Astragaloside IV/lncRNA-TUG1/TRAF5 signaling pathway participates in podocyte apoptosis of diabetic nephropathy rats

Burdock Fructooligosaccharide Protects Against Diabetic Nephropathy in Mice by Regulating Nrf2 Signaling

Diabetic nephropathy (DN) is a common complication of diabetes mellitus, with oxidative stress playing a critical role in its development. Burdock fructooligosaccharide (BFO), a major compound in Burdock, exhibits antioxidative effects. However, its mechanisms of action and effects on diabetic nephropathy are not clear enough. This study aims to explore the mechanisms of BFO and its impact on streptozotocin-induced diabetic nephropathy in mice. Male C57BL/6J mice were randomly divided into normal control, DN, and BFO groups. Relevant serum biochemical parameters were detected using kits. Renal injury was evaluated through fluorescence microscopy, histopathology, and transmission electron microscopy. Nrf2/HO-1 signaling was analyzed via quantitative real-time PCR, western blotting, and immunohistochemistry. In DN mice, BFO significantly reduced fasting blood glucose, kidney index, urine protein, serum creatinine, blood urea nitrogen, total cholesterol, triglyceride, and low-density lipoprotein cholesterol, while significantly increasing high-density lipoprotein, SOD, and CAT levels. Additionally, BFO protected against streptozotocin-induced renal injury, restored podocyte function, increased both mRNA and protein expression of Nrf2, HO-1, and Bcl-2, and decreased those of Bax. In conclusion, BFO can be used to treat streptozotocin-induced renal injury in mice and is a promising candidate for diabetic nephropathy treatment.

Astragaloside IV Alleviates Podocyte Injury in Diabetic Nephropathy through Regulating IRE-1α/NF-κ B/NLRP3 Pathway

OBJECTIVE

To investigate the effects of astragaloside IV (AS-IV) on podocyte injury of diabetic nephropathy (DN) and reveal its potential mechanism.

METHODS

In in vitro experiment, podocytes were divided into 4 groups, normal, high glucose (HG), inositol-requiring enzyme 1 (IRE-1) α activator (HG+thapsigargin 1 µmol/L), and IRE-1α inhibitor (HG+STF-083010, 20 µmol/L) groups. Additionally, podocytes were divided into 4 groups, including normal, HG, AS-IV (HG+AS-IV 20 µmol/L), and IRE-1α inhibitor (HG+STF-083010, 20 µmol/L) groups, respectively. After 24 h treatment, the morphology of podocytes and endoplasmic reticulum (ER) was observed by electron microscopy. The expressions of glucose-regulated protein 78 (GRP78) and IRE-1α were detected by cellular immunofluorescence. In in vivo experiment, DN rat model was established via a consecutive 3-day intraperitoneal streptozotocin (STZ) injections. A total of 40 rats were assigned into the normal, DN, AS-IV [AS-IV 40 mg/(kg·d)], and IRE-1α inhibitor [STF-083010, 10 mg/(kg·d)] groups (n=10), respectively. The general condition, 24-h urine volume, random blood glucose, urinary protein excretion rate (UAER), urea nitrogen (BUN), and serum creatinine (SCr) levels of rats were measured after 8 weeks of intervention. Pathological changes in the renal tissue were observed by hematoxylin and eosin (HE) staining. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expressions of GRP78, IRE-1α, nuclear factor kappa Bp65 (NF-κBp65), interleukin (IL)-1β, NLR family pyrin domain containing 3 (NLRP3), caspase-1, gasdermin D-N (GSDMD-N), and nephrin at the mRNA and protein levels in vivo and in vitro, respectively.

RESULTS

Cytoplasmic vacuolation and ER swelling were observed in the HG and IRE-1α activator groups. Podocyte morphology and ER expansion were improved in AS-IV and IRE-1α inhibitor groups compared with HG group. Cellular immunofluorescence showed that compared with the normal group, the fluorescence intensity of GRP78 and IRE-1α in the HG and IRE-1α activator groups were significantly increased whereas decreased in AS-IV and IRE-1α inhibitor groups (P<0.05). Compared with the normal group, the mRNA and protein expressions of GRP78, IRE-1α, NF-κ Bp65, IL-1β, NLRP3, caspase-1 and GSDMD-N in the HG group was increased (P<0.05). Compared with HG group, the expression of above indices was decreased in the AS-IV and IRE-1α inhibitor groups, and the expression in the IRE-1α activator group was increased (P<0.05). The expression of nephrin was decreased in the HG group, and increased in AS-IV and IRE-1α inhibitor groups (P<0.05). The in vivo experiment results revealed that compared to the normal group, the levels of blood glucose, triglyceride, total cholesterol, BUN, blood creatinine and urinary protein in the DN group were higher (P<0.05). Compared with DN group, the above indices in AS-IV and IRE-1α inhibitor groups were decreased (P<0.05). HE staining revealed glomerular hypertrophy, mesangial widening and mesangial cell proliferation in the renal tissue of the DN group. Compared with the DN group, the above pathological changes in renal tissue of AS-IV and IRE-1α inhibitor groups were alleviated. Quantitative RT-PCR and Western blot results of GRP78, IRE-1α, NF-κ Bp65, IL-1β, NLRP3, caspase-1 and GSDMD-N were consistent with immunofluorescence analysis.

CONCLUSION

AS-IV could reduce ERS and inflammation, improve podocyte pyroptosis, thus exerting a podocyte-protective effect in DN, through regulating IRE-1α/NF-κ B/NLRP3 signaling pathway.

lncRNA TUG1 and kidney diseases

Long noncoding RNAs (lncRNAs) cover a large class of transcribed RNA molecules that are more than 200 nucleotides in length. An increasing number of studies have shown that lncRNAs control gene expression through different mechanisms and play important roles in a range of biological processes including growth, cell differentiation, proliferation, apoptosis, and invasion. TUG1 was originally discovered in a genomic screen of taurine-treated mouse retinal cells. Previous evidences pointed out that lncRNA TUG1 could inhibit apoptosis and the release of inflammatory factors, improve mitochondrial function, thereby protecting cells from damage, and showing a protective role of TUG1 in diseases. Given that TUG1 has multiple targets and can interfere with multiple steps in the oncogenic process, it has been proposed as a therapeutic target. In this review, we summarize the research progress of lncRNA TUG1 in kidney diseases in the past 8 years, and discuss its related molecular mechanisms.

LncRNA TUG1 mitigates chronic kidney disease through miR-542-3p/HIF-1α/VEGF axis

Renal interstitial fibrosis (RIF) is a common pathway in chronic kidney disease (CKD) that ultimately leads to end-stage renal failure, worsening both glomerulosclerosis and interstitial fibrosis. Ten percent of the adult population in the world suffers from CKD, and as the ageing population continues to rise, it is increasingly regarded as a global threat-a silent epidemic. CKD has been discovered to be closely associated with both long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), while the precise molecular processes behind this relationship are still unclear. This study evaluated the impact of miR-542-3p and lncRNA TUG1 on renal fibrosis, along with the underlying regulatory mechanisms. Through in vitro tube formation assays, research demonstrated that knocking down lncRNA TUG1 may enhance angiogenesis and repair damaged endothelial cell-cell connections. We used Western blot and qRT-PCR methods in the unilateral ureteral obstruction (UUO) model to identify tissue hypoxia and fibrotic lesions. Additionally, a cutting-edge method known as fluorescence microangiography (FMA) was employed to detect damage to the peritubular capillaries (PTCs), with MATLAB software utilised for data evaluation. Furthermore, the coexpression of CD31 and α-SMA helped identify cells in the obstructed kidney that were transitioning from endothelium to myofibroblasts. On the contrary, lncRNA TUG1 downregulation showed a protective effect against the transition from endothelial cells to myofibroblasts. Additionally, knocking down lncRNA TUG1 has been shown to reduce the expression of fibrotic markers by alleviating tissue hypoxia. This effect was significantly counteracted by the inhibition of miR-542-3p. Collectively, our findings offer fresh perspectives on how lncRNA TUG1 and the miR-542-3p/HIF-1α/VEGF axis are regulated as renal fibrosis advances.

