Salvianolic acid B plays an anti-obesity role in high fat diet-induced obese mice by regulating the expression of mRNA, circRNA, and lncRNA

The role of circRNA in insulin resistance and its progression induced by adipose inflammation

CircRNAs refer to a type of closed circular non-coding RNA without a 5' cap or a 3' poly (A) structure. They are largely distributed in the cytoplasm or localized in exosomes and cannot be easily degraded by RNA exonuclease activity. Their stable expression is broadly observed across eukaryotic species. Insulin resistance (IR) refers to the inability of insulin to exert its normal biological function, as manifested by the impairment of glucose utilization in peripheral tissues (e.g., muscle and fat tissues). IR is a key factor in the pathogenesis of Type 2 diabetes (T2D) and is closely associated with obesity. Recent studies have shown that certain circRNAs play critical roles in obesity-induced diabetes by regulating IR and participating in inflammatory processes. CircRNAs, with their multiple microRNA (miRNA) binding sites, act as miRNA sponges to eliminate the inhibitory actions of miRNAs and up-regulate the expression of target genes. CircRNAs play a significant role in regulating obesity-induced diabetes through their interactions with disease-related miRNAs. In the present study, we explored the biological characteristics of circRNAs and extensively discussed the role of circRNAs in the development of inflammation and IR in adipocytes, highlighting their potential as therapeutic targets for obesity-induced diabetes. Specific circRNAs (e.g., circARF3 and circ-ZNF609) have been identified as key players in modulating IR and inflammatory responses in adipose tissue. CircRNAs are emerging as important regulators of IR and inflammation in adipocytes, with significant potential for therapeutic intervention in obesity-induced diabetes. Further research is needed to elucidate the mechanisms underlying their actions and to explore strategies for targeting circRNAs in clinical applications.

Serum proteome signatures associated with liver steatosis in adolescents with obesity

PURPOSE

Childhood obesity, a pressing global health issue, significantly increases the risk of metabolic complications, including metabolic dysfunction associated with steatotic liver disease (MASLD). Accurate non-invasive tests for early detection and screening of steatosis are crucial. In this study, we explored the serum proteome, identifying proteins as potential biomarkers for inclusion in non-invasive steatosis diagnosis tests.

METHODS

Fifty-nine obese adolescents underwent ultrasonography to assess steatosis. Serum samples were collected and analyzed by targeted proteomics with the Proximity Extension Assay technology. Clinical and biochemical parameters were evaluated, and correlations among them, the individuated markers, and steatosis were performed. Receiver operating characteristic (ROC) curves were used to determine the steatosis diagnostic performance of the identified candidates, the fatty liver index (FLI), and their combination in a logistic regression model.

RESULTS

Significant differences were observed between subjects with and without steatosis in various clinical and biochemical parameters. Gender-related differences in the serum proteome were also noted. Five circulating proteins, including Cathepsin O (CTSO), Cadherin 2 (CDH2), and Prolyl endopeptidase (FAP), were identified as biomarkers for steatosis. CDH2, CTSO, Leukocyte Immunoglobulin Like Receptor A5 (LILRA5), BMI, waist circumference, HOMA-IR, and FLI, among others, significantly correlated with the steatosis degree. CDH2, FAP, and LDL combined in a logit model achieved a diagnostic performance with an AUC of 0.91 (95% CI 0.75-0.97, 100% sensitivity, 84% specificity).

CONCLUSIONS

CDH2 and FAP combined with other clinical parameters, represent useful tools for accurate diagnosis of fatty liver, emphasizing the importance of integrating novel markers into diagnostic algorithms for MASLD.

Circular RNAs in human diseases

Circular RNAs (circRNAs) are a unique class of RNA molecules formed through back-splicing rather than linear splicing. As an emerging field in molecular biology, circRNAs have garnered significant attention due to their distinct structure and potential functional implications. A comprehensive understanding of circRNAs' functions and potential clinical applications remains elusive despite accumulating evidence of their involvement in disease pathogenesis. Recent research highlights their significant roles in various human diseases, but comprehensive reviews on their functions and applications remain scarce. This review provides an in-depth examination of circRNAs, focusing first on their involvement in non-neoplastic diseases such as respiratory, endocrine, metabolic, musculoskeletal, cardiovascular, and renal disorders. We then explore their roles in tumors, with particular emphasis on exosomal circular RNAs, which are crucial for cancer initiation, progression, and resistance to treatment. By detailing their biogenesis, functions, and impact on disease mechanisms, this review underscores the potential of circRNAs as diagnostic biomarkers and therapeutic targets. The review not only enhances our understanding of circRNAs' roles in specific diseases and tumor types but also highlights their potential as novel diagnostic and therapeutic tools, thereby paving the way for future clinical investigations and potential therapeutic interventions.

