Histological Changes and Differential Diagnosis of Mesenchymal Chondrosarcoma

Eight cases of mesenchymal chondrosarcoma either of skeletal(5 cases) or extrasketetalorigin (3 cases) are reported. According to histopathological and diagnostic criteria,mesenchymal chondrosarcoma were classified into two types cartilage isiand cell type andundifierentiated small cell type It is believed that the application of this classification in the study ofmesenchymal chondrosarcoma is helptul the estimation of its malignancy and choice of treatmentas well al in the prediction of its prognosis. Mesenchymal chondrosarcoma is a highly malignant neoplasm with poor prognosis. None ofthe patients in this series survived more than five years after they were diagnosed. The diffentialdiagnosis of malignant lymphoma, chondrosarcoma, hemangiopericytosarcoma, etc. was discussed.My data support the assumption that mesenchymal chondrosarcoma originates from the secondarymesenchyme rather than the primary mesenchyme.

Mesenchymal Chondrosarcoma of the Infratemporal Fossa—A Rare Case Report

Chondrosarcoma is a malignant neoplasm that results in abnormal bone and cartilage growth. Although Chondrosarcoma is rare, it is the second most common primary bone malignancy. Mesenchymal Chondrosarcoma (MCS) is a rare histological variant of Chondrosarcoma (CS) that accounts for only 1% of all CS and has high predilection for the head and neck region with a peak incidence in 2nd and 3rd decade of life. There is comparable male to female ratio with two thirds of the cases arising from bone and one third from soft tissue. The tumor is unique because of its aggressive growth with a high tendency for late recurrence and delayed metastasis. We present a case of this highly malignant lesion arising from the infratemporal fossa and rapidly involving maxillary tuberosity and mandibular ramus.

Mesenchymal Mandibular Chondrosarcoma: A Case Report and Review of Literature

Introduction: Chondrosarcomas (CS) are malignant cartilaginous tumors of rare maxillary localization. Their evolution is generally slow in time. They have a high tendency for locoregional recurrence after surgical treatment. Their prognosis depends on their degree of differentiation and the quality of resection. The authors report a clinical case of mesenchymal mandibular chondrosarcoma (MC), which is considered to be a subtype of CS, and specify the epidemiological, diagnostic, therapeutic and evolutionary features of this tumor. Case Report: A 73-year-old woman reported in February 2018 in our department complained of a slowly enlarging mass involving the right part of the lower jaw for the last 18 months. On examination a firm multilobular painful mass was palpated with cortical expansion, occupying the right side. A CT scan with 3D reconstruction was achieved and showed osteolysis lesions and cortical thickening. The mass biopsy for histological examination found a grade I well-differentiated bone chon-drosarcoma. We performed a hemi-mandibulectomy with complete resection of the tumor. The anatomopathologic examination of the resection specimen was in favour of a grade II mesenchymal chondrosarcoma. No radiotherapy was needed. The patient’s follow up was uneventful. Discussion: CS grading is the key to its management. Low grade CS (grades I and II) of the facial skeleton are luckily the most common, they are best treated with a local resection using 1.5 cm margins for bone and soft tissue. According to published literature, CS was historically considered as a radio resistant tumor. Radiotherapy and chemotherapy were therefore mainly reserved for high-grade tumors and for non-operable lesions. However, radical local surgery appears to be the treatment of choice for low grade chondrosarcoma. Conclusion: CS’s definitive diagnosis depends on appropriate radiographic evaluation along with adequate biopsy with meticulous histopathological examination and adjunctive immunohistochimical analysis. Neither chemotherapy nor radiotherapy is indicated as primary treatment. A long period follow-up should be advised as recurrence and metastasis are very frequent.

Multimodal therapy in the management of primary orbital mesenchymal chondrosarcoma

