Poricoic acid ZA, a novel RAS inhibitor, attenuates tubulo-interstitial fibrosis and podocyte injury by inhibiting TGF-β/Smad signaling pathway

Novel Sesquiterpenoids with Renoprotective Activities from the Fruits of Alpinae oxyphylla as Potent TGF-β1/Smads Phosphorylation Inhibitors

The fruit of Alpinia oxyphylla Miq is an important food spice in southern China and has been used in the treatment of kidney disorders for centuries. In order to discover the natural products with potent renoprotective activities in A. oxyphylla and provide some references for its usage, systematic phytochemical studies were carried out and 24 new diverse sesquiterpenoids, including seven guaiane sesquiterpenoids (1-7), 10 eudesmane sesquiterpenoids (9-13, 18, 19, and 21-23), six cadinane sesquiterpenoids (31-35 and 38), and an eremophilane sesquiterpenoid (40), along with 24 known analogues were isolated and elucidated by analysis of spectroscopic data and quantum-chemical calculations. Biological evaluation showed that 6 sesquiterpenoids could significantly inhibit the expression of extracellular matrix components, α-SMA in TGF-β1 induced kidney proximal tubular cells (NRK-52e) at low concentrations, and 9 sesquiterpenoids could also downregulate fibronectin and collagen I in a concentration-dependent manner, showing their potential in renal fibrosis. Further action mechanism study displayed that TGF-β1/Smads pathway might be involved in the antifibrotic effects of active sesquiterpenoids 15 and 43. These studies suggest that A. oxyphylla may have a potential to serve as a functional food in preventing renal fibrosis-associated diseases.

Identification of squalene epoxidase in triterpenes biosynthesis in Poria cocos by molecular docking and CRISPR-Cas9 gene editing

BACKGROUND

Squalene epoxidase is one of the rate-limiting enzymes in the biosynthetic pathway of membrane sterols and triterpenoids. The enzyme catalyzes the formation of oxidized squalene, which is a common precursor of sterols and triterpenoids.

RESULT

In this study, the squalene epoxidase gene (PcSE) was evaluated in Poria cocos. Molecular docking between PcSE and squalene was performed and the active amino acids were identified. The sgRNA were designed based on the active site residues. The effect on triterpene synthesis in P. cocos was consistent with the results from ultra-high-performance liquid chromatography-quadruplex time-of-flight-double mass spectrometry (UHPLC-QTOF-MS/MS) analysis. The results showed that deletion of PcSE inhibited triterpene synthesis. In vivo verification of PcSE function was performed using a PEG-mediated protoplast transformation approach.

CONCLUSION

The findings from this study provide a foundation for further studies on heterologous biosynthesis of P. cocos secondary metabolites.

Interaction of estradiol and renin-angiotensin system with microRNAs-21 and -29 in renal fibrosis: focus on TGF-β/smad signaling pathway

Kidney fibrosis is one of the complications of chronic kidney disease (CKD (and contributes to end-stage renal disease which requires dialysis and kidney transplantation. Several signaling pathways such as renin-angiotensin system (RAS), microRNAs (miRNAs) and transforming growth factor-β1 (TGF-β1)/Smad have a prominent role in pathophysiology and progression of renal fibrosis. Activation of classical RAS, the elevation of angiotensin II (Ang II) production and overexpression of AT1R, develop renal fibrosis via TGF-β/Smad pathway. While the non-classical RAS arm, Ang 1-7/AT2R, MasR reveals an anti-fibrotic effect via antagonizing Ang II. This review focused on studies illustrating the interaction of RAS with sexual female hormone estradiol and miRNAs in the progression of renal fibrosis with more emphasis on the TGF-β signaling pathway. MiRNAs, especially miRNA-21 and miRNA-29 showed regulatory effects in renal fibrosis. Also, 17β-estradiol (E2) is a renoprotective hormone that improved renal fibrosis. Beneficial effects of ACE inhibitors and ARBs are reported in the prevention of renal fibrosis in patients. Future studies are also merited to delineate the new therapy strategies such as miRNAs targeting, combination therapy of E2 or HRT, ACEis, and ARBs with miRNAs mimics and antagomirs in CKD to provide a new therapeutic approach for kidney patients.

Screening, isolation, and activity evaluation of potential xanthine oxidase inhibitors in Poria Cum Radix Pini and mechanism of action in the treatment of gout disease

Poria Cum Radix Pini is a rare medicinal fungus that contains several potential therapeutic ingredients. On this basis, a particle swarm mathematical model was used to optimize the extraction process of total triterpenes from P. Cum Radix Pini, and xanthine oxidase inhibitors were screened using affinity ultrafiltration mass spectrometry. Meanwhile, the accuracy of the ultrafiltration assay was verified by molecular docking experiments and molecular dynamics analysis, and the mechanism of action of the active compounds for the treatment of gout was analyzed by enzymatic reaction kinetics and network pharmacology. A high-speed countercurrent chromatography method combined with the consecutive injection and the economical two-phase solvent system preparation using functional activity coefficient of universal quasichemical model (UNIFAC) mathematical model was developed for increasing the yield of target compound. In addition, dehydropachymic acid and pachymic acid were used as competitive inhibitors, and 3-O-acetyl-16alpha-hydroxydehydrotrametenolic acid and dehydrotrametenolic acid were used as mixed inhibitors. Then, activity-oriented separation and purification were performed by high-speed countercurrent chromatography combined with semi-preparative high-performance liquid chromatography and the purity of the four compounds isolated was higher than 90%. It will help to provide more opportunities to discover and develop new potential therapeutic remedies from health care food resources.

Antioxidant therapy against TGF-β/SMAD pathway involved in organ fibrosis

Fibrosis refers to excessive build-up of scar tissue and extracellular matrix components in different organs. In recent years, it has been revealed that different cytokines and chemokines, especially Transforming growth factor beta (TGF-β) is involved in the pathogenesis of fibrosis. It has been shown that TGF-β is upregulated in fibrotic tissues, and contributes to fibrosis by mediating pathways that are related to matrix preservation and fibroblasts differentiation. There is no doubt that antioxidants protect against different inflammatory conditions by reversing the effects of nitrogen, oxygen and sulfur-based reactive elements. Oxidative stress has a direct impact on chronic inflammation, and as results, prolonged inflammation ultimately results in fibrosis. Different types of antioxidants, in the forms of vitamins, natural compounds or synthetic ones, have been proven to be beneficial in the protection against fibrotic conditions both in vitro and in vivo. In this study, we reviewed the role of different compounds with antioxidant activity in induction or inhibition of TGF-β/SMAD signalling pathway, with regard to different fibrotic conditions such as gastro-intestinal fibrosis, cardiac fibrosis, pulmonary fibrosis, skin fibrosis, renal fibrosis and also some rare cases of fibrosis, both in animal models and cell lines.

Is the proximal tubule the focus of tubulointerstitial fibrosis?

Tubulointerstitial fibrosis (TIF), a common end result of almost all progressive chronic kidney diseases (CKD), is also the best predictor of kidney survival. Almost all cells in the kidney are involved in the progression of TIF. Myofibroblasts, the primary producers of extracellular matrix, have previously received a great deal of attention; however, a large body of emerging evidence reveals that proximal tubule (PT) plays a central role in TIF progression. In response to injury, renal tubular epithelial cells (TECs) transform into inflammatory and fibroblastic cells, producing various bioactive molecules that drive interstitial inflammation and fibrosis. Here we reviewed the increasing evidence for the key role of the PT in promoting TIF in tubulointerstitial and glomerular injury and discussed the therapeutic targets and carrier systems involving the PT that holds particular promise for treating patients with fibrotic nephropathy.

