Transplantation of mesenchymal stem cells genetically engineered to overexpress interleukin-10 promotes alternative inflammatory response in rat model of traumatic brain injury

Non-pharmacological interventions for traumatic brain injury

Heterogeneity and variability of symptoms due to the type, site, age, sex, and severity of injury make each case of traumatic brain injury (TBI) unique. Considering this, a universal treatment strategy may not be fruitful in managing outcomes after TBI. Most of the pharmacological therapies for TBI aim at modifying a particular pathway or molecular process in the sequelae of secondary injury rather than a holistic approach. On the other hand, non-pharmacological interventions such as hypothermia, hyperbaric oxygen, preconditioning with dietary adaptations, exercise, environmental enrichment, deep brain stimulation, decompressive craniectomy, probiotic use, gene therapy, music therapy, and stem cell therapy can promote healing by modulating multiple neuroprotective mechanisms. In this review, we discussed the major non-pharmacological interventions that are being tested in animal models of TBI as well as in clinical trials. We evaluated the functional outcomes of various interventions with an emphasis on the links between molecular mechanisms and outcomes after TBI.

Innovative Insights into Traumatic Brain Injuries: Biomarkers and New Pharmacological Targets

A traumatic brain injury (TBI) is a major health issue affecting many people across the world, causing significant morbidity and mortality. TBIs often have long-lasting effects, disrupting daily life and functionality. They cause two types of damage to the brain: primary and secondary. Secondary damage is particularly critical as it involves complex processes unfolding after the initial injury. These processes can lead to cell damage and death in the brain. Understanding how these processes damage the brain is crucial for finding new treatments. This review examines a wide range of literature from 2021 to 2023, focusing on biomarkers and molecular mechanisms in TBIs to pinpoint therapeutic advancements. Baseline levels of biomarkers, including neurofilament light chain (NF-L), ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1), Tau, and glial fibrillary acidic protein (GFAP) in TBI, have demonstrated prognostic value for cognitive outcomes, laying the groundwork for personalized treatment strategies. In terms of pharmacological progress, the most promising approaches currently target neuroinflammation, oxidative stress, and apoptotic mechanisms. Agents that can modulate these pathways offer the potential to reduce a TBI's impact and aid in neurological rehabilitation. Future research is poised to refine these therapeutic approaches, potentially revolutionizing TBI treatment.

Effects of bone marrow mesenchymal stromal cells-derived therapies for experimental traumatic brain injury： A meta-analysis

Background

Bone-marrow-derived mesenchymal stromal (stem) cells [also called MSC(M)] and their extracellular vesicles (EVs) are considered a potentially innovative form of therapy for traumatic brain injury (TBI). Nevertheless, their application to TBI particularly remains preclinical, and the effects of these cells remain unclear and controversial. Therefore, an updated meta-analysis of preclinical studies is necessary to assess the effectiveness of MSC(M) and MSC(M) derived EVs in clinical trials.

Methods

The following databases were searched (to December 2022): PubMed, Web of Science, and Embase. In this study, we measured functional outcomes based on the modified neurological severity score (mNSS), cognitive outcomes based on the Morris water maze (MWM), and histopathological outcomes based on lesion volume. A random effects meta-analysis was conducted to evaluate the effect of mNSS, MWM, and lesion volume.

Results

A total of 2163 unique records were identified from our search, with Fifty-five full-text articles satisfying inclusion criteria. A mean score of 5.75 was assigned to the studies' quality scores, ranging from 4 to 7. MSC(M) and MSC(M) derived EVs had an overall positive effect on the mNSS score and MWM with SMDs -2.57 (95 % CI -3.26; -1.88; p < 0.01) and - 2.98 (95 % CI -4.21; -1.70; p < 0.01), respectively. As well, MSC(M) derived EVs were effective in reducing lesion volume by an SMD of - 0.80 (95 % CI -1.20; -0.40; p < 0.01). It was observed that there was significant variation among the studies, but further analyses could not determine the cause of this heterogeneity.

Conclusions

MSC(M) and MSC(M) derived EVs are promising treatments for TBI in pre-clinical studies, and translation to the clinical domain appears warranted. Besides, large-scale trials in animals and humans are required to support further research due to the limited sample size of MSC(M) derived EVs.

Effect of fentanyl and remifentanil on neuron damage and oxidative stress during induction neurotoxicity

Opioids can be used for medical and non-medical purposes. Chronic pain such as cancer, as well as the frequent use of such drugs in places such as operating rooms and intensive care units, and in non-medical areas like drug abuse the effects and side effects of these drugs need to be examined in more detail. For this purpose, the effects of fentanyl and remifentanil drugs on neuroinflammation, oxidative stress and cholinesterase metabolism were investigated. Neuron cells (CRL-10742) were used for the evaluation of the toxicity of fentanyl and remifentanil. MTT, PON1 activity and total thiol levels for its effect on oxidative stress, AChE and BChE activities for its effect on the cholinergic system, and TNF, IL-8 and IL-10 gene levels for its neuroinflammation effect were determined. The highest neurotoxic dose of fentanyl and remifentanil was determined as 10 μg/mL. It was observed that the rate of neuron cells in this dose has decreased by up to 61.80% and 56.89%, respectively. The IL-8 gene expression level in both opioids was down-regulated while IL 10 gene level was up-regulated in a dose-dependent manner compared to the control. In our results, the TNF gene expression level differs between the two opioids. In the fentanyl group, it was seen to be up-regulated in a dose-dependent manner compared to the control. Fentanyl and remifentanil showed an inhibitory effect against PON1, while remifentanil showed an increase in total thiol levels. PON1, BChE and total thiol activities showed similarity with MTT.

Left Barrel Cortical Neurons Activity following Transplantation of Stem Cells into Right Lesioned-Barrel Cortex in Rats

OBJECTIVE

Stem cells (SCs) can improve the functional defects of brain injury. Rodents use their whiskers to get tactile information from their surroundings. The aim of this study was to investigate whether the transplantation of SCs into the lesioned barrel cortex can help neuronal function in the contralateral cortex.

MATERIALS AND METHODS

Sixteen male Wistar rats (200-230 g) were used in this experimental study. We induced a mechanical lesion in the right barrel cortex area of rats by removing this area by a 3 mm skin punch. Four groups containing one intact group of rats: group 1: control, and three lesion groups, group 2: lesion+un-differentiated dental pulp SCs (U-DPSCs), group 3: lesion+differentiated dental pulp SCs (D-DPSCs), and group 4: cell medium (vehicle) that were injected in the lesion area. Three weeks after transplantation of SCs or cell medium, the rats' responses of left barrel cortical neurons to controlled deflections of right whiskers were recorded by using the extracellular single-unit recordings technique.

RESULTS

The results showed that the neural spontaneous activity and response magnitude of intact barrel cortex neurons in the lesion group decreased significantly (P<0.05) compared to the control group while ON and OFF responses were improved in the D-DPSCs (P<0.001) group compared to the vehicle group three weeks after transplantation.

CONCLUSION

Transplantation of dental pulp mesenchymal SCs significantly improved the neural responses of the left barrel cortex that was depressed in the vehicle group.

Mesenchymal stem cells overexpressing interleukin-10 prevent allergic airway inflammation

BACKGROUNDS

Allergic airway inflammation is prevalent worldwide and imposes a considerable burden on both society and affected individuals. This study aimed to investigate the therapeutic advantages of mesenchymal stem cells (MSCs) overexpressed interleukin-10 (IL-10) for the treatment of allergic airway inflammation, as both IL-10 and MSCs possess immunosuppressive properties.

