Schisandrin B attenuates renal fibrosis via miR-30e-mediated inhibition of EMT

MicroRNA-26a alleviates tubulointerstitial fibrosis in diabetic kidney disease by targeting PAR4

Our previous study found that miR-26a alleviates aldosterone-induced tubulointerstitial fibrosis (TIF). However, the effect of miR-26a on TIF in diabetic kidney disease (DKD) remains unclear. This study clarifies the role and possible mechanism of exogenous miR-26a in controlling the progression of TIF in DKD models. Firstly, we showed that miR-26a was markedly decreased in type 2 diabetic db/db mice and mouse tubular epithelial cells (mTECs) treated with high glucose (HG, 30 mM) using RT-qPCR. We then used adeno-associated virus carrying miR-26a and adenovirus miR-26a to enhance the expression of miR-26a in vivo and in vitro. Overexpressing miR-26a alleviated the TIF in db/db mice and the extracellular matrix (ECM) deposition in HG-stimulated mTECs. These protective effects were caused by reducing expression of protease-activated receptor 4 (PAR4), which involved in multiple pro-fibrotic pathways. The rescue of PAR4 expression reversed the anti-fibrosis activity of miR-26a. We conclude that miR-26a alleviates TIF in DKD models by directly targeting PAR4, which may provide a novel molecular strategy for DKD therapy.

Schisandrin B Alleviates Renal Tubular Cell Epithelial-Mesenchymal Transition and Mitochondrial Dysfunction by Kielin/Chordin-like Protein Upregulation via Akt Pathway Inactivation and Adenosine 5'-Monophosphate (AMP)-Activated Protein Kinase Pathway Activation in Diabetic Kidney Disease

Diabetic kidney disease is a common complication of diabetes and remains the primary cause of end-stage kidney disease in the general population. Schisandrin B (Sch B) is an active ingredient in Schisandra chinensis. Our study illustrates that Sch B can mitigate renal tubular cell (RTC) epithelial-mesenchymal transition (EMT) and mitochondrial dysfunction in db/db mice, accompanied by the downregulation of TGF-β1 and the upregulation of PGC-1α. Similarly, Sch B demonstrated a protective effect by reducing the expression of TGF-β1, α-SMA, fibronectin, and Col I, meanwhile enhancing the expression of E-cadherin in human RTCs (HK2 cells) stimulated with high glucose. Moreover, under high glucose conditions, Sch B effectively increased mitochondrial membrane potential, lowered ROS production, and increased the ATP content in HK2 cells, accompanied by the upregulation of PGC-1α, TFAM, MFN1, and MFN2. Mechanistically, the RNA-seq results showed a significant increase in KCP mRNA levels in HK2 cells treated with Sch B in a high glucose culture. The influence of Sch B on KCP mRNA levels was confirmed by real-time PCR in high glucose-treated HK2 cells. Depletion of the KCP gene reversed the impact of Sch B on TGF-β1 and PGC-1α in HK2 cells with high glucose level exposure, whereas overexpression of the KCP gene blocked EMT and mitochondrial dysfunction. Furthermore, the PI3K/Akt pathway was inhibited and the AMPK pathway was activated in HK2 cells exposed to a high concentration of glucose after the Sch B treatment. Treatment with the PI3K/Akt pathway agonist insulin and the AMPK pathway antagonist compound C attenuated the Sch B-induced KCP expression in HK2 cells exposed to a high level of glucose. Finally, molecular autodock experiments illustrated that Sch B could bind to Akt and AMPK. In summary, our findings suggested that Sch B could alleviate RTC EMT and mitochondrial dysfunction by upregulating KCP via inhibiting the Akt pathway and activating the AMPK pathway in DKD.

