Aim To investigate the effects of endur-ance exercise(EE)on rats following cerebral ischemi-a/reperfusion injury(CI/RI)and to explore its rela-tionship with the Mas signaling pathway.Methods Seventy-two adult male SD rats were randomly divided into four groups(n=18 each):sham group,model group,EE group(group E),and A779 pretreatment group(group A).The CI/RI model was established u-sing middle cerebral artery occlusion method Rats in both group E and group A underwent regular running for four weeks before model preparation,while rats in group A were injected with A779 30 minutes before model preparation.The cognitive function of rats was evaluated using the Neurological Disability Score(NDS)and Morris water maze test.After intravenous injection of Evans blue(EB)for one hour,the rats were euthanized,and brain tissues were collected to measure the infarction volume,EB content,ROS con-tent,and the percentage of apoptotic neurons of the hippocampal CA1 region.The protein expression relat-ed to the Mas pathway was detected by Western blot.Results Compared with the model group,the learning and memory ability as well as the neurological function in group E exhibited a significant improvement(P＜0.05).Both the cerebral infarction volume and the ap-optotic neuron percentage in the ischemic hippocampal CA1 region showed a significant reduction in group E(P＜0.05).The ROS content along with the EB con-tent in the brain tissue significantly decreased in group E(P＜0.05).Furthermore,the expressions of Mas/PKA/CREB/UCP2 pathway related proteins were sig-nificantly enhanced in group E(P＜0.05).However,the Mas receptor antagonist A779 significantly inhibited these neurological effects(P＜0.05).Conclusion EE may inhibit oxidative stress and alleviate CI/RI in rats by activating the Mas/PKA/CREB/UCP2 signaling pathway.

OBJECTIVE: Based on the PTEN-induced hypothetical kinase 1 (PINK1)/Parkin pathway, the effect of acupuncture pretreatment on the expression of mitochondrial autophagy-related proteins in gastrocnemius muscle tissue of rats with exercise-induced muscle damage (EIMD) was observed, and the underlying mechanism of acupuncture pretreatment for the prevention and treatment of EIMD was explored. METHODS: Of 88 SD male rats, aged 6 weeks, 8 rats were randomly selected as a blank group, and the remaining 80 rats were randomized into a model group and an acupuncture pretreatment group, with 40 rats in each group. Either the model group or the acupuncture pretreatment group was subdivided randomly into 5 subgroups with 8 rats in each one according to the time points of sample collection, 0 h, 12 h, 24 h, 48 h and 72 h after modeling. An intermittent downhill running centrifugal exercise was carried out on an animal experimental treadmill to establish the EIMD model in the model group and the acupuncture pretreatment group. The rats in the acupuncture pretreatment group received acupuncture at "Guanyuan" (CV6) and bilateral "Zusanli" (ST36), once a day for 20 min each time, for 7 consecutive days before EIMD model preparation. Transmission electron microscopy was used to observe the ultrastructure of gastrocnemius muscle tissue in each group. The contents of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) in serum were detected by ELISA. Western blot was used to detect the protein expression of PINK1, Parkin, sequestosome 1 (p62) and microtubule-associated protein light chain 3B (LC3B) in rat gastrocnemius muscle tissue. Real-time PCR was adopted to detect the mRNA expression of PINK1, Parkin, p62 and LC3B in rat gastrocnemius muscle tissue. RESULTS: Compared with the blank group, the mitochondria of gastrocnemius muscles showed obvious swelling in the 0 h, 12 h, 24 h, and 48 h model subgroups , autophagosomes were formed in the 12 h and 24 h model subgroups, and the mitochondrial morphology returned to normal gradually in the 72 h model subgroup. The serum MDA contents of rats in 5 model subgroups increased (P<0.01, P<0.05). The contents of SOD and CAT in the subgroups of 0 h, 12 h, 24 h and 48 h decreased (P<0.05, P<0.01). The protein and mRNA expression levels of PINK1, Parkin and LC3B in gastrocnemius muscle tissue of rats in 0 h, 12 h and 24 h subgroups were elevated (P<0.01); and the protein and mRNA expression levels of p62 in the 0 h, 12 h, 24 h and 48 h subgroups were reduced (P<0.01, P<0.05). Compared with the model subgroup at the same time point, the myofibril damage and the degree of mitochondrial swelling were mild in each acupuncture pretreatment subgroup, and the numbers of autophagosomes were fewer. The contents of MDA in the acupuncture pretreatment subgroups decreased at 0 h, 12 h, 24 h, and 48 h (P<0.05, P<0.01). The contents of SOD and CAT in the 12 h acupuncture pretreatment subgroup increased (P<0.05, P<0.01). The protein and mRNA expression levels of PINK1 and Parkin in the 0 h, 12 h, and 24 h acupuncture pretreatment subgroups decreased (P<0.01, P<0.05). The protein and mRNA expression levels of LC3B in the 12 h acupuncture pretreatment subgroup decreased (P<0.01), and that of p62 in the 0 h and 24 h acupuncture pretreatment subgroups increased (P<0.01, P<0.05). CONCLUSION The intermittent downhill running centrifugal exercise induces the excessive mitochondrial autophagy. Acupuncture pretreatment may attenuate EIMD, and the underlying mechanism is related to the regulation of PINK1/Parkin signaling pathway expression, reducing oxidative stress damage in skeletal muscle cells, and inhibiting mitochondrial autophagy overactivation.
