Therapeutic efficacy of neuregulin 1-expressing human adipose-derived mesenchymal stem cells for ischemic stroke

Priming and Combined Strategies for the Application of Mesenchymal Stem Cells in Ischemic Stroke: A Promising Approach

Ischemic stroke (IS) is a leading cause of death and disability worldwide. Tissue plasminogen activator (tPA) administration and mechanical thrombectomy are the main treatments but have a narrow time window. Mesenchymal stem cells (MSCs), which are easily scalable in vitro and lack ethical concerns, possess the potential to differentiate into various types of cells and secrete a great number of growth factors for neuroprotection and regeneration. Moreover, MSCs have low immunogenicity and tumorigenic properties, showing safety and preliminary efficacy both in preclinical studies and clinical trials of IS. However, it is unlikely that MSC treatment alone will be sufficient to maximize recovery due to the low survival rate of transplanted cells and various mechanisms of ischemic brain damage in the different stages of IS. Preconditioning was used to facilitate the homing, survival, and secretion ability of the grafted MSCs in the ischemic region, while combination therapies are alternatives that can maximize the treatment effects, focusing on multiple therapeutic targets to promote stroke recovery. In this case, the combination therapy can yield a synergistic effect. In this review, we summarize the type of MSCs, preconditioning methods, and combined strategies as well as their therapeutic mechanism in the treatment of IS to accelerate the transformation from basic research to clinical application.

Mesenchymal stem cells and their extracellular vesicles as emerging therapeutic tools in the treatment of ischemic stroke

Ischemic stroke (IS) is a neurological condition characterized by severe long-term consequences and an unfavorable prognosis for numerous patients. Despite advancements in stroke treatment, existing therapeutic approaches possess certain limitations. However, accumulating evidence suggests that mesenchymal stem/stromal cells (MSCs) hold promise as a potential therapy for various neurological disorders, including IS, owing to their advantageous properties, such as immunomodulation and tissue regeneration. Additionally, MSCs primarily exert their therapeutic effects through the release of extracellular vesicles (EVs), highlighting the significance of their paracrine activities. These EVs are small double-layered phospholipid membrane vesicles, carrying a diverse cargo of proteins, lipids, and miRNAs that enable effective cell-to-cell communication. Notably, EVs have emerged as attractive substitutes for stem cell therapy due to their reduced immunogenicity, lower tumorigenic potential, and ease of administration and handling. Hence, this review summarizes the current preclinical and clinical studies performed to investigate the safety and therapeutic potential of MSCs and their EVs derived from different sources, including bone marrow, adipose tissue, umbilical cord blood, and Wharton's jelly in IS.

Chorionic villus-derived mesenchymal stem cell-mediated NRG1 upregulation promotes HTR-8/SVneo cells proliferation through the activation of the NF-κB signaling pathway

In a prior study, our group found that chorionic villus-derived mesenchymal stem cells (CV-MSCs) were capable of promoting trophoblast proliferative and invasive activity. The mechanistic basis for this activity, however, has yet to be clarified. As such, an RNA-Seq analysis was conducted using trophoblasts that were treated with or without CV-MSC-conditioned media. Of the differentially expressed genes identified when comparing these two groups of cells, 23 proliferation-associated genes were identified and knocked down to test their functional roles in trophoblasts. These analyses revealed that inhibiting neuregulin 1 (NRG1) expression was sufficient to suppress proliferation and induce cell cycle arrest in trophoblasts. Placental samples from patients with preeclampsia exhibited significantly increased NRG1 expression relative to samples from healthy pregnancies. Following treatment with CV-MSC-conditioned media, NRG1 was upregulated in trophoblasts at the mRNA and protein levels. Relative to control trophoblasts, those in which NRG1 had been knocked down exhibited significantly impaired proliferation and DNA replication with the inactivation of the NF-κB signaling pathway. In contrast, overexpressing NRG1 yielded the opposite trophoblast phenotypes. Even in cells overexpressing NRG1, inhibition of NF-κB signaling was sufficient to significantly suppress trophoblast proliferation (P < 0.05). These results indicate that elevated NRG1 expression may play a role in the ability of CV-MSCs to induce proliferative activity in trophoblasts through the NF-κB signaling axis.

