Objective
To summarize the role of cellular senescence and senescent secretary phenotype in the intervertebral disc (IVD) degeneration.
Methods
Relevant articles that discussed the roles of cellular senescence in the IVD degeneration were extensively reviewed, and retrospective and comprehensive analysis was performed. The senescent phenomenon during IVD degeneration, senescent secretary phenotype of the disc cells, senescent pathways within the IVD microenvironment, as well as the anti-senescent approaches for IVD regeneration were systematically reviewed.
Results
During aging and degeneration, IVD cells gradually and/or prematurely undergo senescence by activating p53-p21-retinoblastoma (RB) or p16INK4A-RB senescent pathways. The accumulation of senescent cells not only decreases the self-renewal ability of IVD, but also deteriorates the disc microenvironment by producing more inflammatory cytokines and matrix degrading enzymes. More specific senescent biomarkers are required to fully understand the phenotype change of senescent disc cells during IVD degeneration. Molecular analysis of the senescent disc cells and their intracellular signaling pathways are needed to get a safer and more efficient anti-senescence strategy for IVD regeneration.
Conclusion
Cellular senescence is an important mechanism by which IVD cells decrease viability and degenerate biological behaviors, which provide a new thinking to understand the pathogenesis of IVD degeneration.
Objective To observe the replicative senescence of rat articular chondrocyte cultured in vitro so as to provide reference for the succeeding experiment of using medicine interfere and reverse the cataplasia of tissue engineering cartilage or probing cataplasia mechanism．Methods Different generations(P1, P2, P3 and P4) of the chondrocytes were detected with the methods of histochemistry for β-galactosidase (β-gal)， electronmicroscope for ultromicrostructure， immunocytochemistry for proliferating cell nuclear antigen (PCNA)，alcian blue stain for content and structure of sulfatglycosaminoglycan (GAG) of extracellular matrix (ECM)，reverse transcriptionpolymerase chain reaction (RTPCR) for content of collagen Ⅱ，flow cytometry for cell life cycle and proliferative index(PI) to observe senescence of chondrocytes．Results In the 4th passage，the chondrocytes emerging quantitively positive express of β-gal，cyto-architecture cataplasia such as caryoplasm ratio increasing and karyopycnosis emerging under electronmicroscope ，cell life cycle being detented on G1 phase(83．8％)，while in P1, P2, P3 the content of G1 phase was 79.1%, 79.2%, 80.8% respectively. In the 4th passage, PI decreased(16．2％)，while in P1, P2, P3, it was 20.9%, 20.8%, 19.2%. The positive percentage of PCNA，the content of GAG(long chain molecule) and the positive expression of collagen Ⅱ diminished,all detections above were significantly different (Plt;0.01) when compared the 4th passage with the preceding passages．Conclusion Chondrocytes show the onset of senescence in the 4th passage．
Objective To investigate the phenotypic change and proliferation of fibroblasts in human inflammatory strictured bile duct wall. Methods We observed the density and ultrastructure of fibroblasts, and the histologic structure in human normal bile duct wall and inflammatory strictured bile duct wall by light and electron microscope.Results The results showed that fibroblasts were the main source of extracellular matrix production in bile duct wall. The phenotype of fibroblasts in inflammatory strictured bile duct wall changed obviously, quiescent fibroblasts were activated and transformed to myofibroblasts, with massive proliferation. Conclusion These data suggest that massive proliferation of activated fibroblasts and myofibroblasts is the main source of extracellular matrix overproduction which results in inflammatory bile duct stricture.
Objective To observe the effect of pilose antler polypeptides(PAP)on the apoptosis of rabbit marrow mesenchymal stem cells (MSCs) differentiated into chondrogenic phenotype by interleukin 1β (IL-1β) so as to optimize the seeding cells in cartilage tissue engineering. Methods The MSCs were separated from the nucleated cells fraction of autologus bone marrow by density gradient centrifuge and cultured in vitro. The MSCs were induced into chondrogenic phenotype by transforming growth factor β1(TGF-β1) and basic fibroblast growth factor(bFGF). According to different medias, the MSCs were randomly divided into four groups: group A as black control group, group B(100 ng IL-1β)，group C(10 μg/ml PAP+100 ng IL-1β) and group D(100 ng/ml TGF-β1 +100 ng IL-1β). The samples were harvested and observed by morphology, flow cytometry analysis, RT-PCR and ELISA at 24, 48 and 72 hours. Results The intranuclear chromatin agglutinated into lump and located under nulear membranes which changed into irregular shapeat 24 hours. The intranuclear chromatin agglutinated intensifily at 48 hours. Then the nucear fragments agglutinated into apoptosic corpuscles at 72 hours in group B. The structure change of cells in groups C and D was later than that in group B, and the number of cells changed shape was fewer than that in group B. The structure change of cells in group A was not significant. The apoptosic rate of cells, the mRNA expression of Caspase-3 and the enzymatic activity of Caspase-3 gradually increased in group B, and there were significant differences compared with groups A,C and D(Plt;0.01). Conclusion Caspase-3 is involved in aoptosis of the MSCs differentiated into chondrogenic phenotype cultured in vitro. PAP could prevent from or reverse apoptosis of these MSCs by decreasing the expression of Caspase-3 and inhibiting the activity of Caspase-3.
