Treatment with adipose tissue-derived mesenchymal stem cells exerts anti-diabetic effects, improves long-term complications, and attenuates inflammation in type 2 diabetic rats. Stem Cell Res Ther. 2019;10:333. [PMID: 31747961 PMCID: PMC6868748 DOI: 10.1186/s13287-019-1474-8]

Stromal Vascular Fraction and Mesenchymal Stem Cells from Human Adipose Tissue: A Comparison of Immune Modulation and Angiogenic Potential

INTRODUCTION

In recent years, both stromal vascular fraction (SVF) from adipose tissue and mesenchymal stem cells (MSC) from adipose tissues were extensively used in both preclinical and clinical treatment for various diseases. Some studies reported differences in treatment efficacy between SVFs and MSCs in animals as well as in humans. Therefore, this study is aimed to evaluate the immune modulation and angiogenic potential of SVFs and MSCs from the same SVF samples to support an explanation when SVFs or MSCs should be used.

METHODS

The adipose tissue samples from ten female donors with consent forms were collected. SVFs from these samples were isolated according to the published protocols. The existence of mesenchymal cells that positive with CD44, CD73, CD90, and CD105 and endothelial progenitor cells that positive with CD31 and CD34 was determined using flow cytometry. Three samples of SVFs with similar percentages of mesenchymal cell portion and endothelial progenitor cell portion were used to isolate MSCs. Obtained MSCs were confirmed as MSCs using the ISCT minimal criteria. To compare the immune modulation of SVF and MSCs, the mixed lymphocyte assay was used. The lymphocyte proliferation, as well as IFN-gamma and TNF-alpha concentrations, were determined. To compare the angiogenic potential, the angiogenesis in quail embryo assay was used. The angiogenesis efficacy was measured based on the vessel areas formed in the embryos after 7 days.

RESULTS

The results showed that all SVF samples contained the portions of mesenchymal cells and endothelial progenitor cells. MSCs from SVFs meet all minimal criteria of MSCs that suggested by ISCT. MSCs from SVFs efficiently suppressed the immune cell proliferation compared to the SVFs, especially at ratios of 1:4 (1 MSCs: 4 immune cells). MSCs also inhibited the IFN-gamma and TNF-alpha production more efficiently than SVFs (p < 0.05). However, in quail embryo models, SVFs triggered the angiogenesis and neovessel formation better than MSCs with more significant vessel areas after 7 days (p < 0.05).

CONCLUSION

This study suggested that SVFs and MSCs have different potentials for immune modulation and angiogenesis. SVFs help the angiogenesis better than MSCs, while MSCs displayed the more significant immune modulation. These results can guide the usage of SVFs or MSCs in disease treatment.

Human umbilical cord-derived mesenchymal stem cells alleviate insulin resistance in diet-induced obese mice via an interaction with splenocytes

Background

Previous research has demonstrated that the spleen plays an important role in mesenchymal stem cell (MSC)-mediated alleviation of acute inflammation, as MSC infusion increases the spleen-derived anti-inflammatory cytokine interleukin 10 (IL-10) levels. However, studies on splenic involvement in MSC-induced protection against chronic inflammatory diseases are limited. Obesity is characterized by chronic low-grade inflammation, a key driver of insulin resistance. This study aims to evaluate the effects of MSCs on obesity-related insulin resistance and explore the underlying mechanism, particularly regarding splenic involvement.

Methods

We induced obesity in mice by feeding them high-fat diets for 20 weeks. Human umbilical cord-derived MSCs (UC-MSCs) were systemically infused into the obese mice once per week for 6 weeks. Systemic glucose metabolic homeostasis and insulin sensitivity in epididymal adipose tissue (EAT) were evaluated. Then, we conducted in vivo blockade of IL-10 during UC-MSC infusion by intraperitoneally administrating an IL-10-neutralizing antibody twice per week. We also investigated the therapeutic effects of UC-MSCs on obese mice after removal of the spleen by splenectomy.

Results

UC-MSC infusions improved systemic metabolic homeostasis and alleviated insulin resistance in EAT but elicited no change in weight. Despite rare engraftment of UC-MSCs in EAT, UC-MSC infusions attenuated insulin resistance in EAT by polarizing macrophages into the M2 phenotype, coupled with elevated serum IL-10 levels. In vivo blockade of IL-10 blunted the effects of UC-MSCs on obese mice. Furthermore, UC-MSCs overwhelmingly homed to the spleen, and the ability of UC-MSCs to elevate serum IL-10 levels and alleviate insulin resistance was impaired in the absence of the spleen. Further in vivo and in vitro studies revealed that UC-MSCs promoted the capacity of regulatory T cells (Treg cells) to produce IL-10 in the spleen.

Conclusions

Our results demonstrated that UC-MSCs elevated serum IL-10 levels and subsequently promoted macrophage polarization, leading to alleviation of insulin resistance in EAT. The underlying mechanism was that UC-MSCs improved the capacity of Treg cells to produce IL-10 in the spleen. Our findings indicated that the spleen played a critical role in amplifying MSC-mediated immunomodulatory effects, which may contribute to maximizing MSC efficacy in clinical applications in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02791-6.