Targeting programmed cell death in diabetic kidney disease: from molecular mechanisms to pharmacotherapy

Diabetic kidney disease (DKD), one of the most prevalent microvascular complications of diabetes, arises from dysregulated glucose and lipid metabolism induced by hyperglycemia, resulting in the deterioration of renal cells such as podocytes and tubular epithelial cells. Programmed cell death (PCD), comprising apoptosis, autophagy, ferroptosis, pyroptosis, and necroptosis, represents a spectrum of cell demise processes intricately governed by genetic mechanisms in vivo. Under physiological conditions, PCD facilitates the turnover of cellular populations and serves as a protective mechanism to eliminate impaired podocytes or tubular epithelial cells, thereby preserving renal tissue homeostasis amidst hyperglycemic stress. However, existing research predominantly elucidates individual modes of cell death, neglecting the intricate interplay and mutual modulation observed among various forms of PCD. In this comprehensive review, we delineate the diverse regulatory mechanisms governing PCD and elucidate the intricate crosstalk dynamics among distinct PCD pathways. Furthermore, we review recent advancements in understanding the pathogenesis of PCD and explore their implications in DKD. Additionally, we explore the potential of natural products derived primarily from botanical sources as therapeutic agents, highlighting their multifaceted effects on modulating PCD crosstalk, thereby proposing novel strategies for DKD treatment.

Possible mechanism for the protective effect of active ingredients of astragalus membranaceus on diabetes nephropathy

Astragali Radix (AR), a common traditional Chinese medicinal herb, exhibits protective effects on diabetic nephropathy (DN) in extensive researches. Aticles focusing on AR in PubMed were collected and reviewed in order to summarize the latest pharmacological effects on DN. The action mechanisms for protectiving effects of AR were associated with regulation of anti-fibrosis, anti-inflammation, anti-oxidative stress, anti-podocyte apoptosis, restoration of mitochondrial function, restoration of endothelial function in diabetes nephropathy experimental models. Consequently, AR hold promise as potential novel therapeutics for the treatment of DN.

Radix Astragali and Its Representative Extracts for Diabetic Nephropathy: Efficacy and Molecular Mechanism

Diabetic nephropathy (DN) is a common microvascular complication of diabetes mellitus (DM). Radix Astragali (RA), a frequently used Chinese herbal medicine in the Leguminosae family, Astragalus genus, with its extracts, has been proven to be effective in DN treatment both in clinical practice and experimental studies. RA and its extracts can reduce proteinuria and improve renal function. They can improve histopathology changes including thickening of the glomerular basement membrane, mesangial cell proliferation, and injury of endothelial cells, podocytes, and renal tubule cells. The mechanisms mainly benefited from antioxidative stress which involves Nrf2/ARE signaling and the PPARγ-Klotho-FoxO1 axis; antiendoplasmic reticulum stress which involves PERK-ATF4-CHOP, PERK/eIF2α, and IRE1/XBP1 pathways; regulating autophagy which involves SIRT1/NF-κB signaling and AMPK signaling; anti-inflammation which involves IL33/ST2 and NF-κB signaling; and antifibrosis which involves TGF-β1/Smads, MAPK (ERK), p38/MAPK, JNK/MAPK, Wnt/β-catenin, and PI3K/AKT/mTOR signaling pathways. This review focuses on the clinical efficacy and the pharmacological mechanism of RA and its representative extracts on DN, and we further document the traditional uses of RA and probe into the TCM theoretical basis for its application in DN.

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

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

The role of long non-coding RNAs in the development of diabetic kidney disease and the involved clinical application

Diabetic kidney disease (DKD), one of the common microvascular complications of diabetes, is increasing in prevalence worldwide and can lead to End-stage renal disease. However, there are still gaps in our understanding of the pathophysiology of DKD, and both current clinical diagnostic methods and treatment strategies have drawbacks. According to recent research, long non-coding RNAs (lncRNAs) are intimately linked to the developmental process of DKD and could be viable targets for clinical diagnostic decisions and therapeutic interventions. Here, we review recent insights gained into lncRNAs in pathological changes of DKD such as mesangial expansion, podocyte injury, renal tubular injury, and interstitial fibrosis. We also discuss the clinical applications of DKD-associated lncRNAs as diagnostic biomarkers and therapeutic targets, as well as their limitations and challenges, to provide new methods for the prevention, diagnosis, and treatment of DKD.

Diabetes and diabetic associative diseases: An overview of epigenetic regulations of TUG1

The epigenetic regulation of lncRNA TUG1 has garnered significant attention in the context of diabetes and its associated disorders. TUG1's multifaceted roles in gene expression modulation, and cellular differentiation, and it plays a major role in the growth of diabetes and the issues that are related to it due to pathological processes. In diabetes, aberrant epigenetic modifications can lead to dysregulation of TUG1 expression, contributing to disrupted insulin signaling, impaired glucose metabolism, and beta-cell dysfunction. Moreover, it has been reported that TUG1 contributes to the development of problems linked to diabetes, such as nephropathy, retinopathy, and cardiovascular complications, through epigenetically mediated mechanisms. Understanding the epigenetic regulations of TUG1 offers novel insights into the primary molecular mechanisms of diabetes and provides a possible path for healing interventions. Targeting epigenetic modifications associated with TUG1 holds promise for restoring proper gene expression patterns, ameliorating insulin sensitivity, and mitigating the inception and development of diabetic associative diseases. This review highlights the intricate epigenetic landscape that governs TUG1 expression in diabetes, encompassing DNA methylation and alterations in histone structure, as well as microRNA interactions.

The state of astragaloside IV research: A bibliometric and visualized analysis

BACKGROUND

Astragaloside IV has emerged as a pharmaceutical monomer with great medical applications and potential. Astragaloside IV has many effects such as improving myocardial ischemia, cerebral ischemia-reperfusion injury, anti-inflammatory, analgesic, antiviral, promoting lymphocyte proliferation, and antitumor effects. However, there are few bibliometric studies on astragaloside IV.

OBJECTIVES

We aim to visualize the hotspots and trends in astragaloside IV research through bibliometric analysis to further understand the future development of basic and clinical research. Methods The articles and reviews on astragaloside IV were screened from the Web of Science Core Collection, and knowledge maps were generated using CiteSpace software. Bibliometric analysis was performed on 971 articles published from 1998 to 2022.

RESULTS

The number of articles on astragaloside IV increased yearly. These publications came from 42 countries/regions, with China being the largest. The primary research institutions were Shanghai University of Traditional Chinese Medicine and Guangzhou University of Traditional Chinese Medicine. Journal of Ethnopharmacology was the most studied journal and co-cited journal. A total of 473 authors were included, among which Hongxin Wang had the highest number of publications and Zhang Wd had the highest total citation frequency. After analysis, the most common keywords are astragaloside IV, expression, and oxidative stress. Cardiovascular disease, cerebral ischemia, cancer, and kidney disease are current and developing research fields.

CONCLUSION

This study used bibliometrics and visualization methods to analyze the research hotspots and trends of astragaloside IV. Astragaloside IV on ischemia-reperfusion injury, cancer, and tumor may become the focus of future research.

A systematic review of astragaloside IV effects on animal models of diabetes mellitus and its complications

Context

Diabetes mellitus (DM) is one of the fastest-growing diseases worldwide; however, its pathogenesis remains unclear. Complications seriously affect the quality of life of patients in the later stages of diabetes, ultimately leading to suffering. Natural small molecules are an important source of antidiabetic agents.

Objective

Astragaloside IV (AS-IV) is an active ingredient of Astragalus mongholicus (Fisch.) Bunge. We reviewed the efficacy and mechanism of action of AS-IV in animal and cellular models of diabetes and the mechanism of action of AS-IV on diabetic complications in animal and cellular models. We also summarized the safety of AS-IV and provided ideas and rationales for its future clinical application.

Methods

Articles on the intervention in DM and its complications using AS-IV, such as those published in SCIENCE, PubMed, Springer, ACS, SCOPUS, and CNKI from the establishment of the database to February 2022, were reviewed. The following points were systematically summarized: dose/concentration, route of administration, potential mechanisms, and efficacy of AS-IV in animal models of DM and its complications.

Results

AS-IV has shown therapeutic effects in animal models of DM, such as alleviating gestational diabetes, delaying diabetic nephropathy, preventing myocardial cell apoptosis, and inhibiting vascular endothelial dysfunction; however, the potential effects of AS-IV on DM should be investigated.

Conclusion

AS-IV is a potential drug for the treatment of diabetes and its complications, including diabetic vascular disease, cardiomyopathy, retinopathy, peripheral neuropathy, and nephropathy. In addition, preclinical toxicity studies indicate that it appears to be safe, but the safe human dose limit is yet to be determined, and formal assessments of adverse drug reactions among humans need to be further investigated. However, additional formulations or structural modifications are required to improve the pharmacokinetic parameters and facilitate the clinical use of AS-IV.

