herein, we investigate the effect of lncRNA Gas5 deficiency in renal fibrosis induced by the operation of unilateral ureteric obstruction (UUO) in mice.

MAIN METHODS

Sera and urine of mice were used to detect markers of renal function. Further, Masson and immunohistochemical staining, western blotting as well as qRT-PCR were performed to observe the distribution and expression of fibrosis marker in the kidney tissue of the mice.

KEY FINDINGS

Unlike the wild type mice, the obstructed kidney in Gas5+/- mice showed more severe renal fibrosis and collagen deposition. In the UUO-Gas5+/- group, the serum levels of uric acid, serum creatinine, and the urine levels of albumin-to-creatinine ratio were higher. Moreover, the expression of mRNA and protein of α-smooth muscle actin (α-SMA), vimentin, collagen IV, fibronectin, and matrix metalloproteinase 9 (MMP9) were higher, whereas that of phosphatase and tensin homolog (PTEN) were lower with the difference being statistically significant (p < 0.05).

SIGNIFICANCE

lncRNA Gas5 was up-regulated in renal fibrosis tissues, and its deficiency exacerbated renal fibrosis in the UUO mice model.

miR-301a-PTEN-AKT Signaling Induces Cardiomyocyte Proliferation and Promotes Cardiac Repair Post-MI

Adult hearts are hard to recover after cardiac injury due to the limited proliferative ability of cardiomyocytes. Emerging evidence indicates the induction of cell cycle reentry of cardiomyocytes by special treatment or stimulation, which offers adult heart regenerative potential. Herein, a microRNA (miRNA) screening in cardiomyocytes identified miR-301a enriched specially in the neonatal cardiomyocytes from rats and mice. Overexpression of miR-301a in primary neonatal cardiomyocytes and H9C2 cells induced G1/S transition of the cell cycle, promoted cellular proliferation, and protected cardiomyocytes against hypoxia-induced apoptosis. Adeno-associated virus (AAV)9-mediated cardiac delivery of miR-301a to the mice model with myocardial infarction (MI) dramatically promoted cardiac repair post-MI in vivo. Phosphatase and tensin homolog (PTEN)/phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway was confirmed to mediate miR-301a-induced cell proliferation in cardiomyocytes. Loss of function of PTEN mimicked the miR-301a-induced phenotype, while gain of function of PTEN attenuated the miR-301a-induced cell proliferation in cardiomyocytes. Application of RG7440, a small molecule inhibitor of AKT, blocked the function of miR-301a in cardiomyocytes. The current study revealed a miRNA signaling in inducing the cell cycle reentry of cardiomyocytes in the injured heart, and it demonstrated the miR-301a/PTEN/AKT signaling as a potential therapeutic target to reconstitute lost cardiomyocytes in mammals.

Quantitative and network pharmacology: A case study of rhein alleviating pathological progress of renal interstitial fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

The current network pharmacology model focuses mainly on static and qualitative characterisation between drugs and targets or molecular pathway networks, but it does not reflect the multi-scale, dynamic and quantitative process of drug action.

AIM OF THE STUDY

In this study, we developed a new model known as quantitative and network pharmacology (QNP) to characterise the dynamic and quantitative interventions of drugs within a multi-scale biological network.

MATERIALS AND METHODS

Firstly, we used a systems biology method to construct a molecule-cell dynamic network model to simulate the pathological processes of diseases. Secondly, according to the principles of enzymatic kinetics, we generated a multi-scale drug intervention model to simulate the intervention of drugs in multi-scale networks at different concentrations and pathological stages. Finally, we took rhein treatment of renal interstitial fibrosis (RIF) as an example to illustrate the QNP model.

RESULTS

We successfully constructed the a QNP model that includes both a multi-scale dynamic network disease model and drug intervention model. The QNP model accurately simulated the pathological process of RIF, and the simulation results were validated by a series of cell and animal experiments. Meanwhile, the QNP model demonstrated that rhein can delay the pathological process at the studied concentrations of 5 nM, 10 nM, and 20 nM, and can also exert a better therapeutic effect on fibrosis before the proliferation stage of RIF. Furthermore, through uncertainty and sensitivity analysis, we identified that FAK and Smad3 may be potential targets for RIF.

CONCLUSION

Our QNP model provides a molecular-cellular understanding of the pathological mechanisms of RIF, serving as a new approach and strategy for the construction of dynamic multi-scale network model of diseases and drug intervention.

