Emodin ameliorates renal fibrosis in rats via TGF-β1/Smad signaling pathway and function study of Smurf 2

Advances in drug delivery-based therapeutic strategies for renal fibrosis treatment

Renal fibrosis is the result of all chronic kidney diseases and is becoming a major global health hazard. Currently, traditional treatments for renal fibrosis are difficult to meet clinical needs due to shortcomings such as poor efficacy or highly toxic side effects. Therefore, therapeutic strategies that target the kidneys are needed to overcome these shortcomings. Drug delivery can be attained by improving drug stability and addressing controlled release and targeted delivery of drugs in the delivery category. By combining drug delivery technology with nanosystems, controlled drug release and biodistribution can be achieved, enhancing therapeutic efficacy and reducing toxic cross-wise effects. This review discusses nanomaterial drug delivery strategies reported in recent years. Firstly, the present review describes the mechanisms of renal fibrosis and anti-renal fibrosis drug delivery. Secondly, different nanomaterial drug delivery strategies for the treatment of renal injury and fibrosis are highlighted. Finally, the limitations of these strategies are also discussed. Investigating various anti-renal fibrosis drug delivery strategies reveals the characteristics and therapeutic effects of various novel nanosystem-derived drug delivery approaches. This will serve as a reference for future research on drug delivery strategies for renal fibrosis treatment.

Emodin improves renal fibrosis in chronic kidney disease by regulating mitochondrial homeostasis through the mediation of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α)

Chronic kidney disease (CKD) is a leading public health issue associated with high morbidity worldwide. However, there are only a few effective therapeutic strategies for CKD. Emodin, an anthraquinone compound from rhubarb, can inhibit fibrosis in tissues and cells. Our study aims to investigate the antifibrotic effect of emodin and the underlying molecular mechanism. A unilateral ureteral obstruction (UUO)-induced rat model was established to evaluate the effect of emodin on renal fibrosis development. Hematoxylin and eosin staining, Masson's trichrome staining, and immunohistochemistry staining were performed to analyze histopathological changes and fibrotic features after emodin treatment. Subsequently, a transforming growth factor-beta 1 (TGF-β1)-induced cell model was used to assess the inhibition of emodin on cell fibrosis in vitro. Furthermore, Western blot analysis and real-time quantitative reverse transcription-polymerase chain reaction were performed to validate the regulatory mechanism of emodin on renal fibrosis progression. As a result, emodin significantly improved histopathological abnormalities in rats with UUO. The expression of fibrosis biomarkers and mitochondrial biogenesis-related proteins also decreased after emodin treatment. Moreover, emodin blocked TGF-β1-induced fibrotic phenotype, lipid accumulation, and mitochondrial homeostasis in NRK-52E cells. Conversely, peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α) silencing significantly reversed these features in emodin-treated cells. Collectively, emodin plays an important role in regulating PGC-1α-mediated mitochondria function and energy homeostasis. This indicates that emodin exhibits great inhibition against renal fibrosis and acts as a promising inhibitor of CKD.

Natural products in traditional Chinese medicine: molecular mechanisms and therapeutic targets of renal fibrosis and state-of-the-art drug delivery systems

Renal fibrosis (RF) is the end stage of several chronic kidney diseases. Its series of changes include excessive accumulation of extracellular matrix, epithelial-mesenchymal transition (EMT) of renal tubular cells, fibroblast activation, immune cell infiltration, and renal cell apoptosis. RF can eventually lead to renal dysfunction or even renal failure. A large body of evidence suggests that natural products in traditional Chinese medicine (TCM) have great potential for treating RF. In this article, we first describe the recent advances in RF treatment by several natural products and clarify their mechanisms of action. They can ameliorate the RF disease phenotype, which includes apoptosis, endoplasmic reticulum stress, and EMT, by affecting relevant signaling pathways and molecular targets, thereby delaying or reversing fibrosis. We also present the roles of nanodrug delivery systems, which have been explored to address the drawback of low oral bioavailability of natural products. This may provide new ideas for using natural products for RF treatment. Finally, we provide new insights into the clinical prospects of herbal natural products.

Pharmacological potential of Astragali Radix for the treatment of kidney diseases

BACKGROUND

With the increasing prevalence of hypertension, diabetes, and obesity, the incidence of kidney diseases is also increasing, resulting in a serious public burden. Conventional treatments for kidney diseases have unsatisfactory effects and are associated with adverse reactions. Traditional Chinese medicines have good curative effects and advantages over conventional treatments for preventing and treating kidney diseases. Astragali Radix is a Chinese herbal medicine widely used to treat kidney diseases.

PURPOSE

To review the potential applications and molecular mechanisms underlying the renal protective effects of Astragali Radix and its components and to provide direction and reference for new therapeutic strategies and future research and development of Astragali Radix.

STUDY DESIGN AND METHODS

PubMed, Google Scholar, and Web of Science were searched using keywords, including "Astragali Radix," "Astragalus," "Astragaloside IV" (AS-IV), "Astragali Radix polysaccharide" (APS), and "kidney diseases." Reports on the effects of Astragali Radix and its components on kidney diseases were identified and reviewed.

RESULTS

The main components of Astragali Radix with kidney-protective properties include AS-IV, APS, calycosin, formononetin, and hederagenin. Astragali Radix and its active components have potential pharmacological effects for the treatment of kidney diseases, including acute kidney injury, diabetic nephropathy, hypertensive renal damage, chronic glomerulonephritis, and kidney stones. The pharmacological effects of Astragali Radix are manifested through the inhibition of inflammation, oxidative stress, fibrosis, endoplasmic reticulum stress, apoptosis, and ferroptosis, as well as the regulation of autophagy.

CONCLUSION

Astragali Radix is a promising drug candidate for treating kidney diseases. However, current research is limited to animal and cell studies, underscoring the need for further verifications using high-quality clinical data.

The association between circulatory, local pancreatic PCSK9 and type 2 diabetes mellitus: The effects of antidiabetic drugs on PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a potent modulator of cholesterol metabolism and plays a crucial role in the normal functioning of pancreatic islets and the progression of diabetes. Islet autocrine PCSK9 deficiency can lead to the enrichment of low-density lipoprotein (LDL) receptor (LDLR) and excessive LDL cholesterol (LDL-C) uptake, subsequently impairing the insulin secretion in β-cells. Circulatory PCSK9 levels are primarily attributed to hepatocyte secretion. Notably, anti-PCSK9 strategies proposed for individuals with hypercholesterolemia chiefly target liver-derived PCSK9; however, these anti-PCSK9 strategies have been associated with the risk of new-onset diabetes mellitus (NODM). In the current review, we highlight a new direction in PCSK9 inhibition therapy strategies: screening candidates for anti-PCSK9 from the drugs used in type 2 diabetes mellitus (T2DM) treatment. We explored the association between circulating, local pancreatic PCSK9 and T2DM, as well as the relationship between PCSK9 monoclonal antibodies and NODM. We discussed the emergence of artificial and natural drugs in recent years, exhibiting dual benefits of antidiabetic activity and PCSK9 reduction, confirming that the diverse effects of these drugs may potentially impact the progression of diabetes and associated disorders, thereby introducing novel avenues and methodologies to enhance disease prognosis.

Neuroprotective effect of aloe emodin against Huntington's disease-like symptoms in R6/1 transgenic mice

Aloe emodin is a natural anthraquinone derived from aloe or rhubarb, showing anti-renal fibrosis, anti-atherosclerosis and anti-cancer effects. Aloe emodin also shows neuroprotective effects in ischemic stroke rats. Naturally, anthraquinone derivatives generally have the effect of inhibiting the transforming growth factor-β1 (TGF-β1) pathway. There is an increase in the calcium/calmodulin-dependent protein kinase II (CaMKII) and TGF-β1 levels in both Huntington's disease (HD) patients' brains and HD transgenic mice. Thus, we hypothesized that aloe emodin may inhibit the phosphorylation of CaMKII (p-CaMKII) and TGF-β1/sma- and mad-related protein (Smad) signaling in the brain, further preventing motor and cognitive dysfunction. Aloe emodin was orally administered to 10- to 20-week-old HD R6/1 transgenic mice. Aloe emodin improved the motor coordination of R6/1 transgenic mice in the rotarod test and attenuated visual recognition impairment in the novel object recognition test. Aloe emodin downregulated levels of the mutant huntingtin protein, p-CaMKII and TGF-β1, but not the TGF-β2 or TGF-β3 levels, in the brains of R6/1 mice. Aloe emodin could also inhibit neuronal apoptosis in the hippocampus of R6/1 mice. Altogether, these results indicated that aloe emodin prevents several HD-like symptoms through the inhibition of CaMKII/Smad and TGF-β1/Smad signaling in mice.

