EgSeverin and Eg14-3-3zeta from Echinococcus granulosus are potential antigens for serological diagnosis of echinococcosis in dogs and sheep.

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the metacestode larva of Echinococcus granulosus. In this study, two-dimensional gel electrophoresis (2-DE) coupled with immunoblot analysis revealed that E. granulosus severin and 14-3-3zeta proteins (named EgSeverin and Eg14-3-3zeta, respectively) might be two potential biomarkers for serological diagnosis of echinococcosis. The recombinant EgSeverin (rEgSeverin, 45 kDa) and Eg14-3-3zeta (rEg14-3-3zeta, 35 kDa) were administered subcutaneously to BALB/c mice to obtain polyclonal antibodies for immunofluorescence analyses (IFAs). And IFAs showed that both proteins were located on the surface of protoscoleces (PSCs). Western blotting showed that both proteins could react with sera from E. granulosus-infected sheep, dog, and mice. Indirect ELISAs (rEgSeverin- and rEg14-3-3zeta-iELISA) were developed, respectively, with sensitivities and specificities ranging from 83.33% to 100% and a coefficient of variation (CV %) of less than 10%. The rEgSeverin-iELISA showed cross-reaction with both E. granulosus and E. multilocularis, while the rEg14-3-3zeta-iELISA showed no cross-reaction with other sera except for the E. granulosus-infected ones. The field sheep sera from Xinjiang and Qinghai were analyzed using rEgSeverin-iELISA, rEg14-3-3zeta-iELISA, and a commercial kit respectively, and no significant differences were found among the three methods (p > 0.05). However, the CE positive rates in sheep sera from Qinghai were significantly higher than those from Xinjiang (p < 0.01). Overall, the results suggest that EgSeverin and Eg14-3-3zeta could be promising diagnostic antigens for E. granulosus infection.

TNF-α Inhibits FoxO1 by Upregulating miR-705 to Aggravate Oxidative Damage in Bone Marrow-Derived Mesenchymal Stem Cells during Osteoporosis.

Decline of antioxidant defense after estrogen deficiency leads to oxidative damage in bone marrow-derived mesenchymal stem cells (BMMSCs), resulting a defect of bone formation in osteoporosis. Forkhead box O1 (FoxO1) protein is crucial for defending physiological oxidative damage in bone. But whether FoxO1 is involved in the oxidative damage during osteoporosis is largely unknown. In this study, we found that FoxO1 protein accumulation was decreased in BMMSCs of ovariectomized mice. The decrease of FoxO1 resulted in the suppression of manganese superoxide dismutase (Sod2) and catalase (Cat) expression and accumulation of reactive oxygen species (ROS), inhibiting the osteogenic differentiation of BMMSCs. The decline of FoxO1 protein was caused by tumor necrosis factor-alpha (TNF-α) accumulated after estrogen deficiency. Mechanistically, TNF-α activated NF-κB pathway to promote microRNA-705 expression, which function as a repressor of FoxO1 through post-transcriptional regulation. Inhibition of NF-κB pathway or knockdown of miR-705 largely prevented the decline of FoxO1-mediated antioxidant defense caused by TNF-α and ameliorated the oxidative damage in osteoporotic BMMSCs. Moreover, the accumulated ROS further activated NF-κB pathway with TNF-α, which formed a feed-forward loop to persistently inhibiting FoxO1 protein accumulation in BMMSCs. In conclusion, our study revealed that the decline of FoxO1 is an important etiology factor of osteoporosis and unclosed a novel mechanism of FoxO1 regulation by TNF-α. These findings suggested a close correlation between inflammation and oxidative stress in stem cell dysfunction during degenerative bone diseases.

Meta-analysis shows strong positive association of the TNF-α gene with tumor stage in bladder cancer.

There is no consensus on the association between the tumor necrosis factor-α (TNF-α) gene promoter -308 A/G single nucleotide polymorphisms and bladder cancer risk. To obtain a more precise estimation of this correlation, we conducted a meta-analysis. The PubMed, MEDLINE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched for relevant published studies. Seven case-control studies with a total of 1,311 cases and 1,436 controls were identified and analyzed. A notable correlation was observed between the TNF-α genotype and bladder cancer grade (AA+GA vs. GG; odds ratio 1.96, 95% confidence interval 1.37-2.80, p = 0.0002). In summary, this meta-analysis demonstrates that the TNF-α -308 AA+GA genotype may be a marker to the tumor-invasive stage of bladder cancer.

