Objective The aim of this study was to investigate the prospective association between physical activity (PA),independently or in conjunction with other contributing factors,and osteoporosis (OP) outcomes. Methods The Physical Activity in Osteoporosis Outcomes (PAOPO) study was a community-based cohort investigation. A structured questionnaire was used to gather the participants' sociodemographic characteristics. Bone mineral density (BMD) measurements were performed to assess OP outcomes,and the relationship between BMD and OP was evaluated within this cohort. Results From 2013 to 2014,8,471 participants aged 18 years and older were recruited from Tangshan,China's Jidong community. Based on their PA level,participants were categorized as inactive,moderately active,or very active. Men showed higher physical exercise levels than women across the activity groups. BMD was significantly higher in the very active group than in the moderately active and inactive groups. Individuals aged>50 years are at a higher risk of developing OP and osteopenia. Conclusion The PAOPO study offers promising insights into the relationship between PA and OP outcomes,encouraging the implementation of PA in preventing and managing OP.

The healing after skin injury is a dynamic process of the interaction of various cells, cytokines, and extracellular matrix, and the abnormality of any link will affect the speed and quality of wound healing. Circadian rhythm is a spontaneous periodic oscillation cycle in organisms, which plays an important role in maintaining homeostasis and regulating physiological activities. Studies have shown that circadian rhythm genes play a key role in wound healing. This review summarizes the effects of circadian rhythm genes on different stages of wound healing and its possible mechanism of action, in order to provide a new perspective for wound healing and provide theoretical basis for formulating more effective treatment strategies for refractory wounds.

The healing process after skin injury is a dynamic process of interaction between various cells, cytokines, and extracellular matrix. Fibrosis is one of the main ways of skin injury repair. The process of fibrosis involves the regulation of many factors. Studies have shown that nerve regeneration-related protein (NREP) plays a key role in the fibrosis of skin tissue and organs. Based on the mechanism of skin fibrosis, this paper discusses the construction of tertiary structure of NREP, summarizes the effects of NREP and different cells in the skin on skin fibrosis and the research progress of mechanism of NREP in skin fibrosis, thus providing new ideas for the treatment of skin fibrosis diseases.

Objective:To investigate the efficacy of TiRobot navigation combined with ankle arthroscopy in the reduction and internal fixation of Hawkins type Ⅱ talus neck fracture.Methods:From January 2019 to September 2020, a total of 13 patients with Hawkins type Ⅱ talus neck fracture were admitted to Department of Foot and Ankle Surgery, Xuzhou Renci Hospital. They were 8 males and 5 females, with a mean age of 35.8 years (from 22 to 61 years). All fractures were reduced and fixated using TiRobot navigation combined with ankle arthroscopy. Time for fracture reduction assisted by intraoperative arthroscopy, time for internal fixation assisted by TiRobotic navigation, fracture union time and complications were recorded. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was used at the last follow-up to evaluate the functional outcomes.Results:All the operations were finished within 2 hour. The primary screw placement succeeded in all. The time for fracture reduction assisted by intraoperative arthroscopy averaged 52.8 min (from 43 to 66 min) and the time for internal fixation assisted by TiRobotic navigation 43.6 min (from 33 to 55 min). All the patients were followed up for an average 13.3 months(from 12 to 15 monhs). They obtained bony union within 3 months. One patient developed traumatic subtalar arthritis with mild pain and was treated conservatively. None of the patients had complications like incision infection or talus necrosis. The average AOFAS ankle-hindfoot score was 91.0 points (from 83 to 94 points) at the last follow-up.Conclusion:In the reduction and internal fixation of Hawkins type Ⅱ talus neck fracture, TiRobot navigation combined with ankle arthroscopy shows advantages of minimal invasion, accurate reduction and screw placement, and limited complications, leading to fine short-term functional outcomes.