Overexpression of PKMYT1 Facilitates Tumor Development and Is Correlated with Poor Prognosis in Clear Cell Renal Cell Carcinoma

BACKGROUND Protein kinase membrane-associated tyrosine/threonine (PKMYT1) has been found in many tumors, but its association with clear cell renal cell carcinoma (ccRCC) remains unclear. MATERIAL AND METHODS PKMYT1 expression in ccRCC was examined in the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Tumor Immune Estimation Resource databases. The correlation between PKMYT1 expression and clinicopathological parameters was explored via the chi-square test. Receiver operating characteristic curves were used to estimate the diagnostic performance of PKMYT1. Kaplan-Meier curves, a Cox model, nomogram, time-dependent receiver operating characteristic curves, and decision curve analysis (DCA) were used to evaluate the prognostic value and clinical utility of PKMYT1. Genes coexpressed with PKMYT1 in ccRCC were identified based on TCGA, the gene expression profiling interactive, and cBioPortal. Gene Set Enrichment Analysis revealed biological pathways associated with PKMYT1 in ccRCC. RESULTS Weighted gene coexpression network analysis identified PKMYT1 as one of the genes most significantly correlated with progression of histological grade. PKMYT1 was significantly upregulated in ccRCC compared with normal tissue (P<0.001), with a trend toward differentiating between individuals with ccRCC and those who were healthy (area under the curve=0.942). High PKMYT1 expression was correlated with unsatisfactory survival (hazard ratio=1.67, P=0.001), indicating that it is a risk factor for ccRCC. A nomogram incorporating PKMYT1 level was created and showed a clinical net benefit. PKMYT1 was strongly positively correlated with the anti-silencing function of 1B histone chaperone (ASF1B) gene in ccRCC. CONCLUSIONS PKMYT1 is upregulated in ccRCC and its presence indicates poor prognosis, making it a potential therapeutic target for ccRCC.

Fuzheng Huayu recipe, a traditional Chinese compound herbal medicine, attenuates renal interstitial fibrosis via targeting the miR-21/PTEN/AKT axis

OBJECTIVE

MicroRNAs (miRNAs) may be viable targets for treating renal interstitial fibrosis (RIF). Fuzheng Huayu recipe (FZHY), a traditional Chinese compound herbal medicine, is often used in China to treat fibrosis. This study sought to assess the mechanisms through which FZHY influences miRNAs to treat RIF.

METHODS

RIF was induced in rats by mercury chloride and treated with FZHY. Hydroxyproline content, Masson's staining and type I collagen expression were used to evaluate renal collagen deposition. Renal miRNA profiles were evaluated using a miRNA microarray. Those miRNAs that were differentially expressed following FZHY treatment were identified and subjected to bioinformatic analyses. The miR-21 target gene phosphatase and tensin homolog (PTEN) expression and AKT phosphorylation in kidney tissues were assessed via Western blotting. In addition, HK-2 human proximal tubule epithelial cells were treated using angiotensin II (Ang-II) to induce epithelial-to-mesenchymal transition (EMT), followed by FZHY exposure. miR-21 and PTEN expressions were evaluated via quantitative reverse transcription-polymerase chain reaction (qRT-PCR), while E-cadherin and α-smooth muscle actin (α-SMA) expressions were assessed by immunofluorescent staining and qRT-PCR. Western blotting was used to assess PTEN and AKT phosphorylation.

RESULTS

FZHY significantly decreased kidney collagen deposition, hydroxyproline content and type I collagen level. The miRNA microarray identified 20 miRNAs that were differentially expressed in response to FZHY treatment. Subsequent bioinformatic analyses found that miR-21 was the key fibrosis-related miRNA regulated by FZHY. FZHY also decreased PTEN expression and AKT phosphorylation in fibrotic kidneys. Results from in vitro tests also suggested that FZHY promoted E-cadherin upregulation and inhibited α-SMA expression in Ang-II-treated HK-2 cells, effectively reversing Ang-II-mediated EMT. We also determined that FZHY reduced miR-21 expression, increased PTEN expression and decreased AKT phosphorylation in these cells.

CONCLUSION

miR-21 is the key fibrosis-related miRNA regulated by FZHY. The ability of FZHY to modulate miR-21/PTEN/AKT signaling may be a viable approach for treating RIF.