Effect of Qiling Jiaogulan Powder on Pulmonary Fibrosis and Pulmonary Arteriole Remodeling in Low-Temperature-Exposed Broilers

Chinese herbal medicine plays an important role in regulating the nutritional metabolism of poultry and maintaining or improving normal physiological functions and animal health. The present study investigated the effects of dietary supplementation with Qiling Jiaogulan Powder (QLJP) on pulmonary fibrosis and pulmonary arteriole remodeling in low temperature-exposed broilers. Seven-day-old Ross 308 broilers (n = 240) were reared adaptively to 14 days of age. The broilers were randomly divided into six groups: A control group (basal diet and normal feeding temperature); model group (basal diet); low-, medium- and high-dose QLJP groups (basal diet supplemented with 1 g/kg, 2 g/kg, 4 g/kg QLJP); and L-Arg group (basal diet supplemented with 10 g/kg L-arginine). Additionally, all the broilers, except the broilers in the control group, from the age of 14 days old, had a house temperature continuously lowered by 2 °C each day until it reached 12 °C at 21 days of age, and the low temperature was maintained until the end of the experiment. There were four replicates per group and 10 birds per replicate. The results showed that the structure of the lung tissue was clearer and basically intact in the broilers in the QLJP groups, with a small number of collagen fibers formed, and the content of hydroxyproline (HYP) was significantly reduced. QLJP improved pulmonary arteriole lesions, such as tunica media thickening, intimal hyperplasia, arterial wall hypertrophy, and lumen narrowing. QLJP reduced the relative media thickness (%) and relative medial area (%) of the pulmonary arteriole, and significantly decreased the expression level of the alpha-smooth muscle actin (α-SMA) protein in pulmonary arteriole, which alleviated pulmonary arteriole remodeling. The quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA) results showed that QLJP treatment significantly reduced the gene and protein levels of transforming growth factor-beta l (TGF-β1) and Smad2 in the lung and downregulated the gene and protein levels of collagen type I alpha 1 (COL1A1) and matrix metalloproteinase 2 (MMP2). In conclusion, the results of our study suggested that dietary supplementation with QLJP improved pulmonary fibrosis and pulmonary arteriole remodeling by inhibiting the expression of genes related to the TGF-β1/Smad2 signaling pathway and inhibited the occurrence and development of pulmonary arterial hypertension in low-temperature-exposed broilers.

Quercetin prevents chronic kidney disease on mesangial cells model by regulating inflammation, oxidative stress, and TGF-β1/SMADs pathway

Background

Chronic kidney disease (CKD) happens due to decreasing kidney function. Inflammation and oxidative stress have been shown to result in the progression of CKD. Quercetin is widely known to have various bioactivities including antioxidant, anticancer, and anti-inflammatory activities.

Objective

To evaluate the activity of quercetin to inhibit inflammation, stress oxidative, and fibrosis on CKD cells model (mouse mesangial cells induced by glucose).

Methods and Material

The SV40 MES 13 cells were plated in a 6-well plate with cell density at 5,000 cells/well. The medium had been substituted for 3 days with a glucose-induced medium with a concentration of 20 mM. Quercetin was added with 50, 10, and 5 µg/mL concentrations. The negative control was the untreated cell. The levels of TGF-β1, TNF-α, and MDA were determined using ELISA KIT. The gene expressions of the SMAD7, SMAD3, SMAD2, and SMAD4 were analyzed using qRT-PCR.

Results

Glucose can lead to an increase in inflammatory cytokines TNF-α, TGF-β1, MDA as well as the expressions of the SMAD2, SMAD3, SMAD4, and a decrease in SMAD7. Quercetin caused the reduction of TNF-α, TGF-β1, MDA as well as the expression of the SMAD2, SMAD3, SMAD4, and increased SMAD7.

Conclusion

Quercetin has anti-inflammation, antioxidant, antifibrosis activity in the CKD cells model. Thus, quercetin is a promising substance for CKD therapy and further research is needed to prove this in CKD animal model.

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.

The Traditional Usages, Chemical Components and Pharmacological Activities of Wolfiporia cocos: A Review

As an endemic species,Wolfiporia cocos (F.A. Wolf) Ryvarden & Gilb. is widely distributed, such as in China, Korea, Japan, and North America, which have had a dual-purpose resource for medicines and food for over 2000 years. The applications of W. cocos were used to treat diseases including edema, insomnia, spleen deficiency, and vomiting. What's more, there have been wide uses of such edible fungi as a function food or dietary supplement recently. Up until now, 166 kinds of chemical components have been isolated and identified from W. cocos including triterpenes, polysaccharides, sterols, diterpenes, and others. Modern pharmacological studies showed that the components hold a wide range of pharmacological activities both in vitro and in vivo, such as antitumor, anti-inflammatory, antibacterial, anti-oxidant, and antidepressant activities. In addition, present results showed that the mechanisms of pharmacological activities were closely related to chemical structures, molecular signaling paths and the expression of relate proteins for polysaccharides and triterpenes. For further in-depth studies on this fungus based on the recent research status, this review provided some perspectives and systematic summaries of W. cocos in traditional uses, chemical components, pharmacological activities, separation and analysis technologies, and structure-activity relationships.

Protective Effect of Melatonin for Renal Ischemia-Reperfusion Injury: A Systematic Review and Meta-Analysis

Background: Renal ischemia-reperfusion (I/R) injury is one of the major causes related to acute kidney damage. Melatonin has been shown as a powerful antioxidant, with many animal experiments have been designed to evaluate the therapeutic effect of it to renal I/R injury.

Objectives: This systematic review aimed to assess the therapeutic effect of melatonin for renal I/R injury in animal models.

Methods and Results: The PubMed, Web of Science, Embase, and Science Direct were searched for animal experiments applying melatonin to treat renal I/R injury to February 2021. Thirty-one studies were included. The pooled analysis showed a greater reduction of blood urea nitrogen (BUN) (21 studies, weighted mean difference (WMD) = −30.00 [−42.09 to −17.91], p < 0.00001), and serum creatinine (SCr) (20 studies, WMD = −0.91 [−1.17 to −0.66], p < 0.00001) treated with melatonin. Subgroup analysis suggested that multiple administration could reduce the BUN compared with control. Malondialdehyde and myeloperoxidase were significantly reduced, meanwhile, melatonin significantly improved the activity of glutathione, as well as superoxide dismutase. The possible mechanism for melatonin to treat renal I/R injury is inhibiting endoplasmic reticulum stress, apoptosis, inflammation, autophagy, and fibrillation in AKI to chronic kidney disease.

Conclusions: From the available data of small animal studies, this systematic review demonstrated that melatonin could improve renal function and antioxidative effects to cure renal I/R injury through, then multiple administration of melatonin might be more appropriate. Nonetheless, extensive basic experiments are need to study the mechanism of melatonin, then well-designed randomized controlled trials to explore the protective effect of melatonin.

Jeopardy of COVID-19: Rechecking the Perks of Phytotherapeutic Interventions

The novel coronavirus disease (COVID-19), the reason for worldwide pandemic, has already masked around 220 countries globally. This disease is induced by Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2). Arising environmental stress, increase in the oxidative stress level, weak immunity and lack of nutrition deteriorates the clinical status of the infected patients. Though several researches are at its peak for understanding and bringing forward effective therapeutics, yet there is no promising solution treating this disease directly. Medicinal plants and their active metabolites have always been promising in treating many clinical complications since time immemorial. Mother nature provides vivid chemical structures, which act multi-dimensionally all alone or synergistically in mitigating several diseases. Their unique antioxidant and anti-inflammatory activity with least side effects have made them more effective candidate for pharmacological studies. These medicinal plants inhibit attachment, encapsulation and replication of COVID-19 viruses by targeting various signaling molecules such as angiotensin converting enzyme-2, transmembrane serine protease 2, spike glycoprotein, main protease etc. This property is re-examined and its potency is now used to improve the existing global health crisis. This review is an attempt to focus various antiviral activities of various noteworthy medicinal plants. Moreover, its implications as prophylactic or preventive in various secondary complications including neurological, cardiovascular, acute kidney disease, liver disease are also pinpointed in the present review. This knowledge will help emphasis on the therapeutic developments for this novel coronavirus where it can be used as alone or in combination with the repositioned drugs to combat COVID-19.

