Antioxidant-upregulated mesenchymal stem cells reduce inflammation and improve fatty liver disease in diet-induced obesity

Potential diagnostic markers and biological mechanism for osteoarthritis with obesity based on bioinformatics analysis

Numerous observational studies have shown that obesity (OB) is a significant risk factor in the occurrence and progression of osteoarthritis (OA), but the underlying molecular mechanism between them remains unclear. The study aimed to identify the key genes and pathogeneses for OA with OB. We obtained two OA and two OB datasets from the gene expression omnibus (GEO) database. First, the identification of differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA), and machine learning algorithms were used to identify key genes for diagnosing OA with OB, and then the nomogram and receiver operating characteristic (ROC) curve were conducted to assess the diagnostic value of key genes. Second, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to explore the pathogenesis of OA with OB. Third, CIBERSORT was created to investigate immunocyte dysregulation in OA and OB. In this study, two genes (SOD2, ZNF24) were finally identified as key genes for OA with OB. These two key genes had high diagnostic values via nomogram and ROC curve calculation. Additionally, functional analysis emphasized that oxidative stress and inflammation response were shared pathogenesis of OB and AD. Finally, in OA and OB, immune infiltration analysis showed that SOD2 closely correlated to M2 macrophages, regulatory T cells, and CD8 T cells, and ZNF24 correlated to regulatory T cells. Overall, our findings might be new biomarkers or potential therapeutic targets for OA and OB comorbidity.

Stem cells therapy for diabetes: from past to future

Diabetes mellitus is a chronic disease of carbohydrate metabolism characterized by uncontrolled hyperglycemia due to the body's impaired ability to produce or respond to insulin. Oral or injectable exogenous insulin and its analogs cannot mimic endogenous insulin secreted by healthy individuals, and pancreatic and islet transplants face a severe shortage of sources and transplant complications, all of which limit the widespread use of traditional strategies in diabetes treatment. We are now in the era of stem cells and their potential in ameliorating human disease. At the same time, the rapid development of gene editing and cell-encapsulation technologies has added to the wings of stem cell therapy. However, there are still many unanswered questions before stem cell therapy can be applied clinically to patients with diabetes. In this review, we discuss the progress of strategies to obtain insulin-producing cells from different types of stem cells, the application of gene editing in stem cell therapy for diabetes, as well as summarize the current advanced cell encapsulation technologies in diabetes therapy and look forward to the future development of stem cell therapy in diabetes.

Mesenchymal Stem/Stromal Cells Therapy for Metabolic Syndrome: Potential Clinical Application?

Mesenchymal stem/stromal cells (MSCs), a class of cells with proliferative, immunomodulatory, and reparative functions, have shown therapeutic potential in a variety of systemic diseases, including metabolic syndrome (MetS). The cluster of morbidities that constitute MetS might be particularly amenable for the application of MSCs, which employ an arsenal of reparative actions to target multiple pathogenic pathways simultaneously. Preclinical studies have shown that MSCs can reverse pathological changes in MetS mainly by inhibiting inflammation, improving insulin resistance, regulating glycolipid metabolism, and protecting organ function. However, several challenges remain to overcome before MSCs can be applied for treating MetS. For example, the merits of autologous versus allogeneic MSCs sources remain unclear, particularly with autologous MSCs obtained from the noxious MetS milieu. The distinct characteristics and relative efficacy of MSCs harvested from different tissue sources also require clarification. Moreover, to improve the therapeutic efficacy of MSCs, investigators have explored several approaches that improved therapeutic efficacy but may involve potential safety concerns. This review summarized the potentially useful MSCs strategy for treating MetS, as well as some hurdles that remain to be overcome. In particular, larger-scale studies are needed to determine the therapeutic efficacy and safety of MSCs for clinical application.

Influence of type 2 diabetes and obesity on adipose mesenchymal stem/stromal cell immunoregulation