Animals ; Ubiquitin-Protein Ligases/genetics* ; Male ; Rats ; Acupuncture Therapy ; Protein Kinases/genetics* ; Rats, Sprague-Dawley ; Mitophagy ; Humans ; Muscle, Skeletal/metabolism* ; Physical Conditioning, Animal ; Muscular Diseases/physiopathology* ; Signal Transduction

Aim To investigate the effects of endur-ance exercise(EE)on rats following cerebral ischemi-a/reperfusion injury(CI/RI)and to explore its rela-tionship with the Mas signaling pathway.Methods Seventy-two adult male SD rats were randomly divided into four groups(n=18 each):sham group,model group,EE group(group E),and A779 pretreatment group(group A).The CI/RI model was established u-sing middle cerebral artery occlusion method Rats in both group E and group A underwent regular running for four weeks before model preparation,while rats in group A were injected with A779 30 minutes before model preparation.The cognitive function of rats was evaluated using the Neurological Disability Score(NDS)and Morris water maze test.After intravenous injection of Evans blue(EB)for one hour,the rats were euthanized,and brain tissues were collected to measure the infarction volume,EB content,ROS con-tent,and the percentage of apoptotic neurons of the hippocampal CA1 region.The protein expression relat-ed to the Mas pathway was detected by Western blot.Results Compared with the model group,the learning and memory ability as well as the neurological function in group E exhibited a significant improvement(P＜0.05).Both the cerebral infarction volume and the ap-optotic neuron percentage in the ischemic hippocampal CA1 region showed a significant reduction in group E(P＜0.05).The ROS content along with the EB con-tent in the brain tissue significantly decreased in group E(P＜0.05).Furthermore,the expressions of Mas/PKA/CREB/UCP2 pathway related proteins were sig-nificantly enhanced in group E(P＜0.05).However,the Mas receptor antagonist A779 significantly inhibited these neurological effects(P＜0.05).Conclusion EE may inhibit oxidative stress and alleviate CI/RI in rats by activating the Mas/PKA/CREB/UCP2 signaling pathway.

Objective:To explore the role of NK cells in allogeneic hematopoietic stem cell micro-transplantation(MST)in the treatment of patients with acute myeloid leukemia(AML).Methods:Data from 93 AML patients treated with MST at our center from 2013-2018 were retrospectively analyzed.The induction regimen was anthracycline and cytarabine combined with peripheral blood stem cells transplantation mobilization by granulocyte colony stimulating factor(GPBSC),followed by 2-4 courses of intensive treatment with medium to high doses of cytarabine combined with GPBSC after achieving complete remission(CR).The therapeutic effects of one and two courses of MST induction therapy on 42 patients who did not reach CR before transplantation were evaluated.Cox proportional hazards regression analysis was used to analyze the impact of donor NK cell dose and KIR genotype,including KIR ligand mismatch,2DS1,haplotype,and HLA-Cw ligands on survival prognosis of patients.Results:Forty-two patients received MST induction therapy,and the CR rate was 57.1％after 1 course and 73.7％after 2 courses.Multivariate analysis showed that,medium and high doses of NK cells was significantly associated with improved disease-free survival(DFS)of patients(HR=0.27,P=0.005;HR=0.21,P=0.001),and high doses of NK cells was significantly associated with improved overall survival(OS)of patients(HR=0.15,P=0.000).Donor 2DS1 positive significantly increases OS of patients(HR=0.25,P=0.011).For high-risk patients under 60 years old,patients of the donor-recipient KIR ligand mismatch group had longer DFS compared to the nonmismatch group(P=0.036);donor 2DS1 positive significantly prolonged OS of patients(P=0.009).Conclusion:NK cell dose,KIR ligand mismatch and 2DS1 influence the therapeutic effect of MST,improve the survival of AML patients.