RAAS, ACE2 and COVID-19; a mechanistic review

The use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in coronavirus disease 2019 (COVID-19) patients has been claimed as associated with the risk of COVID-19 infection and its subsequent morbidities and mortalities. These claims were resulting from the possibility of upregulating the expression of angiotensin-converting enzyme 2 (ACE2), facilitation of SARS-CoV-2 entry, and increasing the susceptibility of infection in such treated cardiovascular patients. ACE2 and renin-angiotensin-aldosterone system (RAAS) products have a critical function in controlling the severity of lung injury, fibrosis, and failure following the initiation of the disease. This review is to clarify the mechanisms beyond the possible deleterious effects of angiotensin II (Ang II), and the potential protective role of angiotensin 1-7 (Ang 1-7) against pulmonary fibrosis, with a subsequent discussion of the latest updates on ACEIs/ARBs use and COVID-19 susceptibility in the light of these mechanisms and biochemical explanation.

Circular RNAs; powerful microRNA sponges to overcome diabetic nephropathy

Diabetic nephropathy (DN), also known as diabetic kidney disease (DKD), is a drastic renal complication of type 1 and type 2 diabetes mellitus (DM). Poorly controlled DM over the years, may disrupt kidneys' blood vessels, leading to the hypertension (HTN) and DN onset. During DN, kidneys' waste filtering ability becomes disturbed. Being on a healthy lifestyle and controlling both DM and HTN are now the best proceedings to prevent or at least delay DN occurrence. Unfortunately, about one-fourth of diabetic individuals eventually experience the corresponding renal failure, and thus it is critical to discover effective diagnostic biomarkers and therapeutic strategies to combat DN. In the past few years, circular RNAs (circRNAs), as covalently closed endogenous non-coding RNAs (ncRNAs), are believed to affect DN pathogenesis in a positive manner. CircRNAs are able to impact different cellular processes and signaling pathways by targeting biological molecules or various molecular mechanisms. Still, as a key regulatory axis, circRNAs can select miRNAs as their molecular targets, in which they are considered as miRNA sponges. In this way, circRNA-induced suppression of particular miRNAs may prevent from DN progression or promotes the DN elimination. Since the expression of circRNAs has also been reported to be increased in DN-associated cells and tissues, they can be employed as either diagnostic biomarkers or therapeutic targets.

Natural product therapies in chronic kidney diseases: An update

Chronic kidney disease is one of the major worldwide public health problems. Traditional Chinese medications have been widely used for chronic kidney disease treatment. As the development of modern phytochemistry technology, natural products have been isolated from traditional Chinese medications, which provide a more precise method for the investigation of traditional Chinese medications. In this article, we selected eight natural products from traditional Chinese medications for chronic kidney disease therapy to summarize the recent advances for the development of new medications.

Uncovering the pharmacological mechanisms of Xijiao Dihuang decoction combined with Yinqiao powder in treating influenza viral pneumonia by an integrative pharmacology strategy

Xijiao Dihuang decoction combined with Yinqiao powder (XDD-YQP) is a classical combination formula; however, its therapeutic effects in treating influenza viral pneumonia and the pharmacological mechanisms remain unclear. The therapeutic effect of XDD-YQP in influenza viral pneumonia was evaluated in mice. Subsequently, an everted gut sac model coupled with UPLC/Q-TOF MS were used to screen and identify the active compounds of XDD-YQP. Furthermore, network pharmacological analysis was adopted to probe the mechanisms of the active compounds. Lastly, we verified the targets predicted from network pharmacological analysis by differential bioinformatics analysis. Animal experiments showed that XDD-YQP has a therapeutic effect on influenza viral pneumonia. Moreover, 113 active compounds were identified from intestinal absorbed solutions of XDD-YQP. Using network pharmacological analysis, 90 major targets were selected as critical in the treatment of influenza viral pneumonia through 12 relevant pathways. Importantly, the MAPK signaling pathway was found to be closely associated with the other 11 pathways. Moreover, seven key targets, EGFR, FOS, MAPK1, MAP2K1, HRAS, NRAS, and RELA, which are common targets in the MAPK signaling pathway, were investigated. These seven key targets were identified as differentially expressed genes (DEGs) between influenza virus-infected and uninfected individuals. Hence, the seven key targets in the MAPK signaling pathway may play a vital role in the treatment of influenza viral pneumonia with XDD-YQP. This research may offer an integrative pharmacology strategy to clarify the pharmacological mechanisms of traditional Chinese medicines. The results provide a theoretical basis for a broader clinical application of XDD-YQP.

Nanomedicine for the treatment of diabetes-associated cardiovascular diseases and fibrosis

Cardiomyopathy and fibrosis are the main causes of heart failure in diabetes patients. For therapeutic purposes, a delivery system is required to enhance antidiabetic drug efficacy and specifically target profibrotic pathways in cardiomyocytes. Nanoparticles (NPs) have distinct advantages, including biocompatibility, bioavailability, targeting efficiency, and minimal toxicity, which make them ideal for antidiabetic treatment. In this review, we overview the latest information on the pathogenesis of cardiomyopathy and fibrosis in diabetes patients. We summarize how NP applications improve insulin and liraglutide efficacy and their sustained release upon oral administration. We provide a comprehensive review of the results of NP clinical trials in diabetes patients and of animal studies investigating the effects of NP-mediated anti-fibrotic treatments. Collectively, the application of advanced NP delivery systems in the treatment of cardiomyopathy and fibrosis in diabetes patients is a promising and innovative therapeutic strategy.

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.

Phytochemistry and Biological Activities of Poria

Poria is a common Traditional Chinese Medicine in clinic. In recent years, the chemical and pharmacological studies of Poria have made great progress, triterpenes and polysaccharides have been isolated, and various types of compounds containing lipids, octanoic acids, fatty acids, and trace elements have been found. In this paper, we reviewed the literature, summarized the main compound types, and reviewed in detail their pharmacological effects in antitumor, immunomodulatory, effects on kidney, hepatoprotective activity, effects on blood sugar, antioxidant effects, anti-inflammatory effects, effects on the gut, antidepressant, and so on, and also categorized the compounds with the same or similar pharmacological effects to provide a reference for the in-depth study of the material basis of the pharmacological effect, quality standards, and pharmacological activity of Poria.

Epiberberine ameliorated diabetic nephropathy by inactivating the angiotensinogen (Agt) to repress TGFβ/Smad2 pathway

BACKGROUND

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes with prominent morbidity and mortality. At present, there are hardly any effective drugs to treat DN. Epiberberine (EPI), an isoquinoline alkaloid, has attracted considerable attention due to its anti-hyperglycemic, anti-hyperlipidemic, and anti-inflammatory functions. However, whether there is a protective effect of EPI on DN has not been reported.

PURPOSE

The research was aimed to investigate the activities of EPI alleviating kidney damage in db/db mice and to explore its possible mechanisms.

STUDY DESIGN

The db/db mice and high-glucose (HG) induced glomerular mesangial cells (GMCs) were used to explore the protective effect of EPI on DN in vivo and in vitro.

METHODS

The changes in fasting blood glucose, metabolic index, renal function, and histopathological morphology in db/db mice were detected to evaluate the therapeutic effect of EPI. Then, renal transcriptome and molecular docking were used to screen the key targets. Subsequently, HG-induced GMCs through mimicing the pathological changes in DN were utilized to study the renal protective effects of EPI and its potential mechanism.