Type 2 diabetes (T2D), associated with obesity, represents a state of metabolic inflammation and oxidative stress leading to insulin resistance and progressive insulin deficiency. Adipose-derived stem cells (ASCs) are adult mesenchymal stem/stromal cells identified within the stromal vascular fraction of adipose tissue. These cells can regulate the immune system and possess anti-inflammatory properties. ASCs are a potential therapeutic modality for inflammatory diseases including T2D. Patient-derived (autologous) rather than allogeneic ASCs may be a relatively safer approach in clinical perspectives, to avoid occasional anti-donor immune responses. However, patient characteristics such as body mass index (BMI), inflammatory status, and disease duration and severity may limit the therapeutic utility of ASCs. The current review presents human ASC (hASC) immunoregulatory mechanisms with special emphasis on those related to T lymphocytes, hASC implications in T2D treatment, and the impact of T2D and obesity on hASC immunoregulatory potential. hASCs can modulate the proliferation, activation, and functions of diverse innate and adaptive immune cells via direct cell-to-cell contact and secretion of paracrine mediators and extracellular vesicles. Preclinical studies recommend the therapeutic potential of hASCs to improve inflammation and metabolic indices in a high-fat diet (HFD)-induced T2D disease model. Discordant data have been reported to unravel intact or detrimentally affected immunomodulatory functions of ASCs, isolated from patients with obesity and/or T2D patients, in vitro and in vivo. Numerous preconditioning strategies have been introduced to potentiate hASC immunomodulation; they are also discussed here as possible options to potentiate the immunoregulatory functions of hASCs isolated from patients with obesity and T2D.

Mesenchymal stromal/stem cells and their extracellular vesicles in liver diseases: insights on their immunomodulatory roles and clinical applications

Liver disease is a leading cause of mortality and morbidity that is rising globally. Liver dysfunctions are classified into acute and chronic diseases. Various insults, including viral infections, alcohol or drug abuse, and metabolic overload, may cause chronic inflammation and fibrosis, leading to irreversible liver dysfunction. Up to now, liver transplantation could be the last resort for patients with end-stage liver disease. However, liver transplantation still faces unavoidable difficulties. Mesenchymal stromal/stem cells (MSCs) with their broad ranging anti-inflammatory and immunomodulatory properties can be effectively used for treating liver diseases but without the limitation that are associated with liver transplantation. In this review, we summarize and discuss recent advances in the characteristics of MSCs and the potential action mechanisms of MSCs-based cell therapies for liver diseases. We also draw attention to strategies to potentiate the therapeutic properties of MSCs through pre-treatments or gene modifications. Finally, we discuss progress toward clinical application of MSCs or their extracellular vesicles in liver diseases.

Gene Therapy Based on Mesenchymal Stem Cells Derived from Adipose Tissue for the Treatment of Obesity and Its Metabolic Complications

Obesity is a highly prevalent condition often associated with dysfunctional adipose tissue. Stem cell-based therapies have become a promising tool for therapeutic intervention in the context of regenerative medicine. Among all stem cells, adipose-derived mesenchymal stem cells (ADMSCs) are the most easily obtained, have immunomodulatory properties, show great ex vivo expansion capacity and differentiation to other cell types, and release a wide variety of angiogenic factors and bioactive molecules, such as growth factors and adipokines. However, despite the positive results obtained in some pre-clinical studies, the actual clinical efficacy of ADMSCs still remains controversial. Transplanted ADMSCs present a meager rate of survival and proliferation, possibly because of the damaged microenvironment of the affected tissues. Therefore, there is a need for novel approaches to generate more functional ADMSCs with enhanced therapeutic potential. In this context, genetic manipulation has emerged as a promising strategy. In the current review, we aim to summarize several adipose-focused treatments of obesity, including cell therapy and gene therapy. Particular emphasis will be given to the continuum from obesity to metabolic syndrome, diabetes, and underlying non-alcoholic fatty liver disease (NAFLD). Furthermore, we will provide insights into the potential shared adipocentric mechanisms involved in these pathophysiological processes and their remediation using ADMSCs.

Novel Therapeutics in Nonalcoholic Fatty Liver Disease: A Focus on Adult Stem Cells

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder that is associated with abnormal accumulation of fat in the liver, which can lead to a wide variety of pathological liver defects and associated insulin resistance (IR), obesity, hypertension, dyslipidemia, diabetes, and cardiovascular disease. The molecular mechanisms that cause the initiation and progression of NAFLD are not fully understood. Increased lipolysis and de novo hepatic lipid synthesis lead to oxidative stress induced by reactive oxygen species and inflammation. Both these two entities could be interrelated and be an important mechanistic pathway, which can lead to tissue injury and hepatic cell death. Mechanisms for worsening of NAFLD include mitochondrial abnormalities, downregulation of glutathione (GSH), decreased activity of GSH-dependent antioxidants, accumulation of activated macrophages, hepatic inflammation, systemic inflammation, IR, and poorly controlled type 2 diabetes mellitus. Although no specific therapy has been approved for NAFLD, we review the latest medical therapeutics with emphasis on stem cell-based possibilities based on the presumed pathophysiology of NAFLD.