Objective To observe the improvement of motor dysfunction and serum levels of C-reactive protein(CRP),blood glucose and blood lipid in post-stroke patients treated with scalp acupuncture at different needle retention time.Methods A total of 120 patients with motor dysfunction after stroke were randomly divided into control group,observation group 1 and observation group 2,with 40 cases in each group.The patients in the 3 groups were treated with scalp acupuncture,body acupuncture and routine rehabilitation exercise,once a day and 6 times a week,lasting for 2 weeks.The control group was given scalp acupuncture with retaining of needles for 30 minutes,the observation group 1 was given scalp acupuncture with retaining of needles for one hour,and the observation group 2 was given scalp acupuncture with retaining of needles for 2 hours.Before and after treatment,the 3 groups were observed in the changes of the scale scores of National Institutes of Health Stroke Scale(NIHSS),Fugl-Meyer Assessment(FM A),Berg Balance Scale(BBS)and modified Barthel Index(MBI),and the levels of laboratory indicators of peripheral blood CRP,fasting plasma glucose(FPG),total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C).After treatment,the clinical safety of the three groups was evaluated.Results(1)After treatment,the scale scores of NIHSS in the three groups were lower(P＜0.01)and the scale scores FMA,BBS and MBI were higher than those before treatment(P＜0.05 or P＜0.01).The comparison of post-treatment scale scores showed that the differences among the three groups were statistically significant(P＜0.01).The intergroup comparison showed that the decrease of NIHSS score and the increase of FMA,BBS and MBI scores in the observation group 2 were significantly superior to those in the control group and the observation group 1(P＜0.01);the improvement of FMA score in the observation group 1 was significantly superior to that in the control group(P＜0.01),while the improvement of NIHSS,BBS and MBI scores tended to be superior to that in the control group without statistically significant differences(P＞0.05).The results indicated that the curative effect of scalp acupuncture plus exercise regimen was positively correlated with the duration of needle retention for scalp acupuncture.(2)After treatment,the laboratory indicator levels of CRP and FPG in the peripheral blood of the three groups,the levels of TG and LDL-C in the two observation groups and the level of HDL-C in the observation group 2 were improved compared with those before treatment(P＜0.05 or P＜0.01).Statistically significant differences were presented in the post-treatment levels of CRP and TG in peripheral blood among the three groups(P＜0.05 or P＜0.01).The intergroup comparison showed that the improvement of CRP and TG levels in the observation group 2 was significantly superior to that in the control group,and the improvement of CRP level in the observation group 2 was significantly superior to that in the observation group 1,the differences being statistically significant(P＜0.05 or P＜0.01).The TC level in the three groups after treatment did not differ from that before treatment,and there was no significant difference in TC level after treatment among the three groups either(P＞0.05).(3)During the treatment,no adverse reactions such as fainting,needle breaking and hematoma occurred in the three groups,the vital signs of the patients were stable,and there were no obvious abnormal changes in pulse,blood pressure and respiratory rate.Conclusion Scalp acupuncture can effectively improve the motor function of post-stroke patients in a pasitive time-effect relationship with the needle retention,and better the curative effect can be achieved by retaining of the needle for 2 h.