Mechanisms and efficacy of traditional Chinese herb monomers in diabetic kidney disease

Diabetic kidney disease (DKD) is a serious complication of diabetes and is the primary cause of end-stage renal disease. Current treatment strategies primarily focus on the inhibition of the renin-angiotensin-aldosterone system and the attainment of blood glucose control. Although current medical therapies for DKD have been shown to delay disease progression and improve long-term outcomes, their efficacy is limited and they may be restricted in certain cases, particularly when hyperkalemia is present. Traditional Chinese medicine (TCM) treatment has emerged as a significant complementary approach for DKD. TCM monomers, derived from various Chinese herbs, have been found to modulate multiple therapeutic targets and exhibit a broad range of therapeutic effects in patients with DKD. This review aims to summarize the mechanisms of action of TCM monomers in the treatment of DKD, based on findings from clinical trials, as well as cell and animal studies. The results of these investigations demonstrate the potential effective use of TCM monomers in treating or preventing DKD, offering a promising new direction for future research in the field. By providing a comprehensive overview of the mechanisms and efficacy of TCM monomers in DKD, this review highlights the potential of these natural compounds as alternative therapeutic options for improving outcomes in patients with DKD.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

Animal models for induction of diabetes and its complications

Objectives

Animal models are widely used to develop newer drugs for treatment of diabetes and its complications. We conducted a systematic review to find various animal models to induce diabetes and also the suitable methods in various diabetic complications. With an emphasis on the animal models of diabetes induction, this review provides a basic overview of diabetes and its various types. It focused on the use of rats and mice for chemical, spontaneous, surgical, genetic, viral, and hormonal induction approaches.

Methods

All observations and research conducted on Diabetes and its complications published up to 18 May 2023 in PubMed, Web of Science, Scopus and Conchrane Library databases were included. Main outcome measures were reporting the induction of diabetes in experimental animals, the various animal models for diabetic complications including diabetic nephropathy, diabetic retinopathy, diabetic neuropathy and diabetic osteopathy. The quality of reporting of included articles and risk of bias were assessed.

Results

We reached various articles and found that rats and mice are the most frequently used animals for inducing diabetes. Chemical induction is the most commonly used followed by spontaneous and surgical methods. With slight modification various breeds and species are developed to study and induce specific complications on eyes, kidneys, neurons and bones.

Conclusions

Our review suggested that rats and mice are the most suitable animals. Furthermore, chemical induction is the method frequently used by experimenters. Moreover, high quality studies are required to find the suitable methods for diabetic complications.

METTL14 promotes the development of diabetic kidney disease by regulating m6A modification of TUG1

BACKGROUND

Diabetic kidney disease (DKD) is one of the most common diabetic complications. Endoplasmic reticulum stress (ERS) is an important step for renal tubular epithelial cell apoptosis during DKD progression. Herein, the role and regulatory mechanism of METTL14 in ERS during DKD progression were investigated.

METHODS

DKD animal and cell models were established by streptozotocin (STZ) and high glucose (HG), respectively. HE and Masson staining were performed to analyze renal lesions in DKD mouse. Cell viability and proliferation were determined by MTT and EdU staining, respectively. HK2 cell apoptosis was analyzed by flow cytometry. TUG1 m6A level was determined by Me-RIP. The interaction between TUG1, LIN28B and MAPK1 was analyzed by RIP and RNA pull-down assays.

RESULTS

HG stimulation promoted apoptosis and increased ERS marker proteins (GRP78, CHOP and caspase12) expression in HK2 cells, while these changes were reversed by METTL14 knockdown. METTL14 inhibited TUG1 stability and expression level in an m6A-dependent manner. As expected, TUG1 knockdown abrogated METTL14 knockdown's inhibition on HG-induced HK2 cell apoptosis and ERS. In addition, TUG1 inactivated MAPK1/ERK signaling by binding with LIN28B. And TUG1 overexpression's repression on HG-induced HK2 cell apoptosis and ERS was abrogated by MAPK1 signaling activation. Meanwhile, METTL14 knockdown or TUG1 overexpression protected against STZ-induced renal lesions and renal fibrosis in DKD mouse.

CONCLUSION

METTL14 promoted renal tubular epithelial cell apoptosis and ERS by activating MAPK/ERK pathway through m6A modification of TUG1, thereby accelerating DKD progression.

Could Cyclosiversioside F Serve as a Dietary Supplement to Prevent Obesity and Relevant Disorders?

Obesity is the basis of numerous metabolic diseases and has become a major public health issue due to its rapidly increasing prevalence. Nevertheless, current obesity therapeutic strategies are not sufficiently effective, so there is an urgent need to develop novel anti-obesity agents. Naturally occurring saponins with outstanding bio-activities have been considered promising drug leads and templates for human diseases. Cyclosiversioside F (CSF) is a paramount multi-functional saponin separated from the roots of the food-medicinal herb Astragali Radix, which possesses a broad spectrum of bioactivities, including lowering blood lipid and glucose, alleviating insulin resistance, relieving adipocytes inflammation, and anti-apoptosis. Recently, the therapeutic potential of CSF in obesity and relevant disorders has been gradually explored and has become a hot research topic. This review highlights the role of CSF in treating obesity and obesity-induced complications, such as diabetes mellitus, diabetic nephropathy, cardiovascular and cerebrovascular diseases, and non-alcoholic fatty liver disease. Remarkably, the underlying molecular mechanisms associated with CSF in disease therapy have been partially elucidated, especially PI3K/Akt, NF-κB, MAPK, apoptotic pathway, TGF-β, NLRP3, Nrf-2, and AMPK, with the aim of promoting the development of CSF as a functional food and providing references for its clinical application in obesity-related disorders therapy.

The beneficial effects of astragaloside IV on ameliorating diabetic kidney disease

Diabetic kidney disease (DKD) has become the major cause of chronic kidney disease or end-stage renal disease. There is still a need for innovative treatment strategies for preventing, arresting, treating, and reversing DKD, and a plethora of scientific evidence has revealed that Chinese herbal monomers can attenuate DKD in multiple ways. Astragaloside IV (AS-IV) is one of the active ingredients of Astragalus membranaceus and was selected as a chemical marker in the Chinese Pharmacopeia for quality control purposes. An increasing amount of studies indicate that AS-IV is a promising novel drug for the treatment of DKD. AS-IV has been shown to improve DKD by combating oxidative stress, attenuating endoplasmic reticulum stress, regulating calcium homeostasis, alleviating inflammation, improving vascular function, improving epithelial to mesenchymal transition and so on. This review briefly summarizes the pathogenesis of DKD, systematically reviews the mechanisms by which AS-IV improves DKD, and aims to facilitate related pharmacological research and development to promote the utilization of Chinese herbal monomers in DKD.

Fufang shenhua tablet, astragali radix and its active component astragaloside IV: Research progress on anti-inflammatory and immunomodulatory mechanisms in the kidney

Background: Given the limited treatment options available for kidney disease, a significant number of patients turn to alternative therapies, including traditional Chinese medicine. Among these therapies, the Fufang Shenhua tablet (SHT) has garnered attention for its effectiveness in addressing the most common deficiency of Qi and Yin in chronic glomerulonephritis. Notably, the sovereign drug of SHT is Astragali Radix (AR), with the most abundant and effective component being Astragaloside IV (AS-IV). AS-IV has been shown to possess anti-inflammatory and immunomodulatory properties, and it is extensively used in treating kidney diseases. Nevertheless, the molecular mechanisms underlying its action are numerous and intricate, and a comprehensive understanding is yet to be achieved. Aim of the review: Thus, we have thoroughly examined the existing research and outlined the advancements made in investigating the anti-inflammatory and immunomodulatory mechanisms of SHT, AR and its active component AS-IV, in relation to kidney health. This serves as a dependable foundation for conducting more comprehensive investigations, evaluating efficacy, and making further improvements in the future. Materials and methods: We conducted a comprehensive literature search utilizing multiple globally recognized databases, including Web of Science, Google Scholar, PubMed, ScienceDirect, Wiley, ACS, Springer, and CNKI. The search keywords used in this study were "Fufang Shenhua tablet," "Astragali Radix," "Astragaloside IV," and "Anti-inflammatory" or "Immunity." Results: The mechanism of inflammation inhibition by SHT, AR and its active component AS-IV is mainly related to the signaling pathways such as NF-κB, TLRs, PI3K/AKT, Wnt/β-catenin, and JAK-STAT. Immunomodulation exerts not only activating, stimulating, and regulating effects on macrophages and dendritic cells, but also on immune organs, T-lymphocytes, B-lymphocytes, and a myriad of cytokines. Moreover, the SHT, AR and its active component AS-IV also demonstrate regulatory effects on renal cells, including glomerular mesangial cells, tubular epithelial cells, and podocytes. Conclusion: To summarize, SHT, AR and its active component AS-IV, exhibit notable therapeutic effects in kidney-related ailments, and their molecular mechanisms for anti-inflammatory and immunomodulatory effects have been extensively explored. However, further standard clinical trials are necessary to evaluate their safety and efficacy in the adjunctive treatment of kidney-related diseases. Moreover, in-depth studies of unverified chemical components and regulatory mechanisms in SHT are required. It is our belief that with continued research, SHT, AR and its active component AS-IV are poised to pave the way for enhancing therapeutic outcomes in kidney-related ailments.