METHODS

Induced pluripotent stem cell (iPSC)-derived MSCs were engineered to overexpress IL-10 via lentiviral transfection (designated as IL-10-MSCs). MSCs and IL-10-MSCs were administered intravenously to mice with allergic inflammation induced by ovalbumin (OVA), and the features of allergic inflammation including inflammatory cell infiltration, Th cells in the lungs, and T helper 2 cell (Th2) cytokine levels in bronchoalveolar lavage fluid (BALF) were examined. MSCs and IL-10-MSCs were co-cultured with CD4+ T cells from patients with allergic rhinitis (AR), and the levels of Th2 cells and corresponding type 2 cytokines were studied. RNA-sequence was performed to further investigate the potential effects of MSCs and IL-10-MSCs on CD4+ T cells.

RESULTS

Stable IL-10-MSCs were established and characterised by high IL-10 expression. IL-10-MSCs significantly reduced inflammatory cell infiltration and epithelial goblet cell numbers in the lung tissues of mice with allergic airway inflammation. Inflammatory cell and cytokine levels in BALF also decreased after the administration of IL-10-MSCs. Moreover, IL-10-MSCs showed a stronger capacity to inhibit the levels of Th2 after co-cultured with CD4+ T cells from patients with AR. Furthermore, we elucidated lower levels of IL-5 and IL-13 in IL-10-MSCs treated CD4+ T cells, and blockade of IL-10 significantly reversed the inhibitory effects of IL-10-MSCs. We also reported the mRNA profiles of CD4+ T cells treated with IL-10-MSCs and MSCs, in which IL-10 played an important role.

CONCLUSION

IL-10-MSCs showed positive effects in the treatment of allergic airway inflammation, providing solid support for the use of genetically engineered MSCs as a potential novel therapy for allergic airway inflammation.

The role and mechanisms of mesenchymal stem cells regulating macrophage plasticity in spinal cord injury

Spinal Cord Injury (SCI) is a devastating neurological disorder comprising primary mechanical injury and secondary inflammatory response-mediated injury for which an effective treatment is still unavailable. It is well known that secondary inflammatory responses are a significant cause of difficulties in neurological recovery. An immune imbalance between M1/M2 macrophages at the sites of injury is involved in developing and progressing the secondary inflammatory response. Recently, Mesenchymal Stem Cells (MSCs) have shown significant therapeutic potential in tissue engineering and regenerative medicine due to their potential multidirectional differentiation and immunomodulatory properties. Accumulating evidence shows that MSCs can regulate the balance of M1/M2 macrophage polarization, suppress downstream inflammatory responses, facilitate tissue repair and regeneration, and improve the prognosis of SCI. This article briefly overviews the impact of macrophages and MSCs on SCI and repair. It discusses the mechanisms by which MSCs regulate macrophage plasticity, including paracrine action, release of exosomes and apoptotic bodies, and metabolic reprogramming. Additionally, the article summarizes the relevant signaling pathways of MSCs that regulate macrophage polarization.

Umbilical Cord Mesenchymal Stem Cells Overexpressing Heme Oxygenase-1 Promotes Symptoms Recovery in Cystitis Rats by Alleviating Neuroinflammation

Interstitial cystitis/bladder pain syndrome (IC/BPS) seriously reduces the patient's quality of life, yet current therapies only provide partial relief. In the spinal dorsal horn (SDH), neuroinflammation plays a pivotal role in the development of IC. Injection of human umbilical cord mesenchymal stem cells (hUMSCs) to reduce inflammation is an effective strategy, and heme oxygenase-1 (HO-1) exhibits anti-nociceptive effect in neuroinflammatory pain. This study aimed to test the therapeutic effects of hUMSCs overexpressing HO-1 on cyclophosphamide-induced cystitis rat model. Cystitis rats were transplanted with altered cells and then assessed for 3 weeks. A series of behavioral measurements would be trial including suprapubic mechanical allodynia, depressive-like behaviors, micturition frequency, and short-term memory function. Additionally, western blot, immunofluorescence staining, and ELISA kit test for anti-inflammation effect. HUMSCs were capable of being transduced to overexpress HO-1. Injection of hUMSCs overexpressing HO-1 was more effective than hUMSCs alone in alleviating behavioral symptoms in rats. Furthermore, hUMSCs overexpressing HO-1 inhibited the activation of glial and TLR4/p65/NLRP3 pathway, decreased the levels of pro-inflammatory cytokines in the SDH region. Surprisingly, it markedly increased anti-inflammatory cytokine IL-10, reduced MDA content, and protected GSH concentrations in local environment. Our results suggest that injecting hUMSCs overexpressing HO-1 intrathecally can significantly promote functional outcomes in cystitis rats by reducing neuroinflammation, at least, partly through downregulating TLR4/p65/NLRP3 signaling pathway in the SDH region. This cell therapy affords a new strategy for IC/BPS treatment.

MesenchymAl stromal cells for Traumatic bRain Injury (MATRIx): a study protocol for a multicenter, double-blind, randomised, placebo-controlled phase II trial

BACKGROUND

Traumatic brain injury (TBI) is a significant cause of death and disability, with no effective neuroprotective drugs currently available for its treatment. Mesenchymal stromal cell (MSC)-based therapy shows promise as MSCs release various soluble factors that can enhance the injury microenvironment through processes, such as immunomodulation, neuroprotection, and brain repair. Preclinical studies across different TBI models and severities have demonstrated that MSCs can improve functional and structural outcomes. Moreover, clinical evidence supports the safety of third-party donor bank-stored MSCs in adult subjects. Building on this preclinical and clinical data, we present the protocol for an academic, investigator-initiated, multicenter, double-blind, randomised, placebo-controlled, adaptive phase II dose-finding study aiming to evaluate the safety and efficacy of intravenous administration of allogeneic bone marrow-derived MSCs to severe TBI patients within 48 h of injury.

METHODS/DESIGN

The study will be conducted in two steps. Step 1 will enrol 42 patients, randomised in a 1:1:1 ratio to receive 80 million MSCs, 160 million MSCs or a placebo to establish safety and identify the most promising dose. Step 2 will enrol an additional 36 patients, randomised in a 1:1 ratio to receive the selected dose of MSCs or placebo. The activity of MSCs will be assessed by quantifying the plasmatic levels of neurofilament light (NfL) at 14 days as a biomarker of neuronal damage. It could be a significant breakthrough if the study demonstrates the safety and efficacy of MSC-based therapy for severe TBI patients. The results of this trial could inform the design of a phase III clinical trial aimed at establishing the efficacy of the first neurorestorative therapy for TBI.

DISCUSSION

Overall, the MATRIx trial is a critical step towards developing an effective treatment for TBI, which could significantly improve the lives of millions worldwide affected by this debilitating condition. Trial Registration EudraCT: 2022-000680-49.

Knowledge Gaps in Generating Cell-Based Drug Delivery Systems and a Possible Meeting with Artificial Intelligence

Cell-based drug delivery systems are new strategies in targeted delivery in which cells or cell-membrane-derived systems are used as carriers and release their cargo in a controlled manner. Recently, great attention has been directed to cells as carrier systems for treating several diseases. There are various challenges in the development of cell-based drug delivery systems. The prediction of the properties of these platforms is a prerequisite step in their development to reduce undesirable effects. Integrating nanotechnology and artificial intelligence leads to more innovative technologies. Artificial intelligence quickly mines data and makes decisions more quickly and accurately. Machine learning as a subset of the broader artificial intelligence has been used in nanomedicine to design safer nanomaterials. Here, how challenges of developing cell-based drug delivery systems can be solved with potential predictive models of artificial intelligence and machine learning is portrayed. The most famous cell-based drug delivery systems and their challenges are described. Last but not least, artificial intelligence and most of its types used in nanomedicine are highlighted. The present Review has shown the challenges of developing cells or their derivatives as carriers and how they can be used with potential predictive models of artificial intelligence and machine learning.