Nanoparticle and Stem Cell Combination Therapy for the Management of Stroke

Stroke is currently one of the primary causes of morbidity and mortality worldwide. Unfortunately, the available treatments for stroke are still extremely limited. Indeed, stem cell (SC) therapy is a new option for the treatment of stroke that could significantly expand the therapeutic time window of stroke. Some proposed mechanisms for stroke-based SC therapy are the incorporation of SCs into the host brain to replace dead or damaged cells/tissues. Moreover, acute cell delivery can inhibit apoptosis and decrease lesion size, providing immunomudolatory and neuroprotection effects. However, several major SC problems related to SCs such as homing, viability, uncontrolled differentiation, and possible immune response, have limited SC therapy. A combination of SC therapy with nanoparticles (NPs) can be a solution to address these challenges. NPs have received considerable attention in regulating and controlling the behavior of SCs because of their unique physicochemical properties. By reviewing the pathophysiology of stroke and the therapeutic benefits of SCs and NPs, we hypothesize that combined therapy will offer a promising future in the field of stroke management. In this work, we discuss recent literature in SC research combined with NP-based strategies that may have a synergistic outcome after stroke incidence.

Synergic Effect of Combined Therapy of Hyperbaric Oxygen and Adipose-Derived Mesenchymal Stem Cells on Improving Locomotor Recovery After Acute Traumatic Spinal Cord Injury in Rat Mainly Through Downregulating Inflammatory and Cell-Stress Signalings

This study tested whether combined hyperbaric oxygen (HBO) and allogenic adipose-derived mesenchymal stem cells (ADMSCs) would be superior to either one for improving the locomotor recovery in rat after acute traumatic spinal cord injury (TSCI) in rat. Adult-male Sprague-Dawley rats were equally categorized into group 1 (sham-operated control), group 2 (TSCI), group 3 (TSCI + HBO for 1.5 h/day for 14 consecutive days after TSCI), group 4 (TSCI + ADMSCs/1.2 × 10⁶ cells by intravenous injection at 3 h and days 1/2 after TSCI), and group 5 (TSCI + HBO + ADMSCs), euthanized, and spinal cord tissue was harvested by day 49 after TSCI. The protein expressions of oxidative-stress (NOX-1/NOX-2), inflammatory-signaling (TLR-4/MyD88/IL-1β/TNF-α/substance-p), cell-stress signaling (PI3K/p-AKT/p-mTOR), and the voltage-gated sodium channel (Nav1.3/1.8/1.9) biomarkers were highest in group 2, lowest in group 1, and significantly lower in group 5 than in groups 3/4 (all <i>P</i> &lt;0.0001), but they did not differ between groups 3 and 4. The spinal cord damaged area, the cellular levels of inflammatory/DNA-damaged biomarkers (CD68+/GFAP+/γ-H2AX+ cells), mitogen-activated protein kinase family biomarkers (p-P38/p-JNK/p-ERK1/2), and cellular expressions of voltage-gated sodium channel (Nav.1.3, Nav.1.8, and Nav.1.9 in NF200+ cells) as well as the pain-facilitated cellular expressions (p-P38+/peripherin+ cells, p-JNK+/peripherin+ cells, p-ERK/NF200+ cells) exhibited an identical pattern of inflammation, whereas the locomotor recovery displayed an opposite pattern of inflammation among the groups (all <i>P</i> &lt; 0.0001). Combined HBO-ADMSCs therapy offered additional benefits for preserving the neurological architecture and facilitated the locomotor recovery against acute TSCI.