LncRNA SNHG16 regulates RAS and NF-κB pathway-mediated NLRP3 inflammasome activation to aggravate diabetes nephropathy through stabilizing TLR4

AIMS

LncRNA SNHG16 and Toll-like receptor-4 (TLR4) participate in diabetes nephropathy. This study investigated whether SNHG16 regulates diabetic renal injury (DRI) via TLR4 and its related mechanism.

METHODS

Diabetic mice and high glucose (HG)-induced HRMCs were used to examine the expressions of SNHG16 and TLR4. The SNHG16 expression, cytokines, reactive oxygen species, MDA, SOD, GSH, and fibrosis-related proteins were evaluated in HG-induced HRMCs transfected with sh-NC or sh-SHNG16. RNA immunoprecipitation and RNA pull-down determined the interaction between SNHG16 and EIF4A3 or TLR4 and EIF4A3. We used HG-treated HRMCs or diabetic mice to investigate the roles of TLR4 or SNHG16 in renal injuries.

RESULTS

Both SNHG16 and TLR4 were upregulated in diabetic conditions. HG increased serum Scr and BUN, led to significant fibrosis, increased inflammation- and renal fibrosis-related proteins in mice, and increased ROS, MDA, and decreased SOD and GSH in HRMCs. SNHG16 silencing diminished HG-upregulated SNHG16, decreased HG-increased cytokines secretion, ROS, MDA, and fibrosis but increased SOD and GSH. RIP and RNA pull-down confirmed that SNHG16 recruits EIF4A3 to stabilize TLR4 mRNA. TLR4 knockdown alleviated HG-induced renal injuries by suppressing RAS and NF-κB-mediated activation of NLRP3 inflammasomes. SNHG16 knockdown alleviated HG-induced renal injuries in HG-induced HRMCs or diabetic mice. Interestingly, TLR4 overexpression reversed the effects of SNHG16 knockdown. Mechanistically, SNHG16 knockdown alleviated HG-induced renal injuries by suppressing TLR4.

CONCLUSION

SNHG16 accelerated HG-induced renal injuries via recruiting EIF4A3 to enhance the stabilization of TLR4 mRNA. The SNGHG16/ELF4A3/TLR4 axis might be a novel target for treating DRI.

Astragalus membranaceus formula for moderate-high risk idiopathic membranous nephropathy: A meta-analysis

BACKGROUND

Idiopathic membranous nephropathy (IMN) is a noninflammatory autoimmune glomerulonephropathy. Based on the risk stratification for disease progression, conservative nonimmunosuppressive and immunosuppressive therapy strategies have been recommended. However, there remains challenges. Therefore, novel approaches to treat IMN are needed. We evaluated the efficacy of Astragalus membranaceus (A membranaceus) combined with supportive care or immunosuppressive therapy in the treatment of moderate-high risk IMN.

METHODS

We comprehensively searched PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure, the Database for Chinese Technical Periodicals, Wanfang Knowledge Service Platform, and SinoMed. We then performed a systematic review and cumulative meta-analysis of all randomized controlled trials assessing the two therapy methods.

RESULTS

The meta-analysis included 50 studies involving 3423 participants. The effect of A membranaceus combined with supportive care or immunosuppressive therapy is better than that of supportive care or immunosuppressive therapy along in regulating for improving 24 hours urinary total protein (MD = -1.05, 95% CI [-1.21, -0.89], P = .000), serum albumin (MD = 3.75, 95% CI [3.01, 4.49], P = .000), serum creatinine (MD = -6.24, 95% CI [-9.85, -2.63], P = .0007), complete remission rate (RR = 1.63, 95% CI [1.46, 1.81], P = .000), partial remission rate (RR = 1.13, 95% CI [1.05, 1.20], P = .0004).

CONCLUSIONS

Adjunctive use of A membranaceus preparations combined with supportive care or immunosuppressive therapy have a promising treatment for improving complete response rate, partial response rate, serum albumin, and reducing proteinuria, serum creatinine levels compared to immunosuppressive therapy in people with MN being at moderate-high risk for disease progression. Given the inherent limitations of the included studies, future well-designed randomized controlled trials are required to confirm and update the findings of this analysis.

Long non-coding RNAs TUG1 and MEG3 in patients with type 2 diabetes and their association with endoplasmic reticulum stress markers

BACKGROUND

Long non-coding RNAs (lncRNAs), including taurine upregulated gene 1 (TUG1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), and maternally expressed 3 (MEG3) play a regulatory role in endoplasmic reticulum (ER) stress. The present study aimed to investigate the expression of these lncRNAs in patients with type 2 diabetes and their association with biochemical and ER stress parameters.

MATERIALS AND METHODS

Participants included 57 patients with diabetes and 32 healthy individuals. Real-time PCR was performed to assess MALAT1, TUG1, MEG3, ATF4, and CHOP gene expression in peripheral blood mononuclear cells. Plasma GRP78, advanced glycation end products (AGEs), and insulin were measured using enzyme-linked immunosorbent assay (ELISA), and insulin resistance (IR) was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

The expression of TUG1, MEG3, ATF4, and CHOP genes was significantly increased in the patients with diabetes compared to healthy individuals. MALAT1 gene expression was also higher in patients group; although it did not reach significant levels. TUG1 and MEG3 expression revealed significant positive correlations with the indices of glycemic control, including FBS, HbA1c, HOMA-IR, and AGEs, as well as markers of ER stress. MALAT1 expression was also positively correlated with ATF4 and AGEs.

CONCLUSION

The expression levels of TUG1 and MEG3 lncRNAs were increased in patients with diabetes and were associated with glycemic control and components of ER stress. Thus, these lncRNAs might be considered appropriate markers to identify ER stress due to hyperglycemia.

Research progress on the antitumor effects of astragaloside IV

One of the most important and effective components of Astragalus membranaceus is astragaloside IV (AS-IV), which can exert anti-tumor effects through various pathways. For instance, AS-IV exerts an anti-tumor effect by acting at the cellular level, regulating the phenotype switch of tumor-associated macrophages, or inhibiting the development of tumor cells. Furthermore, AS-IV inhibits tumor cell progression by enhancing its sensitivity to antitumor drugs or reversing the drug resistance of tumor cells. This article reviews the different mechanisms of AS-IV inhibition of epithelial-mesenchymal transition (EMT), migration, proliferation, and invasion of tumor cells, inducing apoptosis and improving the sensitivity of anti-tumor drugs. This review summarizes recent progress in the current research into AS-IV anti-tumor effect and provides insight on the next anti-tumor research of AS-IV.

Astragaloside IV Targets Macrophages to Alleviate Renal Ischemia-Reperfusion Injury via the Crosstalk between Hif-1α and NF-κB (p65)/Smad7 Pathways

(1) Background: Astragaloside IV (AS-IV) is derived from Astragalus membranous (AM), which is used to treat kidney disease. Macrophages significantly affect the whole process of renal ischemia-reperfusion (I/R). The regulation of macrophage polarization in kidneys by AS-IV was the focus. (2) Methods: Renal tubular injury and fibrosis in mice were detected by Hematoxylin and Eosin staining and Masson Trichrome Staining, separately. An ELISA and quantitative real-time polymerase chain reaction were used to explore the cytokine and mRNA expression. Western blot was used to determine protein expression and siRNA technology was used to reveal the crosstalk of signal pathways in RAW 264.7 under hypoxia. (3) Results: In the early stages of I/R injury, AS-IV reduced renal damage and macrophage infiltration. M1-associated markers were decreased, while M2 biomarkers were increased. The NF-κB (p65)/Hif-1α pathway was suppressed by AS-IV in M1. Moreover, p65 dominated the expression of Hif-1α. In the late stages of I/R injury, renal fibrosis was alleviated, and M2 infiltration also decreased after AS-IV treatment. Hif-1α expression was reduced by AS-IV, while Smad7 expression was enhanced. Hif-1α interferes with the expression of Smad7 in M2. (4) Conclusions: AS-IV promoted the differentiation of M1 to M2, relieving the proinflammatory response to alleviate the kidney injury during the early stages. AS-IV attenuated M2 macrophage infiltration to prevent kidney fibrosis during the later stages.

