BACKGROUND:A large number of studies have confirmed that the therapeutic effectiveness of mesenchymal stem cell secretome is comparable to that of mesenchymal stem cells,but the mechanism of its action is still unclear. OBJECTIVE:To summarize the research progress of mesenchymal stem cell secretome in recent years,to investigate the molecular mechanism of its therapeutic effect,to analyze the current problems and to look forward to the future development. METHODS:The terms"exosomes,mesenchymal stem cells secrete,extracellular vesicles,mesenchymal stem cells,mechanism"were used as English search terms in the PubMed database.Articles that were not related to the research purpose of the article and duplicated articles were excluded.At the same time,we combined the method of literature tracking.Finally,109 articles that met the criteria were incuded for the review. RESULTS AND CONCLUSION:(1)The mesenchymal stem cell secretome promotes tissue repair and regeneration through delivering genetic material,immunomodulatory factors,growth factors,etc.to target cells,by activating anti-apoptotic,regulating angiogenesis,modulating fibrosis and pro-survival pathways in target cells.(2)The potential of mesenchymal stem cell secretome in disease therapy has also been confirmed.Numerous research results have shown that mesenchymal stem cell secretome can be used as a new cell-free treatment for inflammatory and degenerative diseases.(3)Mesenchymal stem cell secretome has been engineered to have more efficient therapeutic effects in recent years.However,due to the heterogeneity of the mesenchymal stem cell secretome and the complexity of its components,the exact mechanism of its therapeutic effect is still unclear.(4)At present,further research is needed to identify the key targets of mesenchymal stem cell secretome,and innovative specific and enhanced mesenchymal stem cell secretome should be developed by combining with engineering and genetic engineering technologies in the future.

ObjectiveTo investigate the optimal ratio of goat horn replacing antelope horn in Fufang Lingjiao Jiangya pills and the blood pressure-lowering mechanism of this medicine. MethodsThe blood pressure-lowering efficacy of Fufang Lingjiao Jiangya pills with varying proportions of goat horn replacing antelope horn was evaluated on spontaneous hypertensive rats （SHR）. In this experiment， 50 SHR rats were randomly grouped as follows： model （n=8）， captopril （0.01 g·kg^-1） （n=6）， low-dose blank Fufang Lingjiao Jiangya pills （0.342 g·kg^-1） （n=6）， high-dose blank Fufang Lingjiao Jiangya pills （0.684 g·kg^-1） （n=6）， low-dose antelope horn-containing Fufang Lingjiao Jiangya pills （0.378 g·kg^-1） （n=6）， high-dose antelope horn-containing Fufang Lingjiao Jiangya pills （0.756 g·kg^-1） （n=6）， low-dose goat horn-containing Fufang Lingjiao Jiangya pills （0.378 g·kg^-1） （n=6）， and high-dose goat horn-containing Fufang Lingjiao Jiangya pills （0.756 g·kg^-1） （n=6）. Additionally， 8 WKY rats were used as the normal group. Drugs were administered by gavage for 4 weeks while an equal volume of distilled water was administered for the normal and model groups. Blood pressure was measured before administration， 3 h post administration， and biweekly thereafter. In the experiment for Fufang Lingjiao Jiangya pills with goat horn replacing antelope horn in different proportions， 48 SHR rats were randomly grouped as follows： model， blank Fufang Lingjiao Jiangya pills （0.684 g·kg^-1）， antelope horn-containing Fufang Lingjiao Jiangya pills （0.756 g·kg^-1）， 2× goat horn-containing Fufang Lingjiao Jiangya pills （0.824 g·kg^-1）， 4× goat horn Fufang Lingjiao Jiangya pills （0.969 g·kg^-1）， and 6× goat horn Fufang Lingjiao Jiangya pills （1.112 g·kg^-1）. The normal group included 8 WKY rats， and the normal group and model group received an equal volume of distilled water. The treatment lasted for 2 weeks， and blood pressure was recorded at various time points （pre-administration， 3 h post administration， and on days 4， 7， 10， and 14 of administration）. Serum levels of angiotensin-converting enzyme （ACE）， angiotensin Ⅱ（Ang Ⅱ）， renin， and interleukin-6 （IL-6） were measured by enzyme-linked immunosorbent assay. Histopathological changes in the heart， kidney， and thoracic aorta were observed by hematoxylin-eosin staining. The protein levels of ACE2， angiotensin Ⅱ type 1 receptor （AT1R）， and angiotensinogen （AGT） in the kidney tissue were determined by Western blot， while the expression of nuclear factor （NF）-κB p65 and Toll-like receptor 4 （TLR4） in the thoracic aorta tissue was assessed by immunohistochemistry. ResultsCompared with the model group， all treatment groups showed lowered blood pressure （P<0.05， P<0.01）， and the 6× goat horn-containing Fufang Lingjiao Jiangya pills group showed consistent blood pressure-lowering effect with the antelope horn-containing Fufang Lingjiao Jiangya pills group. Compared with the normal group， the model group showed elevated serum levels of