Nephroprotective and nephrotoxic effects of Rhubarb and their molecular mechanisms

Rhubarb, in the form of a traditional Chinese medicine, is used in the treatment of chronic kidney disease (CKD). Previous studies have demonstrated that Rhubarb possesses a good nephroprotective effect, which primarily protects the kidneys from fibrosis, oxidation, inflammation, autophagy, and apoptosis. However, studies have shown that the long-term inappropriate use of Rhubarb may cause damage to renal function. Therefore, how to correctly understand and scientifically evaluate the pharmacodynamics and toxicity of Rhubarb with regard to CKD is a scientific question that urgently needs to be answered. In this review, we explain and illustrate how Rhubarb exerts its nephroprotective effect against CKD. We also describe the mechanisms of action that may cause its nephrotoxicity. Valuable and practical clinical guidance is proposed with regard to methods for mitigating the nephrotoxicity of Rhubarb.

A comprehensive review of emodin in fibrosis treatment

Emodin is the main pharmacodynamic components of rhubarb, with significant pharmacological effects and clinical efficacy.Emodin has a variety of therapy effects, such as anti-cancer, anti-fibrosis effects, and is widely used to treat encephalitis, diabetic cataract and organ fibrosis. Several studies have shown that emodin has a good treatment effect on organ fibrosis, but the mechanism is complex. Moreover, the evidence of some studies is conflicting and confusing. This paper reviewed the mechanism, pharmacokinetics and toxicology of emodin in fibrosis treatment, and briefly discussed relevant cutting-edge new formulations to improve the efficacy, the result can provide some reference for future study.

The emerging insight into E3 ligases as the potential therapeutic target for diabetic kidney disease

Diabetic kidney disease (DKD) is a major diabetic complication and global health concern, occurring in nearly 30 % to 40 % of people with diabetes. Importantly, several therapeutic strategies are being used against DKD; however, available treatments are not uniformly effective and the continuous rise in the prevalence of DKD demands more potential therapeutic approaches or targets. Epigenetic modifiers are regarded for their potential therapeutic effects against DKD. E3 ligases are such epigenetic modifier that regulates the target gene expression by attaching ubiquitin to the histone protein. In recent years, the E3 ligases came up as a potential therapeutic target as it selectively attaches ubiquitin to the substrate proteins in the ubiquitination cascade and modulates cellular homeostasis. The E3 ligases are also actively involved in DKD by regulating the expression of several proteins involved in the proinflammatory and profibrotic pathways. Burgeoning reports suggest that several E3 ligases such as TRIM18 (tripartite motif 18), Smurf1 (Smad ubiquitination regulatory factor 1), and NEDD4-2 (neural precursor cell-expressed developmentally downregulated gene 4-2) are involved in kidney epithelial-mesenchymal transition, inflammation, and fibrosis by regulating respective signaling pathways. However, the various signaling pathways that are regulated by different E3 ligases in the progression of DKD are poorly understood. In this review, we have discussed E3 ligases as potential therapeutic target for DKD. Moreover, different signaling pathways regulated by E3 ligases in the progression of DKD have also been discussed.

Network pharmacology, molecular docking, and experimental verification reveal the mechanism of San-Huang decoction in treating acute kidney injury

Background: Cisplatin is an effective anti-tumor drug. However, its usage is constrained by side effects such as nephron toxicity. Cisplatin-induced acute kidney injury (AKI) appears in approximately 20%-30% of cases. Hence, finding an effective protective strategy is necessary. San-Huang decoction (SHD) is a Chinese herbal decoction with good efficacy in treating chronic kidney disease (CKD). Nevertheless, the mechanism of SHD on AKI remains unclear. Consequently, we proposed to explore the potential mechanism of SHD against cisplatin-induced AKI. Methods: Active compounds, core target proteins, and associated signaling pathways of SHD were predicted through network pharmacology. Then confirmed by molecular docking. In vivo experiment, Cisplatin + SHD group was treated with SHD (6.5 g/kg/day) for 6 days before building the model. An AKI model was established with a single intraperitoneal injection of cisplatin at 20 mg/kg. After 72 h of cisplatin injection, all mice were sacrificed to collect blood and kidney tissues for verification of network pharmacology analysis. Results: We found that calycosin, rhein, and ginsenoside Rh2 may be SHD's primary active compounds in treating cisplatin-induced AKI, and AKT, TNF-α, IL-6, IL-1β, caspase-3, and MMP9 are the core target proteins. The relationship between the compound and target protein was further confirmed by molecular docking. The Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses predicted that SHD has an anti-inflammatory role through the TNF and IL-17 signaling pathway. Moreover, Western blot and immunohistochemistry validated the potential molecular mechanisms of SHD, predicted from network pharmacology analysis. The mechanism of cisplatin-induced AKI involves apoptosis and inflammation. In apoptosis, Caspase-3, caspase-8, caspase-9, and Bax proteins were down-regulated, while Bcl-2 was up-regulated by SHD. The differential expression of MMP protein is involved in the pathological process of AKI. MMP9 protects from glomerular tubule damage. MMP9 and PI3K/AKT anti-apoptosis pathway were up-regulated by SHD. In addition, we discovered that SHD alleviated AKI by inhibiting the NF-κB signaling pathway. Conclusion: SHD plays a critical role in anti-inflammation and anti-apoptosis via inhibiting the NF-κB signaling pathway and activating PI3K/AKT anti-apoptosis pathway, indicating that SHD is a candidate herbal drug for further investigation in treating cisplatin-induced AKI.

Emodin suppresses oxaliplatin-induced neuropathic pain by inhibiting COX2/NF-κB mediated spinal inflammation

Oxaliplatin (OXA) is a common chemotherapy drug for colorectal, gastric, and pancreatic cancers. The anticancer effect of OXA is often accompanied by neurotoxicity and acute and chronic neuropathy. The symptoms present as paresthesia and pain which adversely affect patients' quality of life. Herein, five consecutive intraperitoneal injections of OXA at a dose of 4 mg/kg were used to mimic chemotherapy. OXA administration induced mechanical allodynia, activated spinal astrocytes, and increased inflammatory response. To develop an effective therapeutic measure for OXA-induced neuropathic pain, emodin was intrathecally injected into OXA rats. Emodin developed an analgesic effect, as demonstrated by a significant increase in the paw withdrawal threshold of OXA rats. Moreover, emodin treatment reduced the pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-1β) which upregulated in OXA rats. Furthermore, autodock data showed four hydrogen bonds were formed between emodin and cyclooxygenase-2 (COX2), and emodin treatment decreased COX2 expression in OXA rats. Cell research further proved that emodin suppressed nuclear factor κB (NF-κB)-mediated inflammatory signal and reactive oxygen species level. Taken together, emodin reduced spinal COX2/NF-κB mediated inflammatory signal and oxidative stress in the spinal cord of OXA rats which consequently relieved OXA-induced neuropathic pain.

Emodin ameliorates renal injury and fibrosis via regulating the miR-490-3p/HMGA2 axis

Renal fibrosis is a major pathological feature of chronic kidney disease (CKD). While emodin is reported to elicit anti-fibrotic effects on renal injury, little is known about its effects on microRNA (miRNA)-modulated mechanisms in renal fibrosis. In this study, we established a unilateral ureteral obstruction (UUO) model and a transforming growth factor (TGF)-β1-induced normal rat renal tubular epithelial cell line (NRK-52E) model to investigate the protective effects of emodin on renal fibrosis and its miRNA/target gene mechanisms. Dual-luciferase assay was performed to confirm the direct binding of miRNA and target genes in HEK293 cells. Results showed that oral administration of emodin significantly ameliorated the loss of body weight and the increase in physicochemical parameters, including serum uric acid, creatinine, and urea nitrogen in UUO mice. Inflammatory cytokines, including tumor necrosis factor-α, monocyte chemoattractant protein-1, and interleukin (IL)-1β, but not IL-6, were down-regulated by emodin administration. Emodin decreased the expression levels of TGF-β1 and fibrotic-related proteins, including alpha-smooth muscle actin, Collagen IV, and Fibronectin, and increased the expression of E-cadherin. Furthermore, miR-490-3p was decreased in UUO mice and negatively correlated with increased expression of high migration protein A2 (HMGA2). We further confirmed HMGA2 was the target of miR-490-3p. Transfection of miR-490-3p mimics decreased, while transfection of miR-490-3p inhibitors increased fibrotic-related proteins and HMGA2 expression levels in TGF-β1-induced NRK-52E cells. Furthermore, transfection of miR-490-3p mimics enhanced the anti-fibrotic effects of emodin, while transfection of miR-490-3p inhibitors abolished the protective effects of emodin. Thus, as a novel target of emodin that prevents renal fibrosis in the HMGA2-dependent signaling pathway, miR-490-3p has potential implications in CKD pathology.