This study aimed to investigate the effect of aucubin(AU) on injury of nucleus pulposus cells and extracellular matrix(ECM) degradation and its mechanism. The nucleus pulposus cell injury model was established by interleukin-1β(IL-1β) and treated with AU or phosphatidylinositol 3-kinase(PI3K) inhibitor LY294002. CCK-8 experiment was conducted to test cell proliferation. EdU staining method was employed to detect cell injury. Flow cytometry was used to detect cell apoptosis. Western blot was used to detect protein levels of cleaved-caspase-3, B-cell lymphoma(Bcl-2), Bcl-2 associated X protein(Bax), type Ⅱ collagen(collagen Ⅱ), aggregation proteoglycans(aggrecan), PI3K, and mammalian target of rapamycin(mTOR). qPCR was used to detect the rRNA level of 5S, 18S, and 28S. Ethynyluridine was used to label nascent RNA. The results showed that IL-1β could significantly cause injury of nucleus pulposus cells and increase the apoptosis rate of nucleus pulposus cells and the expression of apoptosis protein cleaved-caspase-3 and Bax. At the same time, IL-1β down-regulated the expression of anti-apoptotic protein Bcl-2 and collagen Ⅱ and aggrecan, the main components of ECM. On this basis, AU intervention could improve the injury of nucleus pulposus cells, reduce the apoptosis of nucleus pulposus cells and the expression of cleaved-caspase-3 and Bax, and increase the expression of Bcl-2, collagen Ⅱ, and aggrecan. Compared with IL-1β, AU could up-regulate the phosphorylation level of PI3K and mTOR, and LY294002 could reverse the injury of nucleus pulposus cells and improve ECM degradation induced by AU. In addition, AU also could save lowered rRNA levels of 5S, 18S, and 28S induced by IL-1β and improve RNA synthesis. PI3K inhibitor LY294002 intervention could reduce the promoting effect of AU on ribosome biogenesis. The above results suggest that AU can improve the injury of nucleus pulposus cells and ECM degradation, and its mechanism of action is related to its activation of the PI3K/mTOR pathway to promote ribosome biogenesis.
Nucleus Pulposus/cytology* ; Extracellular Matrix/drug effects* ; Animals ; Iridoid Glucosides/pharmacology* ; Apoptosis/drug effects* ; Interleukin-1beta/metabolism* ; Phosphatidylinositol 3-Kinases/genetics* ; Rats ; Cell Proliferation/drug effects* ; TOR Serine-Threonine Kinases/genetics* ; Rats, Sprague-Dawley ; Humans ; Signal Transduction/drug effects* ; Caspase 3/genetics* ; Proto-Oncogene Proteins c-bcl-2/genetics*

This study aimed to investigate the potential mechanism and the compatibility significance of Tanyu Tongzhi Formula in treating atherosclerosis(AS) in mice based on the transforming growth factor-β(TGF-β)/Smad2/3 signaling pathway. Eight C57BL/6J mice were as assigned to a normal control group and fed a regular diet, while 35 ApoE~(-/-) mice of the same strain were fed a high-fat diet for 8 weeks to establish an AS model. The model mice were randomly divided into a model group, a Tanyu Tongzhi group(18.2 mg·kg~(-1)), a Huatan(phlegm-resolving) group(10.4 mg·kg~(-1)), and a Quyu(blood stasis-resolving) group(7.8 mg·kg~(-1)), with 8 mice in each group. Except for the normal group, all other groups continued to be fed a high-fat diet for 8 weeks to maintain the AS model, and then the mice were treated by gavage for 8 weeks. Plasma levels of total cholesterol(TC), triglycerides(TG), low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C), interleukin-1β(IL-1β), and interleukin-18(IL-18) were measured using enzyme-linked immunosorbent assay(ELISA). Hematoxylin and eosin(HE) staining, oil red O staining, and Russell-Movat pentachrome staining were performed to observe the pathological changes in the aortic tissue. The proportions of aortic plaque area, lipid-stained area, collagen fibers, and elastic fibers were calculated. Immunofluorescence was used to detect the protein expression levels of matrix metalloproteinase 2(MMP2) and tissue inhibitor of metalloproteinases 2(TIMP2). Western blot was used to detect the protein expression levels of TGF-β1, TGF-β2, Smad2/3, and Smad7 in aortic tissue. Real-time fluorescence quantitative PCR(RT-qPCR) was used to measure the mRNA expression levels of TGF-β receptor(TGF-βR), TGF-β1, Smad2/3, Smad7, intercellular adhesion molecule-1(ICAM-1), and vascular cell adhesion molecule-1(VCAM-1) in aortic tissue. The results showed that compared with the normal control group, the model group had