Danshen-Shanzha formula for the treatment of atherosclerosis: ethnopharmacological relevance, preparation methods, chemical constituents, pharmacokinetic properties, and pharmacological effects

Danshen-Shanzha Formula (DSF) is a well-known herbal combination comprising Radix Salvia Miltiorrhiza (known as Danshen in Chinese) and Fructus Crataegi (known as Shanzha in Chinese), It has been documented to exhibit considerable benefits for promoting blood circulation and removing blood stasis, and was used extensively in the treatment of atherosclerotic cardiac and cerebral vascular diseases over decades. Despite several breakthroughs achieved in the basic research and clinical applications of DSF over the past decades, there is a lack of comprehensive reviews summarizing its features and research, which hinders further exploration and exploitation of this promising formula. This review aims to provide a comprehensive interpretation of DSF in terms of its ethnopharmacological relevance, preparation methods, chemical constituents, pharmacokinetic properties and pharmacological effects. The related information on Danshen, Shanzha, and DSF was obtained from internationally recognized online scientific databases, including Web of Science, PubMed, Google Scholar, China National Knowledge Infrastructure, Baidu Scholar, ScienceDirect, ACS Publications, Online Library, Wan Fang Database as well as Flora of China. Data were also gathered from documentations, printed works and classics, such as the Chinese Pharmacopoeia, Chinese herbal classics, etc. Three essential avenues for future studies were put forward as follows: a) Develop and unify the standard preparation method of DSF as to achieve optimized pharmacological properties. b) Elucidate the functional mechanisms as well as the rationality and rule for the compatibility art of DSF by focusing on the clinic syndromes together with the subsequent development of preclinic study system in vitro and in vivo with consistent pathological features, pharmacokinetical behaviour and biomarkers. c) Perform more extensive clinical studies towards the advancement of mechanism-based on evidence-based medicine on the safety application of DSF. This review will provide substantial data support and broader perspective for further research on the renowned formula.

Salvianolic Acid B: A Review of Pharmacological Effects, Safety, Combination Therapy, New Dosage Forms, and Novel Drug Delivery Routes

Salvianolic acid B is extracted from the roots and rhizomes of Danshen (Salvia miltiorrhiza Bge., family Labiatae). It is a water-soluble, weakly acidic drug that has demonstrated antitumor and anti-inflammatory effects on various organs and tissues such as the lung, heart, kidney, intestine, bone, liver, and skin and protective effects in diseases such as depression and spinal cord injury. The mechanisms underlying the protective effects of salvianolic acid B are mainly related to its anti-inflammatory, antioxidant, anti- or pro-apoptotic, anti- or pro-autophagy, anti-fibrotic, and metabolism-regulating functions. Salvianolic acid B can regulate various signaling pathways, cells, and molecules to achieve maximum therapeutic effects. This review summarizes the safety profile, combination therapy potential, and new dosage forms and delivery routes of salvianolic acid B. Although significant research progress has been made, more in-depth pharmacological studies are warranted to identify the mechanism of action, related signaling pathways, more suitable combination drugs, more effective dosage forms, and novel routes of administration of salvianolic acid B.

An Integrative Pharmacology-Based Strategy to Uncover the Mechanism of Zuogui Jiangtang Shuxin Formula in Diabetic Cardiomyopathy

Purpose

This study aimed to explore the mechanism of Zuogui Jiangtang Shuxin formula (ZGJTSXF) in the treatment of diabetic cardiomyopathy (DCM) by an integrative strategy combining serum pharmacochemistry, network pharmacology analysis, and experimental validation.

Methods

An Ultra high performance liquid chromatography-high resolution mass spectrometry (UPLC-Q-Exactive-Orbitrap-MS) method was constructed to identify compounds in rat serum after oral administration of ZGJTSXF. A component-target network between the targets of ZGJTSXF ingredients and DCM was established using Cytoscape. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed to deduce ZGJTSXF-associated targets and pathways. The DCM model mice were treated with ZGJTSXF, and the predicted important signaling pathways were verified using quantitative PCR and Western blot.

Results

We identified 78 compounds in serum of medicated rats, which mainly included flavonoids, small peptides, nucleosides, organic acids, phenylpropanoids, alkaloids, phenanthrenequinones, iridoids, phenols, and saponins. Network pharmacology analysis revealed that ZGJTSXF may regulate targets including ALB, TNF, AKT1, GAPDH, VEGFA, EGFR, SRC, CASP3, MAPK3, JUN, and PI3K/AKT signaling pathway in the treatment of DCM. ZGJTSXF administration improved blood sugar levels, heart function, and cardiac morphological changes in DCM mice. Notably, ZGJTSXF inhibited cardiomyocytes apoptosis, which was associated with restored PI3K/Akt signaling and upregulated Bcl-2 and Bcl-xL proteins expression.

Conclusion

Our preliminary results proposed the material basis and possible mechanisms of ZGJTSXF in treating DCM, which is related to the activation of the PI3K/AKT signaling pathway and apoptosis inhibition. These findings shed new light in developing ZGJTSXF-based therapeutics in treating DCM.