LIM and Cysteine-Rich Domains 1 Promotes Transforming Growth Factor β1–Induced Epithelial–Mesenchymal Transition in Human Kidney 2 Cells

Renal fibrosis is the major pathologic manifestation of chronic kidney disease (CKD). LIM and cysteine-rich domains 1 (LMCD1) is upregulated in the kidney tissue from patients with CKD and the transforming growth factor β1 (TGF-β1)-treated human renal tubular epithelial cell line human kidney 2 (HK-2) (Gene Expression Omnibus: GSE66494 and GSE23338). Previously, we have demonstrated that the knockdown of LMCD1 ameliorated renal fibrosis in mice by blocking the activation of the extracellular signal-regulated kinase pathway. In this study, we sought to further investigate whether LMCD1 affects TGF-β1-induced epithelial-mesenchymal transition (EMT) of kidney tubular epithelial cells and its potential role in the TGF-β1/Smad signaling pathway. First, we confirmed that LMCD1 expression was increased in the fibrotic kidneys of patients with CKD compared with that in normal kidneys and that LMCD1 was predominantly localized in the renal tubules. LMCD1 and mesenchymal markers were upregulated in obstructed kidney tissues of mice at 21 days after unilateral ureteral obstruction surgery compared with the tissues in sham mice. Next, we demonstrated that TGF-β1 significantly increased LMCD1 expression through Smad-mediated transcription in HK-2 cells in vitro. In turn, LMCD1 acted as a transcriptional coactivator of E2F transcription factor 1 to promote the transcription of TGF-β1. Moreover, TGF-β1 increased the interaction between LMCD1 and Smad ubiquitination regulatory factor 2 (Smurf2) and accelerated Smurf2-mediated LMCD1 degradation via the ubiquitination system. The knockdown of LMCD1 inhibited TGF-β1-induced EMT in both HK-2 cells and unilateral ureteral obstruction mice. Our results indicate a positive feedback loop between TGF-β1 and LMCD1 for EMT induction in HK-2 cells and that Smurf2 acts as a negative regulator in this process by accelerating LMCD1 degradation.

Chitosan oligosaccharide alleviates renal fibrosis through reducing oxidative stress damage and regulating TGF-β1/Smads pathway

Renal fibrosis (RF) is the common pathway for a variety of chronic kidney diseases that progress to end-stage renal disease. Chitosan oligosaccharide (COS) has been identified as possessing many health functions. However, it is not clear whether COS can prevent RF. The purpose of this paper was to explore the action and mechanism of COS in alleviating RF. First, an acute unilateral ureteral obstruction operation (UUO) in male BALB/c mice was performed to induce RF, and COS or fosinopril (positive control drug) were administered for 7 consecutive days. Data from our experiments indicated that COS treatment can significantly alleviate kidney injury and decrease the levels of blood urea nitrogen (BUN) and serum creatinine (SCr) in the UUO mouse model. More importantly, our results show that COS can reduce collagen deposition and decrease the expression of fibrosis proteins, such as collagen IV, fibronectin, collagen I, α-smooth muscle actin (α-SMA) and E-cadherin, ameliorating experimental renal fibrosis in vivo. In addition, we also found that COS suppressed oxidative stress and inflammation in RF model mice. Further studies indicated that the mechanism by which COS alleviates renal fibrosis is closely related to the regulation of the TGF-β1/Smad pathway. COS has a therapeutic effect on ameliorating renal fibrosis similar to that of the positive control drug fosinopril. Taken together, COS can alleviate renal fibrosis induced by UUO by reducing oxidative stress damage and regulating the TGF-β1/Smad pathway.

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.

Deoxycholic acid-chitosan coated liposomes combined with in situ colonic gel enhances renal fibrosis therapy of emodin

BACKGROUND

Renal fibrosis is the final common pathological feature of various chronic kidney diseases (CKD). Despite recent advances, development of new treatments strategy is needed. Emodin (EMO), an important ingredient of Chinese medicine, rhubarb (Polygonaceae Rheum palmatum l.), has been reported to inhibit the development of renal fibrosis effectively. However, the poor oral bioavailability of EMO and the insufficient monotherapy therapy compromise its efficacy.

PURPOSE

In order to enhance renal fibrosis therapy of emodin, an innovative combination therapy based on deoxycholic acid-chitosan coated liposomes (DCS-Lips) and in situ colonic gel (IGE) was developed.

METHODS

For one, the DCS-Lips were prepared via electrostatic interaction by mixing anionic conventional Lips with cationic DCS, deoxycholic acid conjugated on the backbone of chitosan. The cellular uptake of FITC-labeled DCS-Lips in Caco-2 cell monolayer was evaluated by CLSM and flow cytometry, respectively. Permeability study was carried out using Caco-2 cell monolayer. For another, EMO-loaded in situ colonic gel (EMO-IGE) was prepared by mixing EMO nanosuspensions and plain in situ gel, which was obtained by the cold method. The EMO-IGE was assessed for morphology, gelation temperature, viscosity and in vitro drug release. Finally, the therapeutic efficacy of the combination strategy, oral DCS-Lips formulations and in situ colonic gel, was evaluated in unilateral ureteral obstruction (UUO) rat model. Additionally, 16S rDNA sequencing was performed on rats faces to investigate whether the combination strategy improves the microbial dysbiosis in UUO rats.

RESULTS

The prepared DCS-Lips produced small, uniformly sized nanoparticles, and significantly enhanced the cellular uptake and in vitro permeability of EMO compared to non-coated liposomes. Moreover, the EMO-IGE was characterized by short gelation time, optimal gelling temperature, and excellent viscosity. In UUO model, the combination of DCS-Lips (gavage) and IGE (enema) attenuated renal fibrosis effectively. The results of 16S rDNA sequencing illustrated that IGE could restore the gut microbial dysbiosis of UUO rats.

CONCLUSION

Overall, the combination of DCS-Lips and EMO-IGE alleviated renal fibrosis effectively, resulting from the improved oral bioavailability of EMO by DCS-Lips and the restoration of gut microbiota by EMO-IGE, thus, presenting an innovative and promising potential for renal fibrosis treatment.

Polygonum cuspidatum Extract (Pc-Ex) Containing Emodin Suppresses Lung Cancer-Induced Cachexia by Suppressing TCF4/TWIST1 Complex-Induced PTHrP Expression

Cachexia, which is characterised by the wasting of fat and skeletal muscles, is the most common risk factor for increased mortality rates among patients with advanced lung cancer. PTHLH (parathyroid hormone-like hormone) is reported to be involved in the pathogenesis of cancer cachexia. However, the molecular mechanisms underlying the regulation of PTHLH expression and the inhibitors of PTHLH have not yet been identified. The PTHLH mRNA levels were measured using quantitative real-time polymerase chain reaction, while the PTHrP (parathyroid hormone-related protein) expression levels were measured using Western blotting and enzyme-linked immunosorbent assay. The interaction between TCF4 (Transcription Factor 4) and TWIST1 and the binding of the TCF4–TWIST1 complex to the PTHLH promoter were analysed using co-immunoprecipitation and chromatin immunoprecipitation. The results of the mammalian two-hybrid luciferase assay revealed that emodin inhibited TCF4–TWIST1 interaction. The effects of Polygonum cuspidatum extract (Pc-Ex), which contains emodin, on cachexia were investigated in vivo using A549 tumour-bearing mice. Ectopic expression of TCF4 upregulated PTHLH expression. Conversely, TCF4 knockdown downregulated PTHLH expression in lung cancer cells. The expression of PTHLH was upregulated in cells ectopically co-expressing TCF4 and TWIST1 when compared with that in cells expressing TCF4 or TWIST1 alone. Emodin inhibited the interaction between TCF4 and TWIST1 and consequently suppressed the TCF4/TWIST1 complex-induced upregulated mRNA and protein levels of PTHLH and PTHrP. Meanwhile, emodin-containing Pc-Ex significantly alleviated skeletal muscle atrophy and downregulated fat browning-related genes in A549 tumour-bearing mice. Emodin-containing Pc-Ex exerted therapeutic effects on lung cancer-associated cachexia by inhibiting TCF4/TWIST1 complex-induced PTHrP expression.

TGF-β/Smad Signaling Pathway in Tubulointerstitial Fibrosis

Chronic kidney disease (CKD) was a major public health problem worldwide. Renal fibrosis, especially tubulointerstitial fibrosis, is final manifestation of CKD. Many studies have demonstrated that TGF-β/Smad signaling pathway plays a crucial role in renal fibrosis. Therefore, targeted inhibition of TGF-β/Smad signaling pathway can be used as a potential therapeutic measure for tubulointerstitial fibrosis. At present, a variety of targeting TGF-β1 and its downstream Smad proteins have attracted attention. Natural products used as potential therapeutic strategies for tubulointerstitial fibrosis have the characteristics of acting on multiple targets by multiple components and few side effects. With the continuous research and technique development, more and more molecular mechanisms of natural products have been revealed, and there are many natural products that inhibited tubulointerstitial fibrosis via TGF-β/Smad signaling pathway. This review summarized the role of TGF-β/Smad signaling pathway in tubulointerstitial fibrosis and natural products against tubulointerstitial fibrosis by targeting TGF-β/Smad signaling pathway. Additionally, many challenges and opportunities are presented for inhibiting renal fibrosis in the future.