increased plasma TC and LDL-C, significantly decreased HDL-C, and significantly elevated plasma IL-1β and IL-18 levels. The model group also exhibited an increased proportion of aortic plaque area, lipid-stained area, and collagen fiber area, along with significantly upregulated MMP2 and downregulated TIMP2 expression in the aortic arch. Additionally, the expression levels of TGF-βR, TGF-β1, and p-Smad2/3 proteins and mRNA in the aortic tissue were significantly elevated, while Smad7 expression was decreased. Compared with the model group, the Tanyu Tongzhi group showed significantly reduced plasma TC and LDL-C levels, significantly increased HDL-C levels, and significantly decreased plasma IL-1β and IL-18 levels. The Tanyu Tongzhi group also exhibited a significant reduction in aortic plaque size and severity, a significant downregulation of MMP2 expression in the aortic arch, and significantly decreased ICAM-1 and VCAM-1 mRNA expression levels. Moreover, the Tanyu Tongzhi group demonstrated significantly reduced expression levels of TGF-β1 and p-Smad2/3 proteins and mRNA in the aortic tissue, and an increased expression level of Smad7 protein to varying degrees. Compared with the Tanyu Tongzhi group, the Quyu group had significantly higher LDL-C levels and elevated plasma IL-1β and IL-18 levels. The Huatan group showed upregulated MMP2 expression and downregulated TIMP2 expression in the aortic arch. In conclusion, Tanyu Tongzhi Formula, which is composed based on the pathogenesis of phlegm and blood stasis, maintains vascular homeostasis by primarily regulating lipid metabolism and controlling inflammatory factors through the Huatan group, and maintaining vascular wall permeability, inhibiting plaque development, and stabilizing plaques through the Quyu group. The mechanism of action may involve inhibiting TGF-β1 expression in the aorta, reducing Smad2/3 phosphorylation, and simultaneously increasing Smad7 expression.
Animals ; Atherosclerosis/metabolism* ; Signal Transduction/drug effects* ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Mice, Inbred C57BL ; Male ; Transforming Growth Factor beta/genetics* ; Humans ; Homeostasis/drug effects* ; Aorta/metabolism* ; Smad2 Protein/genetics* ; Smad3 Protein/genetics*

Objective: Total neoadjuvant therapy has been used to improve tumor responses and prevent distant metastases in patients with locally advanced rectal cancer (LARC). Patients with complete clinical responses (cCR) then have the option of choosing a watch and wait (W&W) strategy and organ preservation. It has recently been shown that hypofractionated radiotherapy has better synergistic effects with PD-1/PD-L1 inhibitors than does conventionally fractionated radiotherapy, increasing the sensitivity of microsatellite stable (MSS) colorectal cancer to immunotherapy. Thus, in this trial we aimed to determine whether total neoadjuvant therapy comprising short-course radiotherapy (SCRT) combined with a PD-1 inhibitor improves the degree of tumor regression in patients with LARC. Methods: TORCH is a prospective, multicenter, randomized, phase II trial (TORCH Registration No. NCT04518280). Patients with LARC (T3-4/N+M0, distance from anus ≤10 cm) are eligible and are randomly assigned to consolidation or induction arms. Those in the consolidation arm receive SCRT (25Gy/5 Fx), followed by six cycles of toripalimab plus capecitabine and oxaliplatin (ToriCAPOX). Those in the induction arm receive two cycles of ToriCAPOX, then undergo SCRT, followed by four cycles of ToriCAPOX. Patients in both groups undergo total mesorectal excision (TME) or can choose a W&W strategy if cCR has been achieved. The primary endpoint is the complete response rate (CR, pathological complete response [pCR] plus continuous cCR for more than 1 year). The secondary endpoints include rates of Grade 3-4 acute adverse effects (AEs) etc. Results: Up to 30 September 2022, 62 patients attending our center were enrolled (Consolidation arm: 34, Induction arm:28). Their median age was 53 (27-69) years. Fifty-nine of them had MSS/pMMR type cancer (95.2%), and only three MSI-H/dMMR. Additionally, 55 patients (88.7%) had Stage III disease. The following important characteristics were distributed as follows: lower location (≤5 cm from anus, 48/62, 77.4%), deeper invasion by primary lesion (cT4 7/62, 11.3%; mesorectal fascia involved 17/62, 27.4%), and high risk of distant metastasis (cN2 