Engineered neutrophil apoptotic bodies ameliorate myocardial infarction by promoting macrophage efferocytosis and inflammation resolution.

Inflammatory response plays a critical role in myocardial infarction (MI) repair. The neutrophil apoptosis and subsequent macrophage ingestion can result in inflammation resolution and initiate regeneration, while the therapeutic strategy that simulates and enhances this natural process has not been established. Here, we constructed engineered neutrophil apoptotic bodies (eNABs) to simulate natural neutrophil apoptosis, which regulated inflammation response and enhanced MI repair. The eNABs were fabricated by combining natural neutrophil apoptotic body membrane which has excellent inflammation-tropism and immunoregulatory properties, and mesoporous silica nanoparticles loaded with hexyl 5-aminolevulinate hydrochloride (HAL). The eNABs actively targeted to macrophages and the encapsulated HAL simultaneously initiated the biosynthesis pathway of heme to produce anti-inflammatory bilirubin after intracellular release, thereby further enhancing the anti-inflammation effects. In in vivo studies, the eNABs efficiently modulated inflammation responses in the infarcted region to ameliorate cardiac function. This study demonstrates an effective biomimetic construction strategy to regulate macrophage functions for MI repair.

Erratum: Resveratrol counteracts bone loss via mitofilin-mediated osteogenic improvement of mesenchymal stem cells in senescence-accelerated mice: Erratum.

[This corrects the article DOI: 10.7150/thno.23620.].

Association Between Ideal Cardiovascular Health and Executive Function in Chinese Primary School Children.

Aims: Little information exists on the associations of cardiovascular health, a new metric proposed by the American Heart Association, and executive function, particularly in children. We aimed to explore this topic. Methods: We studied 3,798 children aged 6-12 years from 5 schools in Guangzhou, China. The executive function of children was evaluated using parent reports of the Behavioral Rating Inventory of Executive Function, which included 2 composite indexes and 8 subscale scores. We calculated the number of ideal cardiovascular health (range: 0-7) based on smoking, body mass index, physical activity (PA), diet, blood pressure, cholesterol, and glucose. A generalized linear mixed model was used to assess the association of the number of ideal cardiovascular health metrics and executive function. Results: Compared with children exhibiting 1-3 ideal cardiovascular health metrics, decreases of 1.37-2.63 points (indicating better performance) in metacognition index and its 5 subscale indexes (initiate, working memory, plan/organize, organization of materials, and monitor) were observed in children who attained 5 or 6-7 ideal metrics (all p for trend <0.001). Ideal diet and ideal PA were independently associated with lower indexes of behavioral regulation and metacognition. Conclusions: The number of ideal cardiovascular health was positively associated with performance of executive function in children.

Association of Sedentary Time and Physical Activity With Executive Function Among Children.

BACKGROUND: This study aimed to examine individual and combined associations between after-school sedentary time (ST) and daily physical activity (PA) with executive function development in children. METHODS: The study included 4304 children aged 6 to 12 years. ST and PA were assessed using the International Physical Activity Questionnaire Short Form, and executive function was assessed using the Behavior Rating Inventory of Executive Function (Parent Version). Participants were classified as low (<2 h per day) or high (≥2 h per day) ST and low (not meeting guidelines) or high (meeting guidelines) PA. Resulting groups were defined as 1) low ST/high PA, 2) low ST/low PA, 3) high ST/high PA, and 4) high ST/low PA. RESULTS: Children in group 4 had the highest mean T-scores for BRIEF indices (48.23 ± 8.44, indicating increased symptoms of executive function dysfunction), followed by those in group 3 (47.10 ± 8.05), group 2 (45.81 ± 7.78), and group 1 (44.41 ± 7.31). ST was positively related to the T-score of all indices, independent of moderate-to-vigorous physical activity (MVPA). Significantly negative associations were observed between MVPA and Metacognition Index only in the high ST subgroup. CONCLUSIONS: Low ST and high PA were positively associated with executive function development in children. Notably, children with high ST and high PA demonstrated more significant deficits in executive function than those with low ST and low PA, suggesting that intervention efforts should focus on ST reduction in addition to promoting PA.