Anti-inflammatory effects of mesenchymal stem cell-conditioned media inhibited macrophages activation in vitro

The immunomodulatory effects of mesenchymal stem cells (MSCs) on macrophages have been reported, however, the underlying mechanism remains unknown. Therefore, this study aimed to investigate the anti-inflammatory effects of MSCs on lipopolysaccharide (LPS)-stimulated macrophages and the subsequent downregulation of their inflammatory mediators. Macrophages were treated with conditioned media from MSCs, without a subsequent change of MSCs responding to the inflammation state. This study also evaluated whether the interleukin (IL) 4 stimulation of MSCs can improve their anti-inflammatory effects. Results demonstrated that the MSC-conditioned medium (MSC-CM) stimulated with IL4 significantly inhibited inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression of LPS-activated macrophages. MSC-CM treatment inhibited the mRNA transcription of the cytokines IL1β and IL6, the chemokines C–C motif ligand (CCL) 2, CCL3, CCL4, and CCL5, and the chemokine receptors CCR2 and CCR5, in LPS-stimulated macrophages. As revealed through western blot and immunofluorescence analyses, the phosphorylation of p38, JNK, and ERK MAPKs, as well as phosphorylation of NF-κB in stimulated macrophages, were also inhibited by the MSC-CM. Further, more potent anti-inflammatory effects were observed with the IL4-stimulated cells, compared with those observed with the non-stimulated cells. The MSC-CM demonstrated a potent anti-inflammatory effect on LPS-activated macrophages, while the IL4 stimulation improved this effect. These findings indicate that MSCs could exert anti-inflammatory effects on macrophages, and may be considered as a therapeutic agent in inflammation treatment.

Calystegines Improve the Metabolic Activity of Human Adipose Derived Stromal Stem Cells (ASCs) under Hyperglycaemic Condition through the Reduction of Oxidative/ER Stress, Inflammation, and the Promotion of the AKT/PI3K/mTOR Pathway

Hyperglycaemia and its resulting glucotoxicity are among the most prominent hallmarks of diabetes mellitus (DM) development. Persistent hyperglycaemia further leads to oxidative stress via mitochondrial dysfunction and subsequent ER stress onset, while associated hyperlipidaemia triggers the adipose tissue to secrete pro-inflammatory cytokines. In this study, the effect of calystegines has been investigated in an experimental model of hyperglycaemia induced on human ASCs cells. Different cellular pathways including apoptosis, oxidative and ER stress, inflammation as well as Pi3K/AKT/mTOR metabolic-associated axis have been evaluated by means on RT-qPCR, western blot, and flow cytometry techniques. Treatment of HuASCs cells with calystegines strongly promoted the hyperglycaemic cells survival and significantly diminished oxidative stress, mitochondrial dynamics failure and ER stress, while improving the endogenous cellular antioxidant defenses. Interestingly, nortropane alkaloids efficiently prevented the hyperglycaemia-mediated inflammatory response, as evidenced by the regulation of the pro- and anti-inflammatory response in HuASCs cells. Finally, we evidenced that calystegines may exert their protective effect on HuASCs cells metabolic functions through the restoration of the defective PI3K/AKT/mTOR pathway. Overall, the present investigation demonstrated that calystegines possess important abilities to protect HuASCs against hyperglycaemia-induced cellular dysfunction, and it evidenced that the observed effects are associated to the promotion of PI3K/AKT/mTOR pathway.

Immune and Metabolic Alterations in Liver Fibrosis: A Disruption of Oxygen Homeostasis?

According to the WHO, “cirrhosis of the liver” was the 11th leading cause of death globally in 2019. Many kinds of liver diseases can develop into liver cirrhosis, and liver fibrosis is the main pathological presentation of different aetiologies, including toxic damage, viral infection, and metabolic and genetic diseases. It is characterized by excessive synthesis and decreased decomposition of extracellular matrix (ECM). Hepatocyte cell death, hepatic stellate cell (HSC) activation, and inflammation are crucial incidences of liver fibrosis. The process of fibrosis is also closely related to metabolic and immune disorders, which are usually induced by the destruction of oxygen homeostasis, including mitochondrial dysfunction, oxidative stress, and hypoxia pathway activation. Mitochondria are important organelles in energy generation and metabolism. Hypoxia-inducible factors (HIFs) are key factors activated when hypoxia occurs. Both are considered essential factors of liver fibrosis. In this review, the authors highlight the impact of oxygen imbalance on metabolism and immunity in liver fibrosis as well as potential novel targets for antifibrotic therapies.

Extracellular vesicles from adipose-derived stem cells promote microglia M2 polarization and neurological recovery in a mouse model of transient middle cerebral artery occlusion

Background

Adipose-derived stem cells (ADSCs) and their extracellular vesicles (EVs) have therapeutic potential in ischemic brain injury, but the underlying mechanism is poorly understood. The current study aimed to explore the contribution of miRNAs in ADSC-EVs to the treatment of cerebral ischemia.

Methods

After the intravenous injection of ADSC-EVs, therapeutic efficacy was evaluated by neurobehavioral tests and brain atrophy volume. The polarization of microglia was assessed by immunostaining and qPCR. We further performed miRNA sequencing of ADSC-EVs and analyzed the relationship between the upregulated miRNAs in ADSC-EVs and microglial polarization-related proteins using Ingenuity Pathway Analysis (IPA).

Results

The results showed that ADSC-EVs reduced brain atrophy volume, improved neuromotor and cognitive functions after mouse ischemic stroke. The loss of oligodendrocytes was attenuated after ADSC-EVs injection. The number of blood vessels, as well as newly proliferated endothelial cells in the peri-ischemia area were higher in the ADSC-EVs treated group than that in the PBS group. In addition, ADSC-EVs regulated the polarization of microglia, resulting in increased repair-promoting M2 phenotype and decreased pro-inflammatory M1 phenotype. Finally, STAT1 and PTEN were highlighted as two downstream targets of up-regulated miRNAs in ADSC-EVs among 85 microglia/macrophage polarization related proteins by IPA. The inhibition of STAT1 and PTEN by ADSC-EVs were confirmed in cultured microglia.

Conclusions

In summary, ADSC-EVs reduced ischemic brain injury, which was associated with the regulation of microglial polarization. miRNAs in ADSC-EVs partly contributed to their function in regulating microglial polarization by targeting PTEN and STAT1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02668-0.