Emodin prevents renal ischemia-reperfusion injury via suppression of CAMKII/DRP1-mediated mitochondrial fission

Acute kidney injury (AKI) is a serious threat to human health. Clinically, ischemia-reperfusion (I/R) injury is considered one of the most common contributors to AKI. Emodin has been reported to alleviate I/R injury in the heart, brain, and small intestine in rats and mice through its anti-inflammatory effects. The present study investigated whether emodin improved AKI induced by I/R and elucidated the molecular mechanisms. We used a mouse model of renal I/R injury and human renal tubular epithelial cell model of hypoxia/reoxygenation (H/R) injury. Ischemia/reperfusion resulted in renal dysfunction. Pretreatment with emodin ameliorated renal injury in mice following I/R injury. Emodin reduced mitochondrial-mediated apoptosis, suppressed the overproduction of mitochondrial reactive oxygen species and accelerated the recovery of adenosine triphosphate both in vivo and in vitro. Emodin prevented mitochondrial fission and restored the balance of mitochondrial dynamics. The phosphorylation of dynamin-related protein 1 (DRP1) at Ser616, a master regulator of mitochondrial fission, was upregulated in both models of I/R and H/R injury, and this upregulation was blocked by emodin. Using computational cognate protein kinase prediction and specific kinase inhibitors, we found that emodin inhibited the phosphorylation of calcium/calmodulin-dependent protein kinase II (https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=1554), thereby inhibiting its kinase activity and reducing the phosphorylation of DRP1 at Ser616. The results demonstrated that emodin pretreatment could protect renal function by improving mitochondrial dysfunction induced by I/R.

Shenkang Injection and Its Three Anthraquinones Ameliorates Renal Fibrosis by Simultaneous Targeting IƙB/NF-ƙB and Keap1/Nrf2 Signaling Pathways

Oxidative stress and inflammation are important and critical mediators in the development and progression of chronic kidney disease (CKD) and its complications. Shenkang injection (SKI) has been widely used to treat patients with CKD. Although the anti-oxidative and anti-inflammatory activity was involved in SKI against CKD, its bioactive components and underlying mechanism remain enigmatic. A rat model of adenine-induced chronic renal failure (CRF) is associated with, and largely driven by, oxidative stress and inflammation. Hence, we identified the anti-oxidative and anti-inflammatory components of SKI and further revealed their underlying mechanism in the adenine-induced CRF rats. Compared with control rats, the levels of creatinine, urea, uric acid, total cholesterol, triglyceride, and low-density lipoprotein cholesterol in serum were significantly increased in the adenine-induced CRF rats. However, treatment with SKI and its three anthraquinones including chrysophanol, emodin, and rhein could reverse these aberrant changes. They could significantly inhibit pro-fibrotic protein expressions including collagen I, α-SMA, fibronectin, and vimentin in the kidney tissues of the adenine-induced CRF rats. Of note, SKI and rhein showed the stronger inhibitory effect on these pro-fibrotic protein expressions than chrysophanol and emodin. Furthermore, they could improve dysregulation of IƙB/NF-ƙB and Keap1/Nrf2 signaling pathways. Chrysophanol and emodin showed the stronger inhibitory effect on the NF-κB p65 protein expression than SKI and rhein. Rhein showed the strongest inhibitory effect on p65 downstream target gene products including NAD(P)H oxidase subunits (p47phox, p67phox, and gp91phox) and COX-2, MCP-1, iNOS, and 12-LO in the kidney tissues. However, SKI and rhein showed the stronger inhibitory effect on the significantly downregulated anti-inflammatory and anti-oxidative protein expression nuclear Nrf2 and its target gene products including HO-1, catalase, GCLC, and NQO1 in the Keap1/Nrf2 signaling pathway than chrysophanol and emodin. This study first demonstrated that SKI and its major components protected against renal fibrosis by inhibiting oxidative stress and inflammation via simultaneous targeting IƙB/NF-ƙB and Keap1/Nrf2 signaling pathways, which illuminated the potential molecular mechanism of anti-oxidative and anti-inflammatory effects of SKI.

Drug-containing serum of rhubarb-astragalus capsule inhibits the epithelial-mesenchymal transformation of HK-2 by downregulating TGF-β1/p38MAPK/Smad2/3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rheum palmatum L; Astragalus membranaceus (Fisch.), is referred to as 'Dahuang, Huangqi' in China. As an important medicinal plant, the rhizome of rhubarb and astragalus is traditionally used in the treatment of kidney diseases associated with renal failure, inflammation and tumors.

AIM OF THE STUDY

This study aimed to investigate the effect of a drug-containing serum of rhubarb-astragalus capsules (composed of rhubarb and astragalus) and to elucidate its mechanism in the epithelial-mesenchymal transformation of renal tubular epithelial cells.

MATERIALS AND METHODS

Epithelial-mesenchymal transformation (EMT) of HK-2 cells was induced by TGF-β1, and rhubarb-astragalus and losartan drug-containing serum from rats, as well as SB203580 (a specific inhibitor of p38 MAPK), were used. High-performance liquid chromatography analysis was performed to determine the main components of the drug-containing serum of rhubarb-astragalus from rats. Western blotting and immunofluorescence analysis were used to determine the levels of protein expression, and real-time quantitative PCR analysis was used to detect the levels of gene expression.

RESULTS

The drug-containing serum of rhubarb-astragalus contained emodin (0.36 μg/ml) and danthraquinone (0.96 μg/ml). Rhubarb-astragalus significantly decreased the protein expression levels of α-SMA, FN, vimentin and N-cadherin in HK-2 cells that were increased by TGF-β1, while it significantly increased the E-cadherin protein expression level that was decreased by TGF-β1. Rhubarb-astragalus also significantly decreased the protein expression levels of TGF-β1 and p38 MAPK and the mRNA expression levels of α-SMA, vimentin, TGF-β1, p38 MAPK, Smad2 and Smad3 in HK-2 cells that were increased by TGF-β1. It is worth noting that SB203580 (a p38 MAPK inhibitor) had similar effects as rhubarb-astragalus in this study.

CONCLUSION

The drug-containing serum of rhubarb-astragalus can inhibit EMT in HK-2 cells by downregulating the TGF-β1/p38 MAPK/Smad2/3 pathway.

Advances in the study of emodin: an update on pharmacological properties and mechanistic basis

Rhei Radix et Rhizoma, also known as rhubarb or Da Huang, has been widely used as a spice and as traditional herbal medicine for centuries, and is currently marketed in China as the principal herbs in various prescriptions, such as Da-Huang-Zhe-Chong pills and Da-Huang-Qing-Wei pills. Emodin, a major bioactive anthraquinone derivative extracted from rhubarb, represents multiple health benefits in the treatment of a host of diseases, such as immune-inflammatory abnormality, tumor progression, bacterial or viral infections, and metabolic syndrome. Emerging evidence has made great strides in clarifying the multi-targeting therapeutic mechanisms underlying the efficacious therapeutic potential of emodin, including anti-inflammatory, immunomodulatory, anti-fibrosis, anti-tumor, anti-viral, anti-bacterial, and anti-diabetic properties. This comprehensive review aims to provide an updated summary of recent developments on these pharmacological efficacies and molecular mechanisms of emodin, with a focus on the underlying molecular targets and signaling networks. We also reviewed recent attempts to improve the pharmacokinetic properties and biological activities of emodin by structural modification and novel material-based targeted delivery. In conclusion, emodin still has great potential to become promising therapeutic options to immune and inflammation abnormality, organ fibrosis, common malignancy, pathogenic bacteria or virus infections, and endocrine disease or disorder. Scientifically addressing concerns regarding the poor bioavailability and vague molecular targets would significantly contribute to the widespread acceptance of rhubarb not only as a dietary supplement in food flavorings and colorings but also as a health-promoting TCM in the coming years.

Emodin - A natural anthraquinone derivative with diverse pharmacological activities

Emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) is a natural anthraquinone derivative that is present in numerous globally renowned herbal medicines. It is recognised as a protein tyrosine kinase inhibitor and as an anticancer drug, active against various tumour cells, including lung, breast, liver, and ovarian cancer cells. Recently, its role in combination chemotherapy with various allopathic medicines, to minimize their toxicity and to enhance their efficacy, has been studied. The use of emodin in these therapies is gaining popularity, due to fewer associated side effects compared with standard anticancer drugs. Emodin has a broad therapeutic window, and in addition to its antineoplastic activity, it displays anti-ulcer, anti-inflammatory, hepatoprotective, neuroprotective, antimicrobial, muscle relaxant, immunosuppressive and antifibrotic activities, in both in vitro and in vivo models. Although reviews on the anticancer activity of emodin have been published, none coherently unite all the pharmacological properties of emodin, particularly the anti-oxidant, antimicrobial, antidiabetic, immunosuppressive and hepatoprotective activities of the compound. Hence, in this review, all of the available data regarding the pharmacological properties of emodin are explored, with particular emphasis on the modes of action of the molecule. In addition, the manuscript details the occurrence, biosynthesis and chemical synthesis of the compound, as well as its toxic effects on biotic systems.