ACE， Ang Ⅱ， renin， and IL-6， while the elevations were declined in the Fufang Lingjiao Jiangya pills groups （P<0.05， P<0.01）. Pathological changes in the heart， kidney， and thoracic aorta were alleviated in all the treatment groups， with the 6× goat horn- and antelope horn-containing Fufang Lingjiao Jiangya pills groups exhibited the best effect. Western blot and immunohistochemistry results showed that all the treatment groups exhibited down-regulated protein levels of AT1R， AGT， NF-κB p65， and TLR4 and up-regulated protein levels of ACE2 （P<0.05， P<0.01） compared with model group， with the 6×goat horn- and antelope horn-containing Fufang Lingjiao Jiangya pills groups showcasing the best effect. ConclusionReplacing antelope horn with 6×goat horn in Fufang Lingjiao Jiangya pills can achieve consistent blood pressure-lowering effect with the original prescription. The prescription may exert the effect by inhibiting the renin-angiotensin-aldosterone system （RAAS） and TLR4/NF-κB signaling pathways.

ObjectiveThe central symptom of Parkinson’s disease (PD) is impaired motor function. Beta-band electrical activity in the motor network of the basal ganglia is closely related to motor function. In this study, we combined scalp electroencephalography (EEG), brain functional network, and clinical scales to investigate the effects of beta burst-period neural electrical activity on brain functional network characteristics, which may serve as a reference for clinical diagnosis and treatment. MethodsThirteen PD patients were included in the PD group, and 13 healthy subjects were included in the healthy control group. Resting-state EEG data were collected from both groups, and beta burst and non-burst periods were extracted. A phase synchronization network was constructed using weighted phase lag indices, and the topological feature parameters of phase synchronization network were compared between the two groups across different periods and four frequency bands. Additionally, the correlation between changes in network characteristics and clinical symptoms was analyzed. ResultsDuring the beta burst period, the topological characteristic parameters of phase synchronization network in all four frequency bands were significantly higher in PD patients compared to healthy controls. The average clustering coefficient of the phase synchronization network in the beta band during the beta burst period was negatively correlated with UPDRS-III scores. In the low gamma band during the non-burst period, the average clustering coefficient of phase synchronization network was positively correlated with UPDRS and UPDRS-III scores, while UPDRS-III scores were positively correlated with global efficiency and average degree. ConclusionThe brain functional network features of PD patients were significantly enhanced during the beta burst period. Moreover, the beta-band brain functional network characteristics during the beta burst period were negatively correlated with clinical scale scores, whereas low gamma-band functional network features during the non-burst period were positively correlated with clinical scale scores. These findings indicate that motor function impairment in PD patients is associated with the beta burst period. This study provides valuable insights for the diagnosis of PD.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

Objective:To prepare the anti-programmed death-ligand 1 (PD-L1) nanoantibody P3C8-C3Fab by ligating with C3Fab and to investigate its role in plasma half-life.Methods:The C3Fab peptide derived from protein G was molecularly fused with the nanobody P3C8 by DNA recombination technology. The nanoantibody P3C8-C3Fab was inducibly expressed and purified in the E. coli BL21 strain, and the binding of it to PD-L1 protein, mouse IgG, and PD-L1-expressing tumor cells was detected by enzyme-linked immunosorbent assay (ELISA). The residual P3C8-C3Fab was detected in mouse serum at different times using double-antibody sandwich ELISA to assess the prolongation of the plasma half-life of PD-L1 nanobodies by C3Fab. Results:The nanoantibody P3C8-C3Fab was successfully constructed, and it could efficiently express itself in soluble form in BL21. The purified NbP3C8-C3Fab protein was obtained with a mass fraction of about 90% at a yield of 7.18 mg/L. The affinity of P3C8-C3Fab for PD-L1 protein and mouse IgG gradually increased with increasing mass concentration and showed a concentration correlation. The binding of P3C8-C3Fab to lung cancer A549 cells showed a concentration correlation. The concentration standard curve of P3C8-C3Fab in mouse serum showed a typical S-shape with a concentration correlation. The plasma half-life of P3C8 was only 0.44 h, while the plasma half-life of P3C8-C3Fab was 21.27-fold higher, up to 9.36 h.Conclusions:The linkage of C3Fab to the nanobodies of P3C8 can significantly prolong the plasma half-life of P3C8, which is valuable for the improvement of in vivo nanobody effects.