Insights into Exosome in the Intervertebral Disc: Emerging Role for Disc Homeostasis and Normal Function

Low back pain (LBP) is a chronic condition that causes great individual suffering and economic burden. The major contributor of LBP is intervertebral disc degeneration (IDD), which is caused by a spectrum of homeostasis alteration, including the apoptosis of nucleus pulposus (NP) and annulus fibrosus (AF) cells, degradation of extracellular matrix (ECM), calcification of cartilaginous endplates (CEP) and so on. Currently, the therapeutic strategy for IDD includes conservative and surgery treatment. Nevertheless, none of them could reverse the progressive destruction of the intervertebral disc. Hence, it is pivotal to pursue a new therapeutic approach. Exosomes, nano-sized substances with diameters of 30-150 nm, can be synthesized and secreted by various types of cells. They play an important role in intercellular communication. Increasing evidence implicates that exosomes could impact the intracellular transcription activities, thereby inhibiting or accelerating the proliferation and apoptosis of cells. Thus, it is a new therapeutic source for IDD. This review chiefly focuses on generalizing and clarifying the roles of exosomes in the onset and deterioration of IDD, and their therapeutic potential.

E3 ligase activity of Carboxyl terminus of Hsc70 interacting protein (CHIP) in Wharton's jelly derived mesenchymal stem cells improves their persistence under hyperglycemic stress and promotes the prophylactic effects against diabetic cardiac damages

Recent studies indicate that umbilical cord stem cells are cytoprotective against several disorders. One critical limitation in using stem cells is reduction in their viability under stressful conditions, such as diabetes. However, the molecular intricacies responsible for diabetic conditions are not fully elucidated. In this study, we found that high glucose (HG) conditions induced loss of chaperone homeostasis, stabilized PTEN, triggered the downstream signaling cascade, and induced apoptosis and oxidative stress in Wharton's jelly derived mesenchymal stem cells (WJMSCs). Increased Carboxyl terminus of Hsc70 interacting protein (CHIP) expression promoted phosphatase and tensin homolog (PTEN) degradation via the ubiquitin-proteasome system and shortened its half-life during HG stress. Docking studies confirmed the interaction of CHIP with PTEN and FOXO3a with the Bim promoter region. Further, it was found that the chaperone system is involved in CHIP-mediated PTEN proteasomal degradation. CHIP depletion stabilizes PTEN whereas PTEN inhibition showed an inverse effect. CHIP overactivation suppressed the binding of FOXO3a with bim. Coculturing CHIP overexpressed WJMSCs suppressed HG-induced apoptosis and oxidative stress in embryo derived cardiac cell lines. CHIP overexpressing and PTEN silenced WJMSCs ameliorated diabetic effects in streptozotocin (STZ) induced diabetic rats and further improved their body weight and heart weight, and rescued from hyperglycemia-induced cardiac injury. Considering these, the current study suggests that CHIP confers resistance to apoptosis and acts as a potentiation factor in WJMSCs to provide protection from degenerative effects of diabetes.

CHIP-overexpressing Wharton's jelly-derived mesenchymal stem cells attenuate hyperglycemia-induced oxidative stress-mediated kidney injuries in diabetic rats

Accumulating studies have demonstrated the protective roles of mesenchymal stem cells against several disorders. However, one of their crucial limitations is reduced viability under stress conditions, including the hyperglycemia induced by diabetes. The molecular mechanisms involved in diabetes-induced kidney injuries are not fully elucidated. In this study, we found that high glucose (HG) reduced human proximal tubular epithelial cell viability. Further, hyperglycemia induced oxidative stress-mediated apoptosis and fibrosis in HK-2 cells via activation of the mitogen-activated protein kinases (MAPKs) including c-Jun N-terminal kinase JNK and p38 kinase. Carboxyl terminus of HSP70 interacting protein (CHIP) overactivation considerably rescued cell viability under HG stress. Moreover, Western blot analysis, flow cytometry, and MitoSOX staining revealed that hyperglycemia-induced mitochondrial oxidative stress production and apoptosis were attenuated in CHIP-overexpressing Wharton's jelly-derived mesenchymal stem cells (WJMSCs). Co-culture with CHIP-expressing WJMSCs maintained HK-2 cell viability, and inhibited apoptosis and fibrosis by attenuating HG-induced ROS-mediated MAPK activation. CHIP-overexpressing WJMSCs also rescued the decreased kidney weight and hyperglycemia-induced kidney damage observed in streptozotocin-induced diabetic rats. Cumulatively, the current research findings demonstrate that CHIP suppresses hyperglycemia-induced oxidative stress and confers resistance to MAPK-induced apoptosis and fibrosis, and suggests that CHIP protects WJMSCs and the high quality WJMSCs have therapeutic effects against diabetes-induced kidney injuries.