RESULTS

The results in vivo showed that EPI administration for 8 weeks significantly alleviated diabetes-related metabolic disorders, improved renal functions, and relieved the histopathological abnormalities of renal tissue, especially renal fibrosis in db/db mice. The results in vitro showed that EPI inhibited the proliferation and induced the G2/M phase arrest of HG-induced GMCs. Moreover, a key gene Angiotensinogen (Agt) was screen out by the RNA-seq of kidney and molecular docking, and EPI reduced Agt, TGFβ1, and Smad2 expression in vitro and in vivo. Noteworthy, Agt knockdown by siRNA significantly attenuated these beneficial efficacies exerted by EPI, indicating that Agt played a crucial role in the process of EPI improving DN.

CONCLUSION

These findings suggested that EPI might be a potential drug for the treatment of DN dependent on the Agt-TGFβ/Smad2 pathway.

The Dysregulation of Eicosanoids and Bile Acids Correlates with Impaired Kidney Function and Renal Fibrosis in Chronic Renal Failure

Chronic renal failure (CRF) is an irreversible deterioration of the renal functions that characterized by fluid electrolyte unbalance and metabolic-endocrine dysfunctions. Increasing evidence demonstrated that metabolic disturbances, especially dyslipidemia and profound changes in lipid and lipoprotein metabolism were involved in CRF. Identification of lipids associated with impaired kidney functions may play important roles in the understanding of biochemical mechanism and CRF treatment. Ultra-performance liquid chromatography coupled with high-definition mass spectrometry-based lipidomics was performed to identify important differential lipids in adenine-induced CRF rats and investigate the undergoing anti-fibrotic mechanism of Polyporus umbellatus (PPU) and ergone (ERG). Linear correlation analysis was performed between lipid species intensities and creatinine levels in serum. Adenine-induced rats exhibited declining kidney function and renal fibrosis. Compared with control rats, a panel of lipid species was identified in the serum of CRF rats. Our further study demonstrated that eight lipids, including leukotrienes and bile acids, presented a strong linear correlation with serum creatinine levels. In addition, receiver operating characteristics analysis showed that eight lipids exhibited excellent area under the curve for differentiating CRF from control rats, with high sensitivity and specificity. The aberrant changes of clinical biochemistry data and dysregulation of eight lipids could be significantly improved by the administration of PPU and ergone. In conclusion, CRF might be associated with the disturbance of leukotriene metabolism, bile acid metabolism and lysophospholipid metabolism. The levels of eicosanoids and bile acids could be used for indicating kidney function impairment in CRF. PPU could improve renal functions and either fully or partially reversed the levels of eicosanoids and bile acids.

Mechanism of herbal medicine on hypertensive nephropathy (Review)

Hypertensive nephropathy is the most common complication of hypertension, and is one of the main causes of end-stage renal disease (ESRD) in numerous countries. The basic pathological feature of hypertensive nephropathy is arteriolosclerosis followed by renal parenchymal damage. The etiology of this disease is complex, and its pathogenesis is mainly associated with renal hemodynamic changes and vascular remodeling. Despite the increased knowledge on the pathogenesis of hypertensive nephropathy, the current clinical treatment methods are still not effective in preventing the development of the disease to ESRD. Herbal medicine, which is used to relieve symptoms, can improve hypertensive nephropathy through multiple targets. Since there are few clinical studies on the treatment of hypertensive nephropathy with herbal medicine, this article aims to review the progress on the basic research on the treatment of hypertensive nephropathy with herbal medicine, including regulation of the renin angiotensin system, inhibition of sympathetic excitation, antioxidant stress and anti-inflammatory protection of endothelial cells, and improvement of obesity-associated factors. Herbal medicine with different components plays a synergistic and multi-target role in the treatment of hypertensive nephropathy. The description of the mechanism of herbal medicine in the treatment of hypertensive nephropathy will contribute towards the progress of modern medicine.

Early intervention with Di-Dang Decoction prevents macrovascular fibrosis in diabetic rats by regulating the TGF-β1/Smad signalling pathway

Macroangiopathy is a complication of Type II Diabetes Mellitus (T2DM), which is mainly caused by fibrosis of blood vessels. Using T2DM rat models, we investigated whether the traditional Chinese medicine, Di-Dang Decoction (DDD), exhibited anti-fibrotic actions on great vessels. T2DM rats were randomly divided into non-intervention group, early-, middle-, late-stage DDD intervention groups and control groups, including pioglitazone group and aminoguanidine group. After administration of DDD to T2DM rats at different times, we detected the amount of extracellular matrix (ECM) deposition in the thoracic aorta. The results showed that early-stage intervention with DDD could effectively protect great vessels from ECM deposition. Considering that TGF-β1 is the master regulator of fibrosis, we further validated at the molecular level that, compared to middle- and late-stage intervention with DDD, early-stage intervention with DDD could significantly decrease the expression levels of factors related to the activated TGF-β1/Smad signalling pathway, as well as the expression levels of downstream effectors including CTGF, MMP and TIMP family proteins, which were directly involved in ECM remodelling. Therefore, early-stage intervention with DDD can reduce macrovascular fibrosis and prevent diabetic macroangiopathy.

Long non-coding RNAs: A double-edged sword in aging kidney and renal disease

Aging as one of intrinsic biological processes is a risk factor for many chronic diseases. Kidney disease is a global problem and health care burden worldwide. The diagnosis of kidney disease is currently based on serum creatinine and urea levels. Novel biomarkers may improve diagnostic accuracy, thereby allowing early prevention and treatment. Over the past few years, advances in genome analyses have identified an emerging class of noncoding RNAs that play critical roles in the regulation of gene expression and epigenetic reprogramming. Long noncoding RNAs (lncRNAs) are pervasively transcribed in the genome and could bind DNA, RNA and protein. Emerging evidence has demonstrated that lncRNAs played an important role in all stages of kidney disease. To date, only some lncRNAs were well identified and characterized, but the complexity of multilevel regulation of transcriptional programs involved in these processes remains undefined. In this review, we summarized the lncRNA expression profiling of large-scale identified lncRNAs on kidney diseases including acute kidney injury, chronic kidney disease, diabetic nephropathy and kidney transplantation. We further discussed a number of annotated lncRNAs linking with complex etiology of kidney diseases. Finally, several lncRNAs were highlighted as diagnostic biomarkers and therapeutic targets. Targeting lncRNAs may represent a precise therapeutic strategy for progressive renal fibrosis.

Investigation of inhibition effect of butanol and water extracts of Matricaria chamomilla L. on angiotensin-converting enzyme purified from human plasma

Angiotensin-converting enzyme (ACE) liable for the regulation of blood pressure was purified from human plasma by affinity chromatography. Impact of water and butanol extracts of Matricaria chamomilla L. on purity ACE was examined. ACE was purified using the affinity chromatography method. The enzyme activity was evaluated at 345 nm by a spectrophotometer. Extracts of M. chamomilla plant with butanol and water were prepared. Lisinopril was utilized as a specific inhibitor. ACE was purified 3,659-fold from human plasma and the specific activity was 1,350 EU/mg protein. The molecular weight and purity of ACE were found by SDS-PAGE and two bands of 60 and 70 kDa on the gel were detected. Water and butanol extracts of M. chamomilla demonstrated inhibitor impact on ACE activity. IC₅₀ constants for water and butanol extracts of M. chamomilla were computed to be 1.292 and 0.353 mg/mL, respectively. The type of inhibition for whole inhibitors was identified as noncompetitive. IC₅₀ and K_i constants for lisinopril were calculated to be 0.781 and 0.662 nM, respectively. These results indicate that butanol and water extracts of M. chamomilla may have an ACE inhibitor potential.

Novel poricoic acids attenuate renal fibrosis through regulating redox signalling and aryl hydrocarbon receptor activation

BACKGROUND

Renal fibrosis is the final manifestation of chronic kidney disease (CKD). Renal fibrosis is largely driven by oxidative stress and inflammation.

PURPOSE

The aim of the current study was to identify novel poricoic acids from Poria cocos and investigated their antifibrotic effects and the underlying mechanism.