Objective:To investigate the relationship between the cerebral small vascular disease (CSVD) total burden and the imaging markers and the degree of unilateral middle cerebral artery (MCA) stenosis.Methods:The study was a cross-sectional study. Clinical and imaging data of patients with chronic unilateral MCA stenosis who underwent multimodal MRI from October 2015 to January 2019 in the First Medical Center of PLA General Hospital were retrospectively analyzed. A total of 261 patients were included, 187 males and 74 females. According to the degree of MCA stenosis, the patients were divided into 102 cases in severe stenosis-occlusion group (stenosis degree ≥70%) and 159 cases in mild-moderate stenosis group (stenosis degree <70%). CSVD imaging marker scores (including white matter hyperintensity, perivascular space, cerebral microbleed, and lacune of presumed vascular origin) were assessed according to the ?standards for reporting vascular changes on neuroimaging 1 in the 2 groups, and the CSVD total burden score was calculated. Mann-Whitney U test was used to compare the indicators between the two groups, and the CSVD total burden score and imaging marker scores were ultimately included in a multifactorial binary logistic regression to assess the association of CSVD imaging markers with severe stenosis-occlusion of the MCA after adjusting for vascular risk factors (age, gender, drinking, smoking, hypertension, hyperlipidemia, atrial fibrillation and coronary heart disease). Results:There were significant differences in the CSVD total burden, centrum semiovale perivascular space and lacune of presumed vascular origin score between the mild-to-moderate stenosis group and the severe stenosis-occlusion group (all P<0.05), and none of the differences in the remaining imaging marker scores were statistically significant (all P>0.05). Multivariate binary logistics regression analysis showed CSVD total burden score ( OR=1.300, 95% CI 1.047-1.613, P=0.017), centrum semiovale perivascular space score ( OR=2.099, 95% CI 1.540-2.860, P<0.001) and lacune of presumed vascular origin score ( OR=2.609, 95% CI 1.294-5.261, P=0.007) were independent associated with severe stenosis-occlusion of MCA. Conclusion:The higher CSVD total burden score, centrum semiovale perivascular space score and lacune of presumed vascular origin score are associated with severe stenosis-occlusion of MCA.

Objective:This study aims to explore the prevalence of hepatitis E virus (HEV) infection in patients and the screening value of serological indicators for HEV infection patients.Methods:Retrospective analysis was conducted on 97 440 cases of anti-HEV IgM and IgG simultaneously tested in two Beijing hospitals from January 1, 2018 to August 31, 2023. Among them, there were 61 005 males and 36 435 females, with an average age of 51.65±13.05 years old. According to the positivity of anti HEV specific antibodies, they were divided into anti-HEV IgM positive group (3 588 cases), anti-HEV IgG positive group (18 083 cases), and anti-HEV antibody negative group (78 892 cases). Results of HEV RNA, liver function, AFP, PIVKA-Ⅱ and PT were collected, and their basic clinical information were recorded. The prevalence of HEV infection in patients, as well as the relationship between the positivity of anti-HEV specific antibodies and the patient′s age group, HEV RNA, and clinical characteristics were analyzed.Results:Among 97 440 patients who tested anti-HEV IgM and IgG simultaneously, the positivity rate of anti-HEV IgM was 3.68% (3 588/97 440), and was 18.56% for anti-HEV IgG (18 083/97 440). The overall positivity rates of anti-HEV IgM in two Beijing hospitals from 2018 to 2023 were 2.51%, 2.53%, 3.02%, 4.59%, 5.72%, and 4.26% ( χ2=1 401.73, P<0.001), while the positivity rates of anti-HEV IgG were 12.56%, 12.32%, 12.85%, 22.65%, 27.42%, and 26.66% ( χ2=1 058.29, P<0.001). These rates showed a gradual increase until 2023 when a decline was observed. The positivity rates of anti-HEV IgM (2.28%, 3.60%, 4.47%) ( χ2=89.62, P<0.001) and IgG (4.71%, 17.86%, 25.94%) ( χ2=2 017.32, P<0.001) increased with age in patients who aged 1-30, >30-60, and over 60 years old. The age and ALB values of patients in the anti-HEV IgM positive group were lower than the IgG-positive group, while the proportion of males, TBIL, ALT, AFP and PT values were higher than the IgG-positive group, and the differences were statistically significance ( P<0.05). Furthermore, patients in both the anti-HEV IgM and IgG positive groups had higher age, male proportion, TBIL, ALT, AFP, PIVKA-Ⅱ, and PT values than the anti-HEV negative group. Additionally, both groups had lower ALB values than the anti-HEV negative group, all of which were statistically significant ( P<0.05). 