Functional tissue-engineered microtissue formed by self-aggregation of cells for peripheral nerve regeneration

Background

Peripheral nerve injury (PNI) is one of the essential causes of physical disability with a high incidence rate. The traditional tissue engineering strategy, Top-Down strategy, has some limitations. A new tissue-engineered strategy, Bottom-Up strategy (tissue-engineered microtissue strategy), has emerged and made significant research progress in recent years. However, to the best of our knowledge, microtissues are rarely used in neural tissue engineering; thus, we intended to use microtissues to repair PNI.

Methods

We used a low-adhesion cell culture plate to construct adipose-derived mesenchymal stem cells (ASCs) into microtissues in vitro, explored the physicochemical properties and microtissues components, compared the expression of cytokines related to nerve regeneration between microtissues and the same amount of two-dimension (2D)-cultured cells, co-cultured directly microtissues with dorsal root ganglion (DRG) or Schwann cells (SCs) to observe the interaction between them using immunocytochemistry, quantitative reverse transcription polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA). We used grafts constructed by microtissues and polycaprolactone (PCL) nerve conduit to repair sciatic nerve defects in rats.

Results

The present study results indicated that compared with the same number of 2D-cultured cells, microtissue could secrete more nerve regeneration related cytokines to promote SCs proliferation and axons growth. Moreover, in the direct co-culture system of microtissue and DRG or SCs, axons of DRG grown in the direction of microtissue, and there seems to be a cytoplasmic exchange between SCs and ASCs around microtissue. Furthermore, microtissues could repair sciatic nerve defects in rat models more effectively than traditional 2D-cultured ASCs.

Conclusion

Tissue-engineered microtissue is an effective strategy for stem cell culture and therapy in nerve tissue engineering.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02676-0.

Adipose-Derived Mesenchymal Stem Cell-Derived Exosomal miR-301a-3p Regulates Airway Smooth Muscle Cells During Asthma by Targeting STAT3

Background

Asthma is a chronic inflammatory disease featured by inflammation and remodeling of airway. Adipose-derived mesenchymal stem cell (ADSCs)-derived exosomal miRNAs have been suggested as promising therapeutic manners for diseases.

Methods

ADSCs and airway smooth muscle cells (ASMCs) were isolated from SD rats. Flow cytometry was conducted to detect the surface biomarkers of isolated cells. Exosomes were extracted by sequentially centrifuge method and identified by Western blotting and nanoparticle tracking analysis (NTA). Uptake of exosomes by ASMCs was detected by confocal assay. ASMCs were treated with platelet-derived growth factor-BB (PDGF-BB) to mimic cell remodeling and inflammation. Cell counting 8 (CCK-8), Transwell, and flow cytometry were performed to determine the viability, migration, and apoptosis of ASMCs. Release of inflammatory factors was detected by enzyme-linked immunosorbent assay (ELISA). Levels of RNAs and proteins were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. Interaction between miR-301a-3p and signal transducer and activator of transcription 3 (STAT3) was determined by luciferase reporter gene assay. The effect of Exosomal miR-301a-3p was analyzed in ovalbumin (OVA)-induced asthma mouse model.

Results

ADSCs-derived exosomes could be effectively internalized by ASMCs. Exosomal miR-301a-3p notably suppressed the PDGF-BB-stimulated proliferation and migration of ASMCs, and enhanced apoptosis, as well as decreased the secretion of inflammatory factors. MiR-301a-3p directly targeted the 3ʹUTR region of STAT3. STAT3 overexpression reversed the suppressive effects of exosomal miR-301a-3p on ASMCs under PDGF-BB stimulation. The expression of miR-301a-3p and STAT3 was negative correlation in specimen from patients with asthma. Exosomal miR-301a-3p inhibited OVA-induced lung injury by targeting STAT3 in mice.

Conclusion

This study exposed that exosomal miR-301a-3p from ADSCs could effectively alleviate PDGF-BB-stimulated remodeling and inflammation of ASMCs via targeting STAT3, presented ADSCs-derived exosomal miR-301a-3p as a promising therapeutic approach for asthma.

Veratrilla baillonii Franch Ameliorates Diabetic Liver Injury by Alleviating Insulin Resistance in Rats

Type 2 diabetes mellitus (T2DM) is a complex and polygenic disorder with diverse complications. Veratrilla baillonii Franch (V. baillonii) has been applied in the intervention and treatment a diverse range of diseases, including diabetes. In this study, we revealed that water extracts of V. baillonii (WVBF) can ameliorate liver injury and insulin resistance in T2DM rat model. To elucidate the anti-diabetic mechanisms of WVBF, we performed liver transcriptome analysis that displayed WVBF treatment significantly suppressed many gene expressions involved in insulin resistance. Furthermore, functional experiments showed that WVBF treatment reduced the pathological damages of liver and pancreas, which may be regulated by Foxo1, Sirt1, G6pc, c-Met, Irs1, Akt1, Pik3r1. These results indicated that WVBF improves diabetic liver injury and insulin resistance in diabetic rats. Therefore, this study demonstrated WVBF could be used as a promising therapeutic agent for intervention and treatment of diabetes.

Metformin attenuates diabetic neuropathic pain via AMPK/NF-κB signaling pathway in dorsal root ganglion of diabetic rats

Neuropathic pain is a common complication of diabetes mellitus with poorly relieved by conventional analgesics. Metformin, a first-line drug for type 2 diabetes, reduces blood glucose by activating adenosine monophosphate protein kinase (AMPK) signalling system. However, the effect of Metformin on diabetic neuropathic pain is still unknown. In the present study, we showed that Metformin was capable of attenuating diabetes induced mechanical allodynia, and the analgesia effect could be blocked by Compound C (an AMPK inhibitor). Importantly, Metformin enhanced the phosphorylation level of AMPK in L4-6 DRGs of diabetic rats but not affect the expression of total AMPK. Intrathecal injection of AICAR (an AMPK agonist) could activate AMPK and alleviate the mechanical allodynia of diabetic rats. Additionally, phosphorylated AMPK and NF-κB was co-localized in small and medium neurons of L4-6 DRGs. Interestingly, the regulation of NF-κB in diabetic rats was obviously reduced when AMPK was activated by AICAR. Notably, Metformin could decrease NF-κB expression in L4-6 DRGs of diabetic rats, but the decrease was blocked by Compound C. In conclusion, Metformin alleviates diabetic mechanical allodynia via activation of AMPK signaling pathway in L4-6 DRGs of diabetic rats, which might be mediated by the downregulation of NF-κB, and this providing certain basis for Metformin to become a potential drug in the clinical treatment of diabetic neuropathic pain.