Therapeutic and delivery strategies of phytoconstituents for renal fibrosis

Chronic kidney disease (CKD) is one of the most common diseases endangering human health and life. By 2030, 14 per 100,000 people may die from CKD. Renal fibrosis (RF) is an important intermediate link and the final pathological change during CKD progression to the terminal stage. Therefore, identifying safe and effective treatment methods for RF has become an important goal. In 2018, the World Health Organization introduced traditional Chinese medicine into its effective global medical program. Various phytoconstituents that affect the RF process have been extracted from different plants. Here, we review the potential therapeutic capabilities of active phytoconstituents in RF treatment and discuss how phytoconstituents can be structurally modified or combined with other ingredients to enhance efficiency and reduce toxicity. We also summarize phytoconstituent delivery strategies to overcome renal barriers and improve bioavailability and targeting.

Protective Effect of Yi Shen Pai Du Formula against Diabetic Kidney Injury via Inhibition of Oxidative Stress, Inflammation, and Epithelial-to-Mesenchymal Transition in db/db Mice

OBJECTIVE

Diabetic kidney disease (DKD) is one of the most common chronic microvascular complications of diabetes; however, there remains a lack of effective therapeutic strategies. Yi Shen Pai Du Formula (YSPDF), a traditional Chinese medicine preparation, has been clinically used in treating chronic kidney disease (CKD) for more than 20 years. However, whether YSPDF has a therapeutic effect on DKD has not been studied.

METHODS

This study was conducted to investigate the effect of YSPDF administration on db/db mice, a model of type 2 diabetes that develops DKD, and reveal its underlying mechanism of action through a high glucose- (HG-) induced renal injury cell model.

RESULTS

We found that YSPDF significantly improved numerous biochemical parameters (fasting blood glucose, serum creatinine, blood urea nitrogen, 24 h urine total protein, total cholesterol, and total triglycerides) and ameliorated the abnormal histology and fibrosis of renal tissue. Moreover, the status of oxidative stress and levels of inflammatory cytokines (TNF-α, IL-6, IL-1β, and MCP-1) were markedly inhibited by YSPDF treatment. YSPDF treatment significantly mitigated renal fibrosis, with evidence suggesting that this was by inhibiting epithelial-to-mesenchymal transition (EMT) via suppression of the TGF-β1/Smad pathway. Interestingly, the expression of Nrf2, HO-1, and NQO1, proteins known to be associated with oxidative stress, were significantly increased upon administration of YSPDF. The levels of NLRP3 inflammasome proteins, including NLRP3, ASC, caspase-1, and cleaved caspase-1 were decreased in the YSPDF-treated group. Cell experiments showed that YSPDF inhibited EMT and the NLRP3 inflammasome in HG-exposed HK-2 cells, possibly via activation of Nrf2.

CONCLUSION

Our study indicates that YSPDF may ameliorate renal damage in db/db mice via inhibition of oxidative stress, inflammation, and EMT, with the mechanism potentially being related to the activation of the Nrf2 pathway.

cMet agonistic antibody prevents acute kidney injury to chronic kidney disease transition by suppressing Smurf1 and activating Smad7

We aimed to investigate the role of cMet agonistic antibody (cMet Ab) in preventing kidney fibrosis during acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Additionally, we explored the effect of cMet Ab on TGF-β1/Smad pathway during the pathogenesis of kidney fibrosis. A unilateral ischemia-reperfusion injury (UIRI) mouse model was established to induce AKI-to-CKD transition. Furthermore, we incubated human proximal tubular epithelial cells (hPTECs) under hypoxic conditions as in vitro model of kidney fibrosis. We analyzed the soluble plasma cMet level in patients with AKI requiring dialysis. Patients who did not recover kidney function and progressed to CKD presented a higher increase in the cMet level. The kidneys of mice treated with cMet Ab showed fewer contractions and weighed more than the controls. The mice in the cMet Ab-treated group showed reduced fibrosis and significantly decreased expression of fibronectin and α-smooth muscle actin. cMet Ab treatment decreased inflammatory markers (MCP-1, TNF-α, and IL-1β) expression, reduced Smurf1 and Smad2/3 level, and increased Smad7 expressions. cMet Ab treatment increased cMet expression and reduced the hypoxia-induced increase in collagen-1 and ICAM-1 expression, thereby reducing apoptosis in the in vitro cell model. After cMet Ab treatment, hypoxia-induced expression of Smurf1, Smad2/3, and TGF-β1 was reduced, and suppressed Smad7 was activated. Down-regulation of Smurf1 resulted in suppression of hypoxia-induced fibronectin expression, whereas treatment with cMet Ab showed synergistic effects. cMet Ab can successfully prevent fibrosis response in UIRI models of kidney fibrosis by decreasing inflammatory response and inhibiting the TGF-β1/Smad pathway.

Smad7 attenuates TGF-β-mediated aging-related hypofunction of submandibular glands

Submandibular glands have essential functions in taste, mastication, swallowing, and digestion. Submandibular gland hypofunction is prevalent in the elderly, impairing the patients' quality of life. Current clinical treatment strategies have not decelerated or reversed the pathological process of submandibular gland hypofunction. Therefore, novel restoration strategies should be explored. However, studies on the mechanism of aging-related submandibular gland hypofunction remain very limited. The role of the TGF-β/Smad pathway in fibrosis has been studied in other organs. Therefore, this study aimed to elucidate the role of TGF-β/Smad signaling in the aging-related submandibular gland hypofunction. The results showed that Smad7 knockout in mice decreased the salivary flow rate. H&E, Masson trichrome, and immunohistochemistry staining of MCP-1 and α-SMA showed that Smad7 knockout in mice resulted in lymphocytic infiltration, acinar cell atrophy, and interstitial fibrosis. The Western blotting of collagen I and III also confirmed extensive fibrosis. We then found that Smad7 depletion resulted in the TGF-β-mediated fibrosis via mir-21, mir-29, and np_5318, and NFκB-driven inflammation activation. This study confirmed the inhibitory role of Smad7 in the aging-related submandibular gland hypofunction. Therefore, it provided a promising treatment target for aging-related dysfunction and sialadenitis of submandibular gland.

Emodin-induced autophagic cell death hinders epithelial-mesenchymal transition via regulation of BMP-7/TGF-β1 in renal fibrosis

We aim to explore the effects of emodin and its mechanisms on renal fibrosis (RF). We firstly modeled adriamycin-induced rat RF with unilateral nephrectomy. In vivo and in vitro pharmacological experiments were performed in this study. The presence of collagen deposition was detected by Masson staining. To verify whether emodin attenuates RF by monitoring autophagy, the immunohistochemistry staining for autophagy protein LC3B was performed. We conducted western blot to detect the expression of the autophagy-related proteins in EMT in vitro model after treating with emotin and BMP-7. In vivo, we demonstrated that emodin could improve renal dysfunction and decrease pathological damage of the kidney by activation of autophagy and inhibition of EMT. Upregulation of BMP-7 was recorded in the RF rats subjected to emodin treatment. In vitro studies, emodin has the capacity of reversing EMT and activating autophagy, and emodin could regulate the expression of BMP-7. The results revealed that the attenuation of EMT by emodin could be blocked after the inhibition of BMP-7 and suppression of autophagy. Our findings demonstrated that emodin alleviates EMT during RF by actuating autophagy through BMP-7, suggesting a role of BMP-7 in RF treatment and prevention.

Effects of bradykinin on proliferation, apoptosis, and cycle of glomerular mesangial cells via the TGF-β1/Smad signaling pathway

We aimed to assess the effects of bradykinin (BK) on the proliferation, apoptosis, and cycle of glomerular mesangial cells via the transforming growth factor-β 1 (TGF-β1)/Smad signaling pathway. Rat glomerular mesangial cells, HBZY-1, were divided into normal group (untreated), model group (5 ng/L TGF-β1), BK group (5 ng/L TGF-β1 + 1 ng/L BK), and inhibitor group [5 ng/L TGF-β1 + 1 ng/L LY2109761 (TGF-β1-specific inhibitor)]. The cell proliferation, cycle, apoptosis, expression of type I collagen (Col-1), and protein expressions of Col-1, TGF-β1, and phosphorylated Smad2 (p-Smad2) were detected by EdU labeling, flow cytometry, acridine orange/ethidium bromide (AO/EB) dual staining, immunofluorescence assay, and Western blotting, respectively. Compared with the normal group, the cell proliferation rate (P = 0.02) and protein expression levels of Col-1 (P = 0.02), TGF-β1 (P = 0.01), p-Smad2 (P = 0.02), and p-Smad7 (P = 0.00) in the model group significantly increased, and apoptosis rate (P = 0.01) significantly decreased. Compared with the model group, the BK and inhibitor groups significantly decreased in proliferation rate (P = 0.01) and protein expression levels of Col-1 (P = 0.01), TGF-β1 (P = 0.01), and p-Smad2 (P = 0.00). Also, they were significantly elevated in apoptosis rate (P = 0.02) and p-Smad7 protein expression (P = 0.02). BK regulates the proliferation, apoptosis, and the cycle of glomerular mesangial cells by inhibiting the TGF-β1/Smad signaling pathway.