Adipokines at the crossroads of obesity and mesenchymal stem cell therapy

Mesenchymal stem cell (MSC) therapy is an emerging treatment strategy to counteract metabolic syndromes, including obesity and its comorbid disorders. However, its effectiveness is challenged by various factors in the obese environment that negatively impact MSC survival and function. The identification of these detrimental factors will provide opportunities to optimize MSC therapy for the treatment of obesity and its comorbidities. Dysregulated production of adipokines, a group of cytokines and hormones derived from adipose tissue, has been postulated to play a pivotal role in the development of obesity-associated complications. Intriguingly, adipokines have also been implicated in the modulation of viability, self-renewal, proliferation, and other properties of MSC. However, the involvement of adipokine imbalance in impaired MSC functionality has not been completely understood. On the other hand, treatment of obese individuals with MSC can restore the serum adipokine profile, suggesting the bidirectionality of the adipokine-MSC relationship. In this review, we aim to discuss the current knowledge on the central role of adipokines in the crosstalk between obesity and MSC dysfunction. We also summarize recent advances in the use of MSC for the treatment of obesity-associated diseases to support the hypothesis that adipokines modulate the benefits of MSC therapy in obese patients.

Mechanisms of Action of Mesenchymal Stem Cells in Metabolic-Associated Fatty Liver Disease

Metabolic-associated fatty liver disease (MAFLD) is currently the most common chronic liver disease worldwide. However, its pathophysiological mechanism is complicated, and currently, it has no FDA-approved pharmacological therapies. In recent years, mesenchymal stem cell (MSC) therapy has attracted increasing attention in the treatment of hepatic diseases. MSCs are multipotent stromal cells that originated from mesoderm mesenchyme, which have self-renewal and multipotent differentiation capability. Recent experiments and studies have found that MSCs have the latent capacity to be used for MAFLD treatment. MSCs have the potential to differentiate into hepatocytes, which could be induced into hepatocyte-like cells (HLCs) with liver-specific morphology and function under appropriate conditions to promote liver tissue regeneration. They can also reduce liver tissue injury and reverse the development of MAFLD by regulating immune response, antifibrotic activities, and lipid metabolism. Moreover, several advantages are attributed to MSC-derived exosomes (MSC-exosomes), such as targeted delivery, reliable reparability, and poor immunogenicity. After entering the target cells, MSC-exosomes help regulate cell function and signal transduction; thus, it is expected to become an emerging treatment for MAFLD. In this review, we comprehensively discussed the roles of MSCs in MAFLD, main signaling pathways of MSCs that affect MAFLD, and mechanisms of MSC-exosomes on MAFLD.

N,N'-Diphenyl-1,4-phenylenediamine Antioxidant's Potential Role in Enhancing the Pancreatic Antioxidant, Immunomodulatory, and Anti-Apoptotic Therapeutic Capabilities of Adipose-Derived Stem Cells in Type I Diabetic Rats

Mesenchymal stem cells (MSCs) are considered to be a promising therapeutic protocol for diabetes mellitus (DM) management. The latter is attributed to their differentiation potentiality to pancreatic β-cells, angiogenesis, and immune-modulatory capabilities by releasing various paracrine factors. Interestingly, antioxidant co-administration increased the MSCs' hypoglycemic and regenerative activities. Thus, this study aims to evaluate the therapeutic implication of type 1 DM after the co-administration of adipose tissue-derived-MSCs (AD-MSCs) and N,N'-d iphenyl-1,4-phenylenediamine (DPPD), compared to the single injection of either of them alone. In our four week long experiment, six rat groups were used as control, DPPD (250 mg/kg, i.p.), STZ-diabetic (D), D+DPPD, D+AD-MSCs (1 × 10⁶ cell/rat, i.p.), and D+AD-MSCs+DPPD groups. Within this context, a single injection of AD-MSCs or DPPD into diabetic rats showed significant pancreatic anti-inflammatory, immunomodulation, antioxidant, and anti-apoptotic capacities, superior to AD-MSCs injection. However, AD-MSCs and DPPD co-administration into diabetic rats manifested the highest hypoglycemic and pancreatic regenerative activities in managing diabetes compared to the single shot of AD-MSCs or DPPD. These results highlight the synergetic role of DPPD as an antioxidant in enhancing AD-MSCs' therapeutic applications.