LncRNA Taurine Up-Regulated 1 plays a proapoptotic role by regulating nuclear-cytoplasmic shuttle of HuR under the condition of neuronal ischemia

The study aimed to identify TUG1 as an essential regulator of apoptosis in HT22 (mouse hippocampal neuronal cells) by direct interaction with the RNA-binding protein HuR. In order to study the role of TUG1 in the context of ischemia, we used mouse hippocampal neuronal cells treated with oxyglucose deprivation to establish an in-vitro ischemia model. A bioinformatic analysis and formaldehyde RNA immunoprecipitation (fRIP) were used to investigate the biological functions. A Western blot assay and reverse transcription polymerase chain reaction were used to explore the expression of the molecules involved. A cell proliferation and cytotoxicity assay was performed to detect neuronal apoptosis. TUG1 exhibits a localization-specific expression pattern in HT22 cells under OGD treatment. The bioinformatics analysis showed a strong correlation between the TUG1 and HuR as predicted, and this interaction was subsequently confirmed by fRIP-qPCR. We found that HuR was translocated from the nucleus to the cytoplasm after ischemia treatment and subsequently targeted and stabilized COX-2 mRNA, which led to elevated COX-2 mRNA levels and apoptosis of the HT22 cells. Furthermore, nuclear-specific disruption of TUG1 prevented the translocation of HuR to the cytoplasm and decreased COX-2 mRNA expression, resulting in increased cell viability and partially reversed apoptosis. In conclusion, it was demonstrated that TUG1 accelerates the process of apoptosis by promoting the transfer of HuR to the cytoplasm and stabilizing COX-2 mRNA. These results provide useful information concerning a therapeutic target for ischemic stroke.

The role of lncRNAs in regulation of DKD and diabetes-related cancer

Diabetes mellitus often results in several complications, such as diabetic kidney disease (DKD) and end-stage renal diseases (ESRDs). Cancer patients often have the dysregulated glucose metabolism. Abnormal glucose metabolism can enhance the tumor malignant progression. Recently, lncRNAs have been reported to regulate the key proteins and signaling pathways in DKD development and progression and in cancer patients with diabetes. In this review article, we elaborate the evidence to support the function of lncRNAs in development of DKD and diabetes-associated cancer. Moreover, we envisage that lncRNAs could be diagnosis and prognosis biomarkers for DKD and cancer patients with diabetes. Furthermore, we delineated that targeting lncRNAs might be an alternative approach for treating DKD and cancer with dysregulated glucose metabolism.

LncRNAs regulate ferroptosis to affect diabetes and its complications

Worldwide, the rapid increase in the incidence of diabetes and its complications poses a serious threat to human health. Ferroptosis, which is a new nonapoptotic form of cell death, has been proven to be closely related to the occurrence and development of diabetes and its complications. In recent years, lncRNAs have been confirmed to be involved in the occurrence and development of diabetes and play an important role in regulating ferroptosis. An increasing number of studies have shown that lncRNAs can affect the occurrence and development of diabetes and its complications by regulating ferroptosis. Therefore, lncRNAs have great potential as therapeutic targets for regulating ferroptosis-mediated diabetes and its complications. This paper reviewed the potential impact and regulatory mechanism of ferroptosis on diabetes and its complications, focusing on the effects of lncRNAs on the occurrence and development of ferroptosis-mediated diabetes and its complications and the regulation of ferroptosis-inducing reactive oxygen species, the key ferroptosis regulator Nrf2 and the NF-κB signaling pathway to provide new therapeutic strategies for the development of lncRNA-regulated ferroptosis-targeted drugs to treat diabetes.

lncRNA TUG1 regulates hyperuricemia-induced renal fibrosis in a rat model

Renal fibrosis is most common among chronic kidney diseases. Molecular studies have shown that long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) participate in renal fibrosis, while the roles of lncRNA taurine upregulated gene 1 (TUG1) and miR-140-3p in hyperuricemia-induced renal fibrosis remain less investigated. In this study, a rat hyperuricemia model is constructed by oral administration of adenine. TUG1, miR-140-3p, and cathepsin D (CtsD) expression levels in rat models are measured. After altering TUG1, miR-140-3p, or CtsD expression in modelled rats, biochemical indices, including uric acid (UA), serum creatine (SCr), blood urea nitrogen (BUN), and 24-h urine protein are detected, pathological changes in the renal tissues, and renal fibrosis are examined. In renal tissues from hyperuricemic rats, TUG1 and CtsD are upregulated, while miR-140-3p is downregulated. Inhibiting TUG1 or CtsD or upregulating miR-140-3p relieves renal fibrosis in hyperuricemic rats. Downregulated miR-140-3p reverses the therapeutic effect of TUG1 reduction, while overexpression of CtsD abolishes the role of miR-140-3p upregulation in renal fibrosis. Collectively, this study highlights that TUG1 inhibition upregulates miR-140-3p to ameliorate renal fibrosis in hyperuricemic rats by inhibiting CtsD.

Astragaloside IV attenuates high glucose-induced human keratinocytes injury via TGF-β/Smad signaling pathway

OBJECTIVES

In this study, we have investigated the effect of Astragaloside IV on keratinocytes' proliferation, migration, oxidative stress, apoptosis, inflammation, and relevant signaling pathway, using human keratinocytes exposed to high glucose.

BACKGROUND

Astragaloside IV is one of the main active ingredients of Astragalus membranaceus (Fisch.) Bunge. Previous studies have found that Astragaloside IV exerts positive effects in various disease models and promotes wound healing.

METHODS

Cell proliferation and migration of keratinocytes, oxidative stress indicators, cell apoptosis rate, inflammatory factors, and key proteins in the TGF-β/Smad signaling pathway were evaluated by molecular biology/biochemical techniques, fluorescence microscope, and flow cytometry.

RESULTS

High glucose inhibited the cell proliferation and migration of keratinocytes, upregulated the levels of MDA, ROS, IL-6, IL-8, and Smad7, and decreased the levels of SOD, IL-10, TGF-β1, p-Smad2, and p-Smad3. Astragaloside IV attenuated the dysfunction of keratinocytes, oxidative stress, cell apoptosis, and inflammation, but activated TGF-β/Smad signaling pathway. Meanwhile, the addition of SB431542 (the inhibitor of TGF-β/Smad signaling pathway) eliminated the impact of Astragaloside IV on high glucose-induced keratinocytes.

CONCLUSIONS

These results strongly suggest that Astragaloside IV may be a potential drug candidate for accelerating diabetic wound healing, by protecting keratinocytes against damages induced by high glucose and TGF-β/Smad pathway is involved in this process at the cellular level.

Silencing long noncoding RNA-CES1P1 suppresses glomerular endothelial cell inflammation in diabetic nephropathy

Diabetic nephropathy (DN) has become the main cause of end-stage renal disease worldwide. Inflammation is associated with the occurrence and development of DN, and long noncoding RNAs (lncRNAs) are involved in the regulation of inflammatory processes. This study aims to determine the role and mechanism of lncRNA-CES1P1 in DN.C57BL/6 mice and human umbilical vein endothelial cells (HUVECs) were used for this experimental study. In vivo experimental intraperitoneal injection of streptozotocin (STZ) to construct a diabetes mellitus (DM) model in C57BL/6 mice caused increased expression of lncRNA-CES1P1, decreased expression of miR-214-3p in kidney tissue, and produced renal inflammation and proteinuria. Exogenous knockdown of lncRNA-CES1P1 expression decreased renal inflammatory infiltration. In vitro experiments using high glucose (HG) stimulation of HUVECs cell revealed increased expression of lncRNA-CES1P1, decreased expression of miR-214-3p, and increased expression of the inflammatory factors IL-17, IκB, NF-κB, and IL-6. Luciferase reporter assays showed direct targets of miR-214-3p interaction with lncRNA-CES1P1 and IL-17. These results suggest that hyperglycemia represses miR-214-3p by inducing lncRNA-CES1P1, which promotes the expression of the inflammatory factors IL-17, IκB, NF-κB and IL-6 ultimately leading to the development of DN. Interfering with lncRNA-CES1P1 can reduce hyperglycemia-induced DN.