Herbal antioxidants in dialysis patients: a review of potential mechanisms and medical implications

The consumption of exogenous antioxidants isolated from herbal extracts has shown beneficial effects on ameliorating dialysis-related complications through debilitating oxidative stress and inflammatory process. Many clinical studies available in public databases have reported the improved consequences of dialysis in patients supplemented with herbal antioxidants. Exploration of such data offers great possibilities for gaining insights into the potential mechanisms and medical implications of herbal antioxidants. In this work, the mechanisms and implications of some famous bioactive substances including silymarin, curcumin, resveratrol, emodin, and quercetin on the consequences of dialysis in chronic kidney disease (CKD) patients were explored. The protective features of silymarin are due to the flavonoid complex silybin. Curcumin is an active element from the root of curcuma longa with extensive beneficial properties, including antioxidant, anti-inflammatory activity, and inhibitory effects on cell apoptosis. Resveratrol can reduce the oxidative stress by neutralization of free radicals. Emodin is known as a natural anthraquinone derivative isolated from Chinese herbs. Finally, quercetin has been reported to exhibit several properties including antioxidant, anti-diabetic, analgesic, antihistaminic, antiviral, cholesterol reducer, and renal hemodynamic modulator. However, potential mechanisms and medical implications of the aforementioned herbal antioxidants seem to be more complicated, that is, more studies are required in this field.

Emodin attenuates silica-induced lung injury by inhibition of inflammation, apoptosis and epithelial-mesenchymal transition

Silicosis is a fatal pulmonary disease caused by the inhalation of silica dust, and characterized by inflammation and fibrosis of the lung, with no effective treatment to date. Here we investigate the effect of emodin, an anthraquinone derivative isolated from rhubarb using a mouse silicosis model and in vitro cultured human macrophages and alveolar epithelial cells. Results from histological examination indicated that emodin reduced the degree of alveolitis and fibrosis in the lungs of mice exposed to silica particles. We also demonstrated that emodin effectively inhibited the phosphorylation of Smad3 and NF-κB and reduced the levels of inflammatory factors in the lung tissue of mice treated with silica particles. In addition, we found that emodin inhibited apoptosis and demonstrated an anti-fibrotic effect by down-regulating the pro-apoptotic protein Bax and up-regulating the anti-apoptotic protein Bcl-2. Furthermore, emodin increased E-cadherin levels, reduced the expression of Vimentin, α-SMA and Col-I, as well as pro-inflammatory factors TGF-β1, TNF-α and IL-1β in vivo and in vitro. These results suggested that emodin can regulate epithelial-mesenchymal transition (EMT) through the inhibition of the TGF-β1/Smad3 signaling pathway and the NF-κB signaling pathway to prevent alveolar inflammation and apoptotic process. Overall, this study showed that emodin can alleviate pulmonary fibrosis in silicosis through regulating the inflammatory response and fibrotic process at multiple levels.

Effects of renalase deficiency on liver fibrosis markers in a nonalcoholic steatohepatitis mouse model

Progression of nonalcoholic steatohepatitis (NASH) is attributed to several factors, including inflammation and oxidative stress. In recent years, renalase has been reported to suppress oxidative stress, apoptosis and inflammation. A number of studies have suggested that renalase may be associated with protecting the liver from injury. The present study aimed to clarify the effects of renalase knockout (KO) in mice with NASH that were induced with a choline-deficient high-fat diet (CDAHFD) supplemented with 0.1% methionine. Wild type (WT) and KO mice (6-week-old) were fed a normal diet (ND) or CDAHFD for 6 weeks, followed by analysis of the blood liver function markers and liver tissues. CDAHFD intake was revealed to increase blood hepatic function markers, lipid accumulation and oxidative stress compared with ND, but no significant differences were observed between the WT and KO mice. However, in the KO-CDAHFD group, the Adgre1 and Tgfb1 mRNA levels were significantly higher, and α-SMA expression was significantly lower compared with the WT-CDAHFD group. Furthermore, the Gclc mRNA and phosphorylated protein kinase B (Akt) levels were significantly lower in the KO-ND group compared with the WT-ND group. The results of the current study indicated that as NASH progressed in the absence of renalase, oxidative stress, macrophage infiltration and TGF-β expression were enhanced, while α-SMA expression in NASH may be partly suppressed due to the decreased phosphorylation of Akt level.

Kanglexin protects against cardiac fibrosis and dysfunction in mice by TGF-β1/ERK1/2 noncanonical pathway

Cardiac fibrosis is a common pathological manifestation accompanied by various heart diseases, and antifibrotic therapy is an effective strategy to prevent diverse pathological processes of the cardiovascular system. We currently report the pharmacological evaluation of a novel anthraquinone compound (1,8-dihydroxy-6-methyl-9,10-anthraquinone-3-oxy ethyl succinate) named Kanglexin (KLX), as a potent cardioprotective agent with antifibrosis activity. Our results demonstrated that the administration of KLX by intragastric gavage alleviated cardiac dysfunction, hypertrophy, and fibrosis induced by transverse aortic constriction (TAC) surgical operation. Meanwhile, KLX administration relieved endothelial to mesenchymal transition of TAC mice. In TGF β1-treated primary cultured adult mouse cardiac fibroblasts (CFs) and human umbilical vein endothelial cells (HUVECs), KLX inhibited cell proliferation and collagen secretion. Also, KLX suppressed the transformation of fibroblasts to myofibroblasts in CFs. Further studies revealed that KLX-mediated cardiac protection was due to the inhibitory role of TGF-β1/ERK1/2 noncanonical pathway. In summary, our study indicates that KLX attenuated cardiac fibrosis and dysfunction of TAC mice, providing a potentially effective therapeutic strategy for heart pathological remodeling.

Emodin ameliorates tubulointerstitial fibrosis in obstructed kidneys by inhibiting EZH2

Emodin, a major component of Chinese herbal rhubarb, delays the progression of chronic renal failure. However, the effect and working mechanisms of Emodin on renal tubulointerstitial fibrosis remains elusive. We hypothesized that emodin inhibits renal tubulointerstitial fibrosis through EZH2, a histone methyltransferase. Our in vivo and in vitro studies demonstrate that emodin reduced extracellular collagen deposition and inhibited Smad3 and CTGF pro-fibrotic signaling pathways, which were correlated with the down-regulation of EZH2 and reduced trimethylation of histone H3 on lysine 27 (H3k27me3) in NRK-49F fibrotic cells and UUO kidneys. Inhibition of EZH2 by 3-DZNeP blocked or attenuated the anti-fibrotic effect of emodin in UUO kidneys and NRK-49F cells. These data indicate that emodin inhibits renal tubulointerstitial fibrosis in obstructed kidneys and this effect is mediated through EZH2.

Shenkang VII Recipe Attenuates Unilateral Ureteral Obstruction-induced Renal Fibrosis via TGF-β/Smad, NF-κB and SHH Signaling Pathway

This study aimed to explore the protective effects of the traditional Chinese Medicine formula Shenkang VII recipe (SK-7) on renal fibrosis and the mechanisms. Renal fibrosis was induced by unilateral ureteral obstruction (UUO) in rats. The rats were then divided into 5 groups: control group (Sham operation), UUO model group, UUO model plus low to high doses of SK-7 (0.5, 1.0, or 2.0 g/kg/day, for 14 days) groups. The animals were sacrificed on the 7th or 14th day. Kidney tissues were collected for histopathological examinations (hematoxylin and eosin and Masson's trichrome staining). Immunohistochemistry was used to detect the expression of collagen type III (Col III), fibronectin (FN), α-smooth muscle actin (α-SMA), TIMP metallopeptidase inhibitor 2 (TIMP2), matrix metallopeptidase 2 (MMP2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and monocyte chemotactic protein-1 (MCP-1). The TGF-β1/Smad, NF-kB and Sonic hedgehog signaling proteins were detected by Western blotting. Our results showed that SK-7 prevented UUO-induced renal injury and accumulation of collagen fibrils. Renal fibrosis biomarkers Col III, FN, α-SMA and TIMP2 were increased in the rats after UUO and decreased by SK-7, while MMP2 was upregulated after treatment. SK-7 also suppressed the levels of TNF-α, IL-1β and MCP-1 in UUO rats. In addition, SK-7 inhibited activation of the TGF-β/Smad, NF-κB and sonic hedgehog signaling (SHH) pathways. Taken together, these findings suggest that SK-7 may regulate the synthesis and degradation of extracellular matrix, reduce inflammation and suppress the proliferation of fibroblasts, by blocking the TGF-β1/Smad, NF-κB and SHH signaling pathways to exert its anti-renal fibrosis effect in UUO rats.