Rutin and quercetagetin enhance the regeneration potential of young and aging bone marrow-derived mesenchymal stem cells in the rat infarcted myocardium

Myocardial infarction (MI) damages cardiomyocytes permanently and compromises cardiac function. Mesenchymal stem cells (MSCs) with the potential to differentiate into multiple lineages are considered as one of the best options for the treatment of MI. However, aging affects their regeneration capability. With age, reactive oxygen species (ROS) accumulate in cells ultimately causing cell death. To successfully utilize these stem cells in clinic, novel strategies to improve their functional capability should be explored. In this study, we aimed to enhance the cardiac regeneration potential of bone marrow MSCs derived from aging rats by treating them with antioxidants, rutin or quercetagetin in separate in vivo experiments. Oxidative stress was induced by treating MSCs of young and aging rats with different concentrations of H₂O₂ which resulted in an increase in the ROS level. MSCs were treated with rutin or quercetagetin at varying concentrations and exposed to H₂O₂. It was observed that both antioxidants significantly (P < 0.001) suppressed H₂O₂-induced intracellular ROS accumulation in a dose-dependent manner. An optimized concentration of 10 µM rutin or quercetagetin was used for the in vivo experiments. MI models were developed in aging rats by ligation of left anterior descending artery and treated MSCs were transplanted in the MI models. Echocardiography was performed after 2 and 4 weeks of cell transplantation to evaluate the functional status of the infarcted heart and histological analysis was performed after 4 weeks to assess cardiac regeneration. Significant improvement was observed in cardiac parameters including LVEF% (P < 0.001), LVFS% (P < 0.01 and P < 0.001), LVIDd (P < 0.01 and P < 0.001), LVIDs (P < 0.001), LVEDV (P < 0.001) and LVESV (P < 0.001) in the treated young as well as aging MSCs. It is concluded from these findings that rutin and quercetagetin treatment enhance the regeneration efficiency of young and aging MSCs in vivo. These antioxidants can be effectively utilized to improve cellular therapy for myocardial infarction by suppressing ROS production.

Silencing SIRT5 induces the senescence of UCB-MSCs exposed to TNF-α by reduction of fatty acid β-oxidation and anti-oxidation

Tumor necrosis factor-α (TNF-α) is an inflammatory cytokine involved in cell survival, apoptosis, and homeostasis. However, the regulatory effect of TNF-α on mesenchymal stem cell (MSC) redox regulation remains unknown. The process of delaying the senescence of MSCs and maintaining antioxidation mechanism is important in transplantation therapy to treat inflammatory diseases that result from restricted immunomodulatory effects of senescent MSCs. Thus, we examined the role of TNF-α-mediated signaling and its regulatory mechanisms on the senescence of umbilical cord blood-derived MSCs (UCB-MSCs) and identified its therapeutic efficacy in a collagen-induced arthritis (CIA) mouse model. We found that TNF-α increased fatty acid synthesis and lipid droplet (LD) formation through NF-κB/SREBP1-mediated FASN, SCD1, and DGAT2 expression, which protects UCB-MSCs from oxidative stress against accumulated toxic lipids. Additionally, DGAT2-mediated LD formation was regulated by TNF-α-activated TNF receptor (TNFR)1 signaling. We also found that storage of unsaturated FAs in LDs is regulated by SIRT5-dependent β-oxidation of FAs, which reduces mitochondrial ROS (mtROS) accumulation. Particularly, mtROS homeostasis was maintained by superoxide dismutase 2 (SOD2) upregulation through TNFR2-mediated SIRT5/Nrf2 signaling. In a CIA mouse model, UCB-MSCs transfected with SIRT5 siRNA exhibited reduced therapeutic effects compared with UCB-MSCs transfected with NT siRNA. Overall, the results indicated that SIRT5 plays a central role in protecting TNF-α-induced UCB-MSC senescence through FA β-oxidation and SOD2-mediated antioxidation.