METHODS

In this study, we identified six novel poricoic acids from Poria cocos and examined their antifibrotic effect using transforming growth factor-β1- (TGF-β1-) induced cultured human kidney proximal tubular epithelial cells (HK-2) and mice with unilateral ureteral obstruction (UUO).

RESULTS

Treatment with six poricoic acids significantly inhibited TGF-β1-induced α-smooth muscle actin expression at both mRNA and protein levels in HK-2 cells. Three compounds with an intact carboxyl group at C-3 position showed a stronger inhibitory effect than that of other three compounds with esterified carboxyl group at the C-3 position. Mechanistically, poricoic acid ZM (PZM) and poricoic acid ZP (PZP) attenuate renal fibrosis through the modulation of redox signalling including the inhibition of proinflammatory nuclear factor kappa B (NF-κB) signalling and its target genes as well as the activation of antioxidative nuclear factor-erythroid-2-related factor 2 (Nrf2) signalling and its downstream target gene in both TGF-β1-induced HK-2 cells and UUO mice. PZM treatment and PZP treatment inhibit the upregulated aryl hydrocarbon receptor and they target the gene expression in UUO mice. Intriguingly, PZM treatment exhibits a stronger inhibitory effect than that of the PZP treatment. Structure-function relationship reveals that the carboxyl group at C-3 position is the most important bioactive function group in secolanostane tetracyclic triterpenoids against renal fibrosis.

CONCLUSIONS

PZM and PZP attenuated renal fibrosis through the modulation of redox signalling and the aryl hydrocarbon receptor signalling pathway. Our findings will provide several promising leading compounds against renal fibrosis.

Deciphering the cellular mechanisms underlying fibrosis-associated diseases and therapeutic avenues

Fibrosis is the excessive deposition of extracellular matrix components, which results in disruption of tissue architecture and loss of organ function. Fibrosis leads to high morbidity and mortality worldwide, mainly due to the lack of effective therapeutic strategies against fibrosis. It is generally accepted that fibrosis occurs during an aberrant wound healing process and shares a common pathogenesis across different organs such as the heart, liver, kidney, and lung. A better understanding of the fibrosis-related cellular and molecular mechanisms will be helpful for development of targeted drug therapies. Extensive studies revealed that numerous mediators contributed to fibrogenesis, suggesting that targeting these mediators may be an effective therapeutic strategy for antifibrosis. In this review, we describe a number of mediators involved in tissue fibrosis, including aryl hydrocarbon receptor, Yes-associated protein, cannabinoid receptors, angiopoietin-like protein 2, high mobility group box 1, angiotensin-converting enzyme 2, sphingosine 1-phosphate receptor-1, SH2 domain-containing phosphatase-2, and long non-coding RNAs, with the goal that drugs targeting these important mediators might exhibit a beneficial effect on antifibrosis. In addition, these mediators show profibrotic effects on multiple tissues, suggesting that targeting these mediators will exert antifibrotic effects on different organs. Furthermore, we present a variety of compounds that exhibit therapeutic effects against fibrosis. This review suggests therapeutic avenues for targeting organ fibrosis and concurrently identifies challenges and opportunities for designing new therapeutic strategies against fibrosis.

Poricoic acid A as a modulator of TPH-1 expression inhibits renal fibrosis via modulating protein stability of β-catenin and β-catenin-mediated transcription

Background

Renal fibrosis is the common feature of chronic kidney disease (CKD). However, few drugs specifically target fibrogenesis due to the lack of an effective therapeutic target. Hence, it is urgent to find a therapeutic strategy that inhibits renal fibrosis. Here, we identified that poricoic acid A (PAA) as the modulator of tryptophan hydroxylase-1 (TPH-1), the key enzyme in tryptophan metabolism, exerted potent anti-fibrotic effects in the kidney.

Methods

Lentiviral vector, luciferase reporter activity assay and co-immunoprecipitation were used. The animal model of unilateral ureteral obstruction and adenine-induced chronic renal failure as well as transforming growth factor (TGF)-β1-treated epithelial cells NRK-52E and fibroblasts NRK-49F were used.

Results

TPH-1 was gradually decreased during CKD progression, while PAA treatment significantly increased TPH-1 expression to suppress renal fibrosis. Pharmacological overexpression of TPH-1 by PAA treatment exhibited anti-fibrosis and was linked to Wnt/β-catenin signaling activity. TPH-1 exhibited anti-fibrotic effects by suppressing epithelial cell injury and fibroblast activation, and PAA promoted TPH-1 expression and then suppressed the Wnt/β-catenin signaling pathway via regulating the protein stability of β-catenin and β-catenin-mediated transcription. TPH-1 overexpression enhanced the anti-fibrotic effects of PAA, while TPH-1 deficiency weakened the anti-fibrotic effects of PAA, indicating that TPH-1 was required for the anti-fibrotic effects of PAA.

Conclusion

PAA as a modulator of TPH-1 expression attenuated renal fibrosis through regulating the Wnt/β-catenin signaling pathway by acting on the protein stability of β-catenin and β-catenin-mediated transcription. TPH-1 was required for PAA to exert anti-fibrosis.

Phytochemistry and Pharmacological Activities of Wolfiporia cocos (F.A. Wolf) Ryvarden & Gilb

Poria cocos is the dried sclerotium of Wolfiporia cocos (F.A. Wolf) Ryvarden & Gilb., which was the current accepted name and was formerly known as Macrohyporia cocos (Schwein.) I. Johans. & Ryvarden, Pachyma cocos (Schwein.) Fr., Poria cocos F.A. Wolf and Sclerotium cocos Schwein. It is one of the most important crude drugs in traditional Chinese medicine, with a wide range of applications in ameliorating phlegm and edema, relieving nephrosis and chronic gastritis and improving uneasiness of minds. Its extensive pharmacological effects have attracted considerable attention in recent years. However, there is no systematic review focusing on the chemical compounds and pharmacological activities of Poria cocos. Therefore, this review aimed to provide the latest information on the chemical compounds and pharmacological effects of Poria cocos, exploring the therapeutic potential of these compounds. We obtained the information of Poria cocos from electronic databases such as SCI finder, PubMed, Web of Science, CNKI, WanFang DATA and Google Scholar. Up to now, two main active ingredients, triterpenes and polysaccharides of Poria cocos, have been identified from Poria cocos. It has been reported that they have pharmacological effects on anti-tumor, anti-bacterial, anti-oxidant, anti-inflammatory, immunomodulation, and liver and kidney protection. The review summarizes the phytochemistry and pharmacological properties of Poria cocos, which suggest that researchers should focus on the development of new drugs about Poria cocos to make them exert greater therapeutic potential.

Alleviation by Mahuang Fuzi and Shenzhuo Decoction in High Glucose-Induced Podocyte Injury by Inhibiting the Activation of Wnt/β-Catenin Signaling Pathway, Resulting in Activation of Podocyte Autophagy

Background

Organ fibrosis is a common endpoint of a variety of diseases. Many studies have shown that the pathogenesis of diabetic kidney disease (DKD) is related to the excessive activation of the Wnt/β-catenin signaling pathway on podocytes, so the treatment of DKD starts from this signaling pathway. At the same time, DKD, as a metabolic disease, has many connections related to podocyte autophagy.

Objectives

We experimented the effects of Mahuang Fuzi and Shenzhuo decoction (MFSD) which is the combination of Mahuang Fuzi decoction and Shenzhuo decoction in traditional Chinese medicine compounds used "The Golden Chamber" in high glucose-induced podocytes, determined whether this effect was related to Wnt/β-catenin signaling pathway, and further investigated the relationship between this effect and autophagy.

Methods

The mice podocytes were stimulated by using 30 mmol/L of high glucose and serum containing MFSD or Wnt/β-catenin signaling pathway inhibitor DKK1 (100 ng/ml) was used to intervene podocytes before high glucose stimulation. Podocyte injury-related proteins, Wnt/β-catenin signaling pathway-related proteins, and autophagy-related proteins were detected by using western blotting and immunofluorescence analysis.