Engineering cells for precision drug delivery: New advances, clinical translation, and emerging strategies

Cells have emerged as a promising new form of drug delivery carriers owing to their distinguished advantages such as naturally bypassing immune recognition, intrinsic capability to navigate biological barriers, and access to hard-to-reach tissues via onboarding sensing and active motility. Over the past two decades, a large body of work has focused on understanding the ability of cell carriers to breach biological barriers and to modulate drug pharmacokinetics and pharmacodynamics. These efforts have led to the engineering of various cells for tissue-specific drug delivery. Despite exciting advances, clinical translation of cell-based drug carriers demands a thorough understanding of the pressing challenges and potential strategies to overcome them. Here, we summarize recent advances and new concepts in cell-based drug carriers and their clinical translation. We also discuss key considerations and emerging strategies to engineering the next-generation cell-based delivery technologies for more precise, targeted drug delivery.

Canine adipose tissue-derived MSCs engineered with mRNA to overexpress TSG-6 and enhance the anti-inflammatory effects in canine macrophages

Background

Mesenchymal stem cells (MSCs) are useful agents in the treatment of various inflammatory diseases. The immunomodulatory effects of MSCs are largely related to their secretory properties. mRNA engineering emerged as a safe alternative to enhance the secretory function of MSCs. Optimization of the untranslated region (UTR) sequence is important for enhancing the translational efficiency of exogenous mRNAs. However, research on the optimization of UTR in canine MSCs has not yet been conducted.

Objectives

We aimed to identify the UTR sequence related to the expression efficiency of in vitro transcription (IVT) mRNA in canine MSCs and investigate whether mRNA-engineered MSCs that overexpress TSG-6 exhibit enhanced anti-inflammatory effects.

Methods

Canine adipose tissue-derived (cAT)-MSCs were transfected with green fluorescence protein (GFP) mRNA with three different UTRs: canine hemoglobin subunit alpha-like 1 (HBA1), HBA2, and hemoglobin subunit beta-like (HBB). The translation efficacy of each mRNA was evaluated using relative fluorescence. TSG-6 mRNA was produced with the UTR optimized according to relative fluorescence results. cAT-MSCs were transfected with TSG-6 mRNA (MSCTSG-6), and TSG-6 expression was analyzed using real-time quantitative PCR, ELISA, and western blotting. To evaluate the anti-inflammatory effects of MSCsTSG-6, DH82 cells were co-cultured with MSCsTSG-6 or treated with dexamethasone, and changes in the expression of inflammatory cytokines were analyzed using qPCR.

Results

The highest fluorescence level was observed in the HBA1 UTR at 24 h post-transfection. TSG-6 mRNA transfection yielded high levels of TSG-6 in the cAT-MSCs. In DH82 cells co-cultured with MSCsTSG-6, the expression of inflammatory cytokines decreased compared to that in co-culturing with naïve MSCs and dexamethasone treatment.

Conclusions

Optimization of the HBA1 UTR improved the translation efficiency of IVT mRNA in canine MSCs. cAT-MSCs engineered with TSG-6 mRNA effectively enhanced the anti-inflammatory effects of the MSCs when co-cultured with LPS-activated DH82 cells.

Efficacy of extracellular vesicles of different cell origins in traumatic brain injury: A systematic review and network meta-analysis

Background

There was still no effective treatment for traumatic brain injury (TBI). Recently, many preclinical studies had shown promising efficacy of extracellular vesicles (EVs) from various cell sources. Our aim was to compare which cell-derived EVs were most effective in treating TBI through a network meta-analysis.

Methods

We searched four databases and screened various cell-derived EVs for use in preclinical studies of TBI treatment. A systematic review and network meta-analysis were conducted for two outcome indicators, modified Neurological Severity Score (mNSS) and Morris Water Maze (MWM), and they were ranked by the surface under the cumulative ranking curves (SUCRA). Bias risk assessment was performed with SYRCLE. R software (version 4.1.3, Boston, MA, USA) was used for data analysis.

Results

A total of 20 studies were included in this study, involving 383 animals. Astrocyte-derived extracellular vesicles (AEVs) ranked first in response to mNSS at day 1 (SUCRA: 0.26%), day 3 (SUCRA: 16.32%), and day 7 (SUCRA: 9.64%) post-TBI. Extracellular vesicles derived from mesenchymal stem cells (MSCEVs) were most effective in mNSS assessment on day 14 (SUCRA: 21.94%) and day 28 (SUCRA: 6.26%), as well as MWM’s escape latency (SUCRA: 6.16%) and time spent in the target quadrant (SUCRA: 86.52%). The result of mNSS analysis on day 21 showed that neural stem cell-derived extracellular vesicles (NSCEVs) had the best curative effect (SUCRA: 6.76%).

Conclusion

AEVs may be the best choice to improve early mNSS recovery after TBI. The efficacy of MSCEVs may be the best in the late mNSS and MWM after TBI.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023377350.

A combination of umbilical cord mesenchymal stem cells and monosialotetrahexosy 1 ganglioside alleviates neuroinflammation in traumatic brain injury

Neuro-inflammation and activated microglia play important roles in neuron damage in the traumatic brain injury (TBI). In this study, we determined the effect of neural network reconstruction after human umbilical cord mesenchymal stem cells (UMSCs) combined with monosialotetrahexosy 1 ganglioside (GM1) transplantation and the effect on the neuro-inflammation and polarization of microglia in a rat model of TBI, which was established in male rats using a fluid percussion brain injury device. Rats survived until day 7 after TBI were randomly treated with normal control (NC), saline (NS), GM1, UMSCs, and GM1 plus UMSCs. Modified neurological severity score (mNSS) was assessed on days 7 and 14, and the brain tissue of the injured region was collected. Immunofluorescence, RT-PCR, and western blot analysis found that inhibitory neuro-inflammatory cytokines TGF-β and CD163 protein expression levels in injured brain tissues were significantly increased in rats treated with GM1 + UMSCs, GM1, or UMSCs and were up-regulated compared to saline-treated rats. Neuro-inflammatory cytokines IL-6, COX-2 and iNOS protein expressions were down-regulated compared to rats treated with saline. The protein expression levels of NE, NF-200, MAP-2 and β-tubulin III were increased in the injured brain tissues from rats treated with GM1 + UMSCs, or GM1 and UMSCs alone compared to those in the rats treated with NS. The protein expression levels in rats treated with GM1 plus UMSCs were most significant on day 7 following UMSC transplantation. The rats treated with GM1 plus UMSCs had the lowest mNSS compared with that in the other groups. These data suggest that UMSCs and GM1 promote neural network reconstruction and reduce the neuro-inflammation and neurodegeneration through coordinating injury local immune inflammatory microenvironment to promote the recovery of neurological functions in the TBI.

Synthetic Biology Technologies And Genetically Engineering Strategies For Enhanced Cell Therapeutics

Stem cell therapy mainly uses natural stem cells for transplantation, and the use of genetic engineering to optimize stem cell products is a very important process. This article reviews successful gene modification methods in the field of immune cell therapy and summarizes some attempts at stem cell gene editing in current research. Cell bridging is an innovative cutting-edge strategy that includes the specific recognition and signal transduction of artificial receptors. The "off-the-shelf" cell strategies mainly introduce the advantages of allogeneic cell therapy and how to overcome issues such as immunogenicity. Gene regulatory systems allow us to manipulate cells with small molecules to control cellular phenotypes. In addition, we also summarize some important genes that can provide a reference for cell genetic engineering. In conclusion, we summarize a variety of technical strategies for gene editing cells to provide useful ideas and experiences for future stem cell therapy research.