AIM:To evaluate the ophthalmic manifestations,radiographic features,and prognosis of Chinese patients with primary orbital mesenchymal chondrosarcoma(MCS).METHODS:The study included 6 cases with primary orbital MCS treated at Tianjin Eye Hospital from January 2009 to December 2019.Patitent ophthalmic manifestations,radiographic features,diagnosis,pathology,therapeutic regimens,and prognosis were retrospectively reviewed.RESULTS:Six patitents with primary orbital MCS were identified.The mean age at the first visit was 33y(range,25-42y).All six patients displayed manifestations of exophthalmos,diplopia,limitation of eye displacement,upper eyelid oedema,decreased visual acuity and ptosis.The mean disease history and range were 5 and 2-8mo,respectively.The tumors were located in the superonasal extraconal compartment(2/6,33.3%),intraconal compartment(2/6,33.3%),and bitemporal extraconal compartment(2/6,33.3%),respectively.Radiographic features were a well-defined,orbital mass with calcification and ossification on computed tomography(CT),and marked heterogenous enhancement on dynamic magnetic resonance imaging(MRI).Five patients were treated with tumor resection and one patient received orbital exenteration.Five patients in the cohort received postoperative radiation therapy,two patients received chemotherapy,and one patient did not receive postoperative adjuvant therapy because he refused.The histopathologic classification revealed a tumour composed of a mixture of mature chondroid tissue surrounded by small,round,and undifferentiated mesenchymal cells.Immunohistochemistry revealed Bcl-2,vimetin,CD99,and S-100 were expressed were expressed.After surgeries,two patients have developed a local recurrence.The median recurrence time of 58 mo(52-64 mo).One patient had distant recurrence included the lungs occurred 52mo after the initial surgery.CONCLUSION:The possibilty of orbital MCS need to be considered when a painless,slowly growing orbital mass with calcification and ossification.From our experience,trimodality treatment of radiation therapy,chemotherapy and surgery maybe the best option.Orbital MCS has a high tendency for late recurrence,regular long-term follow-up after complete excision is mandatory.

Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

Mesenchymalstemcells(MSCs)areidealcandidatesfortreatingmanycardiovasculardiseases.MSCscanmodify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart function.MSCs can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental pulp.MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders.In this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

Dedifferentiated Chondrosarcoma with a High-Grade Mesenchymal Component Mimicking a Gastrointestinal Stromal Tumor

This report presents a dedifferentiated chondrosarcoma with a unique pathologic feature. A 63-year-old man was referred with pain and a soft tissue mass in the left groin. A plain radiograph showed a mineralization in the proximal femur with partially osteolytic foci and an abnormal shadow in the soft tissue. Magnetic resonance imaging scans showed an inhomogeneous lesion with intermediate to partially low signal intensity on T1-weighted image and intermediate to high signal intensity on T2-weighted image. Microscopically, the tumor in the femur is a low-grade chondrosarcoma and the component of soft tissue was a high-grade sarcomatous lesion with an epithelial arrangement of tumor cells. A diffuse immunoreactivity to both vimentin and c-kit (CD117) antibodies was detected in the high-grade component. A dedifferentiated component is similar to those of gastrointestinal stromal tumor (GIST). This is the first case of dedifferentiated chondrosarcoma with a high-grade component mimicking a GIST.

Mesenchymal stem cells and their derived exosomes for the treatment of COVID-19

Coronavirus disease 2019(COVID-19)is an acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).SARS-CoV-2 infection typically presents with fever and respiratory symptoms,which can progress to severe respiratory distress syndrome and multiple organ failure.In severe cases,these complications may even lead to death.One of the causes of COVID-19 deaths is the cytokine storm caused by an overactive immune response.Therefore,suppressing the overactive immune response may be an effective strategy for treating COVID-19.Mesenchymal stem cells(MSCs)and their derived exosomes(MSCs-Exo)have potent homing abilities,immunomodulatory functions,regenerative repair,and antifibrotic effects,promising an effective tool in treating COVID-19.In this paper,we review the main mechanisms and potential roles of MSCs and MSCs-Exo in treating COVID-19.We also summarize relevant recent clinical trials,including the source of cells,the dosage and the efficacy,and the clinical value and problems in this field,providing more theoretical references for the clinical use of MSCs and MSCs-Exo in the treatment of COVID-19.

Small extracellular vesicles from hypoxia-preconditioned bone marrow mesenchymal stem cells attenuate spinal cord injury via miR-146a-5p-mediated regulation of macrophage polarization

Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.

Controversies regarding transplantation of mesenchymal stem cells

Mesenchymal stem cells(MSCs)have tantalized regenerative medicine with their therapeutic potential,yet a cloud of controversies looms over their clinical tran-splantation.This comprehensive review navigates the intricate landscape of MSC controversies,drawing upon 15 years of clinical experience and research.We delve into the fundamental properties of MSCs,exploring their unique immuno-modulatory capabilities and surface markers.The heart of our inquiry lies in the controversial applications of MSC transplantation,including the perennial debate between autologous and allogeneic sources,concerns about efficacy,and lingering safety apprehensions.Moreover,we unravel the enigmatic mechanisms surro-unding MSC transplantation,such as homing,integration,and the delicate balance between differentiation and paracrine effects.We also assess the current status of clinical trials and the ever-evolving regulatory landscape.As we peer into the future,we examine emerging trends,envisioning personalized medicine and innovative delivery methods.Our review provides a balanced and informed perspective on the controversies,offering readers a clear understanding of the complexities,challenges,and potential solutions in MSC transplantation.