Translating MSC Therapy in the Age of Obesity

Mesenchymal stromal cell (MSC) therapy has seen increased attention as a possible option to treat a number of inflammatory conditions including COVID-19 acute respiratory distress syndrome (ARDS). As rates of obesity and metabolic disease continue to rise worldwide, increasing proportions of patients treated with MSC therapy will be living with obesity. The obese environment poses critical challenges for immunomodulatory therapies that should be accounted for during development and testing of MSCs. In this review, we look to cancer immunotherapy as a model for the challenges MSCs may face in obese environments. We then outline current evidence that obesity alters MSC immunomodulatory function, drastically modifies the host immune system, and therefore reshapes interactions between MSCs and immune cells. Finally, we argue that obese environments may alter essential features of allogeneic MSCs and offer potential strategies for licensing of MSCs to enhance their efficacy in the obese microenvironment. Our aim is to combine insights from basic research in MSC biology and clinical trials to inform new strategies to ensure MSC therapy is effective for a broad range of patients.

Human Mesenchymal Stromal Cells Resolve Lipid Load in High Fat Diet-Induced Non-Alcoholic Steatohepatitis in Mice by Mitochondria Donation

Mesenchymal stromal cells (MSC) increasingly emerge as an option to ameliorate non-alcoholic steatohepatitis (NASH), a serious disease, which untreated may progress to liver cirrhosis and cancer. Before clinical translation, the mode of action of MSC needs to be established. Here, we established NASH in an immune-deficient mouse model by feeding a high fat diet. Human bone-marrow-derived MSC were delivered to the liver via intrasplenic transplantation. As verified by biochemical and image analyses, human mesenchymal stromal cells improved high-fat-diet-induced NASH in the mouse liver by decreasing hepatic lipid content and inflammation, as well as by restoring tissue homeostasis. MSC-mediated changes in gene expression indicated the switch from lipid storage to lipid utilization. It was obvious that host mouse hepatocytes harbored human mitochondria. Thus, it is feasible that resolution of NASH in mouse livers involved the donation of human mitochondria to the mouse hepatocytes. Therefore, human MSC might provide oxidative capacity for lipid breakdown followed by restoration of metabolic and tissue homeostasis.

Mesenchymal Stem Cells and Their Small Extracellular Vesicles as Crucial Immunological Efficacy for Hepatic Diseases

Mesenchymal stem cell small extracellular vesicles (MSC-sEVs) are a priority for researchers because of their role in tissue regeneration. sEVs act as paracrine factors and carry various cargos, revealing the state of the parent cells and contributing to cell–cell communication during both physiological and pathological circumstances. Hepatic diseases are mainly characterized by inflammatory cell infiltration and hepatocyte necrosis and fibrosis, bringing the focus onto immune regulation and other regulatory mechanisms of MSCs/MSC-sEVs. Increasing evidence suggests that MSCs and their sEVs protect against acute and chronic liver injury by inducing macrophages (MΦ) to transform into the M2 subtype, accelerating regulatory T/B (Treg/Breg) cell activation and promoting immunosuppression. MSCs/MSC-sEVs also prevent the proliferation and differentiation of T cells, B cells, dendritic cells (DCs), and natural killer (NK) cells. This review summarizes the potential roles for MSCs/MSC-sEVs, including immunomodulation and tissue regeneration, in various liver diseases. There is also a specific focus on the use of MSC-sEVs for targeted drug delivery to treat hepatitis.

Using adipose-derived mesenchymal stem cells to fight the metabolic complications of obesity: Where do we stand?

Obesity is a critical risk factor for the development of metabolic diseases, and its prevalence is increasing worldwide. Stem cell-based therapies have become a promising tool for therapeutic intervention. Among them are adipose-derived mesenchymal stem cells (ADMSCs), secreting numerous bioactive molecules, like growth factors, cytokines, and chemokines. Their unique features, including immunosuppressive and immunomodulatory properties, make them an ideal candidates for clinical applications. Numerous experimental studies have shown that ADMSCs can improve pancreatic islet cell viability and function, ameliorate hyperglycemia, improve insulin sensitivity, restore liver function, counteract dyslipidemia, lower pro-inflammatory cytokines, and reduce oxidative stress in the animal models. These results prompted scientists to use ADMSCs clinically. However, up to date, there have been few clinical studies or ongoing trails using ADMSCs to treat metabolic disorders such as type 2 diabetes mellitus (T2DM) or liver cirrhosis. Most human studies have implemented autologous ADMSCs with minimal risk of cellular rejection. Because the functionality of ADMSCs is significantly reduced in subjects with obesity and/or metabolic syndrome, their efficacy is questioned. ADMSCs transplantation may offer a potential therapeutic approach for the treatment of metabolic complications of obesity, but randomized controlled trials are required to establish their safety and efficacy in humans prior to routine clinical use.

