Potential therapeutic effects of endothelial cells trans-differentiated from Wharton's Jelly-derived mesenchymal stem cells on altered vascular functions in aged diabetic rat model

Therapeutic role of extracellular vesicles from human umbilical cord mesenchymal stem cells and their wide therapeutic implications in inflammatory bowel disease and other inflammatory disorder

The chronic immune-mediated inflammatory condition known as inflammatory bowel disease (IBD) significantly affects the gastrointestinal system. While the precise etiology of IBD remains elusive, extensive research suggests that a range of pathophysiological pathways and immunopathological mechanisms may significantly contribute as potential factors. Mesenchymal stem cells (MSCs) have shown significant potential in the development of novel therapeutic approaches for various medical conditions. However, some MSCs have been found to exhibit tumorigenic characteristics, which limit their potential for medical treatments. The extracellular vesicles (EVs), paracrine factors play a crucial role in the therapeutic benefits conferred by MSCs. The EVs consist of proteins, microRNAs, and lipids, and are instrumental in facilitating intercellular communication. Due to the ease of maintenance, and decreased immunogenicity, tumorigenicity the EVs have become a new and exciting option for whole cell treatment. This review comprehensively assesses recent preclinical research on human umbilical cord mesenchymal stem cell (hUC-MSC)-derived EVs as a potential IBD therapy. It comprehensively addresses key aspects of various conditions, including diabetes, cancer, dermal injuries, neurological disorders, cardiovascular issues, liver and kidney diseases, and bone-related afflictions.

Diabetic Retinopathy: New Treatment Approaches Targeting Redox and Immune Mechanisms

Diabetic retinopathy (DR) represents a severe complication of diabetes mellitus, characterized by irreversible visual impairment resulting from microvascular abnormalities. Since the global prevalence of diabetes continues to escalate, DR has emerged as a prominent area of research interest. The development and progression of DR encompass a complex interplay of pathological and physiological mechanisms, such as high glucose-induced oxidative stress, immune responses, vascular endothelial dysfunction, as well as damage to retinal neurons. Recent years have unveiled the involvement of genomic and epigenetic factors in the formation of DR mechanisms. At present, extensive research explores the potential of biomarkers such as cytokines, molecular and cell therapies, antioxidant interventions, and gene therapy for DR treatment. Notably, certain drugs, such as anti-VEGF agents, antioxidants, inhibitors of inflammatory responses, and protein kinase C (PKC)-β inhibitors, have demonstrated promising outcomes in clinical trials. Within this context, this review article aims to introduce the recent molecular research on DR and highlight the current progress in the field, with a particular focus on the emerging and experimental treatment strategies targeting the immune and redox signaling pathways.

Protective and Therapeutic Effects of Bovine Amniotic Fluids Collected in Different Trimesters on the Epidural Fibrosis After Experimental Laminectomy in Rats

BACKGROUND

The aim of this study was to investigate the protective and therapeutic effects of bovine amniotic fluid (BAF) on the inhibition of epidural fibrosis (EF) after experimental laminectomy.

METHODS

Forty female Sprague Dawley rats were used. The amniotic fluids were collected from each trimester of a pregnant cow. The rats were divided into 5 groups. Whereas no laminectomy was applied to the control group, animals in the sham group underwent laminectomy. Laminectomy was performed in the animals in other groups and the operation area was closed by dripping 1 mL of BAF collected in 3 trimesters of pregnancy. Animals were killed 28 days after the operation.

RESULTS

Compared with control, VEGF gene expression levels were downregulated approximately 5-fold in BAF-2. Whereas IL-6 was upregulated approximately 8-fold in the sham, it was downregulated 5-fold and 3-fold in BAF-1 and BAF-2, respectively. There was downregulation in BAF-2 and BAF-3 in terms of CD105 gene expression levels. TGFβ1 was upregulated approximately 2-fold in the sham group and downregulated in BAF-1 and BAF-2. Although histopathologic alterations including EF grade and fibroblast cell density were found to increase in the sham group, all BAF treatment decreased those of alterations. The highest CD105 immunoreactivity was detected in the sham group. All BAF treatment markedly aggravated fibrosis via decreasing CD105 immunoreactivity. In terms of grading parameters, almost the closest grades to the control were determined in the BAF-2. BAF collected in the second trimester is most effective in healing of scar tissue and preventing fibrosis via decreasing microvessel and fibroblast densities.

CONCLUSIONS

The results indicate that BAF may be used as a potential protective agent to prevent EF.