Different priming strategies improve distinct therapeutic capabilities of mesenchymal stromal/stem cells:Potential implications for their clinical use

Mesenchymal stromal/stem cells(MSCs)have shown significant therapeutic potential,and have therefore been extensively investigated in preclinical studies of regenerative medicine.However,while MSCs have been shown to be safe as a cellular treatment,they have usually been therapeutically ineffective in human diseases.In fact,in many clinical trials it has been shown that MSCs have moderate or poor efficacy.This inefficacy appears to be ascribable primarily to the heterogeneity of MSCs.Recently,specific priming strategies have been used to improve the therapeutic properties of MSCs.In this review,we explore the literature on the principal priming approaches used to enhance the preclinical inefficacy of MSCs.We found that different priming strategies have been used to direct the therapeutic effects of MSCs toward specific pathological processes.Particularly,while hypoxic priming can be used primarily for the treatment of acute diseases,inflammatory cytokines can be used mainly to prime MSCs in order to treat chronic immune-related disorders.The shift in approach from regeneration to inflammation implies,in MSCs,a shift in the production of functional factors that stimulate regenerative or anti-inflammatory pathways.The opportunity to fine-tune the therapeutic properties of MSCs through different priming strategies could conceivably pave the way for optimizing their therapeutic potential.

Multiple pretreatments can effectively improve the functionality of mesenchymal stem cells

In this editorial,we offer our perspective on the groundbreaking study entitled“Hypoxia and inflammatory factor preconditioning enhances the immunosup-pressive properties of human umbilical cord mesenchymal stem cells”,recently published in World Journal of Stem Cells.Despite over three decades of research on the clinical application of mesenchymal stem cells(MSCs),only a few therapeutic products have made it to clinical use,due to multiple preclinical and clinical challenges yet to be addressed.The study proved the hypoxia and inflammatory factor preconditioning led to higher immunosuppressive effects of MSCs without damaging their biological characteristics,which revealed the combination of inflammatory factors and hypoxic preconditioning offers a promising approach to enhance the function of MSCs.As we delve deeper into the intricacies of pretreat-ment methodologies,we anticipate a transformative shift in the landscape of MSC-based therapies,ultimately contributing to improved patient outcomes and advancing the field as a whole.

Extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis through the transport of microRNA-29a

BACKGROUND Knee osteoarthritis(KOA)is a common orthopedic condition with an uncertain etiology,possibly involving genetics and biomechanics.Factors like changes in chondrocyte microenvironment,oxidative stress,inflammation,and immune responses affect KOA development.Early-stage treatment options primarily target symptom relief.Mesenchymal stem cells(MSCs)show promise for treatment,despite challenges.Recent research highlights microRNAs(miRNAs)within MSC-released extracellular vesicles that can potentially promote cartilage regeneration and hinder KOA progression.This suggests exosomes(Exos)as a promising avenue for future treatment.While these findings emphasize the need for effective KOA progression management,further safety and efficacy validation for Exos is essential.AIM To explore miR-29a’s role in KOA,we’ll create miR-29a-loaded vesicles,testing for early treatment in rat models.METHODS Extraction of bone marrow MSC-derived extracellular vesicles,preparation of engineered vesicles loaded with miR-29a using ultrasonication,and identification using quantitative reverse transcription polymerase chain reaction;after establi-shing a rat model of KOA,rats were randomly divided into three groups:Blank control group injected with saline,normal extracellular vesicle group injected with normal extracellular vesicle suspension,and engineered extrace-llular vesicle group injected with engineered extracellular vesicle suspension.The three groups evaluation,histological detection,and immunohistochemical detection to compare and evaluate the progress of various forms of arthritis.RESULTS General behavioral observation results showed that the extracellular vesicle group and engineered extracellular vesicle group had better performance in all four indicators of pain,gait,joint mobility,and swelling compared to the blank control group.Additionally,the engineered extracellular vesicle group had better pain relief at 4 wk and better knee joint mobility at 8 wk compared to the normal extracellular vesicle group.Imaging examination results showed that the blank control group had the fastest progression of arthritis,the normal extracellular vesicle group had a relatively slower progression,and the engineered extracellular vesicle group had the slowest progression.Gross histological observation results showed that the blank control group had the most obvious signs of arthritis,the normal extracellular vesicle group showed signs of arthritis,and the engineered extracellular vesicle group showed no significant signs of arthritis.Using the Pelletier gross score evaluation,the engineered extracellular vesicle group had the slowest progression of arthritis.Results from two types of staining showed that the articular cartilage of rats in the normal extracellular vesicle and engineered extracellular vesicle groups was significantly better than that of the blank control group,and the engineered extracellular vesicle group had the best cartilage cell and joint surface condition.Immunohistochemical detection of type II collagen and proteoglycan showed that the extracellular matrix of cartilage cells in the normal extracellular vesicle and engineered extracellular vesicle groups was better than that of the blank control group.Compared to the normal extracellular vesicle group,the engineered extracellular vesicle group had a better regulatory effect on the extracellular matrix of cartilage cells.CONCLUSION Engineered Exos loaded with miR-29a can exert anti-inflammatory effects and maintain extracellular matrix stability,thereby protecting articular cartilage,and slowing the progression of KOA.