Comparing the Therapeutic Potential of Stem Cells and their Secretory Products in Regenerative Medicine

Cell therapy involves the transplantation of human cells to replace or repair the damaged tissues and modulate the mechanisms underlying disease initiation and progression in the body. Nowadays, many different types of cell-based therapy are developed and used to treat a variety of diseases. In the past decade, cell-free therapy has emerged as a novel approach in regenerative medicine after the discovery that the transplanted cells exerted their therapeutic effect mainly through the secretion of paracrine factors. More and more evidence showed that stem cell-derived secretome, i.e., growth factors, cytokines, and extracellular vesicles, can repair the injured tissues as effectively as the cells. This finding has spurred a new idea to employ secretome in regenerative medicine. Despite that, will cell-free therapy slowly replace cell therapy in the future? Or are these two modes of treatment still needed to address different diseases and conditions? This review provides an indepth discussion about the values of stem cells and secretome in regenerative medicine. In addition, the safety, efficacy, advantages, and disadvantages of using these two modes of treatment in regenerative medicine are also critically reviewed.

Thal protects against paraquat-induced lung injury through a microRNA-141/HDAC6/IκBα-NF-κB axis in rat and cell models

The protective functions of thalidomide in paraquat (PQ)-induced injury have been reported. But the mechanisms remain largely unknown. In this research, a PQ-treated rat model was established and further treated with thalidomide. Oedema and pathological changes, oxidative stress, inflammation, fibrosis and cell apoptosis in rat lungs were detected. A PQ-treated RLE-6TN cell model was constructed, and the viability and apoptosis rate of cells were measured. Differentially expressed microRNAs (miRNAs) after thalidomide administration were screened out. Binding relationship between miR-141 and histone deacetylase 6 (HDAC6) was validated. Altered expression of miR-141 and HDAC6 was introduced to identify their involvements in thalidomide-mediated events. Consequently, thalidomide administration alone exerted no damage to rat lungs; in addition it reduced PQ-induced oedema. The oxidative stress, inflammation and cell apoptosis in rat lungs were reduced by thalidomide. In RLE-6TN cells, thalidomide increased cell viability and decreased apoptosis. miR-141 was responsible for thalidomide-mediated protective events by targeting HDAC6. Overexpression of HDAC6 blocked the protection of thalidomide against PQ-induced injury via activating the IkBα-NF-κB signalling pathway. Collectively, this study evidenced that thalidomide protects lung tissues from PQ-induced injury through a miR-141/HDAC6/IkBα-NF-κB axis.

The Role of Neuregulin and Stem Cells as Therapy Post-Myocardial Infarction

Coronary artery disease, including myocardial infarction (MI), is a leading cause of morbidity and mortality in the United States. Due to the limited self-renewal capacity of cardiac tissue, MIs can lead to progressive heart disease with a lasting impact on health and quality of life. The recent discovery of cardiac stem cells has incited research into their potential therapeutic applications for patients suffering from cardiovascular disease. Studies have demonstrated the ability of stem cells to both generate cardiac tissues in vitro and aid in the recovery of cardiovascular function in vivo in animal models. However, the long-term efficacy of stem cells as regenerative therapy is still unknown. Exploration of alternative therapies is underway, including the use of cardiac growth factor neuregulin-1 (NRG-1). Research has demonstrated that NRG-1 not only has direct effects on cardiomyocytes (CM) but also acts within the tissues supporting the CM. Transplantation of NRG-1 into ischemic cardiac tissue mitigates the progression of heart failure and can reverse cardiac remodeling. Recent publications have sought to study the combined use of these agents, and while the results are promising, they do warrant further research. This review aims to consider these therapies separately as well as in combination.