Differential Expression Analysis of tRNA-Derived Small RNAs from Subcutaneous Adipose Tissue of Obese and Lean Pigs

Epigenetic factors, including non-coding RNA regulation, play a vital role in the development of obesity and have been well researched. Transfer RNA-derived small RNA (tsRNA) is a class of non-coding RNA proven to be involved in various aspects of mammalian biology. Here we take pigs as a model for obesity research and use tsRNA-seq to investigate the difference in tsRNA expression in the subcutaneous adipose tissue of obese and lean pigs to elucidate the role of tsRNA in obesity development. A total of 482 tsRNAs were identified in pig adipose tissue, of which 123 were significantly differentially accumulated tsRNAs compared with the control group. The tRF-5c was the main type of these tsRNAs. The largest number of tsRNAs produced was the Gly-carrying tRNA, which produced 81 tsRNAs. Functional enrichment analysis revealed that differential tsRNAs indirectly participated in MAPK, AMPK, insulin resistance, the TNF signaling pathway, adipocytokine signaling pathway, and other signaling pathways by interacting with target genes. These are involved in bioenergetic metabolic regulatory processes, suggesting that tsRNAs may influence these pathways to mediate the regulation of energy metabolism in porcine adipocytes to promote lipid deposition, thus contributing to obesity. Our findings suggest a potential function of tsRNA in regulating obesity development.

Long Noncoding RNAs in the Pathogenesis of Insulin Resistance

Insulin resistance (IR), designated as the blunted response of insulin target tissues to physiological level of insulin, plays crucial roles in the development and progression of diabetes, nonalcoholic fatty liver disease (NAFLD) and other diseases. So far, the distinct mechanism(s) of IR still needs further exploration. Long non-coding RNA (lncRNA) is a class of non-protein coding RNA molecules with a length greater than 200 nucleotides. LncRNAs are widely involved in many biological processes including cell differentiation, proliferation, apoptosis and metabolism. More recently, there has been increasing evidence that lncRNAs participated in the pathogenesis of IR, and the dysregulated lncRNA profile played important roles in the pathogenesis of metabolic diseases including obesity, diabetes and NAFLD. For example, the lncRNAs MEG3, H19, MALAT1, GAS5, lncSHGL and several other lncRNAs have been shown to regulate insulin signaling and glucose/lipid metabolism in various tissues. In this review, we briefly introduced the general features of lncRNA and the methods for lncRNA research, and then summarized and discussed the recent advances on the roles and mechanisms of lncRNAs in IR, particularly focused on liver, skeletal muscle and adipose tissues.

Salvia miltiorrhiza extract may exert an anti-obesity effect in rats with high-fat diet-induced obesity by modulating gut microbiome and lipid metabolism

BACKGROUND

Studies have shown that a high-fat diet (HFD) can alter gut microbiota (GM) homeostasis and participate in lipid metabolism disorders associated with obesity. Therefore, regulating the construction of GM with the balance of lipid metabolism has become essential for treating obesity. Salvia miltiorrhiza extract (Sal), a common traditional Chinese medicine, has been proven effective against atherosclerosis, hyperlipidemia, obesity, and other dyslipidemia-related diseases.

AIM

To investigate the anti-obesity effects of Sal in rats with HFD-induced obesity, and explore the underlying mechanism by focusing on GM and lipid metabolism.

METHODS

Obesity was induced in rats with an HFD for 7 wk, and Sal (0.675 g/1.35 g/2.70 g/kg/d) was administered to treat obese rats for 8 wk. The therapeutic effect was evaluated by body weight, body fat index, waistline, and serum lipid level. Lipid factors (cAMP, PKA, and HSL) in liver and fat homogenates were analyzed by ELISA. The effect of Sal on GM and lipid metabolism was assessed by 16S rRNA-based microbiota analysis and untargeted lipidomic analysis (LC-MS/MS), respectively.

RESULTS

Sal treatment markedly reduced weight, body fat index, serum triglycerides (TG), total cholesterol (TC), low-density lipoprotein, glucose, free fatty acid, hepatic lipid accumulation, and adipocyte vacuolation, and increased serum high-density lipoprotein (HDL-C) in rats with HFD-induced obesity. These effects were associated with increased concentrations of lipid factors such as cAMP, PKA, and HSL in the liver and adipose tissues, enhanced gut integrity, and improved lipid metabolism. GM analysis revealed that Sal could reverse HFD-induced dysbacteriosis by promoting the abundance of Actinobacteriota and Proteobacteria, and decreasing the growth of Firmicutes and Desulfobacterita. Furthermore, LC-MS/MS analysis indicated that Sal decreased TGs (TG18:2/18:2/20:4, TG16:0/18:2/22:6), DGs (DG14:0/22:6, DG22:6/22:6), CL (18:2/ 18:1/18:1/20:0), and increased ceramides (Cers; Cer d16:0/21:0, Cer d16:1/24:1), (O-acyl)-ω-hydroxy fatty acids (OAHFAs; OAHFA18:0/14:0) in the feces of rats. Spearman's correlation analysis further indicated that TGs, DGs, and CL were negatively related to the abundance of Facklamia and Dubosiella, and positively correlated with Blautia and Quinella, while OAHFAs and Cers were the opposite.

