Adipose mesenchymal stem cell-derived extracellular vesicles reduce glutamate-induced excitotoxicity in the retina

Adipose mesenchymal stem cells(ADSCs)have protective effects against glutamate-induced excitotoxicity,but ADSCs are limited in use for treatment of optic nerve injury.Studies have shown that the extracellular vesicles(EVs)secreted by ADSCs(ADSC-EVs)not only have the function of ADSCs,but also have unique advantages including non-immunogenicity,low probability of abnormal growth,and easy access to target cells.In the present study,we showed that intravitreal injection of ADSC-EVs substantially reduced glutamate-induced damage to retinal morphology and electroretinography.In addition,R28 cell pretreatment with ADSC-EVs before injury inhibited glutamate-induced overload of intracellular calcium,downregulation ofα-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor(AMPAR)subunit GluA2,and phosphorylation of GluA2 and protein kinase C alpha in vitro.A protein kinase C alpha agonist,12-O-tetradecanoylphorbol 13-acetate,inhibited the neuroprotective effects of ADSC-EVs on glutamate-induced R28 cells.These findings suggest that ADSCEVs ameliorate glutamate-induced excitotoxicity in the retina through inhibiting protein kinase C alpha activation.

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.

Outcomes of combined mitochondria and mesenchymal stem cellsderived exosome therapy in rat acute respiratory distress syndrome and sepsis

BACKGROUND The treatment of acute respiratory distress syndrome(ARDS)complicated by sepsis syndrome(SS)remains challenging.AIM To investigate whether combined adipose-derived mesenchymal-stem-cells(ADMSCs)-derived exosome(EXAD)and exogenous mitochondria(mitoEx)protect the lung from ARDS complicated by SS.METHODS In vitro study,including L2 cells treated with lipopolysaccharide(LPS)and in vivo study including male-adult-SD rats categorized into groups 1(sham-operated-control),2(ARDS-SS),3(ARDS-SS+EXAD),4(ARDS-SS+mitoEx),and 5(ARDS-SS+EXAD+mitoEx),were included in the present study.RESULTS In vitro study showed an abundance of mitoEx found in recipient-L2 cells,resulting in significantly higher mitochondrial-cytochrome-C,adenosine triphosphate and relative mitochondrial DNA levels(P<0.001).The protein levels of inflammation[interleukin(IL)-1β/tumor necrosis factor(TNF)-α/nuclear factor-κB/toll-like receptor(TLR)-4/matrix-metalloproteinase(MMP)-9/oxidative-stress(NOX-1/NOX-2)/apoptosis(cleaved-caspase3/cleaved-poly(ADP-ribose)polymerase)]were significantly attenuated in lipopolysaccharide(LPS)-treated L2 cells with EXAD treatment than without EXAD treatment,whereas the protein expressions of cellular junctions[occluding/β-catenin/zonula occludens(ZO)-1/E-cadherin]exhibited an opposite pattern of inflam-mation(all P<0.001).Animals were euthanized by 72 h post-48 h-ARDS induction,and lung tissues were harvested.By 72 h,flow cytometric analysis of bronchoalveolar lavage fluid demonstrated that the levels of inflam-matory cells(Ly6G+/CD14+/CD68+/CD11b/c+/myeloperoxidase+)and albumin were lowest in group 1,highest in group 2,and significantly higher in groups 3 and 4 than in group 5(all P<0.0001),whereas arterial oxygen-saturation(SaO2%)displayed an opposite pattern of albumin among the groups.Histopathological findings of lung injury/fibrosis area and inflammatory/DNA-damaged markers(CD68+/γ-H2AX)displayed an identical pattern of SaO2%among the groups(all P<0.0001).The protein expressions of inflammatory(TLR-4/MMP-9/IL-1β/TNF-α)/oxidative stress(NOX-1/NOX-2/p22phox/oxidized protein)/mitochondrial-damaged(cytosolic-cytochrome-C/dynamin-related protein 1)/autophagic(beclin-1/Atg-5/ratio of LC3B-II/LC3B-I)biomarkers exhibited a similar manner,whereas antioxidants[nuclear respiratory factor(Nrf)-1/Nrf-2]/cellular junctions(ZO-1/E-cadherin)/mitochondrial electron transport chain(complex I-V)exhibited an opposite manner of albumin among the groups(all P<0.0001).CONCLUSION Combined EXAD-mitoEx therapy was better than merely one for protecting the lung against ARDS-SS induced injury.