Chronic obstructive pulmonary disease (COPD) is one of the common chronic airway disorders, which accounts for the third to fourth cause of death worldwide. Recently, the focuses of researches are on the multi-factorial risks for development of COPD, mechanisms related to COPD development, early detection and early intervention of COPD, individualized use of long-term maintenance medications as well as phenotypes of acute exacerbation of COPD and their corresponding management. There are huge amount of COPD patients with variety of risk factors or different phenotypes in China, which makes it possible to establish a network for cohort study or real life registration study of COPD. The results will provide new information on the characteristics of COPD in China. Individualized treatment could be recommended according to the phenotypes or endotypes information. All these new findings or progresses could provide impetus for improvement of the ability of research and clinical management of COPD to the worldwide top level.
ObjectiveTo explore the phenotypic changes of epidermal stem cells (ESCs) differentiating into sweat glands cells (SGCs) in vitro and its mechanisms.
MethodsESCs and SGCs were isolated and cultured in vitro, which were identified using immunofluorescence staining. ESCs at passage 2 were divided into 4 groups: ESCs and SGCs co-cultured by Transwell plates in group A, ESCs cultured by simply adding sweat supernatant in group B, ESCs and SGCs co-cultured on Transwell plate adding epidermal growth factor (EGF) (60 ng/mL) in group C, and ESCs and SGCs co-cultured on transwell plate adding PD98059 (10 mmol/L) in group D. The inverted microscope was used for observing the morphology of ESCs, flow cytometry for detecting ESCs positive phenotype, and Western blot for exploring mitogen-activated protein kinase/extracellular signal regulated kinase (MAPK/ERK) pathway.
ResultsThe morphology observation and immunofluorescence staining suggested that cultured cells were ESCs and SGCs. The inverted phase contrast microscope observation showed that cells had similar morphological changes, with flat polygonal shape at 9 days in groups A, C, and D; cells had slow morphological change in group B, and had similar change to that of other groups at 12 days. Significant decreasing of β1-integrin expression and increasing of carcino-embryonic antigen (CEA) expression of ESCs were observed in group A when compared with group B, which was inhibited by EGF (group C) and enhanced by PD98059 (group D), and there were significant differences among groups A, C, and D (P<0.05). High level of ERK expression was displayed in 4 groups, but it was significantly lower in group B than the other 3 groups (P<0.05). The expression of phosphorylation ERK was the highest in group A and was the lowest in group C, showing significant difference among 4 groups (P<0.05).
ConclusionESCs can be induced to differentiate into SGCs with the phenotypic changes under the condition of co-cultured by Transwell plates. The MAPK/ERK pathway plays a key role in the differentiation of ESCs into SGCs.
Objective To investigate the potential causal associations between 731 immune cell traits and atherosclerosis by Mendelian randomization (MR) analysis. Methods Using single nucleotide polymorphisms (SNPs) as instrumental variables, genome-wide association study (GWAS) summary statistics (GCST90001391 to GCST90002121) for 731 immune cell traits were obtained from the GWAS Catalog database, and the atherosclerosis dataset (finn-b-I9_CORATHER) was retrieved from the IEU database for MR analysis. The inverse variance weighted method, MR-Egger regression, weighted median, simple mode, and weighted mode approaches were employed to estimate the causal effects between the 731 immune cell traits and atherosclerosis, using odds ratio (OR) with 95% confidence interval (CI) as the effect size. Cochran Q test was used to assess heterogeneity. Horizontal pleiotropy was evaluated using the MR-Egger intercept test and the MR-PRESSO method. Leave-one-out analysis was conducted to examine the sensitivity of the causal estimates to individual SNPs. Results MR analysis revealed potential causal associations between 24 immune cell traits and atherosclerosis (P<0.05). Among them, human leucocyte antigen (HLA)-DR on plasmacytoid dendritic cells (DC) [OR=1.035, 95%CI (1.016, 1.054), P<0.001] and hematopoietic stem cell absolute count (HSCAC) [OR=1.049, 95%CI (1.021, 1.077), P<0.001] showed significant positive causal associations with atherosclerosis (P≤0.001), whereas CD86 on CD62L+ myeloid DC [OR=0.953, 95%CI (0.926, 0.981), P=0.001] exhibited a significant negative causal association with atherosclerosis (P≤0.001). The results of Cochran Q test, MR-Egger regression, and MR-PRESSO indicated P-values>0.05, suggesting no evidence of heterogeneity or horizontal pleiotropy in the causal estimates for these three immune cell traits. Reverse MR analysis, using the 24 immune cell traits as outcome variables, showed no evidence of causal association (P>0.05), supporting a unidirectional causal relationship from immune cells to atherosclerosis. Conclusion HLA-DR on plasmacytoid DC and HSCAC may serve as risk factors for atherosclerosis, while CD86 on CD62L+ myeloid DC may play a protective role against atherosclerosis.