CONCLUSION

Sal has an anti-obesity effect by regulating the GM and lipid metabolism.

An Ethnopharmaceutical Study on the Hypolipidemic Formulae in Taiwan Issued by Traditional Chinese Medicine Pharmacies

Globally, approximately one-third of ischemic heart diseases are due to hyperlipidemia, which has been shown to cause various metabolic disorders. This study was aimed to disassemble and analyze hypolipidemic formulae sold by traditional Chinese medicine (TCM) pharmacies. Using commonly used statistical parameters in ethnopharmacology, we identified the core drug combination of the hypolipidemic formulae, thereby exploring the strategy by which the Taiwanese people select hypolipidemic drugs. Most important of all, we preserved the inherited knowledge of TCM. We visited 116 TCM pharmacies in Taiwan and collected 91 TCM formulae. The formulae were mainly disassembled by macroscopical identification, and the medicinal materials with a relative frequency of citation (RFC) >0.2 were defined as commonly used medicinal materials. Subsequently, we sorted the information of medicinal materials recorded in the Pharmacopeia, searched for modern pharmacological research on commonly used medicinal materials using PubMed database, and visualized data based on the statistical results. Finally, the core hypolipidemic medicinal materials used in folk medicine were obtained. Of the 91 TCM formulae collected in this study, 80 traditional Chinese medicinal materials were used, belonging to 43 families, predominantly Lamiaceae. Roots were the most commonly used part as a medicinal material. There were 17 commonly used medicinal materials. Based on medicinal records in Pharmacopeia, most flavors and properties were warm and pungent, the majority traditional effects were “tonifying and replenishing” and “blood-regulating.” Besides, the targeted diseases searching from modern pharmacological studies were diabetes mellitus and dyslipidemia. The core medicinal materials consisted of Astragalus mongholicus Bunge and Crataegus pinnatifida Bunge, and the core formulae were Bu-Yang-Huan-Wu-Tang and Xie-Fu-Zhu-Yu-Tang. In addition, 7 groups of folk misused medicinal materials were found. Although these TCMs have been used for a long period of time, their hypolipidemic mechanisms remain unclear, and further studies are needed to validate their safety and efficacy.

Salvianolic acid B activates chondrocytes autophagy and reduces chondrocyte apoptosis in obese mice via the KCNQ1OT1/miR-128-3p/SIRT1 signaling pathways

Purpose

Salvianolic acid B (Sal B) possesses strong anti-inflammatory and antioxidant activity. This study aims to explore the underlying mechanism of Sal B to improve the obesity-related osteoarthritis (OA).

Methods

C57BL/6 J male mice were fed with a normal control diet (NCD), a high fat diet (HFD), or HFD with Sal B (25 mg/kg), and mouse body weights and osteoarticular inflammatory factor levels were examined. Mouse chondrogenic cell line ATDC5 were transfected with lncRNA KCNQ1 overlapping transcript 1 small hairpin RNA (KCNQ1OT1 shRNA), miR-128-3p mimic or Sirtuin-1 small interfering RNA (SIRT1 siRNA), then stimulated with Palmitic acid (PA) followed by the treatment of Sal B. Then, inflammatory response, apoptosis, and autophagy of ATDC5 cells in different groups were detected.

Results

Sal B reduced the body weight, decreased the levels of inflammatory markers, and improved cartilage damage in OA mice fed with HFD. KCNQ1OT1 was downregulated in OA mice fed with HFD, and PA-stimulated ATDC5 cells. Sal B protected ATDC5 cells against PA-mediated inflammation, apoptosis, and the inhibition of autophagy, while knockdown of KCNQ1OT1 reversed these results. KCNQ1OT1 was found to be functioned as a ceRNA to bind and downregulate the expression of miR-128-3p that was upregulated in PA-induced cells. Furthermore, SIRT1 was verified as a target of miR-128-3p. MiR-128-3p overexpression reversed the effects of Sal B on inflammatory response, apoptosis, and autophagy in PA-stimulated cells, and knockdown of SIRT1 displayed the similar results.

Conclusion

Sal B exerted a chondroprotective effect by upregulating KCNQ1OT1, which indicates Sal B can used for a therapeutic agent in obesity-related OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00686-0.