T cell-depleting nanoparticles ameliorate bone loss by reducing activated T cells and regulating the Treg/Th17 balance.

Estrogen deficiency is one of the most frequent causes of osteoporosis in postmenopausal women. Under chronic inflammatory conditions caused by estrogen deficiency, activated T cells contribute to elevated levels of proinflammatory cytokines, impaired osteogenic differentiation capabilities of bone marrow mesenchymal stem cells (BMMSCs), and disturbed regulatory T cell (Treg)/Th17 cell balance. However, therapeutic strategies that re-establish immune homeostasis in this disorder have not been well developed. Here, we produced T cell-depleting nanoparticles (TDNs) that ameliorated the osteopenia phenotype and rescued the osteogenic deficiency of BMMSCs in ovariectomized (OVX) mice. TDNs consist of monocyte chemotactic protein-1 (MCP-1)-encapsulated mesoporous silica nanoparticles as the core and Fas-ligand (FasL) as the corona. We showed that the delicate design of the TDNs enables rapid release of MCP-1 to recruit activated T cells and then induces their apoptosis through the conjugated FasL both in vitro and in vivo. Apoptotic signals recognized by macrophages help skew the Treg/Th17 cell balance and create an immune tolerant state, further attenuating the osteogenic deficiency of BMMSCs and the osteopenia phenotype. Mechanistically, we found that the therapeutic effects of TDNs were partially mediated by apoptotic T cell-derived extracellular vesicles (ApoEVs), which promoted macrophage transformation towards the M2 phenotype. These findings demonstrate that TDNs may represent a promising strategy for treating osteoporosis and other immune disorders.

Long-term follow-up of in situ extramammary Paget's disease in Asian skin types IV/V treated with photodynamic therapy.

Photodynamic therapy is a potentially advantageous treatment for non-melanoma skin cancers. We evaluated the clinical response, recurrence and adverse events of photodynamic therapy for in situ extramammary Paget's disease in 14 male and 3 female Chinese patients with 21 lesions. Topical 20% 5-aminolevulinic acid was applied for 6 h. Each lesion was irradiated with 633 nm red light three times, 1 week apart, at a total dose of 339 J/cm2, followed by three assessments at 6, 12 and 24 months. Overall complete response (CR) rates were 52.4%, 42.9%, and 33.3% at 6, 12 and 24 months, respectively. The CR rate was significantly higher in scrotal lesions (66.6%) than in non-scrotal lesions (8.3%). The overall recurrence rate was 50%. The highest CR rate was for the lesions < 4 cm in diameter (62.5%), followed by those 4-8 cm (33.3%) and > 8 cm (0%). Most adverse events were well tolerated. In conclusion, photodynamic therapy for extramammary Paget's disease is not recommended as the first option except for scrotal cases or lesions < 4 cm in diameter.

Giant primary cutaneous spindle cell B-cell lymphoma of follicle center cell origin.

Spindle cell B-cell lymphoma is a rare morphologic variant of B-cell lymphoma that is generally associated with follicle center cell origin. It is typically found on the skin and presents as single nodule or plaque with a diameter of several centimeters. It is also characterized by abnormal spindle cells with elongated or spindle-shaped nuclei, and usually stained positive for Bcl-6 and negative for multiple myeloma oncogene 1 (MUM-1). In this report, we describe a giant primary cutaneous spindle cell B-cell lymphoma measured 20 cm × 25 cm, substantially larger than all the previously reported cases. Histologic examination revealed that the neoplasm was mainly located in the dermis and subcutaneous fat, and had infiltrated into striated muscles of the patient's back. The neoplasm cells contained elongated or spindle-shaped nuclei. Immunohistochemistry results demonstrated that the neoplasm cells were stained positive for CD20, CD79, and Bcl-6, negative for Bcl-2 and MUM-1, and focally positive for CD5, CD10, CD31, and CD43. These results collectively indicated that the neoplasm was of follicle center cell origin. The neoplasm was excised and the patient was still alive without systemic involvement after 4 years of follow-up.

Association between weekend catch-up sleep and executive functions in Chinese school-aged children.