Mitogen-activating protein kinase kinase kinase kinase-3, inhibited by Astragaloside IV through H3 lysine 4 monomethylation, promotes the progression of diabetic nephropathy by inducing apoptosis

Astragaloside IV (AS-IV) is a bioactive saponin extracted from the Astragalus root and has been reported to exert a protective effect on diabetic nephropathy (DN). However, the underlying mechanism remains unclear. Herein, we found that AS-IV treatment alleviated DN symptoms in DN mice accompanied by reduced metabolic parameters (body weight, urine microalbumin and creatinine, creatinine clearance, and serum urea nitrogen and creatinine), pathological changes, and apoptosis. Epigenetic histone modifications are closely related to diabetes and its complications, including H3 lysine 4 monomethylation (H3K4me1, a promoter of gene transcription). A ChIP-seq assay was conducted to identify the genes regulated by H3K4me1 in DN mice after AS-IV treatment and followed by a Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. The results showed that there were 16 common genes targeted by H3K4me1 in normal and AS-IV-treated DN mice, 1148 genes were targeted by H3K4me1 only in DN mice. From the 1148 genes, we screened mitogen-activating protein kinase kinase kinase kinase-3 (MAP4K3) for the verification of gene expression and functional study. The results showed that MAP4K3 was significantly increased in DN mice and high glucose (HG)-treated NRK-52E cells, which was reversed by AS-IV. MAP4K3 silencing reduced the apoptosis of NRK-52E cells under HG condition, as evidenced by decreased cleaved caspase 3 and Bax (pro-apoptotic factors), and increased Bcl-2 and Bcl-xl (anti-apoptotic factors). Collectively, AS-IV may downregulate MAP4K3 expression by regulating H3K4me1 binding and further reducing apoptosis, which may be one of the potential mechanisms that AS-IV plays a protective effect on DN.

Astragaloside IV exhibits anti-tumor function in gastric cancer via targeting circRNA dihydrolipoamide S-succinyltransferase (circDLST)/miR-489-3p/ eukaryotic translation initiation factor 4A1(EIF4A1) pathway

Astragaloside IV (AS-IV) is an inartificial saponin separated from astragalus membranaceus, which has exhibited key anti-tumor regulation in some cancers. Circular RNAs (circRNAs) are important regulators in malignant development of gastric cancer (GC). Herein, we focused on the molecular mechanism of AS-IV with circRNA dihydrolipoamide S-succinyltransferase (circDLST) in GC. CircDLST, microRNA-489-3p (miR-489-3p), and eukaryotic translation initiation factor 4A1 (EIF4A1) levels were detected by quantitative real-time polymerase-chain reaction and western blot. Cell functions were assessed by cell counting kit-8 assay, ethynyl-2’-deoxyuridine assay, colony formation assay, and transwell assay. The interaction between miR-489-3p and circDLST or EIF4A1 was analyzed by dual-luciferase reporter assay. Xenograft tumor assay was adopted to check the role of circDLST and AS-IV in vivo. CircDLST and EIF4A1 were upregulated but miR-489-3p was downregulated in GC cells. AS-IV restrained cell proliferation and metastasis in GC cells by downregulating circDLST. CircDLST served as a miR-489-3p sponge, and miR-489-3p inhibition reversed anti-tumor function of AS-IV. EIF4A1 was a target for miR-489-3p and circDLST sponged miR-489-3p to regulate EIF4A1. AS-IV suppressed GC cell progression via circDLST-mediated downregulation of EIF4A1. Also, AS-IV recued tumor growth in vivo via targeting circDLST to regulate miR-489-3p/EIF4A1 axis. AS-IV inhibited the development of GC through circDLST/miR-489-3p/EIF4A1 axis.

miRNA-93-5p in exosomes derived from M2 macrophages improves lipopolysaccharide-induced podocyte apoptosis by targeting Toll-like receptor 4

Diabetic nephropathy (DN) is a common complication of diabetes mellitus which can result in renal failure and severely affect public health. Several studies have revealed the important role of podocyte injury in DN progression. Although, the involvement of exosomes derived from M2 macrophages has been reported in podocyte injury, the underlying molecular mechanism of M2 macrophage-secreted exosomes has not been fully elucidated. Our study suggests that M2 macrophages mitigate lipopolysaccharide (LPS)-induced injury of podocytes via exosomes. Moreover, we observed that miR-93-5p expression was markedly upregulated in exosomes from M2 macrophages. Inhibition of miR-93-5p derived from M2 macrophage exosomes resulted in apoptosis of LPS-treated podocytes. Additionally, TLR4 showed the potential to bind to miR-93-5p. Subsequently, we validated that TLR4 is a downstream target of miR-93-5p. Further findings indicated that silencing of TLR4 reversed the renoprotective effects of miR-93-5p-containing M2 macrophage exosomes on LPS-induced podocyte injury. In summary, our study demonstrated that M2 macrophage-secreted exosomes attenuated LPS-induced podocyte apoptosis by regulating the miR-93-5p/TLR4 axis, which provides a new perspective for the treatment of patients with DN.

Expression of LncRNA KCNQ1Ot1 in diabetic nephropathy and its correlation with MEK/ERK signaling pathway

OBJECTIVE

To explore the expression of LncRNA KCNQ1OT1 in diabetic nephropathy (DN), and its correlation with MEK/ERK signaling pathway.

METHODS

148 patients with type 2 diabetes in our hospital were selected as research subjects, including 83 patients with simple type 2 diabetes (T2D group) and 65 patients with type 2 diabetes with DN (DN group). Another 50 non-diabetic patients were enrolled as the control group. The expressions of LncRNA KCNQ1OT1 and MEK/ERK signaling pathway related molecules in peripheral blood mononuclear cells (PBMCs) of the three groups of subjects were detected and their correlations were analyzed. In addition, 30 Wistar rats were divided into a control group, diabetes group and DN model group, and the expression of LncRNA KCNQ1OT1 and MEK/ERK signal pathway-related molecules in kidney tissue of the three groups was detected and compared.

RESULTS

The relative expression of LncRNA KCNQ1OT1, MEK-5 and ERK2 in the control group was lower than that of the T2D group and DN group (P<0.05), and the relative expression of LncRNA KCNQ1OT1 in T2D group was lower than that of DN group (P<0.05). The expression of LncRNA KCNQ1OT1 was positively-correlated with MEK-5 and ERK2 (P<0.05). The relative expression of LncRNA KCNQ1OT1, MEK-5, and ERK2 in renal tissues of the DN group was higher than those in the control group and diabetes group (P<0.05).

CONCLUSION

The expression of LncRNA KCNQ1OT1 in PBMCs of DN patients is abnormally increased, and may be a biomarker for the diagnosis and treatment of the disease. In addition, an abnormal increase of LncRNA KCNQ1OT1 is associated with the activation of the MEK/ERK signaling pathway.

Long non-coding RNA TUG1 sponges microRNA-9 to protect podocytes from high glucose-induced apoptosis and mitochondrial dysfunction via SIRT1 upregulation

Podocyte apoptosis and mitochondrial dysfunction serve a major role in diabetic nephropathy progression. The present study revealed a molecular mechanism regulating podocyte apoptosis and mitochondrial dysfunction. In vitro models were established using conditionally immortalized mouse podocyte clonal cells treated with high glucose (HG). Reverse quantitative-transcription PCR were used to detect gene expression, western blotting and immunofluorescence were used to detect protein expression, Cell Counting Kit-8 was used to detect cell viability and flow cytometry was used to detect cell apoptosis. HG treatment in the mouse podocyte clonal cells downregulated taurine-upregulated gene 1 (TUG1) expression and decreased viability in a dose-dependent manner. In addition, TUG1 knockdown (KD) increased HG-induced apoptosis, while TUG1 overexpression (OE) reduced HG-induced apoptosis in podocytes. HG-induced mitochondrial dysfunction was identified in podocytes, with increased reactive oxygen species levels, decreased complex I/III activity and decreased basal/maximal oxygen consumption rate. TUG1 KD worsened HG-induced mitochondrial dysfunction, and TUG1 OE reversed these effects. At the molecular level, TUG1 was revealed to promote sirtuin 1 (SIRT1) expression by sponging microRNA (miR)-9, and SIRT1 OE reversed the HG-induced apoptosis and mitochondrial dysfunction increased by TUG1 KD. The present data indicated that downregulation of TUG1 induced by HG was associated with HG-induced apoptosis and mitochondrial dysfunction in podocytes, and that TUG1 protected HG-induced podocytes by promoting SIRT1 expression via miR-9 inhibition.

The Role of LncRNA TUG1 in Obesity-Related Diseases

With the continuous improvement of living standards, obesity has become an inevitable hotspot in our daily life. It remains a chronic and recurrent disease with serious adverse consequences. Over the past few years, several articles suggested that long non-coding RNA taurine increased gene 1（lncRNA TUG1）, a useful RNA, was suggested to show a relationship to obesity-related disease occurrence and development. Exosome is an emerging research field, which contains substances that are actively involved in regulating the molecular mechanisms of disease. This review summarizes the current relevant TUG1 in different molecular pathways of diseases related to obesity, relationship between exosomes and TUG1 or diseases related to obesity. The aim is to explore TUG1 as a novel target for obesity, which can deepen the knowledge regarding epigenetic regulation pathway. Besides, it is likely to be a potential future targeting diseases related to obesity site treatment and diagnosis.