Results

Our results showed that DKK1 and MFSD treatment significantly upregulated the protein expressions of nephrin, podocin, podocalyxin, and podoplanin in high glucose-induced podocytes and downregulated the β-catenin protein expression. Furthermore, the protein expressions of beclin1, LC3B, and P62 were also significantly increased in high glucose-induced podocytes.

Conclusion

Our experiments confirmed that the destruction of podocytes in DKD is related to the excessive activation of Wnt/β-catenin signaling pathway and the inhibition of autophagy after activation. MFSD treatment can inhibit the activation of Wnt/β-catenin signaling pathway in podocytes stimulated by high glucose and helpful in reducing the podocyte injury. This protective mechanism can be related to the enhancement of podocyte autophagy by MFSD treatment.

A novel identified circular RNA, circ_0000491, aggravates the extracellular matrix of diabetic nephropathy glomerular mesangial cells through suppressing miR‑101b by targeting TGFβRI

Circular RNAs (circRNAs) have crucial roles in various diseases; however, the mechanisms of action underlying circRNAs in the occurrence and development of diabetic nephropathy (DN) remains largely unknown. The present study investigated the differentially expressed circRNAs in the DN mice kidney cortex using circRNA sequencing and elucidated the role of circRNAs in mesangial cells. It was revealed that 40 circRNAs were unconventionally expressed, including 18 upregulated circRNAs and 22 downregulated circRNAs. Furthermore, circ_0000491 levels were significantly augmented in both DN mice and high glucose (HG, 30 mM)-induced mouse mesangial cells (MES13 cells). Knockdown of circ_0000491 significantly suppressed the increase of vimentin, fibronectin and α-smooth muscle actin, as well as collagen type I, III and IV, whilst reversing the decrease of E-cadherin in HG-induced MES13 cells. It was further revealed that circRNA_0000491 sponged miR-101b and that miR-101b directly targets TGFβRI. In addition, the expression levels of miR-101b were negatively associated with the transcriptional level of circRNA_0000491 and miR-101b inhibitors reversed the suppression of extracellular matrix (ECM)-associated protein synthesis mediated by knocking-down circRNA_0000491. In conclusion, the present study investigated the circRNA_0000491/miR-101b/TGFβRI axis in ECM accumulation and fibrosis-associated protein expression levels of mesangial cells, which suggested that circRNA_0000491 may be beneficial for the development of an effective therapeutic target for DN.

Potential mechanisms of Chinese Herbal Medicine that implicated in the treatment of COVID-19 related renal injury

Clinical studies have shown that renal injury in Corona Virus Disease 2019 (COVID-19) patients has been a real concern, which is associated with high mortality and an inflammation/apoptosis-related causality. Effective target therapy for renal injury has yet been developed. Besides, potential anti-COVID-19 medicines have also been reported to cause adverse side effects to kidney. Chinese Herbal Medicine (CHM), however, has rich experience in treating renal injury and has successfully applied in China in the battle of COVID-19. Nevertheless, the molecular mechanisms of CHM treatment are still unclear. In this study, we searched prescriptions in the treatment of renal injury extensively and the potential mechanisms to treat COVID-19 related renal injury were investigated. The association rules analysis showed that the core herbs includes Huang Qi, Fu Ling, Bai Zhu, Di Huang, Shan Yao. TCM herbs regulate core pathways, such as AGE-RAGE, PI3K-AKT, TNF and apoptosis pathway, etc. The ingredients (quercetin, formononetin, kaempferol, etc.,) from core herbs could modulate targets (PTGS2 (COX2), PTGS1 (COX1), IL6, CASP3, NOS2, and TNF, etc.), and thereby prevent the pharmacological and non-pharmacological renal injury comparable to that from COVID-19 infection. This study provides therapeutic potentials of CHM to combat COVID-19 related renal injury to reduce complications and mortality.

Poricoic acid A activates AMPK to attenuate fibroblast activation and abnormal extracellular matrix remodelling in renal fibrosis

BACKGROUND

In chronic kidney disease, although fibrosis prevention is beneficial, few interventions are available that specifically target fibrogenesis. Poricoic acid A (PAA) isolated from Poria cocos exhibits anti-fibrotic effects in the kidney, however the underlying mechanisms remain obscure.

PURPOSE

We isolated PAA and investigated its effects and the underlying mechanisms in renal fibrosis.

STUDY DESIGN

Unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (Nx) animal models and TGF-β1-induced renal fibroblasts (NRK-49F) were used to investigate the anti-fibrotic activity of PAA and its underlying mechanisms.

METHODS

Western blots, qRT-PCR, immunofluorescence staining, co-immunoprecipitation and molecular docking methods were used. Knock-down and knock-in of adenosine monophosphate-activated protein kinase (AMPK) in the UUO model and cultured NRK-49F cells were employed to verify the mechanisms of action of PAA.

RESULTS

PAA improved renal function and alleviated fibrosis by stimulating AMPK and inhibiting Smad3 specifically in Nx and UUO models. Reduced AMPK activity was associated with Smad3 induction, fibroblast activation, and the accumulation and aberrant remodelling of extracellular matrix (ECM) in human renal puncture samples and cultured NRK-49F cells. PAA stimulated AMPK activity and decreased fibrosis in a dose-dependent manner, thus showing that AMPK was essential for PAA to exert its anti-fibrotic effects. AMPK deficiency reduced the anti-fibrotic effects of PAA, while AMPK overexpression enhanced its effect.

CONCLUSION

PAA activated AMPK and further inhibited Smad3 specifically to suppress fibrosis by preventing aberrant ECM accumulation and remodelling and facilitating the deactivation of fibroblasts.

MicroRNA-183 exerts a protective role in lupus nephritis through blunting the activation of TGF-β/Smad/TLR3 pathway via reducing Tgfbr1

PURPOSE

The role of microRNA (miR)-183 has been elucidated in systemic lupus erythematosus, while whether it is also engaged in the lupus nephritis (LN) development remains opaque. The intention of this study is to examine the relevance of miR-183 downregulation in the pathogenesis of LN.

METHODS

The expression of miR-183 was first detected in MRL/lpr mice at weeks 8 and 12, followed by the assessment the effects of miR-183 on renal fibrosis and inflammatory response after overexpression or silencing of miR-183 in mice with LN. We further overexpressed or knocked-down miR-183 in human renal glomerular endothelial cells (HRGECs), and detected the expression patterns of inflammatory factors and Vimentin and α-SMA in the cells. Differentially expressed genes in HRGECs overexpressing miR-183 by microarrays were intersected with targeting mRNAs of miR-183 predicted by bioinformatics websites. The effects of transforming growth factor beta receptor 1 (Tgfbr1) and TGF-β/Smad/TLR3 pathway on renal damage in mice were verified by rescue experiments.

RESULTS

miR-183 expression was notably lower in MRL/lpr mice, and increased miR-183 expression inhibited renal fibrosis and inflammatory response in mice with LN. Moreover, miR-183 inhibitor in HRGECs remarkably promoted the expression of Vimentin and α-SMA and the secretion of inflammatory factors. miR-183 protected the mouse kidney from pathological damages by targeting and inhibiting Tgfbr1 expression.

CONCLUSION

miR-183 inhibited the expression of Tgfbr1 by direct targeting to disrupt the TGF-β/Smad/TLR3 pathway, thus repressing renal fibrosis and the secretion of inflammatory factors in LN.