Upregulation of miR-382 contributes to renal fibrosis secondary to aristolochic acid-induced kidney injury via PTEN signaling pathway

Acute kidney injury (AKI) has a critical role in the development of chronic kidney disease (CKD). Building on our previous findings, we explored the role of miR-382 in facilitating the transition of AKI to CKD using the Aristolochic acid (AA) nephropathy model, which was induced by intraperitoneal injection of aristolochic acid I salt (10 or 20 mg/kg). The effects of genetic depletion, pharmacologic inhibition, or overexpression of miR-382 on the PTEN/AKT signaling pathway were examined in vivo and in vitro. Changes in renal pathology and renal epithelial polarity were evaluated. A luciferase reporter assay was performed to investigate the reciprocal suppression relationship between miR-382 and PTEN. Renal fibrosis developed 14 d after AA exposure in a dose- and time-dependent manner. Renal abundance of miR-382 was upregulated following AA treatment, while genetic depletion or pharmacological inhibition of miR-382 partially reversed renal tubulointerstitial fibrosis. Expression of PTEN, a target of miR-382, was downregulated and subsequently its downstream AKT signaling pathway was activated during AKI to CKD transition induced by AA. Inhibition of PTEN in vitro resulted in the acquisition of the EMT phenotypes. Furthermore, upregulation of miR-382 in renal epithelial cells was partially mediated by the activation of NF-kB signaling, with a substantial elevation of proinflammatory cytokines. An in vivo study revealed that either miR-382 knockdown or miR-382 knockout was pivotal for inflammatory suppression, while an in vitro experiment confirmed that upregulation of miR-382 in cultured MTEC cells under AA exposure was remarkably reversed by NF-kB siRNA. These data indicated a novel role for the NF-κB/miR-382/PTEN/AKT axis in the pathogenesis of tubulointerstitial fibrosis following AA-induced acute renal tubular epithelial injury. Targeting miR-382 may lead to a potential novel therapeutic approach for retarding the AKT to CKD transition.

Progress in drug delivery system for fibrosis therapy

Fibrosis is a necessary process in the progression of chronic disease to cirrhosis or even cancer, which is a serious disease threatening human health. Recent studies have shown that the early treatment of fibrosis is turning point and particularly important. Therefore, how to reverse fibrosis has become the focus and research hotspot in recent years. So far, the considerable progress has been made in the development of effective anti-fibrosis drugs and targeted drug delivery. Moreover, the existing research results will lay the foundation for more breakthrough delivery systems to achieve better anti-fibrosis effects. Herein, this review summaries anti-fibrosis delivery systems focused on three major organ fibrotic diseases such as liver, pulmonary, and renal fibrosis accompanied by the elaboration of relevant pathological mechanisms, which will provide inspiration and guidance for the design of fibrosis drugs and therapeutic systems in the future.

miR-130a-3p inhibition protects against renal fibrosis in vitro via the TGF-β1/Smad pathway by targeting SnoN

BACKGROUND

Renal fibrosis, a common pathological outcome of chronic kidney disease (CKD), is characterized by extracellular matrix (ECM) accumulation, damage to the tubular epithelium, and the proliferation and activation of fibroblasts. SnoN, a TGF-β1/Smad transcriptional co-suppressor, is downregulated in obstructive nephropathy. However, the relationship between miR-130a-3p and SnoN expression in the regulation of renal fibrosis is still unknown.

METHODS

We used human renal proximal tubular epithelial cells (HRPTEpiCs, HK-2 and primary HRPTEpiCs) treated with TGF-β1 to establish an in vitro renal fibrosis model. The expression of miR-130a-3p, SnoN and other proteins related to epithelial mesenchymal transition (EMT) and TGF-β1/Smad signalling was investigated by western blotting or qRT-PCR. A luciferase reporter assay was conducted to confirm the interaction of SnoN mRNA and miR-130a-3p. The translocation of p-Smad 2/3 and Smad 7 was determined using immunofluorescence staining.

RESULTS

After TGF-β1 treatment, miR-130a-3p was highly expressed in renal tubular epithelial cells, while SnoN was poorly expressed. The cell morphology changed to fibroblast-like, indicating evidence of EMT. The levels of EMT and fibrosis-related proteins were decreased through miR-130a-3p inhibition. Additionally, miR-130a-3p acted upon the 3'-UTR of SnoN directly to suppress SnoN expression. Furthermore, miR-130a-3p/SnoN promoted the activation of TGF-β1/Smad signalling, as revealed by p-Smad 2/3 and Smad 7 expression levels and distribution patterns.

CONCLUSION

Our study verified that miR-130a-3p facilitates the TGF-β1/Smad pathway in renal tubular epithelial cells and may participate in renal fibrosis by targeting SnoN, which could be a possible strategy for renal fibrosis treatment.