Upregulation of miRNA-1228-3p alleviates TGF-β-induced fibrosis in renal tubular epithelial cells

BACKGROUND

Chronic kidney disease (CKD) has become a major public health issue, which can lead to renal fibrosis regardless of the initial injury. It has been previously reported that miRNA-1228-3p was correlate with the progression of kidney fibrosis. However, the mechanism by which miRNA-1228-3p regulates renal fibrosis remains unclear.

METHODS

Renal tubular epithelial cells (HK-2) were treated with TGF-β1 (10 ng/ml) in an in vitro model of renal fibrosis. Gene and protein expressions in HK-2 cells were measured by Western-blot and RT-qPCR, respectively. The relation between miRNA-1228-3p and its target gene was investigated by dual luciferase report analysis.

RESULTS

Upregulation of miRNA-1228-3p significantly inhibited TGF-β1-induced fibrosis of HK-2 cells in vitro by targeting GDF11. In addition, miRNA-1228-3p exhibited anti-fibrosis effect through inhibition of the smad2/smad4 signaling pathway.

CONCLUSION

Upregulation of miRNA-1228-3p markedly inhibited the progression of renal fibrosis in vitro, indicating that miRNA-1228-3p may serve as a potential novel target for the treatment of renal fibrosis.

Hirudin Ameliorates Renal Interstitial Fibrosis via Regulating TGF-β1/Smad and NF-κB Signaling in UUO Rat Model

Purpose

Hirudin, a polypeptide structure containing 65 amino acids, is a potent natural thrombin inhibitor with anticoagulant property extracted from Hirudo medicinalis. It has been reported to have anti-inflammatory and antifibrotic property. Here we explored the renoprotective effect of hirudin on unilateral ureteral obstruction (UUO) induced renal interstitial fibrosis (RIF).

Methods

Rats were randomly divided into five groups: sham group, UUO alone group, and three UUO + hirudin-treatment groups (10, 20, or 40 IU/kg/d, for 14 continuous days). At the end of the experiment period, animals were sacrificed. Pathologic changes in renal specimens were observed using hematoxylin and eosin (HE) staining and Masson staining. The expressions of collagen III (Col III), fibronectin (FN), α-smooth muscle actin (α-SMA), protease-activated receptor 1 (PAR-1), and proteins in the TGF-β1/Smad and NF-κB pathways in renal tissues were examined by immunohistochemistry and/or Western blotting.

Results

HE and Masson staining showed that hirudin-treated UUO rats had lower extent of renal injury and deposition of extracellular matrix (ECM) in renal interstitium than those in the UUO group. The results of immunohistochemistry and WB indicated decreased protein expressions of Col III, FN, α-SMA, PAR-1, and inflammatory markers such as tumor necrosis factor-α and interleukin-6 after hirudin treatment. Furthermore, hirudin reduced the expressions of transforming growth factor β1 (TGF-β1), phosphorylated-Smad2, and phosphorylated-Smad3 in the UUO model. In parallel, we found inhibited nuclear factor-κB (NF-κB) signaling after hirudin treatment, with downregulated protein expressions of P65, phosphorylated-P65, and phosphorylated-iκBα and increased iκBα.

Conclusion

Hirudin improves kidney injury and suppresses inflammatory response and ECM accumulation in UUO rats; its underlying mechanism may be associated with the inhibition of TGF-β1/Smad and NF-κB signaling.

Deciphering the Pharmacological Mechanisms of Taohe-Chengqi Decoction Extract Against Renal Fibrosis Through Integrating Network Pharmacology and Experimental Validation In Vitro and In Vivo

Taohe-Chengqi decoction (THCQ), a classical traditional Chinese medicinal (TCM) formula, has been extensively used for treating chronic kidney disease (CKD). However, the biological activity and mechanisms of action of its constituents against renal fibrosis have not yet been investigated thoroughly. This study was aimed at devising an integrated strategy for investigating the bioactivity constituents and possible pharmacological mechanisms of the n-butanol extract of THCQ (NE-THCQ) against renal fibrosis. The n-butanol extract of THCQ was prepared by the solvent extraction method. The components of NE-THCQ were analyzed using UPLC-Q/TOF-MS/MS techniques and applied for screening the active components of NE-THCQ according to their oral bioavailability and drug-likeness index. Then, we speculated the potential molecular mechanisms of NE-THCQ against renal fibrosis through pharmacological network analysis. Based on data mining techniques and topological parameters, gene ontology, and pathway enrichment, we established compound-target (C-T), protein-protein interaction (PPI) and compound-target-pathway (C-T-P) networks by Cytoscape to identify the hub targets and pathways. Finally, the potential molecular mechanisms of NE-THCQ against renal fibrosis, as predicted by the network pharmacology analyses, were validated experimentally in renal tubular epithelial cells (HK-2) in vitro and against unilateral ureteral obstruction models in the rat in vivo. We identified 26 components in NE-THCQ and screened seven bioactive ingredients. A total of 118 consensus potential targets associated with renal fibrosis were identified by the network pharmacology approach. The experimental validation results demonstrated that NE-THCQ might inhibit the inflammatory processes, reduce ECM deposition and reverse EMT via PI3K/AKT/mTOR and HIF-1α/VEGF signaling pathways to exert its effect against renal fibrosis. This study identified the potential ingredients of the NE-THCQ by UPLC-Q/TOF-MS/MS and explained the possible mechanisms of NE-THCQ against renal fibrosis by integrating network pharmacology and experimental validation.

Silibinin Augments the Antifibrotic Effect of Valsartan Through Inactivation of TGF-β1 Signaling in Kidney

Background

Chronic kidney disease (CKD) has become a major public health issue. Meanwhile, renal fibrosis caused by diabetic nephropathy can lead to CKD, regardless of the initial injury. It has been previously reported that silibinin or valsartan could relieve the severity of renal fibrosis. However, the effect of silibinin in combination with valsartan on renal fibrosis remains unclear.

Material and Methods

Proximal tubular cells (HK-2) were treated with TGF-β1 (5 ng/mL) to mimic in vitro model of fibrosis. The proliferation of HK-2 cells was tested by CCK-8. Epithelial-mesenchymal transition (EMT) and inflammation-related gene and protein expressions in HK-2 cells were measured by qRT-PCR and Western-blot, respectively. ELISA was used to test the level of TNF-αNF-A. Additionally, HFD-induced renal fibrosis mice model was established to investigate the effect of silibinin in combination with valsartan on renal fibrosis in vivo.

Results

Silibinin significantly increased the anti-fibrosis effect of valsartan in TGF-β1-treated HK-2 cells via inhibition of TGF-β1 signaling pathway. Furthermore, silibinin significantly enhanced the anti-fibrosis effect of valsartan on HFD-induced renal fibrosis in vivo through inactivation of TGF-β1 signaling pathway.

Conclusion

These data indicated that silibinin markedly increased anti-fibrosis effect of valsartan in vitro and in vivo. Thus, silibinin in combination with valsartan may act as a potential novel strategy to treat renal fibrosis caused by diabetic nephropathy.

Emodin Retarded Renal Fibrosis Through Regulating HGF and TGFβ-Smad Signaling Pathway

BACKGROUND

Renal fibrosis is a frequently occurring type of chronic kidney disease that can cause end-stage renal disease. It has been verified that emodin or HGF can inhibit the development of renal fibrosis. However, the antifibrotic effect of emodin in combination with HGF remains unclear.

METHODS

Cell viability was detected with CCK8. Gene and protein expression in HK2 cells was detected by qRT-PCR and Western blot, respectively. Moreover, a unilateral ureteral obstruction-induced mouse model of renal fibrosis was established for investigating the antifibrotic effect of emodin in combination with HGF in vivo.

RESULTS

HGF notably increased the expression of collagen II in TGFβ-treated HK2 cells. In addition, HGF-induced increase in collagen II expression was further enhanced by emodin. In contrast, fibronectin, αSMA and Smad2 expression in TGFβ-stimulated HK2 cells was significantly inhibited by HGF and further decreased by combination treatment (emodin plus HGF). Moreover, we found that combination treatment exhibited better antifibrotic effects compared with emodin or HGF in vivo.

CONCLUSION

These data demonstrated that emodin plus HGF exhibited better antifibrotic effects compared with emodin or HGF. As such, emodin in combination with HGF may serve as a new possibilty for treatment of renal fibrosis.