Reenvisioning Traditional to Regenerative Therapeutic Advances in Managing Nonalcoholic Fatty Liver Disease in Diabetes Mellitus

Reports indicate the increasing prevalence of liver disorders in diabetes mellitus (DM) patients. Clinically, it has also been revealed that the existence of nonalcoholic fatty liver disease (NAFLD) enhances the incidence of type 2 diabetes mellitus (T2DM), while T2DM exacerbates NAFLD to extremely severe forms of steatohepatitis, cirrhosis, and hepatocellular carcinoma. This implies the coexistence and bidirectional nature of NAFLD and T2DM, which function synergistically to drive adverse consequences in clinical practice. For treatment of such comorbid state, though the existing practices such as lifestyle management, traditional Chinese medicines (TCM), and pharmaceuticals have offered somewhat relief, the debate continues about the optimal therapeutic impacts. Recent developments in the field of tissue engineering have led to a renewed interest in novel biomaterial alternatives such as stem cells. This might be attributable to their differentiation potential towards hepatic and pancreatic lineage. These cellular therapies could be further complemented by platelet-derived biomaterials, TCM formulations, or any specific drug. Based on these abovementioned approaches, we aimed to comprehensively analyze various preclinical and clinical studies from traditional to regenerative therapeutic approaches in managing concomitant NAFLD and T2DM.

Melatonin Promotes the Therapeutic Effect of Mesenchymal Stem Cells on Type 2 Diabetes Mellitus by Regulating TGF-β Pathway

Abundant evidence proves the therapeutic effect of adipose-derived mesenchymal stem cells (ADMSCs) in the treatment of diabetes mellitus. However, the problems have not been solved that viability of ADMSCs were inconsistent and the cells quickly undergo senescence after in vitro cell culture. In addition, the therapeutic effect of ADMSCs is still not satisfactory. In this study, melatonin (MLT) was added to canine ADMSC culture medium, and the treated cells were used to treat type 2 diabetes mellitus (T2DM). Our research reveals that adding MLT to ADMSC culture medium can promote the viability of ADMSCs. This effect depends on the binding of MLT and MLT receptors, which activates the transforming growth factor β (TGF-β) pathway and then changes the cell cycle of ADMSCs and improves the viability of ADMSCs. Since ADMSCs were found to be used to treat T2DM by anti-inflammatory and anti-endoplasmic reticulum (ER) stress capabilities, our data demonstrate that MLT augment several effects of ADMSCs in remission hyperglycemia, insulin resistance, and liver glycogen metabolism in T2DM patients. This suggest that ADMSCs and MLT-ADMSCs is safe and vabulable for pet clinic.

Where Do We Stand in Stem Cell Therapy for the Management of Diabetes Mellitus?-A Scientometric Research Trend Analysis from 1990 to 2020

Stem cell therapy has been considered a promising strategy in the management of both type I and type II diabetes mellitus (DM) because of its immunomodulatory and regenerative capability to restore the beta cell number and function. Various modalities of cellular therapy like transplantation of pancreatic islet cells, transplantation of pancreatic ductal stem cells, and mesenchymal stromal cell transplantation have been tried, and the modality is undergoing rapid advancements that may become the reality in the near future. In the course of its evolution, it is essential to have a comprehensive summary of the progress for a greater capacity to refine our future directives. With technological developments like data mining, graphic drawing, and information analytics combined with computational statistics, visualization of scientific metrology has become a reality. With a newer perspective, we intend to use scientometric tools including text mining, co-word analysis, word frequency analysis, co-citation analysis, cluster network analysis, to perform a systematic and comprehensive analysis of the research trend in stem cell therapy in the management of DM over the past three decades (1990-2020) and to identify the future research hotspots.

Adipose-derived stem cells and obesity: The spear and shield relationship

With the transformation of modern lifestyles and population ageing, obesity has become a global epidemic, as one of the important threat to human health of chronic non-communicable diseases (NCD). Stem cell therapy seems promising as an alternative strategy for managing obesity and related metabolic problems. Adipose tissue-derived stem cells (ADSCs) have received widespread attention, which provides new ideas for the treatment of obesity and various metabolic-related diseases, due to their abundant reserves, easy acquisition, rapid expansion, and multi-directional differentiation potential, low immunogenicity and many other advantages. Accordingly, there seems to be a "shield and spear paradox" in the relationship between ADSCs and obesity. In this review, we emphatically summarized the role of ADSCs in the occurrence and development of obesity and related metabolic disease processes, in order to pave the way for clinical practice.

MiR-144-5p, an exosomal miRNA from bone marrow-derived macrophage in type 2 diabetes, impairs bone fracture healing via targeting Smad1

BACKGROUND

Patients with diabetes have an increased risk of nonunion and delayed union of fractures. Macrophages have been shown as a key player in diabetic complications. However, it remains obscure how diabetic milieu affects macrophage-derived exosomes and its implications on osteogenic differentiation of BMSCs. In this study, we aim to define the impact of diabetic milieu on macrophage-derived exosomes, role of extracellular vesicles in intercellular communication with BMSCs, and subsequent effects on osteogenic differentiation and fracture repair.