Single-Cell RNA-Seq Analysis of Cells from Degenerating and Non-Degenerating Intervertebral Discs from the Same Individual Reveals New Biomarkers for Intervertebral Disc Degeneration

In this study, we used single-cell transcriptomic analysis to identify new specific biomarkers for nucleus pulposus (NP) and inner annulus fibrosis (iAF) cells, and to define cell populations within non-degenerating (nD) and degenerating (D) human intervertebral discs (IVD) of the same individual. Cluster analysis based on differential gene expression delineated 14 cell clusters. Gene expression profiles at single-cell resolution revealed the potential functional differences linked to degeneration, and among NP and iAF subpopulations. GO and KEGG analyses discovered molecular functions, biological processes, and transcription factors linked to cell type and degeneration state. We propose two lists of biomarkers, one as specific cell type, including C2orf40, MGP, MSMP, CD44, EIF1, LGALS1, RGCC, EPYC, HILPDA, ACAN, MT1F, CHI3L1, ID1, ID3 and TMED2. The second list proposes predictive IVD degeneration genes, including MT1G, SPP1, HMGA1, FN1, FBXO2, SPARC, VIM, CTGF, MGST1, TAF1D, CAPS, SPTSSB, S100A1, CHI3L2, PLA2G2A, TNRSF11B, FGFBP2, MGP, SLPI, DCN, MT-ND2, MTCYB, ADIRF, FRZB, CLEC3A, UPP1, S100A2, PRG4, COL2A1, SOD2 and MT2A. Protein and mRNA expression of MGST1, vimentin, SOD2 and SYF2 (p29) genes validated our scRNA-seq findings. Our data provide new insights into disc cells phenotypes and biomarkers of IVD degeneration that could improve diagnostic and therapeutic options.

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.

MSCs and Inflammatory Cells Crosstalk in Regenerative Medicine: Concerted Actions for Optimized Resolution Driven by Energy Metabolism

Mesenchymal stromal cells (MSCs) are currently widely used in cell based therapy regarding to their remarkable efficacy in controlling the inflammatory status in patients. Despite recent progress and encouraging results, inconstant therapeutic benefits are reported suggesting that significant breakthroughs in the understanding of MSCs immunomodulatory mechanisms of action remains to be investigated and certainly apprehended from original point of view. This review will focus on the recent findings regarding MSCs close relationship with the innate immune compartment, i.e. granulocytes and myeloid cells. The review will also consider the intercellular mechanism of communication involved, such as factor secretion, cell-cell contact, extracellular vesicles, mitochondria transfer and efferocytosis. Immune-like-properties of MSCs supporting part of their therapeutic effect in the clinical setting will be discussed, as well as their potentials (immunomodulatory, anti-bacterial, anti-inflammatory, anti-oxidant defenses and metabolic adaptation…) and effects mediated, such as cell polarization, differentiation, death and survival on various immune and tissue cell targets determinant in triggering tissue regeneration. Their metabolic properties in term of sensing, reacting and producing metabolites influencing tissue inflammation will be highlighted. The review will finally open to discussion how ongoing scientific advances on MSCs could be efficiently translated to clinic in chronic and age-related inflammatory diseases and the current limits and gaps that remain to be overcome to achieving tissue regeneration and rejuvenation.

Mesenchymal Stem Cell-Based Therapy for Diabetes Mellitus: Enhancement Strategies and Future Perspectives

Diabetes mellitus (DM), a chronic disorder of carbohydrate metabolism, is characterized by the unbridled hyperglycemia resulted from the impaired ability of the body to either produce or respond to insulin. As a cell-based regenerative therapy, mesenchymal stem cells (MSCs) hold immense potency for curing DM duo to their easy isolation, multi-differentiation potential, and immunomodulatory property. However, despite the promising efficacy in pre-clinical animal models, naive MSC administration fails to exhibit clinically satisfactory therapeutic outcomes, which varies greatly among individuals with DM. Recently, numbers of innovative strategies have been applied to improve MSC-based therapy. Preconditioning, genetic modification, combination therapy and exosome application are representative strategies to maximize the therapeutic benefits of MSCs. Therefore, in this review, we summarize recent advancements in mechanistic studies of MSCs-based treatment for DM, and mainly focus on the novel approaches aiming to improve the anti-diabetic potentials of naive MSCs. Additionally, the potential directions of MSCs-based therapy for DM are also proposed at a glance.