Ameliorative effect of sesamin in cisplatin-induced nephrotoxicity in rats by suppressing inflammation, oxidative/nitrosative stress, and cellular damage

Nephrotoxicity of cisplatin (CP) involves renal oxidative stress and inflammation, and sesamin (a major liganin in many plants) has strong antioxidant and antiinflammatory actions. Therefore, we investigated here the possible mitigative action of sesamin on CP nephrotoxicity in rats. Sesamin was given orally (5 mg/kg/day, 10 days), and on the 7th day, some of the treated rats were injected intraperitoneally with either saline or CP (5 mg/kg). On the 11th day, rats were sacrificed, and blood and urine samples and kidneys were collected for biochemical estimation of several traditional and novel indices of renal damage in plasma and urine, several oxidative and nitrosative indices in kidneys, and assessment of histopathological renal damage. CP significantly and adversely altered all the physiological, biochemical and histopathological indices of renal function measured. Kidneys of CP-treated rats had a moderate degree of necrosis. This was markedly lessened when CP was given simultaneously with sesamin. Sesamin treatment did not significantly alter the renal CP concentration. The results suggested that sesamin had ameliorated CP nephrotoxicity in rats by reversing the CP-induced oxidative stress and inflammation. Pending further pharmacological and toxicological studies sesamin may be considered a potentially useful nephroprotective agent.

Single Nucleotide Polymorphisms of Ubiquitin-Related Genes were Associated with Allograft Fibrosis of Renal Transplant Fibrosis

BACKGROUND Interstitial fibrosis and tubular atrophy (IF/TA) have been recognized as crucial factors contributing to graft loss resulting from chronic renal allograft injuries. Recent studies have indicated a significant association between the progression of organ fibrosis and single nucleotide polymorphisms (SNPs) found on certain genes. Our research sought to understand these potential associations and detect the potential impact of SNPs on ubiquitin-related genes related to allograft fibrosis in kidney transplant recipients. MATERIAL AND METHODS There were 200 patients enrolled in this study, from which samples were extracted for total DNA. Targeted next-generation sequencing was used to detect SNPs on 9 genes (FBXL21, PIAS1/2, SUMO1/2/3/4, UBE2D1, and UBE2I). Minor allele frequency (MAF) and Hardy-Weinberg equilibrium (HWE) tests were used and followed by linkage disequilibrium analysis. General linear models (GLM) were used to identify significant confounding factors. Finally, multiple inheritance models and haplotype analyses were conducted to explore associations between SNPs and the degree of the severity of renal allograft fibrosis. RESULTS In total, 144 SNPs were identified in targeted sequencing. After filtering based on results from MAF and HWE tests, 15 tagger SNPs were selected for further analyses of associations. GLMs indicated that the administration of sirolimus significantly contributed to the degree of severity of allograft fibrosis (P=0.011). After adjusting for confounding factors and applying a Bonferroni correction, multiple inheritance model analyses indicated that the recessive model of rs644731 of the PIAS2 gene was significantly correlated with the occurrence of IF/TA (P=0.01). Furthermore, single-locus based analysis of rs644731 did not indicate that it had a positive influence on IF/TA in a degree-dependent manner. Finally, linkage disequilibrium analysis revealed 3 haplotypes all lacking significant correlation with respect to the IF/TA experimental cohort. CONCLUSIONS We are the first to reveal that mutations of rs644731 in the PIAS2 gene were significantly correlated with the progression of IF/TA in kidney transplant recipients.

Kidney-targeted rhein-loaded liponanoparticles for diabetic nephropathy therapy via size control and enhancement of renal cellular uptake

The optimization of nanoparticle size for passing through glomerular filtration membrane, inefficient renal cellular uptake and rapid urinary excretion of nanoparticles are the major obstacles for renal disease treatment via a nanoparticle delivery system. Herein, we propose a concept of a two-step nanoparticular cascade of size control and enhancement of renal cellular uptake to overcome the renal delivery obstacles. Methods: We prepared kidney-targeted rhein (RH)-loaded liponanoparticles (KLPPR) with a yolk-shell structure composed by polycaprolactone-polyethyleneimine (PCL-PEI)-based cores and kidney targeting peptide (KTP)-modified lipid layers. The KLPPR size within the range of 30 ~ 80 nm allowed KLPPR distribute into kidney by passing through the glomerular filtration membrane and the KTP (sequence: CSAVPLC) decoration promoted the renal cellular uptake and endocytosis via a non-lysosomal pathway. Results: The KLPPR had an average size of 59.5±6.2 nm and exhibited high RH loading, sustained release, good stability and biocompatibility, rapid cellular uptake in HK-2 cells. In addition, intravenous administration of KLPPR resulted in excellent kidney-targeted distribution and low urinary excretion in mice with streptozocin-induced diabetic nephropathy (DN), lowered the parameters of urea nitrogen, serum creatinine and kidney index, as well as facilitated the recovery of renal physiological function in improving the levels of urinary creatinine and the creatinine clearance rate by suppressing secretion and accumulation of fibronectin and TGF-β1. Conclusion: Definitely, KLPPR were able to target the diseased kidney and improve the therapeutic effect of RH on DN by exploiting the two-step nanoparticular cascade of size control and enhancement of cellular uptake. This study offers a promising strategy for renal diseases treatment using liponanoparticle delivery system.

Emerging Role of Chinese Herbal Medicines in the Treatment of Pancreatic Fibrosis

Pancreatic fibrosis is the main pathologic characteristic in chronic pancreatitis (CP), a common disease that arises from surgery. Pancreatitis is caused by various etiologies, but the mechanism of fibrosis is not completely understood. Existing clinical approaches mainly focus on mitigating the symptoms and therefore do not cure the phenomena. In recent years, there has been a heightened interest in the use of Chinese herbal medicine (CHMs) in the prevention and cure of CP as expressed by increasing numbers of clinical and experimental research. Despite early cell culture and animal models, CHMs are able to interact with plenty of molecular targets involved in the pathogenesis of pancreatic fibrosis mostly via the TGF- β /Smads pathway; however, integrated and up-to-date communication in this domain is unavailable. This review focuses on the research progress of CHMs against pancreatic fibrosis due to CP in vitro and in vivo and summarizes the potential mechanisms. We also outlined the toxicology of some CHMs for fibrosis treatment in order to provide a fuller understanding of drug safety. This review may provide reference for further innovative drug research and the future development of treatments for CP with pancreatic fibrosis.

C-reactive protein exacerbates epithelial-mesenchymal transition through Wnt/β-catenin and ERK signaling in streptozocin-induced diabetic nephropathy

Previous studies have reported the pathogenic role of C-reactive protein (CRP) during diabetic kidney disease (DKD) in human CRP transgenic and Crp^-/- mice. However, because humans and mice have inverse acute phase expression patterns of CRP and serum amyloid P component, this could lead to the inaccurate evaluation of CRP function with the above-mentioned CRP transgenic mouse. But different from mice, rats have the same acute phase protein expression pattern as human, which might avoid this problem and be a better choice for CRP function studies. To dispel this doubt and accurately define the role of CRP during diabetic nephropathy, we created the first Crp^-/- rat model, which we treated with streptozocin to induce DKD for in vivo studies. Moreover, an established cell line (human kidney 2) was used to further investigate the pathologic mechanisms of CRP. We found that CRP promotes epithelial-mesenchymal transition (EMT) through Wnt/β-catenin and ERK1/2 signaling, which are dependent on CRP binding to FcγRII on apoptotic cells. By promoting EMT, CRP was demonstrated to accelerate the development of DKD. We thus present convincing evidence demonstrating CRP as a therapeutic target for DKD treatment.-Zhang, L., Shen, Z.-Y., Wang, K., Li, W., Shi, J.-M., Osoro, E. K., Ullah, N., Zhou, Y., Ji, S.-R. C-reactive protein exacerbates epithelial-mesenchymal transition through Wnt/β-catenin and ERK signaling in streptozocin-induced diabetic nephropathy.

Astaxanthin ameliorates renal interstitial fibrosis and peritubular capillary rarefaction in unilateral ureteral obstruction

Loss of peritubular capillaries is a notable feature of progressive renal interstitial fibrosis. Astaxanthin (ASX) is a natural carotenoid with various biological activities. The present study aimed to evaluate the effect of ASX on unilateral ureteral obstruction (UUO)‑induced renal fibrosis in mice. For that purpose, mice were randomly divided into five treatment groups: Sham, ASX 100 mg/kg, UUO, UUO + ASX 50 mg/kg and UUO + ASX 100 mg/kg. ASX was administered to the mice for 7 or 14 days following UUO. The results demonstrated that UUO‑induced histopathological changes in the kidney tissue were prevented by ASX. Renal function was improved by ASX treatment, as evidenced by decreased blood urea nitrogen and serum creatinine levels. Furthermore, the extent of renal fibrosis and collagen deposition induced by UUO was suppressed by ASX. The levels of collagen I, fibronectin and α‑smooth muscle actin were increased by UUO in mice or by transforming growth factor (TGF)‑β1 treatment in NRK‑52E cells, and were reduced by ASX administration. In addition, ASX inhibited the UUO‑induced decrease in peritubular capillary density by upregulating vascular endothelial growth factor and downregulating thrombospondin 1 levels. Inactivation of the TGF‑β1/Smad signaling pathway was involved in the anti‑fibrotic mechanism of ASX in UUO mice and TGF‑β1‑treated NRK‑52E cells. In conclusion, ASX attenuated renal interstitial fibrosis and peritubular capillary rarefaction via inactivation of the TGF‑β1/Smad signaling pathway.