A biomimetic adipocyte mesenchymal stem cell membrane-encapsulated drug delivery system for the treatment of rheumatoid arthritis

Rheumatoid arthritis(RA)is a chronic,progressive,and inflammatory systemic autoimmune disease.Effective drug therapy for RA is hindered by severe side effects due to inefficient delivery to the disease site and broad drug distribution.Inspired by biomimetic biology,this study developed a drug delivery system of adipose-derived mesenchymal stem cell membrane-encapsulated nanoparticles for the treatment of RA.The intact adipose-derived mesenchymal stem cell(ADSC)membrane was coated on poly(lactic-co-glycolic acid)(PLGA)nanoparticles and loaded with tacrolimus(FK506),a T cell inhibitor.The ADSC membrane encapsulated on nanoparticles retains the original homing properties of ADSC,targeting the inflamed joints and enhancing tacrolimus anti-inflammatory effect.Both in vitro and in vivo experiments proved that the synergistic effect of the ADSC-membrane and tacrolimus effectively inhibited inflammation in vivo and reduced the expression of pro-inflammatory factors(IL-1β,IL-6,tumor necrosis factor-α(TNF-α)),and increased the expression of anti-inflammatory factors(IL-10).In addition,collagen-induced arthritis(CIA)model results also showed that the drug delivery system could effectively reduce the destruction of articular cartilage and bone in mice without causing any adverse effects.This study provided a new biomimetic targeting strategy to reshape the inflammatory microenvironment by modulating T cell subsets,providing new inspiration for RA treatment.

Exosomal miR-155 from gastric cancer induces cancerassociated cachexia by suppressing adipogenesis and promoting brown adipose differentiation via C/EPBβ

Objective:The aim of this research was to identify whether exosomes were involved in impairing adipogenesis in cancer-associated cachexia(CAC)by detecting the adipodifferentiation capacity and the expressions of adipogenic proteins in gastric cancer(GC)-associated adipocytes.Methods:Western blotting and RT-PCR were used to investigate the expressions of C/EPBβ,C/EPBα,PPARγ,and UCP1 in adipose mesenchymal stem cells(A-MSCs)to evaluate the function of exosomal miR-155.BALB/c nude mice were intravenously injected in vivo with GC exosomes with different levels of miR-155 to determine changes in adipodifferentiation of A-MSCs.Results:Exosomes derived from GC cells suppressed adipogenesis in A-MSCs as characterized by decreased lipid droplets.Similarly,A-MSCs co-cultured with GC exosomes exhibited increased ATP production through brown adipose differentiation characterized by highly dense mitochondria and enhanced UCP1 expression(P<0.05).Mechanistically,exosomal miR-155 secreted from GC cells suppressed adipogenesis and promoted brown adipose differentiation by targeting C/EPBβ,accompanied by downregulated C/EPBαand PPARγand upregulated UCP1(P<0.05).Moreover,overexpression of miR-155 in GC exosomes improved CAC in vivo,which was characterized by fat loss,suppressed expressions of C/EPBβ,C/EPBα,and PPARγin A-MSCs,and high expression of UCP1(P<0.05).Decreasing the level of miR-155 in injected GC exosomes abrogated the improved CAC effects.Conclusions:GC exosomal miR-155 suppressed adipogenesis and enhanced brown adipose differentiation in A-MSCs by targeting C/EPBβof A-MSCs,which played a crucial role in CAC.

Effect of Optimized Concentrations of Basic Fibroblast Growth Factor and Epidermal Growth Factor on Proliferation of Fibroblasts and Expression of Collagen： Related to Pelvic Floor Tissue Regeneration

Background： Fibroblasts were the main seed cells in the studies of tissue engineering of the pelvic floor ligament. Basic fibroblast growth factor （bFGF） and epidermal growth factor （EGF） were widely studied but at various concentrations. This study aimed to optimize the concentrations of combined bFGF and EGF by evaluating their effects on proliferation and collagen secretion of fibroblasts. Methods： Fibroblasts were differentiated from rat adipose mesenchymal stem cells （ADSCs）. Flow cytometry and immunohistochemistry were used for cell identification. The growth factors were applied at concentrations of 0, 1, 10, and 100 ng/ml as three groups： （1） bFGF alone, （2） EGF alone, and （3） bFGF mixed with EGF. Cell proliferation was evaluated by Cell Counting Kit-8 assays. Expression of Type I and III collagen （Col-I and Col-1II） mRNAs was evaluated by real-time quantitative reverse transcription-polymerase chain reaction. Statistical analysis was performed with SPSS software and GraphPad Prism using one-way analysis of variance and multiple t-test. Results： ADSCs were successfully isolated from rat adipose tissue as identified by expression of typical surface markers CD29, CD44, CD90, and CD45 in flow cytometry. Fibroblasts induced from ADSC, compared with ADSCs, were with higher mRNA expression levels of Col I and Col III （F = 1.29, P = 0.0390）. bFGF, EGF, and the mixture ofbFGF with EGF can enhanced fibroblasts proliferation, and the concentration of 10 ng/ml of the mixture ofbFGF with EGF displayed most effectively （all P 〈 0.05）. The expression levels of Col-I and Col-Ill mRNAs in fibroblasts displayed significant increases in the 10 ng/ml bFGF combined with EGF group （all P 〈 0.05）. Conclusions： The optimal concentration of both bFGF and EGF to promote cell proliferation and collagen expression in fibroblasts was 10 ng/ml at which fibroblasts grew faster and secreted more Type I and III collagens into the extracellular matrix, which might contribute to the stability of the pelvic floor microenvironment.