Traumatic Brain Injury and Secondary Neurodegenerative Disease

Traumatic brain injury (TBI) is a devastating event with severe long-term complications. TBI and its sequelae are one of the leading causes of death and disability in those under 50 years old. The full extent of secondary brain injury is still being intensely investigated; however, it is now clear that neurotrauma can incite chronic neurodegenerative processes. Chronic traumatic encephalopathy, Parkinson's disease, and many other neurodegenerative syndromes have all been associated with a history of traumatic brain injury. The complex nature of these pathologies can make clinical assessment, diagnosis, and treatment challenging. The goal of this review is to provide a concise appraisal of the literature with focus on emerging strategies to improve clinical outcomes. First, we review the pathways involved in the pathogenesis of neurotrauma-related neurodegeneration and discuss the clinical implications of this rapidly evolving field. Next, because clinical evaluation and neuroimaging are essential to the diagnosis and management of neurodegenerative diseases, we analyze the clinical investigations that are transforming these areas of research. Finally, we briefly review some of the preclinical therapies that have shown the most promise in improving outcomes after neurotrauma.

Modulation of Glia Activation by TRPA1 Antagonism in Preclinical Models of Migraine

Preclinical data point to the contribution of transient receptor potential ankyrin 1 (TRPA1) channels to the complex mechanisms underlying migraine pain. TRPA1 channels are expressed in primary sensory neurons, as well as in glial cells, and they can be activated/sensitized by inflammatory mediators. The aim of this study was to investigate the relationship between TRPA1 channels and glial activation in the modulation of trigeminal hyperalgesia in preclinical models of migraine based on acute and chronic nitroglycerin challenges. Rats were treated with ADM_12 (TRPA1 antagonist) and then underwent an orofacial formalin test to assess trigeminal hyperalgesia. mRNA levels of pro- and anti-inflammatory cytokines, calcitonin gene-related peptide (CGRP) and glia cell activation were evaluated in the Medulla oblongata and in the trigeminal ganglia. In the nitroglycerin-treated rats, ADM_12 showed an antihyperalgesic effect in both acute and chronic models, and it counteracted the changes in CGRP and cytokine gene expression. In the acute nitroglycerin model, ADM_12 reduced nitroglycerin-induced increase in microglial and astroglial activation in trigeminal nucleus caudalis area. In the chronic model, we detected a nitroglycerin-induced activation of satellite glial cells in the trigeminal ganglia that was inhibited by ADM_12. These findings show that TRPA1 antagonism reverts experimentally induced hyperalgesia in acute and chronic models of migraine and prevents multiple changes in inflammatory pathways by modulating glial activation.

Mesenchymal stromal cells for the treatment of Alzheimer’s disease: Strategies and limitations

Alzheimer’s disease (AD) is a major cause of age-related dementia and is characterized by progressive brain damage that gradually destroys memory and the ability to learn, which ultimately leads to the decline of a patient’s ability to perform daily activities. Although some of the pharmacological treatments of AD are available for symptomatic relief, they are not able to limit the progression of AD and have several side effects. Mesenchymal stem/stromal cells (MSCs) could be a potential therapeutic option for treating AD due to their immunomodulatory, anti-inflammatory, regenerative, antioxidant, anti-apoptotic, and neuroprotective effects. MSCs not only secret neuroprotective and anti-inflammatory factors to promote the survival of neurons, but they also transfer functional mitochondria and miRNAs to boost their bioenergetic profile as well as improve microglial clearance of accumulated protein aggregates. This review focuses on different clinical and preclinical studies using MSC as a therapy for treating AD, their outcomes, limitations and the strategies to potentiate their clinical translation.

Ectoderm-derived frontal bone mesenchymal stem cells promote traumatic brain injury recovery by alleviating neuroinflammation and glutamate excitotoxicity partially via FGF1

Background

Traumatic brain injury (TBI) leads to cell and tissue impairment, as well as functional deficits. Stem cells promote structural and functional recovery and thus are considered as a promising therapy for various nerve injuries. Here, we aimed to investigate the role of ectoderm-derived frontal bone mesenchymal stem cells (FbMSCs) in promoting cerebral repair and functional recovery in a murine TBI model.

Methods

A murine TBI model was established by injuring C57BL/6 N mice with moderate-controlled cortical impact to evaluate the extent of brain damage and behavioral deficits. Ectoderm-derived FbMSCs were isolated from the frontal bone and their characteristics were assessed using multiple differentiation assays, flow cytometry and microarray analysis. Brain repairment and functional recovery were analyzed at different days post-injury with or without FbMSC application. Behavioral tests were performed to assess learning and memory improvements. RNA sequencing analysis, immunofluorescence staining, and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were used to examine inflammation reaction and neural regeneration. In vitro co-culture analysis and quantification of glutamate transportation were carried out to explore the possible mechanism of neurogenesis and functional recovery promoted by FbMSCs.

Results

Ectoderm-derived FbMSCs showed fibroblast like morphology and osteogenic differentiation capacity. FbMSCs were CD105, CD29 positive and CD45, CD31 negative. Different from mesoderm-derived MSCs, FbMSCs expressed the ectoderm-specific transcription factor Tfap2β. TBI mice showed impaired learning and memory deficits. Microglia and astrocyte activation, as well as neural damage, were significantly increased post-injury. FbMSC application ameliorated the behavioral deficits of TBI mice and promoted neural regeneration. RNA sequencing analysis showed that signal pathways related to inflammation decreased, whereas those related to neural activation increased. Immunofluorescence staining and qRT-PCR data revealed that microglial activation and astrocyte polarization to the A1 phenotype were suppressed by FbMSC application. In addition, FGF1 secreted from FbMSCs enhanced glutamate transportation by astrocytes and alleviated the cytotoxic effect of excessive glutamate on neurons.

Conclusions

Ectoderm-derived FbMSC application significantly alleviated neuroinflammation, brain injury, and excitatory toxicity to neurons, improved cognition and behavioral deficits in TBI mice. Therefore, ectoderm-derived FbMSCs could be ideal therapeutic candidates for TBI which mostly affect cells from the same embryonic origins as FbMSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03032-6.

The Role of Neuroinflammatory Mediators in the Pathogenesis of Traumatic Brain Injury: A Narrative Review

Traumatic brain injury (TBI) is a debilitating acquired neurological disorder that afflicts nearly 74 million people worldwide annually. TBI has been classified as more than just a single insult because of its associated risk toward various long-term neurological and neurodegenerative disorders. This risk may be triggered by a series of postinjury secondary molecular and cellular pathology, which may be dependent on the severity of the TBI. Among the secondary injury mechanisms, neuroinflammation may be the most crucial as it may exacerbate brain damage and lead to fatal consequences when prolonged. This Review aimed to elucidate the influence of neuroinflammatory mediators on the TBI functional and pathological outcomes, particularly focusing on inflammatory cytokines which were associated with neuronal dysfunctions in the acute and chronic stages of TBI. These cytokines include interleukins (IL) such as IL-1(beta)β, IL-4, IL-6, IL8, IL-10, IL-18, IL-33 and tumor necrosis factor alpha (TNF-α), which have been extensively studied. Apart from these, IL-2, interferon gamma (IFN-γ), and transforming growth factor-beta (TGF-β) may also play a significant role in the pathogenesis of TBI. These neuroinflammatory mediators may trigger a series of pathological events such as cell death, microglial suppression, and increased catecholaminergic activity. Interestingly, in the acute phase of TBI, most of these mediators may also play a neuroprotective role by displaying anti-inflammatory properties, which may convert to a pro-inflammatory action in the chronic stages post TBI. Early identification and treatment of these mediators may help the development of more effective treatment options for TBI.