Williams-Beuren Syndrome Related Methyltransferase WBSCR27: From Structure to Possible Function

Williams-Beuren syndrome (WBS) is a genetic disorder associated with the hemizygous deletion of several genes in chromosome 7, encoding 26 proteins. Malfunction of these proteins induce multisystemic failure in an organism. While biological functions of most proteins are more or less established, the one of methyltransferase WBSCR27 remains elusive. To find the substrate of methylation catalyzed by WBSCR27 we constructed mouse cell lines with a Wbscr27 gene knockout and studied the obtained cells using several molecular biology and mass spectrometry techniques. We attempted to pinpoint the methylation target among the RNAs and proteins, but in all cases neither a direct substrate has been identified nor the protein partners have been detected. To reveal the nature of the putative methylation substrate we determined the solution structure and studied the conformational dynamic properties of WBSCR27 in apo state and in complex with S-adenosyl-L-homocysteine (SAH). The protein core was found to form a canonical Rossman fold common for Class I methyltransferases. N-terminus of the protein and the β6–β7 loop were disordered in apo-form, but binding of SAH induced the transition of these fragments to a well-formed substrate binding site. Analyzing the structure of this binding site allows us to suggest potential substrates of WBSCR27 methylation to be probed in further research.

Emerging functions of circular RNA in the regulation of adipocyte metabolism and obesity

As noncoding RNAs, circular RNAs (circRNAs) are covalently enclosed endogenous biomolecules in eukaryotes that have tissue specificity and cell specificity. circRNAs were once considered a rare splicing byproduct. With the development of high-throughput sequencing, it has been confirmed that they are expressed in thousands of mammalian genes. To date, only a few circRNA functions and regulatory mechanisms have been verified. Adipose is the main tissue for body energy storage and energy supply. Adipocyte metabolism is a physiological process involving a series of genes and affects biological activities in the body, such as energy metabolism, immunity, and signal transmission. When adipocyte formation is dysregulated, it will cause a series of diseases, such as atherosclerosis, obesity, fatty liver, and diabetes. In recent years, many noncoding RNAs involved in adipocyte metabolism have been revealed. This review provides a comprehensive overview of the basic structure and biosynthetic mechanism of circRNAs, and further discusses the circRNAs related to adipocyte formation in adipose tissue and liver. Our review will provide a reference for further elucidating the genetic regulation mechanism of circRNAs involved in adipocyte metabolism.

Salvia miltiorrhiza Extract and Individual Synthesized Component Derivatives Induce Activating-Transcription-Factor-3-Mediated Anti-Obesity Effects and Attenuate Obesity-Induced Metabolic Disorder by Suppressing C/EBPα in High-Fat-Induced Obese Mice

Pharmacological studies indicate that Salvia miltiorrhiza extract (SME) can improve cardiac and blood vessel function. However, there is limited knowledge regarding the effects (exerted through epigenetic regulation) of SME and newly derived single compounds, with the exception of tanshinone IIA and IB, on obesity-induced metabolic disorders. In this study, we administered SME or dimethyl sulfoxide (DMSO) as controls to male C57BL/J6 mice after they were fed a high-fat diet (HFD) for 4 weeks. SME treatment significantly reduced body weight, fasting plasma glucose, triglyceride levels, insulin resistance, and adipogenesis/lipogenesis gene expression in treated mice compared with controls. Transcriptome array analysis revealed that the expression of numerous transcriptional factors, including activating transcription factor 3 (ATF3) and C/EBPα homologous protein (CHOP), was significantly higher in the SME group. ST32db, a novel synthetic derivative similar in structure to compounds from S. miltiorrhiza extract, ameliorates obesity and obesity-induced metabolic syndrome in HFD-fed wild-type mice but not ATF3^−/− mice. ST32db treatment of 3T3-L1 adipocytes suppresses lipogenesis/adipogenesis through the ATF3 pathway to directly inhibit C/EBPα expression and indirectly inhibit the CHOP pathway. Overall, ST32db, a single compound modified from S. miltiorrhiza extract, has anti-obesity effects through ATF3-mediated C/EBPα downregulation and the CHOP pathway. Thus, SME and ST32db may reduce obesity and diabetes in mice, indicating the potential of both SME and ST32db as therapeutic drugs for the treatment of obesity-induced metabolic syndrome.

Mediterranean diet enriched in extra-virgin olive oil or nuts modulates circulating exosomal non-coding RNAs

PURPOSE

Exosomes are extracellular vesicles secreted by cells, which can transport different molecules, including nucleic acids. Dietary habits may induce gene regulation through the modulation of exosomal RNAs. We aimed at characterizing exosomal lncRNAs, mRNA and miRNAs modulation after a 1-year adherence to a low-fat diet (LFD) or to Mediterranean-based diets enriched in extra-virgin olive oil (MedDiet + EVOO) or in a mixture of nuts (MedDiet + Nuts).

METHODS

Plasma samples were collected, at baseline and after 1 year of dietary interventions, from 150 participants included in the PREDIMED study (Reus Center). LncRNAs, mRNAs and miRNAs were isolated from plasma exosomes and screened. RT-qPCR validation was performed for miRNAs.