Shen Qi Wan attenuates renal interstitial fibrosis through upregulating AQP1

Renal interstitial fibrosis (RIF) is the crucial pathway in chronic kidney disease (CKD) leading to the end-stage renal failure. However, the underlying mechanism of Shen Qi Wan (SQW) on RIF is not fully understood. In the current study, we investigated the role of Aquaporin 1 (AQP1) in SQW on tubular epithelial-to-mesenchymal transition (EMT). A RIF mouse model induced by adenine and a TGF-β1-stimulated HK-2 cell model were etablished to explore the involvement of AQP 1 in the protective effect of SQW on EMT in vitro and in vivo. Subsequently, the molecular mechanism of SQW on EMT was explored in HK-2 cells with AQP1 knockdown. The results indicated that SQW alleviated kidney injury and renal collagen deposition in the kidneys of mice induced by adenine, increased the protein expression of E-cadherin and AQP1 expression, and decreased the expression of vimentin and α-smooth muscle actin (α-SMA). Similarly, treatmement with SQW-containing serum significantly halted EMT process in TGF-β1 stimulated HK-2 cells. The expression of snail and slug was significantly upregulated in HK-2 cells after knockdown of AQP1. AQP1 knockdown also increased the mRNA expression of vimentin and α-SMA, and decreased the expression of E-cadherin. The protein expression of vimentin increased, while the expression of E-cadherin and CK-18 significantly decreased after AQP1 knockdown in HK-2 cells. These results revealed that AQP1 knockdown promoted EMT. Furthermore, AQP1 knockdown abolished the protective effect of SQW-containing serum on EMT in HK-2 cells. In sum, SQW attentuates EMT process in RIF through upregulation of the expression of AQP1.

Kidney fibrosis: from mechanisms to therapeutic medicines

Chronic kidney disease (CKD) is estimated to affect 10-14% of global population. Kidney fibrosis, characterized by excessive extracellular matrix deposition leading to scarring, is a hallmark manifestation in different progressive CKD; However, at present no antifibrotic therapies against CKD exist. Kidney fibrosis is identified by tubule atrophy, interstitial chronic inflammation and fibrogenesis, glomerulosclerosis, and vascular rarefaction. Fibrotic niche, where organ fibrosis initiates, is a complex interplay between injured parenchyma (like tubular cells) and multiple non-parenchymal cell lineages (immune and mesenchymal cells) located spatially within scarring areas. Although the mechanisms of kidney fibrosis are complicated due to the kinds of cells involved, with the help of single-cell technology, many key questions have been explored, such as what kind of renal tubules are profibrotic, where myofibroblasts originate, which immune cells are involved, and how cells communicate with each other. In addition, genetics and epigenetics are deeper mechanisms that regulate kidney fibrosis. And the reversible nature of epigenetic changes including DNA methylation, RNA interference, and chromatin remodeling, gives an opportunity to stop or reverse kidney fibrosis by therapeutic strategies. More marketed (e.g., RAS blockage, SGLT2 inhibitors) have been developed to delay CKD progression in recent years. Furthermore, a better understanding of renal fibrosis is also favored to discover biomarkers of fibrotic injury. In the review, we update recent advances in the mechanism of renal fibrosis and summarize novel biomarkers and antifibrotic treatment for CKD.

Natural products: potential drugs for the treatment of renal fibrosis

With the increasing prevalence and mortality, chronic kidney disease (CKD) has become a world public health problem. As the primary pathological manifestation in CKD, renal fibrosis is often used as a critical target for the treatment of CKD and inhibits the progression of CKD to end-stage renal disease (ESRD). As a potential drug, natural products have been confirmed to have the potential as a routine or supplementary therapy for chronic kidney disease, which may target renal fibrosis and act through various pharmacological activities such as anti-inflammatory and anti-oxidation of natural products. This article briefly introduces the pathological mechanism of renal fibrosis and systematically summarizes the latest research on the treatment of renal fibrosis with natural products of Chinese herbal medicines.