Animal models of diabetic microvascular complications: Relevance to clinical features

Diabetes has become more common in recent years worldwide, and this growth is projected to continue in the future. The primary concern with diabetes is developing various complications, which significantly contribute to the disease's mortality and morbidity. Over time, the condition progresses from the pre-diabetic to the diabetic stage and then to the development of complications. Years and enormous resources are required to evaluate pharmacological interventions to prevent or delay the progression of disease or complications in humans. Appropriate screening models are required to gain a better understanding of both pathogenesis and potential therapeutic agents. Different species of animals are used to evaluate the pharmacological potentials and study the pathogenesis of the disease. Animal models are essential for research because they represent most of the structural, functional, and biochemical characteristics of human diseases. An ideal screening model should mimic the pathogenesis of the disease with identifiable characteristics. A thorough understanding of animal models is required for the experimental design to select an appropriate model. Each animal model has certain advantages and limitations. The present manuscript describes the animal models and their diagnostic characteristics to evaluate microvascular diabetic complications.

Tubule-specific deletion of LincRNA-p21ameliorates lipotoxic kidney injury

Lipotoxicity has been implicated in the pathogenesis of obesity-related kidney damage and propagates chronic kidney injury like diabetic kidney disease; however, the underlying mechanisms have not yet been fully elucidated. To date, reduction of lipid acquisition and enhancement of lipid metabolism are the major, albeit non-specific, approaches to improve lipotoxic kidney damage. In the kidneys of high-fat diet (HFD)-fed mice and tubule cells cultured with palmitic acid (PA), we observed a dramatic upregulation of the long intergenic non-coding RNA-p21 (LincRNA-p21) through a p53-dependent mechanism. Kidney tubule cell-specific deletion of LincRNA-p21 attenuated oxidative stress, inflammation, apoptosis, and endoplasmic reticulum stress, leading to reduction of histological and functional kidney injury despite persistent obesity and hyperlipidemia. Mechanistically, HFD- or PA-initiated lipotoxicity suppressed the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR)/murine double minute 2 homolog (MDM2) signaling cascade to activate p53 and enhance the transcriptional activity of LincRNA-p21. Collectively, our findings suggest that the p53/LincRNA-p21 axis is the downstream effector in lipotoxic kidney injury and that targeting this axis particularly in the kidney tubule could be a novel therapeutic strategy.

Astragaloside positively regulated osteogenic differentiation of pre-osteoblast MC3T3-E1 through PI3K/Akt signaling pathway

BACKGROUND

Osteoporosis is a widespread chronic disease characterized by low bone density. There is currently no gold standard treatment for osteoporosis. The aim of this study was to explore the role and mechanism of Astragaloside on osteogenic differentiation of MC3T3-E1 cells.

METHODS

MC3T3-E1 cells were divided into control and different dose of Astragaloside (10, 20, 40, 50, and 60 μg/ml). Then, ALP and ARS staining were performed to identify the effects of Astragaloside for early and late osteogenic capacity of MC3T3-E1 cells, respectively. Real-time PCR and western blot were performed to assess the ALP, OCN, and OSX expression. PI3K/Akt signaling pathway molecules were then assessed by Western blot. Finally, PI3K inhibitor, LY294002, was implemented to assess the mechanism of Astragaloside in promoting osteogenic differentiation of MC3T3-E1 cells.

RESULTS

Astragaloside significantly increased the cell viability than the control group. Moreover, Astragaloside enhanced the ALP activity and calcium deposition than the control groups. Compared with the control group, Astragaloside increased the ALP, OCN, and OSX expression in a dose-response manner. Western blot assay further confirmed the real-time PCR results. Astragaloside could significantly increase the p-PI3K and p-Akt expression than the control group. LY294002 partially reversed the promotion effects of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. LY294002 partially reversed the promotion effects of Astragaloside on ALP, OCN, and OSX of MC3T3-E1 cells.

CONCLUSION

The present study suggested that Astragaloside promoted osteogenic differentiation of MC3T3-E1 cells through regulating PI3K/Akt signaling pathway.

LncRNA TUG1 Regulates Proliferation of Cardiac Fibroblast via the miR-29b-3p/TGF-β1 Axis

Background: Atrial fibrillation (AF) is a very common clinical arrhythmia, accompanied by the overproliferation of cardiac fibroblasts (CFs). This study aimed to investigate the role of the long non-coding RNA(lncRNA) taurine upregulated gene 1 (TUG1) in the proliferation of CFs and further investigated its underlying mechanism.

Methods: One hundred four paroxysmal AF patients and 94 healthy controls were recruited. Human cardiac fibroblasts (HCFs) were applied to establish an AF cell model through treatment with angiotensin II (AngII). qRT-PCR was used for the measurement of gene levels. The cell proliferation was detected by cell counting kit-8 (CCK-8). Luciferase reporter assay was performed for target gene analysis.

Results: Elevated levels of TUG1 and low expression of miR-29b-3p were detected in the serum of AF patients compared with the healthy controls. Pearson's correlation analysis exhibited an inverse relationship between TUG1 and miR-29b-3p expression in AF patients (r = −7.106, p < 0.001). Knockdown of TUG1 inhibited AngII-induced CF proliferation. Taurine upregulated gene 1 (TUG1) functions as a competing endogenous RNA (ceRNA) for miR-29b-3p, and downregulation of miR-29b-3p reversed the role of TUG1 in CF proliferation. TGF-β1 is a direct target gene of miR-29b-3p.

Conclusions: Long non-coding RNA taurine upregulated gene 1 is a key regulator in the occurrence of AF. Slicing TUG1 inhibits CF proliferation by regulating the miR-29b-3p/TGF-β1 axis.

Clinical efficacies, underlying mechanisms and molecular targets of Chinese medicines for diabetic nephropathy treatment and management

Diabetic nephropathy (DN) has been recognized as a severe complication of diabetes mellitus and a dominant pathogeny of end-stage kidney disease, which causes serious health problems and great financial burden to human society worldwide. Conventional strategies, such as renin-angiotensin-aldosterone system blockade, blood glucose level control, and bodyweight reduction, may not achieve satisfactory outcomes in many clinical practices for DN management. Notably, due to the multi-target function, Chinese medicine possesses promising clinical benefits as primary or alternative therapies for DN treatment. Increasing studies have emphasized identifying bioactive compounds and molecular mechanisms of reno-protective effects of Chinese medicines. Signaling pathways involved in glucose/lipid metabolism regulation, antioxidation, anti-inflammation, anti-fibrosis, and podocyte protection have been identified as crucial mechanisms of action. Herein, we summarize the clinical efficacies of Chinese medicines and their bioactive components in treating and managing DN after reviewing the results demonstrated in clinical trials, systematic reviews, and meta-analyses, with a thorough discussion on the relative underlying mechanisms and molecular targets reported in animal and cellular experiments. We aim to provide comprehensive insights into the protective effects of Chinese medicines against DN.

Astragalus (Astragalus membranaceus Bunge): botanical, geographical, and historical aspects to pharmaceutical components and beneficial role

Medicinal plants always are part of folk medicine and are nowadays receiving worldwide attention for prophylaxis, management, and treatment of several diseases, as an alternative to chemical drugs. The current work provided a comprehensive overview and analysis of the Astragalus and health relationship in literature. The analysis of their therapeutic potential is thus instrumental to understand their bioactivity. Among these, the flowering medicinal plant Astragalus membranaceus has raised interest due to several beneficial health effects. This perspective review discussed the botanical, geographical, historical, and the therapeutic properties of A. membranaceus, with a special focus on its health improving effects and medicinal applications both in vitro and in vivo.

Graphic abstract

LncRNA TUG1/miR-29c-3p/SIRT1 axis regulates endoplasmic reticulum stress-mediated renal epithelial cells injury in diabetic nephropathy model in vitro

Long non-coding RNAs (lncRNAs) are important regulators in diabetic nephropathy. In this study, we investigated the potential role of lncRNA TUG1 in regulating endoplasmic reticulum stress (ERS)-mediated apoptosis in high glucose induced renal tubular epithelial cells. Human renal tubular epithelial cell line HK-2 was challenged with high glucose following transfection with lncRNA TUG1, miR-29c-3p mimics or inhibitor expression plasmid, either alone or in combination, for different experimental purposes. Potential binding effects between TUG1 and miR-29c-3p, as well as between miR-29c-3p and SIRT1 were verified. High glucose induced apoptosis and ERS in HK-2 cells, and significantly decreased TUG1 expression. Overexpressed TUG1 could prevent high glucose-induced apoptosis and alleviated ERS via negatively regulating miR-29c-3p. In contrast, miR-29c-3p increased HK-2 cells apoptosis and ERS upon high glucose-challenge. SIRT1 was a direct target gene of miR-29c-3p in HK-2 cells, which participated in the effects of miR-29c-3p on HK-2 cells. Mechanistically, TUG1 suppressed the expression of miR-29c-3p, thus counteracting its function in downregulating the level of SIRT1. TUG1 regulates miR-29c-3p/SIRT1 and subsequent ERS to relieve high glucose induced renal epithelial cells injury, and suggests a potential role for TUG1 as a promising diagnostic marker of diabetic nephropathy.