2 162 HEV infected patients were grouped based on HEV RNA positivity. The proportion of anti-HEV IgM single positive, IgG single positive, IgM+IgG double positive, and antibody negative patients in the HEV RNA positive group were 5.42% (18/332), 3.62% (12/332), 90.36% (300/332), and 0.60% (2/332), respectively. Among them, the proportion of anti-HEV IgM+IgG double positive patients in the HEV RNA positive group was higher than that in the HEV RNA negative group ( χ2=302.87, P<0.001), while the proportion of anti-HEV IgG single positive ( χ2=174.36, P<0.001) and anti-HEV antibody negative patients ( χ2=59.28, P<0.001) were lower than that in the HEV RNA negative group, both of which were statistically significant ( P<0.001). In addition, the positive rates of HEV RNA in anti-HEV IgM positive, IgG positive, and antibody negative patients were 29.23% (318/1 088), 17.59% (312/1 774), and 0.65% (2/306), respectively. Conclusion:The HEV infection rate among patients declined in 2023. HEV infection is age-related, with older individuals being more susceptible. Abnormal liver function and jaundice were commonly observed during HEV infection. It is crucial to note that the absence of anti-HEV specific antibodies cannot rule out HEV infection; therefore, additional testing for HEV RNA and/or HEV Ag is necessary for accurate diagnosis.

ObjectiveTo explore the protective mechanism of paeoniflorin on mice with ulcerative colitis （UC） through the adenosine monophosphate-activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR） autophagy pathway. MethodUC mouse model was established by allowing mice freely drink 4% DSS， and 56 BALB/c male mice were randomly divided into model group， AMPK inhibitor group （20 mg·kg^-1）， paeoniflorin （50 mg·kg^-1） + inhibitor （20 mg·kg^-1） group， and high dose （50 mg·kg^-1）， medium dose （25 mg·kg^-1）， and low dose （12.5 mg·kg^-1） paeoniflorin groups. After seven days of drug intervention， the protective effect of paeoniflorin on mice with UC was determined by comparing the body weight， disease activity index （DAI） changes， and Hematoxylin-eosin （HE） staining results. Enzyme linked immunosorbent assay （ELISA） was used to detect the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in the serum of mice in each group， and immunofluorescence was utilized to detect microtubule-associated protein 1 light chain 3 （LC3） content in the colon， AMPK， mTOR proteins， and their phosphorylated proteins including p-AMPK and p-mTOR in the colon tissue were detected by Western blot， and the mRNA expression levels of AMPK， mTOR， Beclin1， LC3， and p62 were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the model group showed a decrease in body mass， an increase in DAI score， and severe pathological damage to the colon. The levels of inflammatory factors including TNF-α and IL-6 increased in serum （P<0.01）， while the protein levels of LC3 and p-AMPK/AMPK were down-regulated in colon tissue， and those of p-mTOR/mTOR were up-regulated （P<0.01）. The mRNA expression levels of AMPK and LC3 were down-regulated， while the mRNA expression levels of mTOR and p62 were up-regulated （P<0.01）. Compared with the model group and the paeoniflorin + inhibitor group， the mice treated with paeoniflorin showed an increase in body mass， a decrease in DAI score， a reduction in pathological damage to colon tissue， and a reduction in the levels of inflammatory factors of TNF-α and IL-6 in serum （P<0.05）. The protein levels of LC3 and p-AMPK/AMPK in colon tissue were up-regulated， while the protein levels of p-mTOR/mTOR were down-regulated （P<0.01）. The mRNA expression levels of AMPK， Beclin1， and LC3 were up-regulated， while the mRNA expression of mTOR and p62 were down-regulated （P<0.01）. The colon tissue of the inhibitor group was severely damaged， and the trend of various indicators was completely opposite to that of the high dose paeoniflorin group. ConclusionPaeoniflorin can enhance autophagy and reduce inflammatory damage in mice with UC by activating the AMPK/mTOR signaling pathway and thus play a protective role.