Role of miRNA and lncRNAs in organ fibrosis and aging

Fibrosis is the endpoint of pathological remodeling. This process contributes to the pathogenesis of several chronic disorders and aging-associated organ damage. Different molecular cascades contribute to this process. TGF-β, WNT, and YAP/TAZ signaling pathways have prominent roles in this process. A number of long non-coding RNAs and microRNAs have been found to regulate organ fibrosis through modulation of the activity of related signaling pathways. miR-144-3p, miR-451, miR-200b, and miR-328 are among microRNAs that participate in the pathology of cardiac fibrosis. Meanwhile, miR-34a, miR-17-5p, miR-122, miR-146a, and miR-350 contribute to liver fibrosis in different situations. PVT1, MALAT1, GAS5, NRON, PFL, MIAT, HULC, ANRIL, and H19 are among long non-coding RNAs that participate in organ fibrosis. We review the impact of long non-coding RNAs and microRNAs in organ fibrosis and aging-related pathologies.

Epigenetics in kidney diseases

Epigenetics examines heritable changes in DNA and its associated proteins except mutations in gene sequence. Epigenetic regulation plays fundamental roles in kidney cell biology through the action of DNA methylation, chromatin modification via epigenetic regulators and non-coding RNA species. Kidney diseases, including acute kidney injury, chronic kidney disease, diabetic kidney disease and renal fibrosis are multistep processes associated with numerous molecular alterations even in individual kidney cells. Epigenetic alterations, including anomalous DNA methylation, aberrant histone alterations and changes of microRNA expression all contribute to kidney pathogenesis. These changes alter the genome-wide epigenetic signatures and disrupt essential pathways that protect renal cells from uncontrolled growth, apoptosis and development of other renal associated syndromes. Molecular changes impact cellular function within kidney cells and its microenvironment to drive and maintain disease phenotype. In this chapter, we briefly summarize epigenetic mechanisms in four kidney diseases including acute kidney injury, chronic kidney disease, diabetic kidney disease and renal fibrosis. We primarily focus on current knowledge about the genome-wide profiling of DNA methylation and histone modification, and epigenetic regulation on specific gene(s) in the pathophysiology of these diseases and the translational potential of identifying new biomarkers and treatment for prevention and therapy. Incorporating epigenomic testing into clinical research is essential to elucidate novel epigenetic biomarkers and develop precision medicine using emerging therapies.

Schisandrin B Inhibits Cell Viability and Migration, and Induces Cell Apoptosis by circ_0009112/miR-708-5p Axis Through PI3K/AKT Pathway in Osteosarcoma

Osteosarcoma is a primary tumor of bone and its incidence is increasing. Schisandrin B (Sch B), a generally used lignan in Chinese medicine, has been found to repress cancer progression. This study aims to reveal the effects and regulatory mechanism of Sch B in the viability, apoptosis and migration of osteosarcoma cells. In this study, we found circ_0009112 expression was higher and miR-708-5p expression was lower in SaOS2 and U2OS cells than in hFOB1.19 cells. Circ_0009112 expression was downregulated, but miR-708-5p was upregulated by Sch B treatment in a dose-dependent manner in SaOS2 and U2OS cells. Sch B exposure inhibited osteosarcoma development in vitro and in vivo; however, these effects were restored by circ_0009112. Furthermore, circ_0009112 acted as a sponge of miR-708-5p. Circ_0009112 regulated PI3K/AKT pathway after Sch B treatment by associating with miR-708-5p. Sch B exposure inhibited cell viability and migration, whereas promoted cell apoptosis by regulating circ_0009112/miR-708-5p axis through PI3K/AKT pathway in osteosarcoma cells. This study provided a theoretical basis for further studying osteosarcoma therapy with Sch B.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Potential Therapeutic Strategy for Acute Kidney Injury

Acute kidney injury (AKI) is a common and potential life-threatening disease in patients admitted to hospital, affecting 10%-15% of all hospitalizations and around 50% of patients in the intensive care unit. Severe, recurrent, and uncontrolled AKI may progress to chronic kidney disease or end-stage renal disease. AKI thus requires more efficient, specific therapies, rather than just supportive therapy. Mesenchymal stem cells (MSCs) are considered to be promising cells for cellular therapy because of their ease of harvesting, low immunogenicity, and ability to expand in vitro. Recent research indicated that the main therapeutic effects of MSCs were mediated by MSC-derived extracellular vesicles (MSC-EVs). Furthermore, compared with MSCs, MSC-EVs have lower immunogenicity, easier storage, no tumorigenesis, and the potential to be artificially modified. We reviewed the therapeutic mechanism of MSCs and MSC-EVs in AKI, and considered recent research on how to improve the efficacy of MSC-EVs in AKI. We also summarized and analyzed the potential and limitations of EVs for the treatment of AKI to provide ideas for future clinical trials and the clinical application of MSC-EVs in AKI.