Research Progress on Mesenchymal Stem Cells for the Treatment of Diabetes and Its Complications

Diabetes mellitus (DM) is a chronic disease that threatens human health. Although many drugs are available to treat DM, various complications caused by DM are unavoidable. As an emerging treatment for DM, mesenchymal stem cells (MSCs) have shown many advantages and are gradually gaining public attention. This review summarizes the clinical studies on the use of MSCs to treat DM and the potential mechanisms of complications such as pancreatic dysfunction, cardiovascular lesions, renal lesions, neurological lesions, and trauma repair. This review focuses on the research progress on MSC-mediated secretion of cytokines, improvements in the microenvironment, repair of tissue morphology, and related signaling pathways. At present, the sample sizes in clinical studies of MSCs in treating DM are small, and there is a lack of standardized quality control systems in the preparation, transportation, and infusion methods, so we need to conduct more in-depth studies. In conclusion, MSCs have shown superior potential for use in the treatment of DM and its complications and will hopefully become a novel therapeutic approach in the future.

Advances in cell therapies using stem cells/progenitors as a novel approach for neurovascular repair of the diabetic retina

BACKGROUND

Diabetic retinopathy, a major complication of diabetes mellitus, is a leading cause of sigh-loss in working age adults. Progressive loss of integrity of the retinal neurovascular unit is a central element in the disease pathogenesis. Retinal ischemia and inflammatory processes drive interrelated pathologies such as blood retinal barrier disruption, fluid accumulation, gliosis, neuronal loss and/or aberrant neovascularisation. Current treatment options are somewhat limited to late-stages of the disease where there is already significant damage to the retinal architecture arising from degenerative, edematous and proliferative pathology. New preventive and interventional treatments to target early vasodegenerative and neurodegenerative stages of the disease are needed to ensure avoidance of sight-loss.

MAIN BODY

Historically, diabetic retinopathy has been considered a primarily microvascular disease of the retina and clinically it is classified based on the presence and severity of vascular lesions. It is now known that neurodegeneration plays a significant role during the pathogenesis. Loss of neurons has been documented at early stages in pre-clinical models as well as in individuals with diabetes and, in some, even prior to the onset of clinically overt diabetic retinopathy. Recent studies suggest that some patients have a primarily neurodegenerative phenotype. Retinal pigment epithelial cells and the choroid are also affected during the disease pathogenesis and these tissues may also need to be addressed by new regenerative treatments. Most stem cell research for diabetic retinopathy to date has focused on addressing vasculopathy. Pre-clinical and clinical studies aiming to restore damaged vasculature using vasoactive progenitors including mesenchymal stromal/stem cells, adipose stem cells, CD34+ cells, endothelial colony forming cells and induced pluripotent stem cell derived endothelial cells are discussed in this review. Stem cells that could replace dying neurons such as retinal progenitor cells, pluripotent stem cell derived photoreceptors and ganglion cells as well as Müller stem cells are also discussed. Finally, challenges of stem cell therapies relevant to diabetic retinopathy are considered.

CONCLUSION

Stem cell therapies hold great potential to replace dying cells during early and even late stages of diabetic retinopathy. However, due to the presence of different phenotypes, selecting the most suitable stem cell product for individual patients will be crucial for successful treatment.

Human umbilical cord-derived mesenchymal stem cells not only ameliorate blood glucose but also protect vascular endothelium from diabetic damage through a paracrine mechanism mediated by MAPK/ERK signaling

BACKGROUND

Endothelial damage is an initial step of macro- and micro-vasculature dysfunctions in diabetic patients, accounting for a high incidence of diabetic vascular complications, such as atherosclerosis, nephropathy, retinopathy, and neuropathy. However, clinic lacks effective therapeutics targeting diabetic vascular complications. In field of regenerative medicine, mesenchymal stem cells, such as human umbilical cord-derived MSCs (hucMSCs), have great potential in treating tissue damage.

METHODS

To determine whether hucMSCs infusion could repair diabetic vascular endothelial damage and how it works, this study conducted in vivo experiment on streptozotocin-induced diabetic rat model to test body weight, fasting blood glucose (FBG), serum ICAM-1 and VCAM-1 levels, histopathology and immunohistochemical staining of aorta segments. In vitro experiment was further conducted to determine the effects of hucMSCs on diabetic vascular endothelial damage, applying assays of resazurin staining, MTT cell viability, wound healing, transwell migration, and matrigel tube formation on human umbilical vein endothelial cells (HUVECs). RNA sequencing (RNAseq) and molecular experiment were conducted to clarify the mechanism of hucMSCs.