Kidney targeted delivery of asiatic acid using a FITC labeled renal tubular-targeting peptide modified PLGA-PEG system

Chronic kidney disease (CKD) is one of the leading public health problems worldwide and finally progresses to end-stage renal disease. The therapeutic options of CKD are very limited. Thus, development of drug delivery systems specific-targeting to kidney may offer more options. Here we developed an efficient kidney-targeted drug delivery system using a FITC labeled renal tubular-targeting peptide modified PLGA-PEG nanoparticles and investigated the intrarenal distribution and cell-type binding. We found that the modified nanoparticles with an approximate diameter of 200 nm exhibited the highest binding capacity with HK-2 cells and fluorescence and immunohistochemical analysis showed they mainly localized in renal proximal tubules by passing through the basolateral side. Furthermore, these kidney-specific nanoparticles could significantly enhance the therapeutic effects of asiatic acid, an insoluble triterpenoid compound as drug delivery carriers. In conclusion, these results suggest the potential of the peptide modified PLGA-PEG nanoparticles as kidneytargeted drug delivery system to proximal tubular cells in treatment of CKD.

Salvianolic acid B attenuates epithelial-mesenchymal transition in renal fibrosis rats through activating Sirt1-mediated autophagy

Renal fibrosis is a kind of progressive kidney disease leading to end-stage renal damage. Epithelial-mesenchymal transition (EMT) is one of the crucial features of renal fibrosis. Salvianolic acid B (SalB), isolated from traditional Chinese medicine Radix Salviae miltiorrhizae, has been proved to be suitable for renal protection. The aims of this study are to investigate the pharmacological effects of SalB on renal fibrosis and explore the underlying mechanisms. In vivo, our study showed that SalB could improve kidney dysfunction and reduce the expression of EMT-related proteins, including fibronectin (FN), α-smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β). In addition, SalB activated autophagy and up-regulated the expression of Sirt1. In vitro, our study showed that SalB reversed EMT in TGF-β1-induced human kidney proximal tubular epithelial cells (HK-2 cells). Further mechanism studies showed that the inhibition of Sirt1 and autophagy could reverse the protective effect of SalB on the EMT process in TGF-β1-induced HK-2 cells. Taken together, this study demonstrated that SalB attenuates EMT in the process of renal fibrosis through activating Sirt1-mediated autophagy, and Sirt1 could be a key target for treatment of renal fibrosis.

Alisol B 23-acetate attenuates CKD progression by regulating the renin-angiotensin system and gut-kidney axis

Background:

Increasing evidence suggests a link between the gut microbiome and various diseases including hypertension and chronic kidney disease (CKD). However, studies examining the efficacy of controlling blood pressure and inhibiting the renin–angiotensin system (RAS) in preventing CKD progression are limited.

Methods:

In the present study, we used 5/6 nephrectomised (NX) and unilateral ureteral obstructed (UUO) rat models and cultured renal tubular epithelial cells and fibroblasts to test whether alisol B 23-acetate (ABA) can attenuate renal fibrogenesis by regulating blood pressure and inhibiting RAS.

Results:

ABA treatment re-established dysbiosis of the gut microbiome, lowered blood pressure, reduced serum creatinine and proteinuria, suppressed expression of RAS constituents and inhibited the epithelial-to-mesenchymal transition in NX rats. Similarly, ABA treatment inhibited expression of collagen I, fibronectin, vimentin, α-smooth muscle actin and fibroblast-specific protein 1 at both mRNA and protein levels in UUO rats. ABA was also effective in suppressing activation of the transforming growth factor-β (TGF-β)/Smad3 and preserving Smad7 expression in both NX and UUO rats. In vitro experiments demonstrated that ABA treatment inhibited the Wnt/β-catenin and mitochondrial-associated caspase pathways.

Conclusion:

These data suggest that ABA attenuated renal fibrosis through a mechanism associated with re-establishing dysbiosis of the gut microbiome and regulating blood pressure, and Smad7-mediated inhibition of Smad3 phosphorylation. Thus, we demonstrate ABA as a promising candidate for treatment of CKD by improving the gut microbiome and regulating blood pressure.

Myricetin Possesses Anthelmintic Activity and Attenuates Hepatic Fibrosis via Modulating TGFβ1 and Akt Signaling and Shifting Th1/Th2 Balance in Schistosoma japonicum-Infected Mice

Schistosomiasis is a zoonotic and debilitating parasitic disease caused by Schistosoma japonicum. Praziquantel remains the choice for treating schistosomiasis, but its efficacy could be hampered by emergence of resistance. In this study, using large-scale drug screening, we selected out myricetin, a natural flavonol compound, having a good anti-schistosome effect. We found that myricetin exhibited dose and time-dependent insecticidal effect on S. japonicum in vitro, with an LC₅₀ of 600 μM for 24 h, and inhibited female spawning. The drug mainly destroyed the body structure of the worms and induced apoptosis of the worm cells, which in turn led to death. In addition, oral administration of myricetin in mice infected with S. japonicum showed a deworming effect in vivo, as evidenced by a significant reduction in the liver egg load. H&E staining, quantitative RT-PCR, and Western blotting assays showed that myricetin significantly alleviated liver fibrosis in mice infected with S. japonicum. Myricetin also effectively inhibited the expression of TGFβ1, Smad2, phospho-Smad2, Smad3, phospho-Smad3, ERK, phospho-ERK, Akt, and phospho-Akt in the liver of infected mice, suggesting that myricetin attenuated liver fibrosis in mice via modulating TGFβ1 and Akt signaling. Flow cytometric analysis of Th subtypes (Th1/Th2/Th17/Treg) in the mouse spleen further revealed that myricetin significantly increased the percentage Th1 cells in infected mice and reduced the proportion of Th2 cells and Th17 cells. Immunology multiplex assay further showed that myricetin attenuated S. japonicum-induced rise in the plasma levels of IL-4, IL-5, IL-10, IL-13, and IL-17A in infected mice while increasing the plasma contents of IFN-γ, IL-12, and IL-7. In conclusion, our study provides the first direct evidence that myricin possesses potent anti-schistosome activities in vitro and in vivo, and offers new insights into the mechanisms of action by myricetin. The present findings suggest that myricetin could be further explored as a therapeutic agent for S. japonicum.

Angiotensin II triggers RIPK3-MLKL-mediated necroptosis by activating the Fas/FasL signaling pathway in renal tubular cells

Our earlier studies proved that RIPK3-mediated necroptosis might be an important mode of renal tubular cell death in rats with chronic renal injury and the necroptotic cell death can be triggered by tumor necrosis factor-α (TNF-α) in vitro, but the triggering role of angiotensin II (AngII), which exerts notable effects on renal cells for the initiation and progression of renal tubulointerstitial fibrosis, is largely unknown. Here, we identified the presence of necroptotic cell death in the tubular cells of AngII-induced chronic renal injury and fibrosis mice and assessed the percentage of necroptotic renal tubular cell death with the disruption of this necroptosis by the addition of necrostatin-1 (Nec-1). Furthermore, the observation was further confirmed in HK-2 cells treated with AngII and RIPK1/3 or MLKL inhibitors. The detection of Fas and FasL proteins led us to investigate the contribution of the Fas/FasL signaling pathway to AngII-induced necroptosis. Disruption of FasL decreased the percentage of necroptotic cells, suggesting that Fas and FasL are likely key signal molecules in the necroptosis of HK-2 cells induced by AngII. Our data suggest that AngII exposure might trigger RIPK3-MLKL-mediated necroptosis in renal tubular epithelial cells by activating the Fas/FasL signaling pathway in vivo and in vitro.