26/62, 41.9%; EMVI+ 11/62, 17.7%). All 62 patients completed the SCRT and at least five cycles of ToriCAPOX, 52/62 (83.9%) completing six cycles of ToriCAPOX. Finally, 29 patients achieved cCR (46.8%, 29/62), 18 of whom decided to adopt a W&W strategy. TME was performed on 32 patients. Pathological examination showed 18 had achieved pCR, four TRG 1, and 10 TRG 2-3. The three patients with MSI-H disease all achieved cCR. One of these patients was found to have pCR after surgery whereas the other two adopted a W&W strategy. Thus, the pCR and CR rates were 56.2% (18/32) and 58.1% (36/62), respectively. The TRG 0-1 rate was 68.8% (22/32). The most common non-hematologic AEs were poor appetite (49/60, 81.7%), numbness (49/60, 81.7%), nausea (47/60, 78.3%) and asthenia (43/60, 71.7%); two patients did not complete this survey. The most common hematologic AEs were thrombocytopenia (48/62, 77.4%), anemia (47/62, 75.8%), leukopenia/neutropenia (44/62, 71.0%) and high transaminase (39/62, 62.9%). The main Grade III-IV AE was thrombocytopenia (22/62, 35.5%), with three patients (3/62, 4.8%) having Grade IV thrombocytopenia. No Grade V AEs were noted. Conclusions: SCRT-based total neoadjuvant therapy combined with toripalimab can achieve a surprisingly good CR rate in patients with LARC and thus has the potential to offer new treatment options for organ preservation in patients with MSS and lower-location rectal cancer. Meanwhile, the preliminary findings of a single center show good tolerability, the main Grade III-IV AE being thrombocytopenia. The significant efficacy and long-term prognostic benefit need to be determined by further follow-up.
Humans ; Middle Aged ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Chemoradiotherapy ; Immune Checkpoint Inhibitors/therapeutic use* ; Neoadjuvant Therapy ; Prospective Studies ; Rectal Neoplasms/pathology* ; Thrombocytopenia/drug therapy* ; Treatment Outcome ; Adult ; Aged

By various chromatographic techniques and extensive spectroscopic methods, 17 abietane diterpenoids were isolated from the dichloromethane fraction of the 95% ethanol cold-soak extracts of the seeds of Pseudolarix amabilis, namely pseudoamaol A(1), 12α-hydroxyabietic acid(2), 12-methoxy-7,13-abietadien-18-oic acid(3), 13-hydroxy-8,11,13-podocarpatrien-18-oic acid(4), 15-hydroxy-7,13-abietadien-12-on-18-oic acid(5), 8(14)-podocarpen-13-on-18-oic acid(6), holophyllin K(7), metaglyptin B(8), 7α-hydroxydehydroabietinsaure-methylester(9), 7-oxodehydroabietic acid(10), 15-hydroxy-7-oxodehydroabietinsaure-methy-lester(11), 15-methoxydidehydroabietic acid(12), 7-oxo-15-hydroxy-dehydroabietic acid(13), 15-hydroxydehydroabietic acid(14), 8,11,13-abietatriene-15,18-diol(15), 8,11,13-abietatriene-15-hydroxy-18-succinic acid(16), and 7β-hydroxydehydroabie-tic acid(17). Compound 1 was a new compound. The isolated compounds were evaluated for their antitumor activities(HepG2, SH-SY5Y, K562), and compounds 8 and 17 showed potential cytotoxic activity against K562 cells, with IC_(50) values of 26.77 and 37.35 μmol·L~(-1), respectively.
Humans ; Molecular Structure ; Neuroblastoma ; Diterpenes/chemistry* ; Antineoplastic Agents

Mesenchymal stem cells (MSCs) are a class of pluripotent cells that can self-renew and differentiate. Numerous studies have shown that MSCs have important roles in areas such as regenerative medicine and tissue engineering. However, it is worth noting that MSCs will gradually age during long-term in vitro expansion with decreased stemness such as weakened migration ability, slowed proliferation rate and decreased differentiation potential, which greatly hinders the application of MSCs. Currently, the microenvironment for cell growth is recognized as one of the factors causing senescence in MSCs. Recent studies point out that the latest technologies such as exogenous administration, oxygen concentration regulation and extracellular matrix (ECM) construction can delay stem cell senescence by simulating or regulating the microenvironment. Here, we review the current knowledge of the characteristics and molecular mechanisms of senescent MSCs and microenvironment strategies to maintain MSCs stemness, which can provide a reference for future large-scale application of MSCs preparations in tissue engineering and clinical studies.
Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Cellular Senescence ; Extracellular Matrix ; Mesenchymal Stem Cells