RESULTS

The in vivo data revealed that hucMSCs partially restore the alterations of body weight, FBG, serum ICAM-1 and VCAM-1 levels, histopathology of aorta and reversed the abnormal phosphorylation of ERK in diabetic rats. By using the conditioned medium of hucMSCs (MSC-CM), the in vitro data revealed that hucMSCs improved cell viability, wound healing, migration and angiogenesis of the high glucose-damaged HUVECs through a paracrine action mode, and the altered gene expressions of IL-6, TNF-α, ICAM-1, VCAM-1, BAX, P16, P53 and ET-1 were significantly restored by MSC-CM. RNAseq incorporated with real-time PCR and Western blot results clarified that high glucose activated MAPK/ERK signaling in HUVECs, while MSC-CM reversed the abnormal phosphorylation of ERK and overexpressions of MKNK2, ERBB3, MYC and DUSP5 in MAPK/ERK signaling pathway.

CONCLUSIONS

HucMSCs not only ameliorated blood glucose but also protected vascular endothelium from diabetic damage, in which MAPK/ERK signaling mediated its molecular mechanism of paracrine action. Our findings provided novel knowledge of hucMSCs in the treatment of diabetes and suggested a prospective strategy for the clinical treatment of diabetic vascular complications.

State of the field: cellular and exosomal therapeutic approaches in vascular regeneration

Pathologies of the vasculature including the microvasculature are often complex in nature, leading to loss of physiological homeostatic regulation of patency and adequate perfusion to match tissue metabolic demands. Microvascular dysfunction is a key underlying element in the majority of pathologies of failing organs and tissues. Contributing pathological factors to this dysfunction include oxidative stress, mitochondrial dysfunction, endoplasmic reticular (ER) stress, endothelial dysfunction, loss of angiogenic potential and vascular density, and greater senescence and apoptosis. In many clinical settings, current pharmacologic strategies use a single or narrow targeted approach to address symptoms of pathology rather than a comprehensive and multifaceted approach to address their root cause. To address this, efforts have been heavily focused on cellular therapies and cell-free therapies (e.g., exosomes) that can tackle the multifaceted etiology of vascular and microvascular dysfunction. In this review, we discuss 1) the state of the field in terms of common therapeutic cell population isolation techniques, their unique characteristics, and their advantages and disadvantages, 2) common molecular mechanisms of cell therapies to restore vascularization and/or vascular function, 3) arguments for and against allogeneic versus autologous applications of cell therapies, 4) emerging strategies to optimize and enhance cell therapies through priming and preconditioning, and, finally, 5) emerging strategies to bolster therapeutic effect. Relevant and recent clinical and animal studies using cellular therapies to restore vascular function or pathologic tissue health by way of improved vascularization are highlighted throughout these sections.

Resveratrol Reverses Osteogenic Decline of Bone Marrow Mesenchymal Stem Cells Via Upregulation of Yes-Associated Protein Expression in Inflammatory Environment

Osteoporosis is an age-related bone disease, characterized by rapid boneloss, decreased bone mineral density (BMD), and consequent risk of fractures. The most prevalent form of clinically significant osteoporosis involves various inflammatory conditions, especially age-dependent osteoporosis and postmenopausal osteoporosis. Tumor necrosis factor-α (TNF-α), a pro-inflammatory cytokine, plays a critical role in the development of inflammatory, which also plays an important role in bone formation and bone loss during osteoporosis. In this report, we examined the effect of TNF-α on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its modulation by resveratrol (Res). We found that TNF-α can upregulate inflammatory cytokines, Il-6, Mmp-9, and Il-1β, and establish an inflammatory environment. High inflammatory cytokine expression significantly inhibited osteogenic differentiation of BMSCs by overactivating upstream Hippo kinases and decreasing the nuclear Yes-associated protein (YAP) signals. With Res treatment, decreasing inflammatory cytokine expression normalized Hippo/YAP signaling and effectively rescued YAP-mediated osteogenesis. Thus, through these studies, we present a mechanism by which TNF-α can affect BMSCs osteogenesis through modulation of Hippo/YAP signaling.

Biological Characteristics of Umbilical Cord Mesenchymal Stem Cells and Its Therapeutic Potential for Hematological Disorders

Umbilical cord mesenchymal stem cells (UC-MSCs) are a class of multifunctional stem cells isolated and cultured from umbilical cord. They possessed the characteristics of highly self-renewal, multi-directional differentiation potential and low immunogenicity. Its application in the field of tissue engineering and gene therapy has achieved a series of results. Recent studies have confirmed their characteristics of inhibiting tumor cell proliferation and migration to nest of cancer. The ability of UC-MSCs to support hematopoietic microenvironment and suppress immune system suggests that they can improve engraftment after hematopoietic stem cell transplantation, which shows great potential in treatment of hematologic diseases. This review will focus on the latest advances in biological characteristics and mechanism of UC-MSCs in treatment of hematological diseases.