AT1 and AT2 receptors modulate renal tubular cell necroptosis in angiotensin II-infused renal injury mice

Abnormal renin-angiotensin system (RAS) activation plays a critical role in the initiation and progression of chronic kidney disease (CKD) by directly mediating renal tubular cell apoptosis. Our previous study showed that necroptosis may play a more important role than apoptosis in mediating renal tubular cell loss in chronic renal injury rats, but the mechanism involved remains unknown. Here, we investigate whether blocking the angiotensin II type 1 receptor (AT1R) and/or angiotensin II type 2 receptor (AT2R) beneficially alleviates renal tubular cell necroptosis and chronic kidney injury. In an angiotensin II (Ang II)-induced renal injury mouse model, we found that blocking AT1R and AT2R effectively mitigates Ang II-induced increases in necroptotic tubular epithelial cell percentages, necroptosis-related RIP3 and MLKL protein expression, serum creatinine and blood urea nitrogen levels, and tubular damage scores. Furthermore, inhibition of AT1R and AT2R diminishes Ang II-induced necroptosis in HK-2 cells and the AT2 agonist CGP42112A increases the percentage of necroptotic HK-2 cells. In addition, the current study also demonstrates that Losartan and PD123319 effectively mitigated the Ang II-induced increases in Fas and FasL signaling molecule expression. Importantly, disruption of FasL significantly suppressed Ang II-induced increases in necroptotic HK-2 cell percentages, and necroptosis-related proteins. These results suggest that Fas and FasL, as subsequent signaling molecules of AT1R and AT2R, might involve in Ang II-induced necroptosis. Taken together, our results suggest that Ang II-induced necroptosis of renal tubular cell might be involved both AT1R and AT2R and the subsequent expression of Fas, FasL signaling. Thus, AT1R and AT2R might function as critical mediators.

Microbiome-metabolomics reveals gut microbiota associated with glycine-conjugated metabolites and polyamine metabolism in chronic kidney disease

Dysbiosis of the gut microbiome and related metabolites in chronic kidney disease (CKD) have been intimately associated with the prevalence of cardiovascular diseases. Unfortunately, thus far, there is a paucity of sufficient knowledge of gut microbiome and related metabolites on CKD progression partly due to the severely limited investigations. Using a 5/6 nephrectomized (NX) rat model, we carried out 16S rRNA sequence and untargeted metabolomic analyses to explore the relationship between colon's microbiota and serum metabolites. Marked decline in microbial diversity and richness was accompanied by significant changes in 291 serum metabolites, which were mediated by altered enzymatic activities and dysregulations of lipids, amino acids, bile acids and polyamines metabolisms. Interestingly, CCr was directly associated with some microbial genera and polyamine metabolism. However, SBP was directly related to certain microbial genera and glycine-conjugated metabolites in CKD rats. Administration of poricoic acid A (PAA) and Poria cocos (PC) ameliorated microbial dysbiosis as well as attenuated hypertension and renal fibrosis. In addition, treatments with PAA and PC lowered serum levels of microbial-derived products including glycine-conjugated compounds and polyamine metabolites. Collectively, the present study confirmed the CKD-associated gut microbial dysbiosis and identified a novel dietary and therapeutic strategy to improve the gut microbial dysbiosis and the associated metabolomic disorders and retarded the progression of kidney disease in the rat model of CKD.

A systems pharmacology approach to investigate the mechanism of Oryeong-san formula for the treatment of hypertension

ETHNOPHARMACOLOGICAL RELEVANCE

Oryeong-san (ORS) is a traditional formula that has long been used for the treatment of dysfunctions of body fluids and electrolyte homeostasis in Korea, China and Japan. Recent reports have shown that ORS may suppress hypertension by controlling the renin-angiotensin-aldosterone system (RAAS) in the kidney, but its action mechanism has not been well defined.

AIM OF THE STUDY

The aim of this study was to decipher the ORS mechanisms in the treatment of hypertension using a systems pharmacology approach.

MATERIALS AND METHODS

The compounds of ORS were obtained from the TM-MC (database of medicinal materials and chemical compounds in Northeast Asian traditional medicine), and the drug-likeness (DL) and oral bioavailability (OB) of the compounds were evaluated. The potential targets of the compounds were identified using various pharmacology databases. To analyze the mechanisms of the ORS for hypertension, a Compound-Target-Disease (C-T-D) network was established with respect to the genes related to hypertension.

RESULTS

A screening evaluation of the DL and OB of the ORS compounds identified a list of 232 active compounds. The pharmacological activity of the targets was investigated by exploring the interaction network between the compounds and the targets. Analysis of the interactions between the compounds and the hypertension-related targets revealed that 14 ORS compounds regulate the RAAS and vasoconstrictors in the kidney.

CONCLUSIONS

This study used the systems pharmacology approach to decipher the mechanisms of action of ORS for the treatment of hypertension. When hypertension drugs and ORS are used in combination for treatment, possible side effects should be considered because most hypertension drugs are related to the RAAS. The results of this study may provide clues to not only analyze the pharmacological activity of ORS for the treatment of hypertension but other diseases as well.

Redox signaling in aging kidney and opportunity for therapeutic intervention through natural products

Kidney diseases are serious public problems with high morbidity and mortality in the general population and heavily retard renal function with aging regardless of the cause. Although myriad strategies have been assigned to prevent or harness disease progression, unfortunately, thus far, there is a paucity of effective therapies partly due to an insufficient knowledge of underlying pathological mechanisms, indicating deeper studies are urgently needed. Additionally, natural products are increasingly recognized as an alternative source for disease intervention owing to the potent safety and efficacy, which might be exploited for novel drug discovery. In this review, we primarily expatiate the new advances on mediators that might be amenable to targeting aging kidney and kidney diseases, including nicotinamide adenine dinucleotide phosphate oxidase (NOX), transforming growth factor-β (TGF-β), renin-angiotensin system (RAS), nuclear factor-erythroid 2 related factor 2 (Nrf2), peroxisome proliferator-activated γ receptor (PPARγ), advanced glycation endproducts (AGEs) as well as microRNAs and vitagenes. Of note, we conclude by highlighting some natural products which have the potential to facilitate the development of novel treatment for patients with myriad renal diseases.

Chronic kidney disease: Biomarker diagnosis to therapeutic targets

Chronic kidney disease (CKD), characterized as renal dysfunction, is recognized as a major public health problem with high morbidity and mortality worldwide. Unfortunately, there are no obvious clinical symptoms in early stage disease until severe damage has occurred. Further complicating early diagnosis and treatment is the lack of sensitive and specific biomarkers. As such, novel biomarkers are urgently needed. Metabolomics has shown an increasing potential for identifying underlying disease mechanisms, facilitating clinical diagnosis and developing pharmaceutical treatments for CKD. Recent advances in metabolomics revealed that CKD was closely associated with the dysregulation of numerous metabolites, such as amino acids, lipids, nucleotides and glycoses, that might be exploited as potential biomarkers. In this review, we summarize recent metabolomic applications based on animal model studies and in patients with CKD and highlight several biomarkers that may play important roles in diagnosis, intervention and development of new therapeutic strategies.

Dietary natural flavonoids treating cancer by targeting aryl hydrocarbon receptor

The role of aryl hydrocarbon receptor (AhR) as a ligand-activated transcription factor in the field of cancer has gradually been unveiled. A strong body of evidence indicated that AhR is implicated in cell proliferation and apoptosis, immune metabolism and other processes, which further affected tumor growth, survival, migration, and invasion. Therefore, AhR targeted therapy may become a new method for cancer treatment and provide a new direction for clinical tumor treatment. Astonishingly, the largest source of exposure of animals and humans to AhR ligands (synthetic and natural) comes from the diet. Myriad studies have described that various natural dietary chemicals can directly activate and/or inhibit the AhR signaling pathway. Of note, numerous natural products contribute to AhR active, of which dietary flavonoids are the largest class of natural AhR ligands. As interest in AhR and its ligands increases, it seems sensible to summarize current research on these ligands. In this review, we highlight the role of AhR in tumorigenesis and focus on the double effect of AhR in cancer therapy. We explored the molecular mechanism of AhR ligands on cancer through a few AhR agonists/antagonists currently in clinical practice. Ultimately, we summarize and highlight the latest progression of dietary flavonoids as AhR ligands in cancer inhibition, including the limitations and deficiencies of it in clinical research. This review will offer a comprehensive understanding of AhR and its dietary ligands which may dramatically pave the way for targeted cancer treatment.