In situ forming and biocompatible hyaluronic acid hydrogel with reactive oxygen species-scavenging activity to improve traumatic brain injury repair by suppressing oxidative stress and neuroinflammation

The efficacy of neural repair and regeneration strategies for traumatic brain injury (TBI) treatment is greatly hampered by the harsh brain lesion microenvironment including oxidative stress and hyper-inflammatory response. Functionalized hydrogel with the capability of oxidative stress suppression and neuroinflammation inhibition will greatly contribute to the repairment of TBI. Herein, antioxidant gallic acid-grafted hyaluronic acid (HGA) was combined with hyaluronic acid-tyramine (HT) polymer to develop an injectable hydrogel by dual-enzymatically crosslinking method. The resulting HT/HGA hydrogel is biocompatible and possesses effective scavenging activity against DPPH and hydroxyl radicals. Meanwhile, this hydrogel improved cell viability and reduced intracellular reactive oxygen species (ROS) production under H₂O₂ insult. The in vivo study showed that in situ injection of HT/HGA hydrogel significantly reduced malondialdehyde (MDA) production and increased glutathione (GSH) expression in lesion area after treatment for 3 or 21 days, which might be associated with the activation of Nrf2/HO-1 pathway. Furthermore, this hydrogel promoted the microglia polarization to M2 (Arg1) phenotype, it also decreased the level of proinflammatory factors including TNF-α and IL-6 and increased anti-inflammatory factor expression of IL-4. Finally, blood-brain barrier (BBB) was protected, neurogenesis in hippocampus was promoted, and the motor, learning and memory ability was enhanced. Therefore, this injectable, biocompatible, and antioxidant hydrogel exhibits a huge potential for treating TBI and allows us to recognize the great value of this novel biomaterial for remodeling brain structure and function.

Interleukin-10 genetically modified clinical-grade mesenchymal stromal cells markedly reinforced functional recovery after spinal cord injury via directing alternative activation of macrophages

Background

After spinal cord injury (SCI), dysregulated or nonresolving inflammatory processes can severely disturb neuronal homeostasis and drive neurodegeneration. Although mesenchymal stromal cell (MSC)-based therapies have showed certain therapeutic efficacy, no MSC therapy has reached its full clinical goal. In this study, we examine interleukin-10 (IL10) genetically modified clinical-grade MSCs (IL10-MSCs) and evaluate their clinical safety, effectiveness, and therapeutic mechanism in a completely transected SCI mouse model.

Methods

We established stable IL10-overexpressing human umbilical-cord-derived MSCs through electric transduction and screened out clinical-grade IL10-MSCs according to the criteria of cell-based therapeutic products, which were applied to mice with completely transected SCI by repeated tail intravenous injections. Then we comprehensively investigated the motor function, histological structure, and nerve regeneration in SCI mice, and further explored the potential therapeutic mechanism after IL10-MSC treatment.

Results

IL10-MSC treatment markedly reinforced locomotor improvement, accompanied with decreased lesion volume, regeneration of axons, and preservation of neurons, compared with naïve unmodified MSCs. Further, IL10-MSC transplantation increased the ratio of microglia to infiltrated alternatively activated macrophages (M2), and reduced the ratio of classically activated macrophages (M1) at the injured spinal cord, meanwhile increasing the percentage of Treg and Th2 cells, and reducing the percentage of Th1 cells in the peripheral circulatory system. In addition, IL10-MSC administration could prevent apoptosis and promote neuron differentiation of neural stem cells (NSCs) under inflammatory conditions in vitro.

Conclusions

IL10-MSCs exhibited a reliable safety profile and demonstrated promising therapeutic efficacy in SCI compared with naïve MSCs, providing solid support for future clinical application of genetically engineered MSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-022-00325-9.

A review of the pathology and treatment of TBI and PTSD

This literature review focuses on the underlying pathophysiology of TBI and PTSD symptoms, while also examining the plethora of stem cell treatment options to ameliorate these neuronal and functional changes. As more veterans return suffering from TBI and/or PTSD, it is vital that researchers discover novel therapies to mitigate the detrimental symptoms of both diagnoses. A variety of stem cell treatments have been studied and offer hopeful options for TBI and PTSD recovery.

Umbilical Cord-Derived Mesenchymal Stem Cells Improve TGF-β, α-SMA and Collagen on Erectile Dysfunction in Streptozotocin-Induced Diabetic Rats

Background

A Erectile dysfunction (ED) is one of the well-known comorbidities in males with diabetes mellitus (DM), whose pathogenesis might be induced by dysregulation of corpus cavernosum smooth muscle cells. UC-MSCs are multipotent cells that attract considerable interest due to immunoregulatory properties and might be a potential strategy to regulate and recover the functional cells and tissues, including tissue improvement in DMED.

Objective

This study aims to determine the efficacy of UC-MSCs in improving the erectile function of DMED rats through analyzing the expression of TGF-β, α-SMA, and collagen.

Methods

Total number of 30 male Sprague-Dawley rats (6 to 8 weeks old) were randomly divided into four groups (negative control group, positive control group, T1 group, and T2 group). After 16 h fast, 24 rats were randomly selected and intraperitoneally injected with streptozotocin to induce DM. At 8 weeks after STZ injection, rats with DMED were identified by unresponsive erectile stimulation within 30 min. PC group received 500 μL; T1 rats treated with 500 μL PBS containing 1x106 UC-MSCs; T2 rats treated with 500 μL PBS containing 3x106 UC-MSCs. After MSCs treatment, the rats were sacrificed and the corpus cavernosum tissues were prepared for histological observations.

Results

This study resulted in the administration of UC-MSCs could downregulate the expression of TGF-β, α-SMA, and collagen leading to the improvement of DMED.

Conclusion

UC-MSCs improve the expression of TGF-β, α-SMA, and collagen on erectile dysfunction in streptozotocin-induced diabetic rats.

Immunomodulatory effects of mesenchymal stem cells in peripheral nerve injury

Various immune cells and cytokines are present in the aftermath of peripheral nerve injuries (PNI), and coordination of the local inflammatory response is of great significance for the recovery of PNI. Mesenchymal stem cells (MSCs) exhibit immunosuppressive and anti-inflammatory abilities which can accelerate tissue regeneration and attenuate inflammation, but the role of MSCs in the regulation of the local inflammatory microenvironment after PNI has not been widely studied. Here, we summarize the known interactions between MSCs, immune cells, and inflammatory cytokines following PNI with a focus on the immunosuppressive role of MSCs. We also discuss the immunomodulatory potential of MSC-derived extracellular vesicles as a new cell-free treatment for PNI.

Cellular and Molecular Targets for Non-Invasive, Non-Pharmacological Therapeutic/Rehabilitative Interventions in Acute Ischemic Stroke

BACKGROUND

Cerebral circulation delivers the blood flow to the brain through a dedicated network of sanguine vessels. A healthy human brain can regulate cerebral blood flow (CBF) according to any physiological or pathological challenges. The brain is protected by its self-regulatory mechanisms, which are dependent on neuronal and support cellular populations, including endothelial ones, as well as metabolic, and even myogenic factors.

OBJECTIVES

Accumulating data suggest that "non-pharmacological" approaches might provide new opportunities for stroke therapy, such as electro-/acupuncture, hyperbaric oxygen therapy, hypothermia/cooling, photobiomodulation, therapeutic gases, transcranial direct current stimulations, or transcranial magnetic stimulations. We reviewed the recent data on the mechanisms and clinical implications of these non-pharmaceutical treatments.