Countering adipose tissue dysfunction could underlie the superiority of telmisartan in the treatment of obesity-related hypertension

BACKGROUND

The prevalence of hypertension and obesity has increased significantly in recent decades. Hypertension and obesity often coexist, and both are associated with increased cardiovascular mortality. Obese hypertensive patients usually require special anti-hypertensive treatment strategy due to the increased risk of treatment resistance. Molecules that can target both obesity and hypertension underlying pathologies should get more attention. Herein, we evaluated the therapeutic effects of telmisartan, with special interest in visceral adipose tissue dysfunction, in obesity-related hypertension rat model.

METHODS

Thirty male Wistar rats weighing 150-200 g were equally divided into: 1-Control group (fed normal laboratory diet for 24 weeks), 2-Diet-induced obesity group (DIO, fed high fat diet for 24 weeks), and 3-Diet-induced obesity treated with telmisartan group (DIO + Tel, fed high fat diet and received telmisartan for 24 weeks). At the end of the study, anthropometrical parameters were evaluated. Systolic blood pressure and heart rate were measured. Blood samples were collected for the measurement of serum lipids, adipokines, cardiac, renal, inflammatory, and oxidative stress biomarkers. Kidneys were removed and used for histopathological studies, and visceral adipose tissue was utilized for histopathological, immunohistochemical and RT-PCR studies.

RESULTS

High fat diet resulted in obesity-related changes in anthropometrical parameters, elevation of blood pressure, increase in heart rate, higher serum levels of cardiac, inflammatory and kidney function biomarkers, with altered serum lipids, adipokines and oxidative stress markers. Morphological changes (H&E and PAS-stained sections) were noticed in kidneys and visceral adipose tissue. Immunohistochemistry and RT-PCR studies confirmed adipose tissue dysfunction and over-expression of inflammatory and oxidative stress proteins. Telmisartan countered obesity-induced alterations in cardiovascular, renal, and adipose tissue functions.

CONCLUSION

Adipose tissue dysfunction could be the core pathophysiology of obesity-related hypertension. Besides its anti-hypertensive effect, telmisartan had profound actions on visceral adipose tissue structure and function. Attention should be given to polymodal molecules targeting adipose tissue-related disorders.

Activation of FoxO1/SIRT1/RANKL/OPG pathway may underlie the therapeutic effects of resveratrol on aging-dependent male osteoporosis

Background

Age-dependent male osteoporosis remains a poorly studied medical problem despite its significance. It is estimated that at least 1 of 5 men will suffer from osteoporotic consequences. Given that multiple mechanisms are involved in the process of senescence, much attention has been given to compounds with polymodal actions. To challenge such a health problem, we tested here the therapeutic potential of resveratrol in male osteoporosis. We also studied the possible molecular mechanisms that may underlie resveratrol effects.

Methods

Thirty male Wistar albino rats were used in the present study. Rats were divided (10/group) into: control (3–4 months old weighing 150–200 g receiving vehicle), aged (18–20 months old, weighing 350–400 g and receiving vehicle), and resveratrol treated aged (18–20 months old, weighing 350–400 g and receiving resveratrol 20 mg/kg/day for 6 weeks) groups. Assessment of serum calcium, phosphate, bone specific alkaline phosphatase, inflammatory cytokines, oxidative stress markers, and rat femur gene expression of FoxO1, SIRT1, RANKL and OPG proteins was carried out. Histopathological assessment of different levels of rat femur was also performed.

Results

Age-dependent osteoporosis resulted in significant increase in serum levels of phosphate, bone specific alkaline phosphatase, hsCRP, IL-1β, IL-6, TNF-α, MDA, NO, and RANKL gene expression. However, there was significant decrease in serum level of GSH, and gene expression of FoxO1, SIRT1 and OPG. Osteoporotic changes were seen in femur epiphysis, metaphysis and diaphysis. Resveratrol restored significantly age-dependent osteoporotic changes.

Conclusion

We concluded that resveratrol can play an important role in the prevention of male osteoporosis. Resveratrol can counter the molecular changes in male osteoporosis via anti-inflammatory, anti-oxidant and gene modifying effects.