ObjectiveTo explore the difference in clinical characteristics and airway inflammation in COPD patients with different bronchodilator test results.
MethodsA total of 237 COPD patients visited between January 2013 and December 2014 were recruited in the study. The ability to complete daily living questionnaire (ADL),modified Medicine Research Council (mMRC) score,6-minute walk distance,pulmonary function,and cell count in induced sputum were measured in the patients. They were divided into a positive group and a negative group according to the response to bronchodilator test and compared.
ResultsThere were 58 cases (24.47%) in the positive group,and 179 cases (75.53%) in the negative group. There were no differences in the cumulative amount of smoking[(44.36±17.51) pack-years vs. (50.15±30.51) pack-years],duration of recurrent cough[(14.1±11.1) years vs. (15.5±11.4) years],history of allergic diseases (22.40% vs. 30.80%),or family history of allergic disease (5.17% vs. 2.23%) between two groups. In the positive group,FEV1%pred[(51.04±13.26)% vs. (44.10±14.66)%] and FVC%pred[(73.81±13.60)% vs. (64.33±15.17)%] were better than those of the negative group (both P<0.05). DLCO%pred[(44.66±13.92)% vs. (40.60±17.31)%] and RV/TLC[(51.80±10.57)% vs. (53.16±11.15)%] had no significant differences between two groups. 43.10% of the patients in the positive group and 61.46% in the negative group felt shortness of breath after walking (P<0.05). The positive group scored 22.6±3.8 points in activities of daily living assessment,1.5±0.9 points in mMRC,436.22±102.83 meters in 6-minute walking test,and 2.7±2.1 points in Borg scale score,which were all better than those in the negative group (all P<0.05). There was no significant difference in cell counting in induced sputum between two groups.
ConclusionsA part of COPD patients have positive response to bronchodilator,with better lung function,better ADL score,better mMRC score,and farther 6-minute walking distance. It suggests that a positive bronchodilator response might be a clinical phenotype of COPD.
ObjectiveTo observe and investigate the related factors that might affect clinical features of familial exudative vitreoretinopaty (FEVR) patients. MethodsA retrospective chart study. From January 2012 and December 2021, 42 patients with 84 eyes with a diagnosis of FEVR from Department of Ophthalmology, Peking University People's Hospital were included in the study. The patients came from 42 separate families. There were 31 males and 11 females, with an average age of first diagnosis was 16.6±33.7 months. There were 21 patients referred from other hospitals for the fundus disease found in eye screening after birth, 21 patients were first seen in our hospital. There were 4 and 38 premature and full-term infants, respectively. Two patients with a positive family history of FEVR. All patients are FEVR stages 1-5. The wide-angle digital pediatric retinal imaging system after general anesthesia for fluorescein fundus angiography (FFA) examination were performed for patients aged ＜5 years. If patients ≥ 5 years old, routine FFA examination was performed. Sixty-eight first-degree relatives from 28 families undergo routine fundus examinations and FFA examination. Genetic examination was performed for 26 families, including 26 probands and 57 first-degree relatives. Genetic examination were performed on gene the coreceptor of low density lipoprotein receptor-associated protein 5 (LRP5), Wnt receptor coiled protein 4 (FZD4), Norrie disease (NDP), tetraporin 12 (TSPAN12), catenin β1 (CTNNB1) genes known to be involved in FEVR. The clinical features and the genotype of FEVR were observed in relation to the clinical phenotype. ResultsAmong the 42 patients, 13 patients were first observed by strabismus and nystagmus, with the median age of 12 months. Eight patients were complained non-chasing or vision-related symptoms. Among the 84 eyes, FEVR stage 1 or 2, 3 or 4, and 5 were 50 (59.5%, 50/84), 31 (36.9%, 31/84), and 3 (3.6%, 3/84) eyes, respectively. Among the 23 patients who were > 3 months at first diagnosis, 16 patients had at least one eye severer than stage 3 (69.6%, 16/23). Of the 68 first-degree relatives, 22 (32.4%, 22/68) had FEVR-like changes. Among the 26 families that underwent genetic detection, 13 families (50%, 13/26) of 16 variants of FEVR-related genes were detected, of which 10 mutations of LRP5 gene were the most common. There were 10 families with single gene mutations, including 6, 2 and 2 families of LRP5, FZD4 and CTNNB1 genes, respectively. One family of LRP5 gene mutations were compound heterozygous mutations, 1 family with LRP5 gene mutaition combined with NDP gene mutation, and 1 family with LRP5 and TSPAN12 gene mutation. Among the proband with FEVR pathogenic genes, 6 cases with similiar stage of both eyes, and 7 cases with inconsistent disease stages, and there was no obvious correlation between gene mutations and clinical phenotypes. ConclusionIn addition to the age of first diagnosis, no exact factors affecting the clinical manifestations of FEVR are found, and the association between clinical phenotypic and genetic heterogeneity still needs to be further explored.