METHODS

To present the state-of-the-art for currently available non-invasive, non-pharmacological-related interventions in acute ischemic stroke, we accomplished this synthetic and systematic literature review based on the Preferred Reporting Items for Systematic Principles Reviews and Meta-Analyses (PRISMA).

RESULTS

The initial number of obtained articles was 313. After fulfilling the five steps in the filtering/selection methodology, 54 fully eligible papers were selected for synthetic review. We enhanced our documentation with other bibliographic resources connected to our subject, identified in the literature within a non-standardized search, to fill the knowledge gaps. Fifteen clinical trials were also identified.

DISCUSSION

Non-invasive, non-pharmacological therapeutic/rehabilitative interventions for acute ischemic stroke are mainly holistic therapies. Therefore, most of them are not yet routinely used in clinical practice, despite some possible beneficial effects, which have yet to be supplementarily proven in more related studies. Moreover, few of the identified clinical trials are already completed and most do not have final results.

CONCLUSIONS

This review synthesizes the current findings on acute ischemic stroke therapeutic/rehabilitative interventions, described as non-invasive and non-pharmacological.

Isolation and Characterization of Extracellular Vesicles Derived from Human Umbilical Cord Mesenchymal Stem Cells

The safety and efficacy of mesenchymal stem cells/marrow stromal cells (MSC) have been widely studied. Since they are hypoimmunogenic, MSC can escape immune recognition, thus making them an attractive tool in clinical settings beyond autologous cell-based therapy. Paracrine factors including extracellular vesicles (EVs) released by MSC play a significant role in exerting therapeutic effects of MSC. Since their first discovery, MSC-EVs have been widely studied in an attempt to tackle the mechanisms of their therapeutic effects in various disease models. However, currently there are no standard methods to isolate EVs. Here, we describe a differential centrifugation-based protocol for isolation of EVs derived from human umbilical cord MSC (huc-MSC). In addition, the protocol describes methods for characterization of the EVs using transmission electron microscope, Western blot, and nanoparticle tracking analysis.

Chronic Administration of 7,8-DHF Lessens the Depression-like Behavior of Juvenile Mild Traumatic Brain Injury Treated Rats at Their Adult Age

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity among the global youth and commonly results in long-lasting sequelae, including paralysis, epilepsy, and a host of mental disorders such as major depressive disorder. Previous studies were mainly focused on severe TBI as it occurs in adults. This study explored the long-term adverse effect of mild TBI in juvenile animals (mTBI-J). Male Sprague Dawley rats received mTBI-J or sham treatment at six weeks old, then underwent behavioral, biochemical, and histological experiments three weeks later (at nine weeks old). TTC staining, H&E staining, and brain edema measurement were applied to evaluate the mTBI-J induced cerebral damage. The forced swimming test (FST) and sucrose preference test (SPT) were applied for measuring depression-like behavior. The locomotor activity test (LAT) was performed to examine mTBI-J treatment effects on motor function. After the behavioral experiments, the dorsal hippocampus (dHip) and ventral hippocampus (vHip) were dissected out for western blotting to examine the expression of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB). Finally, a TrkB agonist 7,8-DHF was injected intraperitoneally to evaluate its therapeutic effect on the mTBI-J induced behavioral abnormalities at the early adult age. Results showed that a mild brain edema occurred, but no significant neural damage was found in the mTBI-J treated animals. In addition, a significant increase of depression-like behaviors was observed in the mTBI-J treated animals; the FST revealed an increase in immobility, and a decrease in sucrose consumption was found in the mTBI-J treated animals. There were no differences observed in the total distance traveled of the LAT and the fall latency of the rotarod test. The hippocampal BDNF expression, but not the TrkB, were significantly reduced in mTBI-J, and the mTBI-J treatment-induced depression-like behavior was lessened after four weeks of 7,8-DHF administration. Collectively, these results indicate that even a mild juvenile TBI treatment that did not produce motor deficits or significant histological damage could have a long-term adverse effect that could be sustained to adulthood, which raises the depression-like behavior in the adult age. In addition, chronic administration of 7,8-DHF lessens the mTBI-J treatment-induced depression-like behaviors in adult rats. We suggest the potential usage of 7,8-DHF as a therapeutic agent for preventing the long-term adverse effect of mTBI-J.

Treating Metastatic Brain Cancers With Stem Cells

Stem cell therapy may present an effective treatment for metastatic brain cancer and glioblastoma. Here we posit the critical role of a leaky blood-brain barrier (BBB) as a key element for the development of brain metastases, specifically melanoma. By reviewing the immunological and inflammatory responses associated with BBB damage secondary to tumoral activity, we identify the involvement of this pathological process in the growth and formation of metastatic brain cancers. Likewise, we evaluate the hypothesis of regenerating impaired endothelial cells of the BBB and alleviating the damaged neurovascular unit to attenuate brain metastasis, using the endothelial progenitor cell (EPC) phenotype of bone marrow-derived mesenchymal stem cells. Specifically, there is a need to evaluate the efficacy for stem cell therapy to repair disruptions in the BBB and reduce inflammation in the brain, thereby causing attenuation of metastatic brain cancers. To establish the viability of stem cell therapy for the prevention and treatment of metastatic brain tumors, it is crucial to demonstrate BBB repair through augmentation of vasculogenesis and angiogenesis. BBB disruption is strongly linked to metastatic melanoma, worsens neuroinflammation during metastasis, and negatively influences the prognosis of metastatic brain cancer. Using stem cell therapy to interrupt inflammation secondary to this leaky BBB represents a paradigm-shifting approach for brain cancer treatment. In this review article, we critically assess the advantages and disadvantages of using stem cell therapy for brain metastases and glioblastoma.

Umbilical cord mesenchymal stem cells promote neurological repair after traumatic brain injury through regulating Treg/Th17 balance

Traumatic brain injury (TBI) is a brain injury resulting from blunt mechanical external forces, which is a crucial public health and socioeconomic problem worldwide. TBI is one of the leading causes of death or disability. The primary injury of TBI is generally irreversible. Secondary injury caused by neuroinflammation could result in exacerbation of patients, which indicated that anti-inflammation and immunomodulatory were necessary for the treatment of TBI. Accumulated evidence reveals that the transplantation of umbilical cord mesenchymal stem cells (UCMSCs) could regulate the microenvironment in vivo and keep a balance of helper T 17(Th17)/ regulatory T cell (Treg). Therefore, it is reasonable to hypothesize that the UCMSCs could repair neurological impairment by maintaining the balance of Th17/Treg after TBI. In the study, we observed the phenomenon of trans-differentiation of T lymphocytes into Th17 cells after TBI. Rats were divided into Sham, TBI, and TBI + UCMSCs groups to explore the effects of the UCMSCs. The results manifested that trans-differentiation of Th17 into Treg was facilitated by UCMSCs, which was followed by promotion of neurological recovery and improvement of learning and memory in TBI rats. Furthermore, UCMSCs decreased the phosphorylation of nuclear factor-kappa B (NF-κB) and increased the expression of mothers against decapentaplegic homolog 3 (Smad3) in vivo and vitro experiments. In conclusion, UCMSCs maintained Th17/Treg balance via the transforming growth factor-β (TGF-β)/ Smad3/ NF-κB signaling pathway.