Reveal more mechanisms of precondition mesenchymal stem cells inhibiting inflammation

Hypoxia can get more ability to inhibit inflammation.But how it impact on survival time of mesenchymal stem cells(MSCs)is confusing and how preconditioned MSCs inhibiting inflammation are partially known.Those issues decided the value of preconditioned MSCs by hypoxia.

Effects of exosomes from mesenchymal stem cells on functional recovery of a patient with total radial nerve injury: A pilot study

BACKGROUND Peripheral nerve injury can result in significant clinical complications that have uncertain prognoses.Currently,there is a lack of effective pharmacological interventions for nerve damage,despite the existence of several small compounds,Despite the objective of achieving full functional restoration by surgical intervention,the persistent challenge of inadequate functional recovery remains a significant concern in the context of peripheral nerve injuries.AIM To examine the impact of exosomes on the process of functional recovery following a complete radial nerve damage.METHODS A male individual,aged 24,who is right-hand dominant and an immigrant,arrived with an injury caused by a knife assault.The cut is located on the left arm,specifically below the elbow.The neurological examination and electrodiagnostic testing reveal evidence of left radial nerve damage.The sural autograft was utilized for repair,followed by the application of 1 mL of mesenchymal stem cell-derived exosome,comprising 5 billion microvesicles.This exosome was split into four equal volumes of 0.25 mL each and delivered microsurgically to both the proximal and distal stumps using the subepineural pathway.The patient was subjected to a period of 180 d during which they had neurological examination and electrodiagnostic testing.RESULTS The duration of the patient’s follow-up period was 180 d.An increasing Tinel’s sign and sensory-motor recovery were detected even at the 10th wk following nerve grafting.Upon the conclusion of the 6-mo post-treatment period,an evaluation was conducted to measure the extent of improvement in motor and sensory functions of the nerve.This assessment was based on the British Medical Research Council scale and the Mackinnon-Dellon scale.The results indicated that the level of improvement in motor function was classified as M5,denoting an excellent outcome.Additionally,the level of improvement in sensory function was classified as S3+,indicating a good outcome.It is noteworthy that these assessments were conducted in the absence of physical therapy.At the 10th wk post-injury,despite the persistence of substantial axonal damage,the nerve exhibited indications of nerve re-innervation as evidenced by control electromyography(EMG).In contrast to the preceding.EMG analysis revealed a significant electrophysiological enhancement in the EMG conducted at the 6th-mo follow-up,indicating ongoing regeneration.CONCLUSION Enhanced comprehension of the neurobiological ramifications associated with peripheral nerve damage,as well as the experimental and therapy approaches delineated in this investigation,holds the potential to catalyze future clinical progress.

Mesenchymal stem cells’“garbage bags”at work:Treating radial nerve injury with mesenchymal stem cell-derived exosomes

Unlike central nervous system injuries,peripheral nerve injuries(PNIs)are often characterized by more or less successful axonal regeneration.However,structural and functional recovery is a senile process involving multifaceted cellular and molecular processes.The contemporary treatment options are limited,with surgical intervention as the gold-standard method;however,each treatment option has its associated limitations,especially when the injury is severe with a large gap.Recent advancements in cell-based therapy and cell-free therapy approaches using stem cell-derived soluble and insoluble components of the cell secretome are fast-emerging therapeutic approaches to treating acute and chronic PNI.The recent pilot study is a leap forward in the field,which is expected to pave the way for more enormous,systematic,and well-designed clinical trials to assess the therapeutic efficacy of mesenchymal stem cell-derived exosomes as a bio-drug either alone or as part of a combinatorial approach,in an attempt synergize the best of novel treatment approaches to address the complexity of the neural repair and regeneration.