STUDY OBJECTIVES: Although weekend catch-up sleep is common among children, the association between weekend catch-up sleep and executive functions remains unclear. We aimed to determine whether weekend catch-up sleep was related to executive functions in school-aged children. METHODS: We analyzed data for 4,699 children (9.00 years ± 1.73 years old, 52.9% boys) from 5 primary schools in Guangzhou, China. Executive functions performance was examined by the Behavior Rating Inventory of Executive Function Parent Form. Validated self-report questionnaires were used to assess sleep status, socioeconomic status, and health behaviors. Multiple linear regression analyses were used to assess the association of weekend catch-up sleep duration with executive functions. RESULTS: Weekday sleep was negatively associated with scores on three composite indices (Behavioral Regulation Index, Metacognition Index, Global Executive Composite), while weekend catch-up sleep was positively associated with them. Children with < 9 hours weekday sleep duration had higher scores in all indices, and there was no correlation between weekend catch-up sleep and scores of all indices (P > .05). For children who slept ≥ 9 hours on weekdays, weekend catch-up sleep of more than 1 hour was associated with increased scores of Behavioral Regulation Index, Metacognition Index, and Global Executive Composite (P < .05). There was no interaction between sex, age, and weekend catch-up sleep and executive functions (P > .05). CONCLUSIONS: Weekend catch-up sleep could not restore the executive functions deficits related to short weekday sleep. Weekend catch-up sleep over 1 hour may have adverse effects on executive functions in school-aged children. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Title: Prospective Cohort Study on Cognition and Cardiovascular Disease of Sedentary Behaviors in Children; URL: https://clinicaltrials.gov/ct2/show/NCT03582709; Identifier: NCT03582709.

Association of Reallocating Time in Different Intensities of Physical Activity with Weight Status Changes among Normal-Weight Chinese Children: A National Prospective Study.

Background: Time spent in different intensity-specific physical activities is codependent, but the substitution effect of different activities on weight status changes in children remains unclear. This study aims to investigate the prospective association between reallocating time in different intensities of physical activity and weight status changes among Chinese children. Methods: A national sample of 15,100 normal-weight children aged 7-18 years (46.7% boys) were recruited in September 2013 and followed up for nine months. Vigorous-intensity physical activity (VPA), moderate-intensity physical activity (MPA), walking, and sedentary time were obtained by International Physical Activity Questionnaire Short Form (IPAQ-SF). Height and weight were objectively measured, by which body mass index (BMI) and BMI z-score were calculated. Weight status was classified by the Chinese criteria for 7- to 18-year-old children. Isotemporal substitution analyses (including single-factor model, partition model, and isotemporal substitution model) were applied to examine the association of time allocation with weight status changes. Results: Each 30 min/day of increase in VPA was favorably associated with a 13.2% reduced risk of incident overweight/obesity in a single-factor model and a 15.6% reduced risk in a partition model. Negative associations were found between VPA, MPA, walking and the risk of being underweight in the single-factor model, but not in the partition model. In substitution models, replacing 30 min/day sedentary time with an equal amount of VPA was favorably associated with a 16.1% reduction of the risk of being overweight/obese. Conclusion: These findings highlight the need for promoting vigorous-intensity physical activity in children.

Exposure to ambient air pollution and executive function among Chinese primary schoolchildren.