IL-10 mRNA Engineered MSCs Demonstrate Enhanced Anti-Inflammation in an Acute GvHD Model

Mesenchymal stem cells (MSCs) are used in various studies to induce immunomodulatory effects in clinical conditions associated with immune dysregulation such as graft versus host disease (GvHD). However, most of these clinical trials failed to go beyond early phase 2 studies because of limited efficacy. Various methods have been assessed to increase the potency of MSCs. IL-10 is an anti-inflammatory cytokine that is known to modulate immune responses in GvHD. In this study, we evaluated the feasibility of transfecting IL-10 mRNA to enhance MSC therapeutic potential. IL-10 mRNA engineered MSCs (eMSCs-IL10) maintained high levels of IL-10 expression even after freezing and thawing. IL-10 mRNA transfection did not appear to alter MSC intrinsic characteristics. eMSCs-IL10 significantly suppressed T cell proliferation relative to naïve MSCs in vitro. In a mouse model for GvHD, eMSCs-IL10 induced a decrease in plasma level of potent pro-inflammatory cytokines and inhibited CD4+ and CD8+ T cell proliferation in the spleen. In summary, our studies demonstrate the feasibility of potentiating MSCs to enhance their immunomodulatory effects by IL-10 mRNA transfection. The use of non-viral transfection may generate a safe and potent MSC product for treatment of clinical conditions associated with immune dysregulation such as GvHD.

Systematic review and meta-analysis of preclinical studies testing mesenchymal stromal cells for traumatic brain injury

Mesenchymal stromal cells (MSCs) are widely used in preclinical models of traumatic brain injury (TBI). Results are promising in terms of neurological improvement but are hampered by wide variability in treatment responses. We made a systematic review and meta-analysis: (1) to assess the quality of evidence for MSC treatment in TBI rodent models; (2) to determine the effect size of MSCs on sensorimotor function, cognitive function, and anatomical damage; (3) to identify MSC-related and protocol-related variables associated with greater efficacy; (4) to understand whether MSC manipulations boost therapeutic efficacy. The meta-analysis included 80 studies. After TBI, MSCs improved sensorimotor and cognitive deficits and reduced anatomical damage. Stratified meta-analysis on sensorimotor outcome showed similar efficacy for different MSC sources and for syngeneic or xenogenic transplants. Efficacy was greater when MSCs were delivered in the first-week post-injury, and when implanted directly into the lesion cavity. The greatest effect size was for cells embedded in matrices or for MSC-derivatives. MSC therapy is effective in preclinical TBI models, improving sensorimotor, cognitive, and anatomical outcomes, with large effect sizes. These findings support clinical studies in TBI.

Challenges and Improvements of Novel Therapies for Ischemic Stroke

Stroke is the third most common disease all over the world, which is regarded as a hotspot in medical research because of its high mortality and morbidity. Stroke, especially ischemic stroke, causes severe neural cell death, and no effective therapy is currently available for neuroregeneration after stroke. Although many therapies have been shown to be effective in preclinical studies of ischemic stroke, almost none of them passed clinical trials, and the reasons for most failures have not been well identified. In this review, we focus on several novel methods, such as traditional Chinese medicine, stem cell therapy, and exosomes that have not been used for ischemic stroke till recent decades. We summarize the proposed basic mechanisms underlying these therapies and related clinical results, discussing advantages and current limitations for each therapy emphatically. Based on the limitations such as side effects, narrow therapeutic window, and less accumulation at the injury region, structure transformation and drug combination are subsequently applied, providing a deep understanding to develop effective treatment strategies for ischemic stroke in the near future.

Mesenchymal Stem Cell-Induced Anti-Neuroinflammation Against Traumatic Brain Injury

Traumatic brain injury (TBI) is a pervasive and damaging form of acquired brain injury (ABI). Acute, subacute, and chronic cell death processes, as a result of TBI, contribute to the disease progression and exacerbate outcomes. Extended neuroinflammation can worsen secondary degradation of brain function and structure. Mesenchymal stem cell transplantation has surfaced as a viable approach as a TBI therapeutic due to its immunomodulatory and regenerative features. This article examines the role of inflammation and cell death in ABI as well as the effectiveness of bone marrow-derived mesenchymal stem/stromal cell (BM-MSC) transplants as a treatment for TBI. Furthermore, we analyze new studies featuring transplanted BM-MSCs as a neurorestorative and anti-inflammatory therapy for TBI patients. Although clinical trials support BM-MSC transplants as a viable TBI treatment due to their promising regenerative characteristics, further investigation is imperative to uncover innovative brain repair pathways associated with cell-based therapy as stand-alone or as combination treatments.

Interleukin-10 Modulates the Metabolism and Osteogenesis of Human Dental Pulp Stem Cells

The osteogenic differentiation of mesenchymal stem cells (MSCs) is strongly related with the inflammatory microenvironment. The ability of osteogenic differentiation of MSCs is vital for the bone tissue engineering. Interleukin (IL)-10, a well-known anti-inflammatory factor, plays a key role in tissue repair. Dental pulp stem cells (DPSCs), with the advantage of convenience of extraction, are suitable for the bone tissue engineering. Therefore, it is meaning to explore the effects of IL-10 on the osteogenic differentiation of DPSCs. The proliferation activity of DPSCs were evaluated by MTS assay (CellTiter 96^® Aqueous One Solution Cell Proliferation Assay [Promega]) and real-time polymerase chain reaction (RT-PCR). The osteogenic differentiation of DPSCs were determined by Alizarin Red staining, RT-PCR, and alkaline phosphatase activity test. The glucose metabolism was detected by Mito Stress test and glycolysis assay. IL-10 (10 or 20 nM) could enhance the osteogenic differentiation of DPSCs and promoted the metabolic switch from glycolysis to oxidative phosphorylation (OXPHOS), whereas IL-10 (5 and 50 nM) has no obvious effects on the osteogenic differentiation of DPSCs. The OXPHOS inhibitor restrained the promotion of osteogenic differentiation induced by IL-10. These findings show that IL-10 can promote the osteogenesis of DPSCs through the activation of OXPHOS, which provides a potential way for enhancing the osteogenic differentiation of DPSCs in bone tissue engineering.

Genetic Modification of Mesenchymal Stem Cells for Neurological Disease Therapy: What Effects Does it Have on Phenotype/Cell Behavior, Determining Their Effectiveness?

Mesenchymal stem cells are a promising tool in regenerative medicine, and their functions can be enhanced through genetic modification. Recent advances in genetic engineering provide several methods that enable gene delivery to mesenchymal stem cells. However, it remains to be decided whether genetic modification of mesenchymal stem cells by vectors carrying reporter or therapeutic genes leads to adverse effects on morphology, phenotypic profiles, and viability of transplanted cells. In this regard, we focus on the description of genetic modification methods of mesenchymal stem cells, their effectiveness, and the impact on phenotype/cell behavior/proliferation and the differentiation ability of these cells in vitro and in vivo. Furthermore, we compare the main effects of genetically modified mesenchymal stem cells with native mesenchymal stem cells when applied in the therapy of neurological diseases.

Synergistic Effect of the Long-Term Overexpression of Bcl-2 and BDNF Lentiviral in Cell Protecting against Death and Generating TH Positive and CHAT Positive Cells from MSC

Mesenchymal stem cells (MSC) are potentially a good material for transplantation in many diseases, including neurodegenerative diseases. The main problem with using them is the low percentage of surviving cells after the transplant procedure and the naturally poor ability of MSC to spontaneously differentiate into certain types of cells, which results in their poor integration with the host cells. The aim and the novelty of this work consists in the synergistic overexpression of two genes, BCL2 and BDNF, using lentiviral vectors. According to our hypothesis, the overexpression of the BCL2 gene is aimed at increasing the resistance of cells to stressors and toxic factors. In turn, the overexpression of the BDNF gene is suspected to direct the MSC into the neural differentiation pathway. As a result, it was shown that the overexpression of both genes and the overproduction of proteins is permanent and persists for at least 60 days. The synergistically transduced MSC were significantly more resistant to the action of staurosporine; 12 days after transduction, the synergistically transduced MSC had a six-times greater survival rate. The overexpression of the Bcl-2 and BDNF proteins was sufficient to stimulate a significant overexpression of the CHAT gene, and under specific conditions, the TH, TPH1, and SYP genes were also overexpressed. Modified MSC are able to differentiate into cholinergic and dopaminergic neurons, and the release of acetylcholine and dopamine may indicate their functionality.