RESULTS

The osteogenic potential and the ability of fracture repair of exosomes derived from diabetic bone marrow-derived macrophages (dBMDM-exos) were revealed to be lower, as compared with non-diabetic bone marrow-derived macrophages (nBMDM-exos) in vitro and in vivo. Interestingly, miR-144-5p levels were sharply elevated in dBMDM-exos and it could be transferred into BMSCs to regulate bone regeneration by targeting Smad1. In addition, the adverse effects of dBMDM-exos on the osteogenic potential and the ability of fracture repair were reversed through the suppression of miR-144-5p inhibition in vitro and vivo.

CONCLUSIONS

The results demonstrated an important role of exosomal miR-144-5p in bone regeneration, offering insight into developing new strategy for the improvement of fracture healing in patients with diabetes mellitus.

Chronic and Transient Hyperglycemia Induces Changes in the Expression Patterns of IL6 and ADIPOQ Genes and Their Associated Epigenetic Modifications in Differentiating Human Visceral Adipocytes

Adipokines secreted by hypertrophic visceral adipose tissue (VAT) instigate low-grade inflammation, followed by hyperglycemia (HG)-related metabolic disorders. The latter may develop with the participation of epigenetic modifications. Our aim was to assess how HG influences selected epigenetic modifications and the expression of interleukin 6 (IL-6) and adiponectin (APN; gene symbol ADIPOQ) during the adipogenesis of human visceral preadipocytes (HPA-v). Adipocytes (Ads) were chronically or transiently HG-treated during three stages of adipogenesis (proliferation, differentiation, maturation). We measured adipokine mRNA, protein, proven or predicted microRNA expression (RT-qPCR and ELISA), and enrichment of H3K9/14ac, H3K4me3, and H3K9me3 at gene promoter regions (chromatin immunoprecipitation). In chronic HG, we detected different expression patterns of the studied adipokines at the mRNA and protein levels. Chronic and transient HG-induced changes in miRNA (miR-26a-5p, miR-26b-5p, let-7d-5p, let-7e-5p, miR-365a-3p, miR-146a-5p) were mostly convergent to altered IL-6 transcription. Alterations in histone marks at the IL6 promoter were also in agreement with IL-6 mRNA. The open chromatin marks at the ADIPOQ promoter mostly reflected the APN transcription during NG adipogenesis, while, in the differentiation stage, HG-induced changes in all studied marks were in line with APN mRNA levels. In summary, HG dysregulated adipokine expression, promoting inflammation. Epigenetic changes coexisted with altered expression of adipokines, especially for IL-6; therefore, epigenetic marks induced by transient HG may act as epi-memory in Ads. Such changes in the epigenome and expression of adipokines could be instrumental in the development of inflammation and metabolic deregulation of VAT.

Anti-obesity effect and mechanism of mesenchymal stem cells influence on obese mice

Mesenchymal stem cells (MSCs) can be obtained from almost all tissues and present promising therapeutic effects for metabolic diseases. Human adipose-derived MSCs (hASCs) have recently been widely studied due to their easy access and low immunity. Thus, we intended to figure out the effects and potential mechanism of hASCs on obesity in high-fat-diet (HFD)-induced obese mice. Following 16 weeks of being fed HFD, hASCs were intravenously injected. Two weeks later, body weight, body composition, and energy expenditure were evaluated. Additionally, the phenotypes of macrophages infiltrating adipose tissue were analyzed. The results revealed that hASCs administration significantly reduced adipose tissue weight, adipocyte size, and fat mass and exerted beneficial effects in serum lipid profile. This anti-obesity effect was mediated by the increased O₂ consumption, CO₂ production, and energy expenditure, which was further evidenced by the upregulation of uncoupling protein-1 (UCP-1) and metabolism-associated genes. Furthermore, hASCs infusion increased the amount of alternatively activated (M2) macrophages in adipose tissue, and the expression of pro-inflammatory cytokines-related genes was reduced. Taken together, these results indicated that hASCs suppressed obesity by increasing UCP-1 expression and enhancing energy expenditure, and this effect might be due to the increased M2 macrophages.

Properties and molecular mechanisms underlying geniposide-mediated therapeutic effects in chronic inflammatory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Geniposide (GE) is ubiquitous in nearly 40 species of plants, among which Gardenia jasminoides J. Ellis has the highest content, and has been used ethnopharmacologically to treat chronic inflammatory diseases. As a traditional Chinese medicine, Gardenia jasminoides J. Ellis has a long history of usage in detumescence and sedation, liver protection and cholestasis, hypotension and hemostasis. It is commonly used in the treatment of diabetes, hypertension, jaundice hepatitis, sprain and contusion. As a type of iridoid glycosides extracted from Gardenia jasminoides J. Ellis, GE has many pharmacological effects, such as anti-inflammatory, anti-angiogenesic, anti-oxidative, etc. AIM OF THE REVIEW: In this article, we reviewed the sources, traditional usage, pharmacokinetics, toxicity and therapeutic effect of GE on chronic inflammatory diseases, and discussed its potential regulatory mechanisms and clinical application.

RESULTS

GE is a common iridoid glycoside in medicinal plants, which has strong activity in the treatment of chronic inflammatory diseases. A large number of in vivo and in vitro experiments confirmed that GE has certain therapeutic value for a variety of chronic inflammation disease. Its mechanism of function is mainly based on its anti-inflammatory, anti-oxidant, neuroprotective properties, as well as regulation of apoptotsis. GE plays a role in the treatment of chronic inflammatory diseases by regulating cell proliferation and apoptosis, realizing the dynamic balance of pro/anti-inflammatory factors, improving the state of oxidative stress, and restoring abnormally expressed inflammation-related pathways.

CONCLUSION

According to its extensive pharmacological effects, GE is a promising drug for the treatment of chronic inflammatory diseases.