RESULTS

Compared with LFD, 413 lncRNAs and 188 mRNAs, and 476 lncRNAs and 235 mRNAs were differentially modulated in response to the MedDiet + EVOO and MedDiet + Nuts interventions, respectively. In addition, after 1 year of dietary interventions, 26 circulating miRNAs were identified as differentially expressed between groups. After 1 year of intervention, 11 miRNAs significantly changed in LFD group, while 8 and 21 were modulated in response to the MedDiet enriched with EVOO or nuts, respectively. Bioinformatic analyses of differentially expressed miRNAs and their validated target genes suggest certain metabolic pathways are modulated by LFD (PI3K-Akt and AMPK), MedDiet + EVOO (PI3K-Akt, NF-kappa B, HIF-1, and insulin resistance), and MedDiet-Nuts (FoxO, PI3K-Akt, AMPK, p53 and HIF-1) interventions.

CONCLUSION

Results show that 1-year MedDiet + Nuts and MedDiet + EVOO dietary interventions modulate exosomal RNA content, with the former affecting a higher number of miRNAs. The modulation of exosomal RNAs could help explain how the adherence to a Mediterranean diet may lead to beneficial effects and deserves further investigation.

Effects of Salvianolic acid B on RNA expression and co-expression network of lncRNAs in brown adipose tissue of obese mice

ETHNOPHARMACOLOGICAL RELEVANCE

Salvianolic acid B (SalB) is a polyphenolic compound in Salvia miltiorrhiza Bunge ("Danshen"), which has been largely used in Traditional Chinese Medicine for the treatment of metabolic syndrome, obesity, diabetes, among others.

AIM OF STUDY

This study was to investigate the effects of Salvianolic acid B (SalB) on mRNA, lncRNA and circRNA's expression profile in brown adipose tissue (BAT) of obese mice.

MATERIALS AND METHODS

High-fat-diet induced obese C57BL/6J mice were treated with SalB (100 mg/kg/day) for 8 weeks. Then, BAT was harvested for RNA-Seq analysis. Differentially expressed mRNAs, lncRNAs and circRNAs were analyzed using the Illumina Hiseq 4000. Following this procedure, bioinformatic tools including Gene ontology (GO), KEGG pathway and lncRNA-mRNA co-network analysis were utilized. Finally, RT-qPCR was performed to validate the differentially expressed RNAs.

RESULTS

Compared with control group, 2532 mRNAs, 774 lncRNAs and 25 circRNAs were differentially expressed in SalB group. Additionally, 40 upregulated and 109 downregulated gene-related pathways were identified in the SalB group. Among them, metabolic pathways showed the highest enrichment coefficient in upregulated genes. Moreover, 54 up-regulated and 626 down-regulated coding mRNAs associated with lncRNA-Hsd11b1 and lncRNA-Vmp1.

CONCLUSIONS

SalB may play an anti-obesity role by adjusting the expression of mRNAs correlated with inflammatory response and energy metabolism through regulating the expression of lncRNA-Hsd11b1. The findings of this research provide new directions to study the mechanisms of SalB, and would open therapeutic avenues for the treatment of obesity.

Salvianolic acid-B improves fat graft survival by promoting proliferation and adipogenesis

Background

Our previous study proved that Salvia miltiorrhiza could enhance fat graft survival by promoting adipogenesis. However, the effect of salvianolic acid B (Sal-B), the most abundant and bioactive water-soluble compound in Salvia miltiorrhiza, on fat graft survival has not yet been investigated.

Objective

This study aims to investigate whether salvianolic acid B could improve fat graft survival and promote preadipocyte differentiation. The underlying mechanism has also been studied.

Methods

In vivo, 0.2 ml of Coleman fat was transplanted into nude mice with salvianolic acid B. The grafts were evaluated by HE and IF at 2 and 4 weeks posttransplantation and by micro-CT at 4 weeks posttransplantation. In vitro, the adipogenesis and proliferative activities of salvianolic acid B were analyzed in cultured human adipose-derived stem cells (h-ADSCs) and 3T3-L1 cells to detect the mechanism by which salvianolic acid B affects graft survival.

Results

In vivo, the weights and volumes of the fat grafts in the Sal-B-treated groups were significantly higher than those of the fat grafts in the control group. In addition, higher fat integrity and more viable adipocytes were observed in the Sal-B-treated groups. In vitro, salvianolic acid B showed the ability to promote 3T3-L1 and h-ADSC proliferation and adipogenesis.

Conclusions

Our in vitro experiments demonstrated that salvianolic acid B can promote the proliferation of adipose stem cells and enhance the differentiation of adipose stem cells. Simultaneously, in vivo experiments showed that salvianolic acid B can improve the survival rate of fat transplantation. Therefore, our research shed light on the potential therapeutic usage of salvianolic acid B in improving the survival rate of fat transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02575-4.