BACKGROUND: Evidence on the associations between particulate matter (PM) and nitrogen dioxide (NO2) exposure with executive function in children is scarce in developing countries. Moreover, few studies investigated ozone (O3) and sulfur dioxide (SO2). This study aimed to investigate the associations between long-term exposure to air pollution and executive function in Chinese children. METHODS: In 2017, we randomly recruited 5028 children aged 6-12 years from 5 schools in Guangzhou city, southern China. Each of 5028 children's executive function were assessed using parent filled questionnaire. We further randomly selected 522 children to take computerized tests to assess working memory, inhibitory control, and cognitive flexibility. The 1-year average residence-based exposure to PM with diameters ≤2.5 (PM2.5) or 10 µm (PM10), NO2, O3, and SO2 exposures were estimated by using an inverse-distance weighting approach. Associations were evaluated by mixed linear regression models. RESULTS: The 1-year average concentrations of PM2.5, PM10, NO2, SO2, and O3 was 39.06 ± 1.12 µg/m3, 60.95 ± 3.49 µg/m3, 53.64 ± 4.44 µg/m3, 12.33 ± 0.79 µg/m3, and 90.07 ± 7.96 µg/m3, respectively. Each interquartile range increment in PM2.5 was associated with 48.04 ms [95% confidence interval (CI): 2.18 to 93.89] increase in inhibitory control and 0.72 (95% CI: -1.14 to -0.29) points decrease in forward recall. PM10 exposure was associated with 0.55 (95% CI: -1.04 to -0.06) and 0.67 points (95% CI: -1.09 to -0.25) reduction in forward and backward recall, respectively. SO2 exposure was associated with 0.69 (95%CI: 0.37 to 1.02) and 0.73 (95%CI: 0.40 to 1.05) high scores of behavioral regulation index and metacognition index, respectively. Significant association was found between O3 exposure and metacognition index (estimate, 95%CI: 0.87, 0.45 to 1.29). No associations for cognitive flexibility were observed. Stratified analyses did not yield any significant modification effects of sex, physical activity, screen time, and parental smoking. CONCLUSIONS: Long-term exposures to PM2.5, PM10, SO2, and O3 were associated with poorer performance in working memory, inhibitory control, behavioral regulation, and metacognition in children.

Air pollution-associated blood pressure may be modified by diet among children in Guangzhou, China.

OBJECTIVES: To assess the associations between long-term air pollution exposure and blood pressure in children, and to explore the modifying effects of diet on prehypertension and hypertension. METHODS: We evaluated 7225 primary school children aged 6-12 years from Guangzhou, China, in 2017. The blood pressure was measured objectively. The individual 1-year average concentration of particles with an aerodynamic diameter of 2.5 µm or less or 10 µm or less (PM2.5, PM10), sulfur dioxide (SO2), and ozone (O3) before each blood pressure measurement were calculated by inverse distance weighting interpolation according to each home address. Generalized linear mixed-effects models were used to examine the health effects and potential effect modifications by diet factors after adjusting for covariates. RESULTS: The results showed that the estimated increase in mean SBP was 0.92 mmHg (95% CI 0.05-1.79) per interquartile range increase in O3. An interquartile range increase in the 1-year mean of SO2 and O3 was associated with odds ratios of 1.26 (95% CI 1.04-1.52) and 1.20 (95% CI 1.06-1.35) for prehypertension, respectively. In addition, an interquartile range increase in PM2.5, SO2, and O3 exposure was positively associated with hypertension, with odds ratios of 1.33 (95% CI 1.11-1.61), 1.70 (95% CI 1.33-2.16), and 1.48 (95% CI 1.20-1.83), respectively. Stronger effect estimates between PM2.5, SO2, and O3 concentration on prehypertension were exhibited among subgroups of children with a higher intake of sugar-sweetened beverages. CONCLUSION: Long-term exposure to PM2.5, SO2, and O3 were associated with higher blood pressure levels in children, and dietary intake might modify these associations.

Apoptotic bodies derived from mesenchymal stem cells promote cutaneous wound healing via regulating the functions of macrophages.

BACKGROUND: As the major interface between the body and the external environment, the skin is liable to various injuries. Skin injuries often lead to severe disability, and the exploration of promising therapeutic strategies is of great importance. Exogenous mesenchymal stem cell (MSC)-based therapy is a potential strategy due to the apparent therapeutic effects, while the underlying mechanism is still elusive. Interestingly, we observed the extensive apoptosis of exogenous bone marrow mesenchymal stem cells (BMMSCs) in a short time after transplantation in mouse skin wound healing models. Considering the roles of extracellular vesicles (EVs) in intercellular communication, we hypothesized that the numerous apoptotic bodies (ABs) released during apoptosis may partially contribute to the therapeutic effects. METHODS: ABs derived from MSCs were extracted, characterized, and applied in mouse skin wound healing models, and the therapeutic effects were evaluated. Then, the target cells of ABs were explored, and the effects of ABs on macrophages were investigated in vitro. RESULTS: We found ABs derived from MSCs promoted cutaneous wound healing via triggering the polarization of macrophages towards M2 phenotype. In addition, the functional converted macrophages further enhanced the migration and proliferation abilities of fibroblasts, which together facilitated the wound healing process. CONCLUSIONS: Collectively, our study demonstrated that transplanted MSCs promoted cutaneous wound healing partially through releasing apoptotic bodies which could convert the macrophages towards an anti-inflammatory phenotype that plays a crucial role in the tissue repair process.