O-linkedβ-N-acetylglucosaminylation may be a key regulatory factor in promoting osteogenic differentiation of bone marrow mesenchymal stromal cells

Cumulative evidence suggests that O-linkedβ-N-acetylglucosaminylation(OGlcNAcylation)plays an important regulatory role in pathophysiological processes.Although the regulatory mechanisms of O-GlcNAcylation in tumors have been gradually elucidated,the potential mechanisms of O-GlcNAcylation in bone metabolism,particularly,in the osteogenic differentiation of bone marrow mesenchymal stromal cells(BMSCs)remains unexplored.In this study,the literature related to O-GlcNAcylation and BMSC osteogenic differentiation was reviewed,assuming that it could trigger more scholars to focus on research related to OGlcNAcylation and bone metabolism and provide insights into the development of novel therapeutic targets for bone metabolism disorders such as osteoporosis.

Interplay between mesenchymal stem cells and macrophages:Promoting bone tissue repair

The repair of bone tissue damage is a complex process that is well-orchestrated in time and space,a focus and difficulty in orthopedic treatment.In recent years,the success of mesenchymal stem cells(MSCs)-mediated bone repair in clinical trials of large-area bone defects and bone necrosis has made it a candidate in bone tissue repair engineering and regenerative medicine.MSCs are closely related to macrophages.On one hand,MSCs regulate the immune regulatory function by influencing macrophages proliferation,infiltration,and phenotype polarization,while also affecting the osteoclasts differentiation of macrophages.On the other hand,macrophages activate MSCs and mediate the multilineage differentiation of MSCs by regulating the immune microenvironment.The cross-talk between MSCs and macrophages plays a crucial role in regulating the immune system and in promoting tissue regeneration.Making full use of the relationship between MSCs and macrophages will enhance the efficacy of MSCs therapy in bone tissue repair,and will also provide a reference for further application of MSCs in other diseases.

Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis

Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols.

Research Progress on the Immunomodulatory Effect of Mesenchymal Stem Cells on Chronic Periodontitis

Periodontal disease is an inflammatory and destructive disease of periodontal support tissue caused by microorganisms in dental plaque. During the development of periodontal disease, host immune regulation plays an important role, and unnecessary excessive immune regulation often exacerbates the course of chronic periodontal disease. Mesenchymal stem cells (MSCs) are adult stem cells with self replication ability and multi-directional differentiation potential. Many studies have found that MSCs have strong immunosuppressive effects on both adaptive and innate immunity. In recent years, literature has reported that MSCs are involved in the immune regulatory effect of chronic periodontal disease, inhibiting its inflammatory response and alveolar bone resorption, but the specific regulatory mechanism has not been elucidated. This article reviews the current research status of the immune regulatory effects of MSCs on chronic periodontitis.

Placenta-derived mesenchymal stem cells attenuate secondary brain injury after controlled cortical impact in rats by inhibiting matrix metalloproteinases

Background:As a form of biological therapy,placenta-derived mesenchymal stem cells(PDMSCs)exhibit considerable promise in addressing the complex pathological processes of traumaticbrain injury(TBI)due to their multi-target and multi-pathway mode of action.Material&Methods:This study investigates the protective mechanisms and benefits of PDMSCs in mitigating the effects of controlled cortical impact(CCI)in rats and glutamate-induced oxidative stress injury in HT22 cells in vitro.Our primary objective is to provide evidence supporting the clinical application of PDMSCs.Results:In the in vivo arm of our investigation,we observed a swift elevation of matrix metalloproteinase-9(MMP-9)in the proximal cortex of injured brain tissues after CCI.PDMSCs,distinguished by their heightened expression of metalloproteinase tissue inhibitors-1 and-2(TIMP-1 and TIMP-2):were intravenously administered via the caudal vein.This intervention yielded significant reductions in the permeability of the blood-brain barrier(BBB):the extent of brain edema,the levels of inflammatory cytokines IL-1βand TNF-αin damaged brain tissue,and the activation status of microglia in CCI-afflicted rats.In the realm of in vitro experiments,PDMSC-conditioned media demonstrated substantial reductions in mortality rates and cleaved caspase-3 levels in glutamate-induced HT22 cells compared with conventional media.Notably,this advantage was negated upon the introduction of neutralizing antibodies targeting TIMP-1 and TIMP-2.Conclusion:Collectively,our findings underscore the potential of PDMSCs in alleviating oxidative stress injury and secondary brain injury in the pathological process of TBI.