Adipose Extracellular Vesicles: Messengers From and to Macrophages in Regulating Immunometabolic Homeostasis or Disorders

Adipose tissue is comprised of heterogenous cell populations that regulate both energy metabolism and immune reactions. Macrophages play critical roles in regulating immunometabolic homeostasis or disorders through cooperation with adipocytes, adipose tissue-derived stem cells (ADSCs) or other cells in adipose tissue. Extracellular vesicles (EVs) are recently recognized as efficient messengers for intercellular communication. Emerging evidences have demonstrated that adipose EVs are actively involved in the mutual interactions of macrophages, adipocytes and ADSCs, which produce considerable influences on immunometabolism under healthy or obese conditions. Here, we will elaborate the production and the characteristics of adipose EVs that are related to macrophages under different metabolic demands or stresses, whilst discuss the roles of these EVs in regulating local or systemic immunometabolic homeostasis or disorders in the context of adipocyte-macrophage dialogue and ADSC-macrophage interaction. Particularly, we provide a profile of dynamic adipose microenvironments based on macrophages. Adipose EVs act as the messengers between ADSCs and macrophages to maintain the balance of metabolism and immunity, while drive a vicious cycle between hypertrophic adipocytes and inflammatory macrophages to cause immunometabolic imbalance. This review may provide valuable information about the physio- or pathological roles of adipose EVs and the application of adipose EVs in the diagnosis and treatment of metabolic diseases.

Melatonin Synergizes With Mesenchymal Stromal Cells Attenuates Chronic Allograft Vasculopathy

Background

Chronic rejection characterized by chronic allograft vasculopathy (CAV) remains a major obstacle to long-term graft survival. Due to multiple complicated mechanisms involved, a novel therapy for CAV remains exploration. Although mesenchymal stromal cells (MSCs) have been ubiquitously applied to various refractory immune-related diseases, rare research makes a thorough inquiry in CAV. Meanwhile, melatonin (MT), a wide spectrum of immunomodulator, plays a non-negligible role in transplantation immunity. Here, we have investigated the synergistic effects of MT in combination with MSCs in attenuation of CAV.

Methods

C57BL/6 (B6) mouse recipients receiving BALB/c mouse donor aorta transplantation have been treated with MT and/or adipose-derived MSCs. Graft pathological changes, intragraft immunocyte infiltration, splenic immune cell populations, circulating donor-specific antibodies levels, cytokine profiles were detected on post-operative day 40. The proliferation capacity of CD4+ and CD8+ T cells, populations of Th1, Th17, and Tregs were also assessed in vitro.

Results

Grafts in untreated recipients developed a typical pathological feature of CAV characterized by intimal thickening 40 days after transplantation. Compared to untreated and monotherapy groups, MT in combination with MSCs effectively ameliorated pathological changes of aorta grafts indicated by markedly decreased levels of intimal hyperplasia and the infiltration of CD4+ cells, CD8+ cells, and macrophages, but elevated infiltration of Foxp3+ cells. MT either alone or in combination with MSCs effectively inhibited the proliferation of T cells, decreased populations of Th1 and Th17 cells, but increased the proportion of Tregs in vitro. MT synergized with MSCs displayed much fewer splenic populations of CD4+ and CD8+ T cells, Th1 cells, Th17 cells, CD4+ central memory T cells (Tcm), as well as effector memory T cells (Tem) in aorta transplant recipients. In addition, the percentage of splenic Tregs was substantially increased in the combination therapy group. Furthermore, MT combined with MSCs markedly reduced serum levels of circulating allospecific IgG and IgM, as well as decreased the levels of pro-inflammatory IFN-γ, TNF-α, IL-1β, IL-6, IL-17A, and MCP-1, but increased the level of IL-10 in the recipients.

Conclusions

These data suggest that MT has synergy with MSCs to markedly attenuate CAV and provide a novel therapeutic strategy to improve the long-term allograft acceptance in transplant recipients.

Three-dimensional-arterial spin labeling perfusion correlation with diabetes-associated cognitive dysfunction and vascular endothelial growth factor in type 2 diabetes mellitus rat

BACKGROUND

Type 2 diabetes mellitus (T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia. The mechanisms of diabetes-associated cognitive dysfunction (DACD) have not been fully elucidated to date. Some studies proved lower cerebral blood flow (CBF) in the hippocampus was associated with poor executive function and memory in T2DM. Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor (VEGF) expression and CBF changes in humans and animal models. In this study, we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional (3D) arterial spin labeling (3D-ASL) and VEGF expression in the hippocampus.

AIM

To assess the correlation between CBF (measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM.

METHODS

Forty Sprague-Dawley male rats were divided into control and T2DM groups. The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM. Cognitive function was assessed using the Morris water maze experiment. The CBF changes were measured by 3D-ASL magnetic resonance imaging. VEGF expression was determined using immunofluorescence.

RESULTS

The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group. The total distance traveled was longer in the T2DM group; also, the platform was crossed fewer times. The percentage of distance in the target zone significantly decreased. CBF decreased in the bilateral hippocampus in the T2DM group. No difference was found between the right CBF value and the left CBF value in the T2DM group. The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value. The escape latency negatively correlated with the CBF value. The number of rats crossing the platform positively correlated with the CBF value.

CONCLUSION

Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD. CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.

Administration of mesenchymal stem cells in diabetic kidney disease: a systematic review and meta-analysis

BACKGROUND

Mesenchymal stem cell (MSC) therapy shows great promise for diabetic kidney disease (DKD) patients. Research has been carried out on this topic in recent years. The main goals of this paper are to evaluate the therapeutic effects of MSCs on DKD through a meta-analysis and address the mechanism through a systematic review of the literature.

METHOD

An electronic search of the Embase, Cochrane Library, ISI Web of Science, PubMed, and US National Library of Medicine (NLM) databases was performed for all articles about MSC therapy for DKD, without species limitations, up to January 2020. Data were pooled for analysis with Stata SE 12.