Exosomes from adipose-derived stem cells alleviate the inflammation and oxidative stress via regulating Nrf2/HO-1 axis in macrophages

ADSCs exosomes, an important means of intercellular communication, can regulate an array of biological processes, including promoting tissue repairs and regeneration, and attenuating inflammation. In this study, we found that ADSCs exosomes could polarize macrophage to an anti-inflammatory phenotype via regulating the expression of Nrf2 and HO-1, and improve inflammatory reaction and injury of multi-organ in sepsis. We revealed that ADSCs exosomes could alleviate LPS induced accumulation of ROS and the expression of inflammatory cytokines IL-1β, TNF-α, and IL-6 in macrophages. Western blot and Flow cytometry results indicated that expression of M1 markers (iNOS and CD86) in LPS stimulated macrophages were significantly declined, while M2 (Arg1 and CD206) were enhanced when pretreated with ADSCs exosomes. Besides, the stress-related molecule HO-1 was upregulated when pretreated with ADSCs exosomes. Further H0-1 interference experiment indicated that anti-inflammatory effect of ADSCs exosomes was dependent on HO-1. Moreover, ADSCs exosomes enhanced expression and nucleus translocation of Nrf2, while downregulated its negative mediator Keap1. In in vivo sepsis models, intravenous injection of ADSCs exosomes relieved inflammatory cytokines storm and organ injury, while promoted expression of HO-1. In conclusion, we proved that ADSCs exosomes alleviated LPS induced inflammation and exerted protective effect in sepsis via regulating Nrf2/HO-1 expression.

Sod2 and catalase improve pathological conditions of intervertebral disc degeneration by modifying human adipose-derived mesenchymal stem cells

OBJECTIVE

To investigate if the modification of human adipose-derived mesenchymal stem cells (hADSCs) by the antioxidants superoxide dismutase 2 (Sod2) and catalase (Cat) can attenuate the pathological conditions of intervertebral disc degeneration (IVD).

METHODS

In vitro, MTT assay and qRT-PCR was used to detect cell proliferation and gene expressions in hADSCs transduced with Ad-null (an adenovirus vector containing no transgene expression cassette), Ad-Sod2 (recombinant adenovirus Sod2) and Ad-Cat. IVD mouse models were generated by needle puncture and treated with hADSCs with/without Ad-null/Ad-Sod2/Ad-Cat. X-ray evaluation, magnetic resonance imaging (MRI) analysis, histological analysis, immunohistochemistry, Western blots, ELISAs and qRT-PCR were performed.

RESULTS

hADSCs transduced with Ad-Sod2 and Ad-Cat showed enhanced cell proliferation with the upregulation of SOX9, ACAN, and COL2. In vivo, IVD mice injected with hADSCs showed increased disc height index, MRI index and mean T2 intensities, as well as the attenuated histologic grading of the annulus fibrosus (AF) and NP accompanied by the upregulation of GAG and COL2, which were further improved in the Ad-Sod2 hADSC + IVD and Ad-Cat hADSC + IVD groups. Furthermore, the increased expression of IL-1β, IL-6 and TNF-α was reduced in IVD mice injected with hADSCs. Compared with the hADSC + IVD group, the Ad-Sod2 hADSC/Ad-Cat hADSC + IVD groups had lower expression of pro-inflammatory factors.

CONCLUSION

Modification of hADSCs by the antioxidants Sod2 and Cat improved the pathological condition of intervertebral disc tissues with increased GAG and COL2 expression, as well as reduced inflammation, thereby demonstrating a therapeutic effect in IVD.

Using adult stem cells to monitor endothelial dysfunction in diabetes mellitus

Diabetes affects approximately 10.5% of adults in the United States and this is projected to nearly double by 2025. Both type 2 diabetes (T2DM) and obesity are associated with endothelial dysfunction, oxidative stress, endothelial cell inflammation, cardiovascular pro-thrombotic states and are the most common causes of endothelial dysfunction, chronic kidney disease (CKD) and cardiovascular disease (CVD). Lately several new diabetes medications have come to clinical use that claim CVD risk improvement, however modalities used to test and monitor CVD risk are not cell based, which bring into question the reproducibility of these studies. Our review is designed to highlight cardiovascular risk reduction with novel diabetes medications while emphasizing cellular outcomes as a biomarker of cardiovascular risk. We are going to highlight studies that comment on peripheral blood derived CD34+ hematopoietic progenitor cells, as biomarkers of endothelial function. CD34+ cells have been extensively investigated by us and several other laboratories for the last two decades, as a viable cardiovascular function biomarker. In this context we will also discuss relevant CVD risk reduction trials that used novel diabetes medications.