Abdominal aortic aneurysm (AAA) and atherosclerosis (AS) have considerable similarities in clinical risk factors and molecular pathogenesis. The aim of our study was to investigate the differences between AAA and AS from the perspective of metabolomics, and to explore the potential mechanisms of differential metabolites via integration analysis with transcriptomics. Plasma samples from 32 AAA and 32 AS patients were applied to characterize the metabolite profiles using untargeted liquid chromatography-mass spectrometry (LC-MS). A total of 18 remarkably different metabolites were identified, and a combination of seven metabolites could potentially serve as a biomarker to distinguish AAA and AS, with an area under the curve (AUC) of 0.93. Subsequently, we analyzed both the metabolomics and transcriptomics data and found that seven metabolites, especially 2'-deoxy-D-ribose (2dDR), were significantly correlated with differentially expressed genes. In conclusion, our study presents a comprehensive landscape of plasma metabolites in AAA and AS patients, and provides a research direction for pathogenetic mechanisms in atherosclerotic AAA.

Extracellular signal-regulated kinase (ERK) is a kind of serine/threonine protein kinase. As a key downstream protein in RAS-RAF-MEK-ERK signaling pathway, its abnormal activation plays an important role in the development of tumors. Selective ERK1/2 inhibitors can block ERK signaling pathway while overcoming drug resistance caused by upstream target mutation. In this paper, the components of MAPK signaling pathway, the structure and functions of ERK and the role of ERK signaling pathway in tumor development are summarized, and some representative ERK inhibitors in clinical or preclinical studies are emphasized.

Objective:To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice.Methods:Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco′s modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10 4 hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 μL of cell suspension containing 1×10 7 hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 μL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results:(1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar ( t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group ( t=14.722, P<0.01). On day 7 in culture, the content of IL-12 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group ( t=13.226, P<0.01), and the content of arginase 1 and IL-10 was significantly higher than that in macrophage alone group ( t=30.172, 31.406, P<0.01). (2) On PID 1, a large number of inflammatory cells infiltration were observed in the skin wounds of both groups. On PID 3, the inflammatory cells infiltration in the skin wounds increased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 7, the inflammatory cells infiltration in the wounds decreased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 14, no obvious inflammatory cells infiltration was observed in the wounds in the two groups. (3) On PID 1 and 14, the percentages of CD68 and iNOS double positive cells and CD68 and arginase 1 double positive cells in the wounds were similar in the two groups ( t1 d=0.134, 0.693, t14 d=1.146, 2.585, P>0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group ( t=6.396, 4.787, P<0.01), while the percentages of CD68 and arginase 1 double positive cells were significantly higher than those of PBS group ( t=3.928, 4.473, P<0.01). (4) On PID 1, the mRNA expressions of IL-10 in the wounds of mice in the two groups were similar ( t=2.005, P>0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group ( t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions:hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

Wound healing is a dynamic process which involves interaction of various types of cells, cytokines, and extracellular matrix. Among them, epithelial cells and mesenchymal cells are the key components which involve in wound healing and scar formation. Related scholars had done a great number of studies about the functions of epithelial cells and fibroblasts(Fbs) in wound healing and scar formation. The results showed that under the stimulation of complex microenvironment, epithelial cells would lose their epithelial characteristics and acquire the typical characteristics and migration ability of mesenchymal cells. At the same time, with the complex changes of cell structure and cell behavior, they would participate in the process of tissue wound repair, including normal or fibrotic repair, by covering the wound with migration. Fbs are the key cells for the wound fibrotic repair, and play important roles in the process of wound healing, including excessive wound healing or delayed wound healing. In the recent years, the researchers realized that the cross-talk between epithelial cells and Fbs in wound healing, which is referred to as epithelial-mesenchymal interaction, significantly changes the biological behaviors of these two cell types, which affects the dermal remodeling and re-epithelialization quality of wound. Epithelial-mesenchymal interaction plays an important role in skin morphogenesis during embryonic development and maintaining the structural integrity of adult skin. In the process of re-epithelialization, Fbs could promote the proliferation and migration of keratinocytes, meanwhile keratinocytes would receive the signals from Fbs to reconstruct functional epithelium, which has become a hot topic in the field of wound healing at present. In this paper, a comprehensive analysis of the literature on the role of epithelial-mesenchymal interaction in wound healing and scar formation at home and abroad in recent years is presented for the reference of relevant scholars.