RESULT

The MSC-treated group showed a large and statistically significant hypoglycemic effect at 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months, and 6 months. Total hypoglycemic effect was observed (SMD = - 1.954, 95%CI - 2.389 to - 1.519, p < 0.001; I² = 85.1%). The overall effects on serum creatinine (SCr) and blood urea nitrogen (BUN) were analyzed, suggesting that MSC decreased SCr and BUN and mitigated the impairment of renal function (SCr: SMD = - 4.838, 95%CI - 6.789 to - 2.887, p < 0.001; I² = 90.8%; BUN: SMD = - 4.912, 95%CI - 6.402 to - 3.422, p < 0.001; I² = 89.3%). Furthermore, MSC therapy decreased the excretion of urinary albumin. Fibrosis indicators were assessed, and the results showed that transforming growth factor-β, collagen I, fibronectin, and α-smooth muscle actin were significantly decreased in the MSC-treated group compared to the control group.

CONCLUSION

MSCs might improve glycemic control and reduce SCr, BUN, and urinary protein. MSCs can also alleviate renal fibrosis. MSC therapy might be a potential treatment for DKD.

Antiobesity Effects of Adipose-Derived Stromal/Stem Cells in a Naturally Aged Mouse Model

OBJECTIVE

Adipose-derived stromal/stem cells (ASCs) have multilineage differentiation potential and functional properties, as well as applications for cell-based therapies in tissue repair and regeneration. However, there is a lack of evidence regarding the efficacy of ASCs as an antiobesity agent in aged organisms. This study aimed to clarify the effectiveness of ASCs at treating obesity using a naturally aged mouse model.

METHODS

Old (22 months) C57BL/6J mice with transplanted young-mice (2 months) donor ASCs were measured for weight change, biochemistry, cytokines, hormone secretion, cell senescence, lipid metabolism, and functional changes of ASCs.

RESULTS

The results indicated that old mice treated with ASCs showed antiaging and antiobesity effects such as significant loss of body and organ weight, improved stem cell plasticity, increased antioxidant capacity (superoxide dismutase and catalase), improved liver and kidney function, improved lipid metabolism, and increased hormone secretion (sex hormone-binding globulin, thyrotropin, and leptin). Treatment with ASCs decreased cell senescence and suppressed secretion of inflammatory agents (interleukin-6 and tumor necrosis factor alpha).

CONCLUSIONS

Traditional drugs used in the treatment of obesity have limitations and are unsuitable for the elderly. Based on the results, the future use of ASCs as primary antiaging and antiobesity agents is suggested because of their positive effects on aged animals.

New Amphiphilic Squalene Derivative Improves Metabolism of Adipocytes Differentiated From Diabetic Adipose-Derived Stem Cells and Prevents Excessive Lipogenesis

Squalene (Sq) is a natural compound, found in various plant oils, algae, and larger quantity in deep-sea shark liver. It is also known as an intermediate of cholesterol synthesis in plants and animals including humans. Although evidences demonstrated its antioxidant, anticancer, hypolipidemic, and hepatoprotective and cardioprotective effects, its biological effects in cellular function might have been underestimated because of the water-insoluble property. To overcome this hydrophobicity, we synthesized new amphiphilic Sq derivative (HH-Sq). On the other hand, adipose-derived stem cells (ASCs) are a valuable source in regenerative medicine for its ease of accessibility and multilineage differentiation potential. Nevertheless, impaired cellular functions of ASCs derived from diabetic donor have still been debated controversially. In this study, we explored the effect of the HH-Sq in comparison to Sq on the adipocyte differentiation of ASCs obtained from subjects with type 2 diabetes. Gene expression profile by microarray analysis at 14 days of adipogenic differentiation revealed that HH-Sq induced more genes involved in intracellular signaling processes, whereas Sq activated more transmembrane receptor pathway-related genes. In addition, more important number of down-regulated and up-regulated genes by Sq and HH-Sq were not overlapped, suggesting the compounds might not only have difference in their chemical property but also potentially exert different biological effects. Both Sq and HH-Sq improved metabolism of adipocytes by enhancing genes associated with energy homeostasis and insulin sensitivity, SIRT1, PRKAA2, and IRS1. Interestingly, Sq increased significantly early adipogenic markers and lipogenic gene expression such as PPARG, SREBF1, and CEBPA, but not HH-Sq. As a consequence, smaller and fewer lipid droplet formation was observed in HH-Sq-treated adipocytes. Based on our findings, we report that both Sq and HH-Sq improved adipocyte metabolism, but only HH-Sq prevented excessive lipogenesis without abrogating adipocyte differentiation. The beneficial effect of HH-Sq provides an importance of synthesized derivatives from a natural compound with therapeutic potentials in the application of cell therapies.

Effect of the ketogenic diet on glycemic control, insulin resistance, and lipid metabolism in patients with T2DM: a systematic review and meta-analysis

Background

At present, the beneficial effect of the ketogenic diet (KD) on weight loss in obese patients is generally recognized. However, a systematic research on the role of KD in the improvement of glycemic and lipid metabolism of patients with diabetes is still found scarce.

Methods

This meta-study employed the meta-analysis model of random effects or of fixed effects to analyze the average difference before and after KD and the corresponding 95% CI, thereby evaluating the effect of KD on T2DM.

Results

After KD intervention, in terms of glycemic control, the level of fasting blood glucose decreased by 1.29 mmol/L (95% CI: −1.78 to −0.79) on average, and glycated hemoglobin A1c by 1.07 (95% CI: −1.37 to −0.78). As for lipid metabolism, triglyceride was decreased by 0.72 (95% CI: −1.01 to −0.43) on average, total cholesterol by 0.33 (95% CI: −0.66 to −0.01), and low-density lipoprotein by 0.05 (95% CI: −0.25 to −0.15); yet, high-density lipoprotein increased by 0.14 (95% CI: 0.03−0.25). In addition, patients’ weight decreased by 8.66 (95% CI: −11.40 to −5.92), waist circumference by 9.17 (95% CI: −10.67 to −7.66), and BMI by 3.13 (95% CI: −3.31 to −2.95).