Effects of salvianolic acid B on glycometabolism and lipid metabolism in rodents: Meta-analysis

Danshen (Salvia miltiorrhiza) is a herb which has been widely used in China. Salvianolic acid B (SalB) is an aqueous bioactive component derived from Danshen. Here, we aimed to estimate the effect of SalB on glycometabolism and lipid metabolism in rats and mice. We searched four databases until November 2020. The outcome measures were fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLc), and low-density lipoprotein cholesterol (LDLc). Twenty-four studies involving 547 animals were included. The meta-analysis showed effects of SalB on decreasing the level of FBG, TC, TG, LDLc, and increasing the level of HDLc compared with the control group. In conclusion, the result showed that SalB may regulate the glycometabolism and lipid metabolism in rats or mice, and may be a potential agent for treating metabolic diseases such as diabetes and hyperlipidemia.

Ginsenoside Rb1, salvianolic acid B and their combination modulate gut microbiota and improve glucolipid metabolism in high-fat diet induced obese mice

Background

To observe the effect of ginsenoside Rb1, salvianolic acid B and their combination on glucolipid metabolism and structural changes of gut microbiota.

Methods

Eight-week-old C57BL/6J mice were fed 45% high-fat diet to induce obesity. The obese mice were randomly divided into four groups, Con group as model control, ginsenoside Rb1 (Rb1) group, salvianolic acid B (SalB) group and ginsenoside Rb1+ salvianolic acid B (Rb1SalB) group. Mice in Rb1, SalB and Rb1SalB group were treated by gavage with ginsenoside Rb1, salvianolic acid B and the combination of the two ingredients, respectively. While mice in Con group were given the same amount of sterile water. The intervention lasted 8 weeks. Body weight and fasting blood glucose were measured every 2 weeks. Oral glucose tolerance test was conducted on the 4th and 8th week of drug intervention. At the end of the experiment, total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol and non-esterified fatty acid content as well as glycated hemoglobin were measured and feces were collected for 16S rDNA sequencing.

Results

Both ginsenoside Rb1 and Rb1SalB combination decreased body weight significantly (P < 0.05). Ginsenoside Rb1, salvianolic acid B and their combination alleviated fasting blood glucose, glycated hemoglobin and blood lipid profiles effectively (P < 0.05, compared with the corresponding indicators in Con group). Oral glucose tolerance test results at the 8th week showed that glucose tolerance was significantly improved in all three treatment groups. Ginsenoside Rb1, salvianolic acid B and their combination reduced the overall diversity of gut microbiota in feces and changed the microbial composition of the obese mice. LDA effect size (LefSe) analysis revealed the key indicator taxa corresponding to the treatment.

Conclusion

Ginsenoside Rb1, salvianolic acid B and their combination could lower blood glucose and lipid level, and improve glucose tolerance of obese mice. The above effect may be at least partially through modulation of gut microbial composition.

The role of long noncoding RNA in lipid, cholesterol, and glucose metabolism and treatment of obesity syndrome

Obesity syndromes, characterized by abnormal lipid, cholesterol, and glucose metabolism, are detrimental to human health and cause many diseases, including obesity and type II diabetes. Increasing evidence has shown that long noncoding RNA (lncRNA), transcripts longer than 200 nucleotides that are not translated into proteins, play an important role in regulating abnormal metabolism in obesity syndromes. For the first time, we systematically summarize how lncRNA is involved in complex obesity metabolic syndromes, including the regulation of lipid, cholesterol, and glucose metabolism. Moreover, we discuss lncRNA involvement in food intake that mediates obesity syndromes. Furthermore, this review might shed new light on a lncRNA-based strategy for the prevention and treatment of obesity syndromes. Recent investigations support that lncRNA is a novel molecular target of obesity syndromes and should be emphasized. Namely, lncRNA plays a crucial role in the development of obesity syndrome process. Various lncRNAs are involved in the process of lipid, cholesterol, and glucose metabolism by regulating gene transcription, signaling pathway, and epigenetic modification of metabolism-related genes, proteins, and enzymes. Food intake could also induce abnormal expression of lncRNA associated with obesity syndrome, especially high-fat diet. Notably, some nanomolecules and natural extracts may target lncRNAs, associated with obesity syndrome, as a potential treatment for obesity syndromes.

Regulatory roles of circRNAs in adipogenesis and lipid metabolism: emerging insights into lipid-related diseases

Disorder of lipid metabolism has become an urgent health problem that brings about a variety of metabolic syndromes, including hepatic steatosis, adipose tissue dysfunction, diabetes and obesity. Circular RNAs (circRNAs), a class of emerging RNA molecules with unique structure and extensive effects, have been verified to participate in various biological programs through distinct mechanisms, especially in lipid-related processes. In this review, the biogenesis, characteristics, and functional mechanisms of circRNAs are discussed. Furthermore, the methods for circRNA identification and expression profiles of circRNAs associated with adipogenesis and lipid metabolism are described. Additionally, we emphasize the regulatory roles of circRNAs in adipogenesis, lipid metabolism, and lipid-related diseases. Finally, the diagnostic and therapeutic potential of circRNAs is highlighted, showing potential for the clinical application of circRNAs in the treatment of lipid-related diseases in the near future.