Pharmacodynamic effects and molecular mechanisms of lignans from Schisandra chinensis Turcz. (Baill.), a current review

Fruit of Schisandra chinensis Turcz. (Baill.) (S. chinensis) is a traditional herbal medicine widely used in China, Korea, and many other east Asian countries. At present, S. chinensis commonly forms Chinese medicinal formulae with other herbal medicines to treat liver disease and neurological disease in clinical. Modern researches indicated that lignans were the main active ingredients of S. chinensis with high content and novel dibenzocyclooctadiene skeletal structure, exhibited considerable antioxidant, anti-inflammatory, and neuroprotective properties. Additionally, some of these lignans also showed certain potentials in anti-cancer, anti-fibrosis, and other effects. In the current review, we summarize literature reported lignans from S. chinensis in the past five years, and highlight the molecular mechanisms of lignans in exerting their biological functions. Also, we point out some deficiencies of existing researches and discuss the future direction of lignans study.

Schisandrin B synergizes docetaxel-induced restriction of growth and invasion of cervical cancer cells in vitro and in vivo

Background

Cervical cancer is a prevalent tumor in women. Here we investigated the synergic effects of Schisandrin B (Sch B), an active compound extracted from the Chinese herb Schisandra Chinensis, in docetaxel (DTX)-induced restriction of growth and invasion of cervical cancer.

Methods

Caski cells were treated with Sch B and DTX for 24 hours. In vitro effects were investigated with Cell counting kit-8, western blotting, colony-forming, Transwell, Annexin V-FITC enabled flow cytometry. Then, in vivo experiments were engaged with Sch B (20 mg/kg) and DTX (10 mg/kg) for 30 days, and IHC were applied to validate the effects in vivo.

Results

Both Sch B and DTX reduced cell viability, inhibited colony formatting, induced apoptosis, and limited cell invasion. Co-administration of Sch B and DTX more significantly enhanced these changes. The relative levels of HPV infection and tumor progression related proteins p-AKT/AKT, NF-kappaB, Cyclin D1, CDK-4, MMP-9, Notch1, β-catenin and p-p38/p38 were markedly inactivated. The effects of Sch B in cervical cancer were further confirmed in Caski cell-xenograft BALB/c nude mice. Co-administration of Sch B enhanced the anti-tumor effects of DTX in vivo, inhibited tumor formation, increased apoptotic cells, and reduced Ki67 and N-cadherin expression.

Conclusions

Altogether, Sch B enhanced the anti-tumor effects of DTX in vitro and in vivo via growth, invasion, and apoptosis regulating. The results supported therapies of co-administering Sch B and DTX to be developed in cervical cancer.

Schisandrin B Inhibits Osteoclastogenesis and Protects Against Ovariectomy-Induced Bone Loss

Osteoporosis is a systemic skeletal disease which is highly prevalent worldwide and considered to be associated with excessive bone resorption mediated by osteoclast. Osteoclast differentiation is featured by the activation of inflammation-related pathways and the generation of reactive oxygen species. Schisandrin B is a bioactive compound with strong antiinflammation and antioxidative properties, we thus speculated that Schisandrin B might serve as a potential candidate for osteoporosis. In the present study, we found that the formation and` function of osteoclasts were dramatically suppressed by Schisandrin B. And consistent with the in vitro results, treatment with Schisandrin B attenuated ovariectomy-induced bone loss in mice. Moreover, Schisandrin B notably inhibited the activation of mitogen activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways and scavenged ROS by activating nuclear factor E2 p45-related factor 2 (Nrf2) signaling. In conclusion, our study indicates that Schisandrin B is an effective approach to treat osteoporosis and other osteoclast-related diseases.