Conclusion

KD not only has a therapeutic effect on glycemic and lipid control among patients with T2DM but also significantly contributes to their weight loss.

Encapsulation of Adipose-Derived Mesenchymal Stem Cells in Calcium Alginate Maintains Clonogenicity and Enhances their Secretory Profile

Adipose-derived mesenchymal stem cells (ASCs) are well known for their secretory potential, which confers them useful properties in cell therapy. Nevertheless, this therapeutic potential is reduced after transplantation due to their short survival in the human body and their migration property. This study proposes a method to protect cells during and after injection by encapsulation in microparticles of calcium alginate. Besides, the consequences of encapsulation on ASC proliferation, pluripotential, and secretome were studied. Spherical particles with a mean diameter of 500 µm could be obtained in a reproducible manner with a viability of 70% after 16 days in vitro. Moreover, encapsulation did not alter the proliferative properties of ASCs upon return to culture nor their differentiation potential in adipocytes, chondrocytes, and osteocytes. Concerning their secretome, encapsulated ASCs consistently produced greater amounts of interleukin-6 (IL-6), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) compared to monolayer cultures. Encapsulation therefore appears to enrich the secretome with transforming growth factor β1 (TGF-β1) and macrophage inflammatory protein-1β (MIP-1β) not detectable in monolayer cultures. Alginate microparticles seem sufficiently porous to allow diffusion of the cytokines of interest. With all these cytokines playing an important role in wound healing, it appears relevant to investigate the impact of using encapsulated ASCs on the wound healing process.

Metabolomic Analysis of the Effects of Adipose-Derived Mesenchymal Stem Cell Treatment on Rats With Sepsis-Induced Acute Lung Injury

Given the high mortality associated with sepsis, there is an urgent need for a full understanding of sepsis pathophysiology and finding new therapeutic regimens. Adipose-derived mesenchymal stem cells (ADMSCs) has been proven to have anti-inflammatory effects and could be used to treat cecal ligation and puncture (CLP) induced lung and liver injury in septic rat models. In this study, we used metabolomics to investigate small molecule metabolites between CLP and ADMSCs treatment groups. Sixty SD rats were randomly assigned to the sham operation group (SC group), the CLP group, and the CLP+ADMSCs group (CLP-ADMSCs group). We used liquid mass spectrometry-chromatography to detect metabolic changes in plasma and lung tissues. Compared with the SC group, the metabolic profile of plasma and lung tissues changed significantly 24 h after CLP. Moreover, 22 and 11 main differential metabolites involved in amino acid and glycerophospholipid metabolism were found in plasma and lung tissues, respectively. After the rats were injected with ADMSCs, these differential metabolites were reverse-regulated both in plasma and lung tissues. Besides, ADMSCs improved the survival rate and down-regulated the concentration of TNF-α and IL-6 at 24 h after CLP. The correlational analysis between plasma of IL-6/TNF-α and metabolites suggested that acetylcholine, spermine, phenylalanine, threonine of plasma and phosphatidylcholine (36:4) of lung tissues were significantly associated with IL-6/TNF-α in CLP and CLP-ADMSCs groups. ADMSCs might reverse abnormal metabolic pathways by reducing anti-inflammatory factors in sepsis-induced ALI. Our findings may provide novel metabolic mechanism of ADMSCs therapy for sepsis.

Efficacy of mesenchymal stem cells in animal models of lupus nephritis: a meta-analysis

BACKGROUND

Lupus nephritis is usually manifested by proteinuria, active urinary sediment, hypertension, and renal failure and is a serious complication with more than 50% occurrence in systemic lupus erythematosus patients. Mesenchymal stem cells (MSC) present remarkable immunomodulatory ability, and these cells are potential therapeutic agents for autoimmune disorders. In clinical trials, the effectiveness of MSC in the treatment of lupus nephritis is still controversial. A meta-analysis was performed to assess whether MSC can achieve good efficacy in the treatment of lupus nephritis in mice.

METHODS

A comprehensive literature search was performed in Cochrane Library, ISI Web of Science, PubMed, and EMBASE from inception to Oct 1, 2019. Two authors independently extracted the data, which were pooled and calculated using RevMan 5.3.

RESULTS

A total of 28 studies met the inclusion criteria. MSC treatment resulted in lower levels of ds-DNA (OR = - 29.58, 95% CI - 29.58, - 17.99; P < 0.00001), ANA (OR = - 70.93, 95% CI - 104.55, - 37.32; P < 0.0001), Scr (OR = - 8.20, 95% CI - 12.71, - 3.69; P = 0.0004), BUN (OR = - 14.57, 95% CI - 20.50, - 8.64; P < 0.00001), proteinuria (OR = - 4.26, 95% CI - 5.15 to - 3.37; P < 0.00001), and renal sclerosis score (OR = - 1.92, 95% CI - 2.66 to - 1.18; P < 0.00001), and MSC treatment could get higher levels of albumin. To detect the potential, the cytokines were also assessed, and the MSC treatment group had lower levels of IL-2, IL-12, IL-17, and IFN-γ when compared with the control group. However, the difference was not notable for IL-4, IL-6, IL-10, TGF-β, MCP-1, TNF-α, Th1, Th17, Foxp3, or Tregs.

CONCLUSION

Our study confirmed that MSC treatment in an animal model for lupus nephritis in the studies included in the meta-analysis resulted in lower levels of ds-DNA, ANA, Scr, BUN, proteinuria, and renal sclerosis score, and MSC treatment could get higher levels of albumin.