LncRNA TUG1 ameliorates diabetic nephropathy via inhibition of PU.1/RTN1 signaling pathway

Diabetic nephropathy (DN) is a leading cause of end-stage renal failure. The study aimed to investigate whether long noncoding RNA taurine-upregulated gene 1 (TUG1) can ameliorate the endoplasmic reticulum stress (ERS) and apoptosis of renal tubular epithelial cells in DN, and the underlying mechanism. The DN mouse model was established by streptozocin injection, and the human renal tubular epithelial cell line HK-2 was treated with high glucose (HG) to mimic DN in vitro. The molecular mechanism was explored through dual-luciferase activity assay, RNA pull-down assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (CHIP) assay. The expression of TUG1 was significantly decreased in the renal tubules of DN model mice. Overexpression of TUG1 reduced the levels of ERS markers and apoptosis markers by inhibiting reticulon-1 (RTN1) expression in HG-induced HK-2 cells. Furthermore, TUG1 down-regulated RTN1 expression by inhibiting the binding of transcription factor PU.1 to the RTN1 promoter, thereby reducing the levels of ERS markers and apoptosis markers. Meanwhile, TUG1-overexpression adenovirus plasmids injection significantly alleviated tubular lesions, and reduced RTN1 expression, ERS markers and apoptosis markers, whereas these results were reversed by injection of PU.1-overexpression adenovirus plasmids. TUG1 restrains the ERS and apoptosis of renal tubular epithelial cells and ameliorates DN through inhibition of transcription factor PU.1.

Astragaloside IV prevents acute myocardial infarction by inhibiting the TLR4/MyD88/NF-κB signaling pathway

Although astragaloside IV protects from acute myocardial infarction (AMI)-induced chronic heart failure (CHF), the underlying mechanism of action is unclear. We determined the potential therapeutic effect of astragaloside IV using molecular docking approaches and validated the findings by the ligation of the left anterior descending (LAD) coronary artery-induced AMI rat model. The interaction between astragaloside IV and myeloid differentiation factor 88 (MyD88) was evaluated by SwissDock. To explore the mechanisms underlying the beneficial effects of astragaloside IV in the LAD coronary artery ligation-induced AMI model, we administered the rats with astragaloside IV for 4 weeks. Hemodynamic indexes were used to evaluate the degree of myocardial injury in model rats. The histopathological changes in myocardium were detected by hematoxylin & eosin (H&E) staining and Masson's staining. Myocardium homogenate contents of collagen I and collagen III were evaluated by ELISA. The level of myocardial hydroxyproline (HYP) was determined by alkaline hydrolysis. Immunohistochemistry was used to examine collagen I. Western blotting was used to examine relevant proteins. As per the molecular docking study results, astragaloside IV may act on MyD88. Furthermore, astragaloside IV improved hemodynamic disorders, alleviated pathological changes, and reduced abnormal collagen deposition and myocardial HYP in vivo. Astragaloside IV significantly reduced the overexpression of TLR4, MyD88, NF-Κb, and TGF-β, which further validated the molecular docking findings. Hence, astragaloside IV ameliorates AMI by reducing inflammation and blocking TLR4/MyD88/NF-κB signaling. These results indicate that astragaloside IV may alleviate AMI. PRACTICAL APPLICATIONS: Astragaloside IV, a small active substance extracted from Astragalus membranaceus, has demonstrated potent protective effects against cardiovascular ischemia/reperfusion, diabetic nephropathy, and other diseases. Molecular docking experiments showed that astragaloside IV might act on the myeloid differentiation factor 88 (MyD88). Astragaloside IV can effectively reduce the overexpression of TLR4, MyD88, and NF-κB p65, indicating that astragaloside IV inhibits inflammation via TLR4/MyD88/NF-κB signaling pathway. These results indicate that astragaloside IV may alleviate acute myocardial infarction.

Treatment with astragaloside IV reduced blood glucose, regulated blood lipids, and protected liver function in diabetic rats

Objectives

To investigate the effects of astragaloside IV on blood glucose, blood lipids, and liver function in diabetic rats.

Methods

Fifty diabetic rats were randomly placed into five groups (n = 10 each): the diabetes mellitus (DM) group received intragastric saline, the metformin hydrochloride group received intragastric metformin hydrochloride, and the astragaloside-30, -60, and -120 groups received intragastric astragaloside 30 mg/kg, 60 mg/kg, and 120 mg/kg for 28 days, respectively. Ten non-diabetic rats received intragastric saline as controls.

Results

Relative to the DM group, fasting blood glucose, triglyceride, total cholesterol, serum alanine transaminase, and serum aspartate aminotransferase levels decreased in the astragaloside-60 and astragaloside-120 groups; serum alkaline phosphatase decreased solely in the astragaloside-120 group. Serum superoxide dismutase (SOD), glutathione (GSH-Px), and catalase (CAT) levels were elevated, while maleic dialdehyde (MDA) decreased in the astragaloside-120 group, relative to the DM group. Relative to the DM group, the liver index and liver cell apoptosis rate were reduced, while histopathological changes in liver tissue were ameliorated in the astragaloside groups; moreover, liver tissue SOD, GSH-Px, and CAT levels were increased, while liver tissue MDA was reduced.

Conclusions

Astragaloside IV can lower blood glucose, regulate blood lipids, and protect liver function in diabetic rats.

Non-Coding RNA and Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the most common chronic microvascular complications of diabetes. In addition to the characteristic clinical manifestations of proteinuria, it also has a complex pathological process that results from the combined effects of multiple factors involving the whole renal structure such as glomeruli, renal tubules, and blood vessels. Non-coding RNAs (ncRNA) are transcripts with no or low coding potential, among which micro RNA (miRNA) has been widely studied as a functional miRNA involved in regulation and a potential biomarker for disease prediction. The abundance of long coding RNA (lncRNA) in vivo is highly expressed with a certain degree of research progress, but the structural similarity makes the research still challenging. The research of circular RNA (circRNA) is still in its early stages. It is more relevant to the study to provide a more relevant link between diseases in the kidney and other tissues or organs. This classification review mainly summarized the biogenesis characteristics, the pathological mechanism of ncRNA-regulating diseases, the ways of ncRNA in the clinical prediction as a potential biomarker, and the interaction networks of ncRNA.

Astragaloside II Ameliorated Podocyte Injury and Mitochondrial Dysfunction in Streptozotocin-Induced Diabetic Rats

Astragaloside II (AS II), a novel saponin purified from Astragalus membranes, has been reported to modulate the immune response, repair tissue injury, and prevent inflammatory response. However, the protective effects of AS II on podocyte injury in diabetic nephropathy (DN) have not been investigated yet. In this study, we aimed to investigate the beneficial effects of AS II on podocyte injury and mitochondrial dysfunction in DN. Diabetes was induced with streptozotocin (STZ) by intraperitoneal injection at 55 mg/kg in rats. Diabetic rats were randomly divided into four groups, namely, diabetic rats and diabetic rats treated with losartan (10 mg·kg⁻¹·d⁻¹) or AS II (3.2 and 6.4 mg·kg⁻¹·d⁻¹) for 9 weeks. Normal Sprague-Dawley rats were chosen as nondiabetic control group. Urinary albumin/creatinine ratio (ACR), biochemical parameters, renal histopathology and podocyte apoptosis, and morphological changes were evaluated. Expressions of mitochondrial dynamics-related and autophagy-related proteins, such as Mfn2, Fis1, P62, and LC3, as well as Nrf2, Keap1, PINK1, and Parkin, were examined by immunohistochemistry, western blot, and real-time PCR, respectively. Our results indicated that AS II ameliorated albuminuria, renal histopathology, and podocyte foot process effacement and podocyte apoptosis in diabetic rats. AS II also partially restored the renal expression of mitochondrial dynamics-related and autophagy-related proteins, including Mfn2, Fis1, P62, and LC3. AS II also increased the expression of PINK1 and Parkin associated with mitophagy in diabetic rats. Moreover, AS II facilitated antioxidative stress ability via increasing Nrf2 expression and decreasing Keap1 protein level. These results suggested that AS II ameliorated podocyte injury and mitochondrial dysfunction in diabetic rats partly through regulation of Nrf2 and PINK1 pathway. These important findings might provide an innovative therapeutic strategy for the treatment of DN.