Mannitol Augments the Effects of Systemical Stem Cell Transplantation without Increasing Cell Migration in a Stroke Animal Model

BACKGROUND

Mannitol increases blood-brain barrier permeability and can improve the efficiency of systemically administered stem cells by facilitating stem cell entry from the periphery into the injured brain. The aim of this study was to elucidate the neuroprotective effects of a combination of mannitol pretreatment and stem cell transplantation on stroke-induced neural injury.

METHODS

The experimental rats were randomly assigned to three groups 24 h after middle cerebral artery occlusion and reperfusion. One group received intravenous (IV) injections of phosphate-buffered saline (vehicle), another group received IV injections of human adipose-derived stem cells (hADSCs), and the last group received IV injections of hADSCs 10 min after IV mannitol injections. Neurobehavioral functions and infarct volume were compared. Immunohistochemistry (IHC) analyses were performed using antibodies against ionized calcium binding adapter-1 (IBA-1), rat endothelial antigen-1 (RECA-1), and bromodeoxyuridine/doublecortin (BrdU/DCX).

RESULTS

PKH-26 labeling revealed no difference in the number of stem cells that had migrated into the injured brain, and hADSC transplantation did not improve the infarct volume. However, neurobehavioral functions improved in the mannitol group. IHC showed higher numbers of RECA-1-positive cells in the peri-infarcted brain and BrdU-/DCX-colocalized cells in the subventricular zone in the mannitol group. IBA-1-positive cell number decreased in the hADSC-only and mannitol-pretreatment groups compared with the vehicle group even though there was no difference between the former two groups.

CONCLUSION

Combinatorial treatment with mannitol and hADSC transplantation may have better therapeutic potential than hADSC monotherapy for ischemic stroke.

Genetic Engineering as a Strategy to Improve the Therapeutic Efficacy of Mesenchymal Stem/Stromal Cells in Regenerative Medicine

Mesenchymal stem/stromal cells (MSCs) have been widely studied in the field of regenerative medicine for applications in the treatment of several disease settings. The therapeutic potential of MSCs has been evaluated in studies in vitro and in vivo, especially based on their anti-inflammatory and pro-regenerative action, through the secretion of soluble mediators. In many cases, however, insufficient engraftment and limited beneficial effects of MSCs indicate the need of approaches to enhance their survival, migration and therapeutic potential. Genetic engineering emerges as a means to induce the expression of different proteins and soluble factors with a wide range of applications, such as growth factors, cytokines, chemokines, transcription factors, enzymes and microRNAs. Distinct strategies have been applied to induce genetic modifications with the goal to enhance the potential of MCSs. This review aims to contribute to the update of the different genetically engineered tools employed for MSCs modification, as well as the factors investigated in different fields in which genetically engineered MSCs have been tested.

In Vitro Cultures of Adipose-Derived Stem Cells: An Overview of Methods, Molecular Analyses, and Clinical Applications

Adipose-derived stem cells (ASCs) exhibiting mesenchymal stem cell (MSC) characteristics, have been extensively studied in recent years. Because they have been shown to differentiate into lineages such as osteogenic, chondrogenic, neurogenic or myogenic, the focus of most of the current research concerns either their potential to replace bone marrow as a readily available and abundant source of MSCs, or to employ them in regenerative and reconstructive medicine. There is close to consensus regarding the methodology used for ASC isolation and culture, whereas a number of molecular analyses implicates them in potential therapies of a number of pathologies. When it comes to clinical application, there is a range of examples of animal trials and clinical studies employing ASCs, further emphasizing the advancement of studies leading to their more widespread use. Nevertheless, in vitro studies will most likely continue to play a significant role in ASC studies, both providing the molecular knowledge of their ex vivo properties and possibly serving as an important step in purification and application of those cells in a clinical setting. Therefore, it is important to consider current methods of ASC isolation, culture, and processing. Furthermore, molecular analyses and cell surface properties of ASCs are essential for animal studies, clinical studies, and therapeutic applications of the MSC properties.