Identification of novel alternative splicing of bovine lncRNA lncFAM200B and its effects on preadipocyte proliferation

Adipogenesis is closely related to human health, livestock growth, and meat quality. A previous study identified that bovine lncFAM200B promoter has high activity in 3T3-L1 mice preadipocytes. Thus, lncFAM200B was a candidate gene for regulating adipogenesis. This study aimed to uncover the role of lncFAM200B in bovine adipogenesis and identify novel genetic variations within the bovine lncFAM200B gene. An expression analysis found that lncFAM200B was expressed higher in fat than that in muscle, but the difference was not related to the total methylation level of the promoter active region. Moreover, the expression of lncFAM200B exhibited a significant positive correlation with the expression of C/EBPa during bovine adipocyte differentiation. To uncover the function of lncFAM200B, the full-length lncFAM200B was cloned, and four kinds of transcript variants were found. Protein-coding potential prediction and prokaryotic expression system analysis showed that these four transcript variants were noncoding RNAs. The quantitative reverse-transcription polymerase chain reaction and 5-ethynyl-2'-deoxyuridine assay showed that the transcript variants decreased the messenger RNA expression of Cyclin D1 and inhibited the proliferation of bovine preadipocytes. Considering the important role of lncFAM200B in adipogenesis, we identified genetic variations in lncFAM200B. Three single-nucleotide polymorphisms (SNPs) were revealed, and two of them (SNP1 and SNP3) were associated with Nanyang cattle body measurement traits. In conclusion, this study found that bovine lncFAM200B inhibited preadipocyte proliferation, and two genetic variations of lncFAM200B could be used in cattle breeding.

Circular RNA SAMD4A controls adipogenesis in obesity through the miR-138-5p/EZH2 axis

A growing body of evidence has suggested that circular RNAs (circRNAs) are crucial for the regulation of gene expression and their dysregulation is implicated in several diseases. However, the function of circRNAs in obesity remains largely unexplored.

Methods: Global changes in the circRNA expression patterns were detected in adipose tissues derived from obese and lean individuals. In particular, circSAMD4A was identified as significantly differentially upregulated and was functionally analyzed, both in vitro and in vivo, using various approaches.

Results: CircSAMD4A overexpression was correlated with a poor prognosis in obese patients. By contrast, circSAMD4A knockdown inhibited differentiation in isolated preadipocytes. In high-fat diet (HFD) -induced obese mice, circSAMD4A knockdown reversed the associated weight gain, reduced food intake, lower body fat, and increased energy expenditure. These mice also exhibited increased insulin sensitivity and glucose tolerance. Furthermore, in vitro experiments indicated that circSAMD4A affected differentiation by binding to miR-138-5p and regulating EZH2 expression.

Conclusions: CircSAMD4A regulated preadipocyte differentiation by acting as a miR-138-5p sponge, and thus increasing EZH2 expression. These results suggested that circSAMD4A can serve as a potential target for obesity treatments and/or as a potential prognostic marker for obese patients following bariatric surgery.

Chemical and pharmacological research on the polyphenol acids isolated from Danshen: A review of salvianolic acids

Danshen, the dried root of Salvia miltiorrhiza Bge, is a common medicinal herb in Traditional Chinese Medicine, which has been used for the treatment of a number of diseases for thousands of years. More than 2000 years ago, the Chinese early pharmacy monograph "Shennong Materia Medica" recorded that Danshen could be used for the treatment of gastrointestinal diseases, cardiovascular diseases, certain gynecological diseases, etc. Since then, Danshen has been widely used clinically in many different prescriptions for many different diseases, especially for the treatment of cardiovascular diseases. Nowadays, many pharmacological studies about the water-soluble components from Danshen have been reported, especially salvianolic acids. It turned out that salvianolic acids showed strong anti-lipid peroxidation and anti-thrombic activities, and among them, SalAA and SalAB were the most potent. This review focused on the achievements in research of salvianolic acids regarding their bioactivities and pharmacological effects. These studies not only shed light on the water-soluble active components of Danshen and their mechanisms at the molecular level, but also provided theoretical information for the development of new medicines from Danshen for the treatment of cardiovascular and cerebrovascular diseases, inflammatory diseases, metabolic diseases, etc.

Salvianolic acid B prevents body weight gain and regulates gut microbiota and LPS/TLR4 signaling pathway in high-fat diet-induced obese mice

Salvianolic acid B prevents body weight gain and improves insulin sensitivity in obese mice. The underlying mechanism behind these effects may be associated with the regulation of metabolic endotoxemia, gut microbiota homeostasis and LPS/TLR4 pathway.