Sucralose promotes accumulation of reactive oxygen species (ROS) and adipogenesis in mesenchymal stromal cells

Abstract

Consumption of non-nutritive sweeteners (NNS) has been consistently associated with obesity and cardiometabolic disease in epidemiologic studies. Herein, we investigated effects of sucralose, a widely used NNS, at a cellular level. We wanted to investigate effect of sucralose on reactive oxygen species accumulation and adipogenesis in a human adipocyte tissue-derived mesenchymal stromal cells (MSCs) in a controlled fashion.

Methods

In vitro experiments were conducted on commercially available MSCs obtained from human adipose tissue. hMSCs were exposed with sucralose at 0.2 mM (a concentration which could plausibly be observed in the circulatory system of high NNS consumers) up to 1.0 mM (supra-physiologic concentration) in the presence of both normal and high glucose media to detect a dose response based on the outcome measures. Reactive oxygen species (ROS) were detected using Mitosox Red staining and further analyzed by ImageJ and gene expression analysis. Effect of sucralose on adipogenic differentiation was observed in different concentrations of sucralose followed by gene expression analysis and Oil Red O staining.

Results

Increased ROS accumulation was observed within 72 h of exposure. Increased adipogenesis was also noted when exposed to higher dose of sucralose.

Conclusion

Sucralose promotes ROS accumulation and adipogenesis in human adipose tissue derived mesenchymal stromal cells.

Mesenchymal stem cells reduce alcoholic hepatitis in mice via suppression of hepatic neutrophil and macrophage infiltration, and of oxidative stress

Mesenchymal stem cells (MSCs) are a population of pluripotent cells that have been tested for the treatment of many inflammatory diseases. It remains unclear whether MSCs were effective in treating mice with alcoholic hepatitis (AH) and its underlying mechanism. In the present study, MSCs were isolated from bone marrow of 4-6 week-old C57BL/6N male mice. AH was induced in female mice by chronic-binge ethanol feeding for 10 days. Intraperitoneal (i.p.) transplantation of MSCs or saline were performed in mice on day 10. Blood samples and hepatic tissues were harvested on day 11. Biochemical, liver histological and flow cytometric analyses were performed. Compared to the control mice, the AH mice had significantly increased liver/body weight ratio, serum alanine aminotransferase (ALT) and aspartate aminotransferases (AST), hepatic total cholesterol (TC), triglyceride (TG), malondialdehyde (MDA), hepatic neutrophil and macrophage infiltration (P<0.001), which were markedly reduced by i.p. transplantation of MSCs (P<0.01). Compared to the control mice, the hepatic glutathione (GSH) was prominently lower in the AH mice (P<0.001), which was markedly enhanced after i.p. injection of MSCs (P<0.001). MSCs were effective for the treatment of AH mice, which might be associated with their ability in inhibiting hepatic neutrophil and macrophage infiltration, and alleviating oxidative stress.

Improved therapeutics of modified mesenchymal stem cells: an update

Background

Mesenchymal stromal cells (MSCs) have attracted intense interest due to their powerful intrinsic properties of self-regeneration, immunomodulation and multi-potency, as well as being readily available and easy to isolate and culture. Notwithstanding, MSC based therapy suffers reduced efficacy due to several challenges which include unfavorable microenvironmental factors in vitro and in vivo.

Body

In the quest to circumvent these challenges, several modification techniques have been applied to the naïve MSC to improve its inherent therapeutic properties. These modification approaches can be broadly divided into two groups to include genetic modification and preconditioning modification (using drugs, growth factors and other molecules). This field has witnessed great progress and continues to gather interest and novelty. We review these innovative approaches in not only maintaining, but also enhancing the inherent biological activities and therapeutics of MSCs with respect to migration, homing to target site, adhesion, survival and reduced premature senescence. We discuss the application of the improved modified MSC in some selected human diseases. Possible ways of yet better enhancing the therapeutic outcome and overcoming challenges of MSC modification in the future are also elaborated.

Conclusion

The importance of prosurvival and promigratory abilities of MSCs in their therapeutic applications can never be overemphasized. These abilities are maintained and even further enhanced via MSC modifications against the inhospitable microenvironment during culture and transplantation. This is a turning point in MSC-based therapy with promising preclinical studies and higher future prospect.