Negative regulation of endogenous protein kinase Calpha on the dynamic change of carbachol-induced intracellular calcium response in different melanoma cells.

Regulations of intracellular protein kinase C (PKC) on carbachol (CCh)-induced intracellular calcium ([Ca(2+)]i) responses were investigated in different stages of melanoma cells. We found that CCh (1 mM) significantly increased [Ca(2+)]i with 6-, 4-, 4-, and 25-folds intensities in WM793B, 451Lu, SK-MEL-5, and A2058 melanoma cells, respectively. Pretreatment of phorbol 12, 13-dibutyrate (PDBu, 2 microM), an activator of intracellular PKC, significantly suppressed CCh-induced peak reactions in WM793B, SK-MEL-5, and A2058 cells. RT-PCR data showed that mRNA levels of PKCalpha were 12-, 4-, 6-, and 0.9-folds higher in above four melanoma cells. Short interfering RNA (siRNA) targeting to PKCalpha in WM793B cells enhanced CCh-induced peak calcium reactions. Present data indicated that CCh-induced [Ca(2+)]i responses were dynamically changed in different stages of melanoma progression. Moreover, intracellular PKCalpha activated by exogenous agonist and expressed through endogenous gene transcription negatively regulated CCh-induced calcium responses. The functional analysis on the relationship between CCh-induced calcium response and endogenous PKCalpha expression might be helpful to predict the development of melanoma.

New Advances in Stem Cell Therapy for Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH) is a common refractory orthopedic disease with multiple etiologies that more frequently occurs in middle-aged and young people. ONFH is the main cause of hip replacement in young patients. Since Professor Hernigou first reported the use of stem cells in the treatment of early stage ONFH, a large number of studies have demonstrated the potential of stem cells in the treatment of adult patients with ONFH. With the rise of interdisciplinary stem cell therapy combined with platelet-rich plasma therapy, gene therapy or other methods have gradually attracted the attention of researchers. This article summarizes the current advances in stem cell therapy for ONFH, as well as the problems and challenges, which may provide reference for further research.

Effects of physical activity and sedentary behaviour on cardiometabolic risk factors and cognitive function in children: protocol for a cohort study.

INTRODUCTION: Although studies showed that physical activity (PA) and sedentary behaviour (SB) were associated with cardiometabolic risk factors and cognitive function, both independent and combined associations among them are inconsistent. Cardiometabolic risk factors are also associated with cognitive function, but research of children is limited. Additionally, the brain level mechanisms have not been fully established. The proposed study aims to explore the associations and mechanisms of PA and SB on cognitive function and cardiometabolic risk factors in children. METHODS AND ANALYSIS: This is a school-based prospective cohort study. A total of 8324 participants of this study are primary school students aged 7-12 years old who are followed up every 2 years from January 2017 to December 2026. We used a stratified cluster random sampling to select five primary schools in Guangzhou, China. There are three phases at baseline. At phase I, we collect PA, SB and cognitive function by questionnaires and also conduct anthropometric and biochemical measurements in all participants. At phase II, PA, SB and cognitive function are measured respectively by accelerometers and cognitive tasks among participants randomly selected from four subgroups with different SB and PA levels. At phase III, event-related potentials are recorded using electroencephalogram during a cognitive task among participants randomly selected from phase II. We plan to follow-up all participants until they graduate from high school. The process applied at baseline and follow-up are approximately identical. ETHICS AND DISSEMINATION: Procedures described in this manuscript have been approved by the Ethical Review Committee for Biomedical Research, School of Public Health, Sun Yat-sen University (L2016-010). All parents or guardians of participants signed the informed consent form voluntarily before participating in the study. The findings of the study will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03582709.

Tension enhances cell proliferation and collagen synthesis by upregulating expressions of integrin αvß3 in human keloid-derived mesenchymal stem cells.