Wogonin Strengthens the Therapeutic Effects of Mesenchymal Stem Cells in DSS-Induced Colitis via Promoting IL-10 Production

Inflammatory bowel diseases (IBD) are prevalent and debilitating diseases; their clinical remedy is desperately unmet. Mesenchymal stem cells (MSCs) are pluripotent stem cells with multiple immunomodulatory effects, which are attributed to their efficacy in the IBD rodent model. Optimization of MSC regimes in IBD is a crucial step for their further clinical application. Wogonin is a flavonoid-like compound, which showed extensive immunomodulatory and adjuvant effects. This research is aimed at investigating whether and how Wogonin boosted the therapeutic efficiency of MSCs on DSS-induced colitis. Our results showed that the MSC treatment with Wogonin significantly alleviated the intestinal inflammation in IBD mice by increased IL-10 expression. In vitro experiments, Wogonin obviously raised the IL-10 production and ROS levels of MSCs in a dose-dependent manner. Meanwhile, western blot data suggested Wogonin improves the IL-10 production by inducing transcript factor HIF-1α expression via AKT/GSK3β signal pathway. Finally, the favorable effects of Wogonin on MSCs were confirmed by IL-10 blockade experiment in vivo. Together, our results suggested that Wogonin significantly increased the IL-10 production and enhanced the therapeutic effects of MSCs in DSS-induced colitis. This work suggested Wogonin as a novel optimal strategy for MSC clinical application.

Interleukin-1 in obesity-related low-grade inflammation: From molecular mechanisms to therapeutic strategies

Since adipose tissue (AT) can upregulate pro-inflammatory interleukins (ILs) via storing extra lipids in obesity, obesity is considered the leading cause of chronic low-grade inflammation. These ILs can pave the way for the infiltration of immune cells into the AT, ultimately resulting in low-grade inflammation and dysregulation of adipocytes. IL-1, which is divided into two subclasses, i.e., IL-1α and IL-1β, is a critical pro-inflammatory factor. In obesity, IL-1α and IL-1β can promote insulin resistance via impairing the function of adipocytes and promoting inflammation. The current study aims to review the detailed molecular mechanisms and the roles of IL-1α and IL-1β and their antagonist, interleukin-1 receptor antagonist(IL-1Ra), in developing obesity-related inflammatory complications, i.e., type II diabetes (T2D), non-alcoholic steatohepatitis (NASH), atherosclerosis, and cognitive disorders. Besides, the current study discusses the recent advances in natural drugs, synthetic agents, and gene therapy approaches to treat obesity-related inflammatory complications via suppressing IL-1.

Transplantation of rat dental pulp stem cells facilities post-lesion recovery in the somatosensory whisker cortex of male Wistar rats

Damage to somatosensory "barrel" cortex reduces the rats' behavioral sensitivity in discrimination of tactile stimuli. Here, we examined how transplantation of stem cells into the lesioned barrel cortex can help in recovery of sensory capacities. We induced mechanical lesions in the right barrel cortex area of male rats. Three days after lesioning, rats received one of three transplantation types: un-differentiated dental pulp stem cells (U-DPSCs) or differentiated dental pulp stem cells (D-DPSCs), or cell medium (vehicle). A fourth group of rats were control without any Surgery. For 4 consecutive weeks, starting one week after transplantation, we evaluated the rats' preference to explore novel textures as a measure of sensory discrimination ability, also measured the expression of glial fibrillary acidic protein (GFAP), Olig 2, nestin, neuronal nuclei (NeuN), brain-derived neurotrophic factor (BDNF) and neuroligin1 by immunohistochemistry and western blotting. Unilateral mechanical lesion decreased the rats' preferential exploration of novel textures compared to the control group across the 4-week behavioral tests. Following stem cell therapy, the rats' performance significantly improved at week 2-4 compared to the vehicle group. Compared to the control group, there was a significant decrease in the expression of nestin, NeuN, Olig 2, BDNF, neuroligin1 and a significant increase in the expression of GFAP in the vehicle group. The expression of the neural markers was significantly higher in DPSCs compared with the vehicle group whereas GFAP level was lower in DPSCs compared to vehicle. We found that DPSCs therapy affected a range of neuronal markers in the barrel cortex post lesion, and improved the rats' recovery for sensory discrimination.

Mesenchymal Stem Cells for Neurological Disorders

Neurological disorders are becoming a growing burden as society ages, and there is a compelling need to address this spiraling problem. Stem cell-based regenerative medicine is becoming an increasingly attractive approach to designing therapies for such disorders. The unique characteristics of mesenchymal stem cells (MSCs) make them among the most sought after cell sources. Researchers have extensively studied the modulatory properties of MSCs and their engineering, labeling, and delivery methods to the brain. The first part of this review provides an overview of studies on the application of MSCs to various neurological diseases, including stroke, traumatic brain injury, spinal cord injury, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, Huntington's disease, Parkinson's disease, and other less frequently studied clinical entities. In the second part, stem cell delivery to the brain is focused. This fundamental but still understudied problem needs to be overcome to apply stem cells to brain diseases successfully. Here the value of cell engineering is also emphasized to facilitate MSC diapedesis, migration, and homing to brain areas affected by the disease to implement precision medicine paradigms into stem cell-based therapies.

Heterogeneity of mesenchymal stem cells in cartilage regeneration: from characterization to application

Articular cartilage is susceptible to damage but hard to self-repair due to its avascular nature. Traditional treatment methods are not able to produce satisfactory effects. Mesenchymal stem cells (MSCs) have shown great promise in cartilage repair. However, the therapeutic effect of MSCs is often unstable partly due to their heterogeneity. Understanding the heterogeneity of MSCs and the potential of different types of MSCs for cartilage regeneration will facilitate the selection of superior MSCs for treating cartilage damage. This review provides an overview of the heterogeneity of MSCs at the donor, tissue source and cell immunophenotype levels, including their cytological properties, such as their ability for proliferation, chondrogenic differentiation and immunoregulation, as well as their current applications in cartilage regeneration. This information will improve the precision of MSC-based therapeutic strategies, thus maximizing the efficiency of articular cartilage repair.

Mechanisms and repair strategies for white matter degeneration in CNS injury and diseases

White matter degeneration is an important pathophysiological event of the central nervous system that is collectively characterized by demyelination, oligodendrocyte loss, axonal degeneration and parenchymal changes that can result in sensory, motor, autonomic and cognitive impairments. White matter degeneration can occur due to a variety of causes including trauma, neurotoxic exposure, insufficient blood flow, neuroinflammation, and developmental and inherited neuropathies. Regardless of the etiology, the degeneration processes share similar pathologic features. In recent years, a plethora of cellular and molecular mechanisms have been identified for axon and oligodendrocyte degeneration including oxidative damage, calcium overload, neuroinflammatory events, activation of proteases, depletion of adenosine triphosphate and energy supply. Extensive efforts have been also made to develop neuroprotective and neuroregenerative approaches for white matter repair. However, less progress has been achieved in this area mainly due to the complexity and multifactorial nature of the degeneration processes. Here, we will provide a timely review on the current understanding of the cellular and molecular mechanisms of white matter degeneration and will also discuss recent pharmacological and cellular therapeutic approaches for white matter protection as well as axonal regeneration, oligodendrogenesis and remyelination.