AIMS: Keloids are a dermal fibrotic disease whose etiology remains totally unknown and for which there is no successful treatment. Mechanical tension, in addition, is closely associated with the germination and development of keloids. In this study, we investigated the influence of human keloid-derived mesenchymal stem cells (KD-MSCs) on cell proliferation, collagen synthesis, and expressions of integrin αvß3 under tension. MAIN METHODS: KD-MSCs and human normal skin-derived mesenchymal stem cells (NS-MSCs) were isolated and cultured in stem cell medium with a gradual increase in the serum concentration. Cell proliferation and collagen synthesis were detected by Cell Counting Kit-8 (CCK-8) assay and hydroxyproline content analysis under tension respectively. We investigated the messenger RNA expressions of nine integrin subunits, including integrin units α2, α3, α5, αv, α8, α10, α11, ß1, and ß3, in KD-MSCs stimulated with tension. Identification of differentially expressed genes was performed by Western blot analysis and immunocytochemistry staining. KEY FINDINGS: We obtained high-purity KD-MSCs and NS-MSCs using the culture method of decreasing serum concentration gradient gradually. Furthermore, we found that tension enhances cell proliferation and collagen synthesis and promotes expressions of integrin αvß3 in KD-MSCs. In addition, blocking experiments showed that increased integrin αvß3 expression affects cell proliferation and collagen synthesis of KD-MSCs under tension. SIGNIFICANCE: Our results suggest that integrin αvß3 receptor may be sensitive molecules of mechanical tension and could contribute to the occurrence and development of keloids. It could lead to novel targets for therapeutic intervention, treatment, and prevention of recurrence for keloid disorders.

Resveratrol counteracts bone loss via mitofilin-mediated osteogenic improvement of mesenchymal stem cells in senescence-accelerated mice.

Rational: Senescence of mesenchymal stem cells (MSCs) and the related functional decline of osteogenesis have emerged as the critical pathogenesis of osteoporosis in aging. Resveratrol (RESV), a small molecular compound that safely mimics the effects of dietary restriction, has been well documented to extend lifespan in lower organisms and improve health in aging rodents. However, whether RESV promotes function of senescent stem cells in alleviating age-related phenotypes remains largely unknown. Here, we intend to investigate whether RESV counteracts senescence-associated bone loss via osteogenic improvement of MSCs and the underlying mechanism. Methods: MSCs derived from bone marrow (BMMSCs) and the bone-specific, senescence-accelerated, osteoblastogenesis/osteogenesis-defective mice (the SAMP6 strain) were used as experimental models. In vivo application of RESV was performed at 100 mg/kg intraperitoneally once every other day for 2 months, and in vitro application of RESV was performed at 10 µM. Bone mass, bone formation rates and osteogenic differentiation of BMMSCs were primarily evaluated. Metabolic statuses of BMMSCs and the mitochondrial activity, transcription and morphology were also examined. Mitofilin expression was assessed at both mRNA and protein levels, and short hairpin RNA (shRNA)-based gene knockdown was applied for mechanistic experiments. Results: Chronic intermittent application of RESV enhances bone formation and counteracts accelerated bone loss, with RESV improving osteogenic differentiation of senescent BMMSCs. Furthermore, in rescuing osteogenic decline under BMMSC senescence, RESV restores cellular metabolism through mitochondrial functional recovery via facilitating mitochondrial autonomous gene transcription. Molecularly, in alleviating senescence-associated mitochondrial disorders of BMMSCs, particularly the mitochondrial morphological alterations, RESV upregulates Mitofilin, also known as inner membrane protein of mitochondria (Immt) or Mic60, which is the core component of the mitochondrial contact site and cristae organizing system (MICOS). Moreover, Mitofilin is revealed to be indispensable for mitochondrial homeostasis and osteogenesis of BMMSCs, and that insufficiency of Mitofilin leads to BMMSC senescence and bone loss. More importantly, Mitofilin mediates resveratrol-induced mitochondrial and osteogenic improvements of BMMSCs in senescence. Conclusion: Our findings uncover osteogenic functional improvements of senescent MSCs as critical impacts in anti-osteoporotic practice of RESV, and unravel Mitofilin as a novel mechanism mediating RESV promotion on mitochondrial function in stem cell senescence.