Objective:To investigate the feasibility of in vitro inflammatory wound microenvironment simulated by using inflammatory wound tissue homogenate of mice.Methods:(1) Ten eight-week-old C57BL/6 male mice were collected and full-thickness skin tissue with diameter of 1.0 cm on both sides of the midline of the back was taken with a perforator to make the normal skin tissue homogenate supernatant. At 48 h after the full-thickness skin defect wound was established, the wound tissue within 2 mm from the wound edge was taken to make inflammatory wound tissue homogenate supernatant. Two kinds of tissue homogenate supernatant were taken to adjust the total protein concentration to 1 mg/mL, and the tumor necrosis factor α (TNF-α) content was detected by enzyme-linked immunosorbent assay. The number of sample was 6. (2) The primary passage of human umbilical cord mesenchymal stem cells (hUCMSCs) were collected and cultured to the 3rd passage with the normal exosomes being extracted from the hUCMSCs after cultured for 48 h. Another batch of hUCMSCs in the 3rd passage was collected and stimulated with inflammatory wound tissue homogenate supernatant of 30, 50, and 100 μg/mL total protein and normal skin tissue homogenate supernatant of 30, 50, and 100 μg/mL total protein, respectively. After cultured for 48 h, the exosomes stimulated with normal protein of 30, 50, and 100 μg/mL and exosomes stimulated with inflammatory protein of 30, 50, and 100 μg/mL were extracted. Normal exosomes, exosomes stimulated with 30 μg/mL normal protein, and exosomes stimulated with 30 μg/mL inflammatory protein were collected, the morphology was observed by transmission electron microscope, the particle size was detected by nanoparticle tracking analyzer, and the expressions of CD9 and CD63 were detected by Western blotting. (3) Twenty one-day-old C57BL/6 mice were taken to isolate the primary passage of fibroblasts (Fbs) and the 3rd passage of Fbs, whose morphology was observed under the inverted phase contrast microscope. The Fbs of 3rd passage were collected to observe the expression of vimentin by cell crawling method combined with immunofluorescence method at culture hour (CH) 2. (4) The Fbs of 3rd passage were divided into control group, normal exosome group, 30, 50, 100 μg/mL normal protein stimulating exosome group, and 30, 50, 100 μg/mL inflammatory protein stimulating exosome group according to the random number table, with 4 wells in each group. Cells in control group received no treatment, and cells in the other 7 groups were respectively added with normal exosomes, exosomes stimulated with normal protein of 30, 50, and 100 μg/mL, and exosomes stimulated with inflammatory protein of 30, 50, and 100 μg/mL prepared in experiment (2). The final mass concentration of exosomes was adjusted to 10 μg/mL. The cell viability was detected by cell count kit 8 at CH 48. (5) Two batches of Fbs in the 3rd passage were divided and treated as those in experiment (4), with 4 wells in each group, and the final mass concentration of exosomes was adjusted to 1 and 10 μg/mL, respectively. The cell mobility was detected by cell scratch test at CH 6, 12, and 24. (6) Two batches of the Fbs of 3rd passage were collected, divided, and treated as those in experiment (4) except with no control group, with 3 wells in each group, and the final mass concentration of exosomes was respectively adjusted to 1 and 10 μg/mL. The mRNA expression levels of transforming growth factor β 1 (TGF-β 1), TGF-β 3, and α smooth muscle actin (α-SMA) were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction at CH 48. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and Bonferroni method. Results:(1) The content of TNF-α in inflammatory wound tissue homogenate supernatant of mice was (116±3) pg/mL, significantly higher than (97±5) pg/mL in normal skin tissue homogenate supernatant at post injury hour 48 ( t=3.306, P<0.05). (2) Normal exosomes, exosomes stimulated with 30 μg/mL normal protein, and exosomes stimulated with 30 μg/mL inflammatory protein of hUCMSCs showed the typical saucer-like shape. The particle sizes of the three exosomes of hUCMSCs were 30-150 nm, which were all within the normal particle size range of exosome. Three exosomes of hUCMSCs positively expressed CD9 and CD63. (3) The primary passage of cells were clearly defined and showed protruding spindle shape, irregular polygon shape, or slender strip shape. The morphology of the 3rd and the primary passage of cells is similar. At CH 2, vimentin in cells was positively expressed, and the cells were identified as Fbs. (4) At CH 48, the cell viability was (137.4±2.8)% in 30 μg/mL inflammatory protein stimulating exosome group, obviously higher than 100%, (107.5±2.4)%, (113.3±3.2)%, (104.0±2.0)%, and (101.9±1.5)% in control group, normal exosome group, 30 μg/mL normal protein stimulating exosome group, and 50 and 100 μg/mL inflammatory protein stimulating exosome groups, respectively ( P<0.01), and cell viability in 30 μg/mL normal protein stimulating exosome group was obviously higher than that in control group, normal exosome group, and 50 and 100 μg/mL normal protein stimulating exosome groups [(103.4±2.2)% and (102.5±1.4)%], respectively ( P<0.01). (5) At CH 6, 12, and 24, the mobility rate of cells in 30 μg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group, normal exosome group, 30 μg/mL normal protein stimulating exosome group, and 50 and 100 μg/mL inflammatory protein stimulating exosome groups, respectively, when the final mass concentrations of exosome was 1 μg/mL ( P<0.05) . At CH 12, the mobility rate of cells in 30 μg/mL normal protein stimulating exosome group was obviously higher than that in control group, normal exosome group, and 50 and 100 μg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 1 μg/mL ( P<0.05). At CH 6, the mobility rate of cells in 30 μg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group and normal exosome group ( P<0.05), and the mobility rate of cells in 30 μg/mL normal protein stimulating exosome group was significantly higher than that in 50 and 100 μg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 10 μg/mL ( P<0.05). At CH 12 and 24, the mobility rate of cells in 30 μg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group, normal exosome group, and 50 and 100 μg/mL inflammatory protein stimulating exosome groups ( P<0.05), and the mobility rate of cells in 30 μg/mL normal protein stimulating exosome group was significantly higher than that in control group, normal exosome group, and 50 and 100 μg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 10 μg/mL ( P<0.05). (6) There were no statistically significant differences in mRNA expression levels of TGF-β 1, TGF-β 3, and α-SMA of cells among the 7 groups at CH 48 when the final mass concentration of exosome was 1 μg/mL ( F=1.123, 1.537, 1.653, P>0.05). There were no statistically significant differences in mRNA expression levels of TGF-β 1 and α-SMA of cells among the 7 groups at CH 48 when the final mass concentration of exosome was 10 μg/mL ( F=1.487, 1.308, P>0.05), and mRNA expression level of TGF-β 3 of cells in 50 μg/mL inflammatory protein stimulating exosome group at CH 48 was significantly higher than that in normal exosome group, 50 μg/mL normal protein stimulating exosome group, and 30 and 100 μg/mL inflammatory protein stimulating exosome groups when the final mass concentration of exosome was 10 μg/mL ( P<0.05). Conclusions:The pretreatment with inflammatory wound tissue homogenate supernatant of mice has no significant effect on the total protein of hUCMSCs exosomes. The hUCMSCs exosomes stimulated by low concentration inflammatory wound tissue homogenate supernatant can significantly promote the proliferation and migration ability of Fbs. The content of inflammatory mediators in the wound tissue homogenate supernatant during the inflammatory phase is extremely low, which may be the reason that the anti-inflammation and tissue repair paracrine effects of mesenchymal stem cell cannot be effectively started.

Fatigue is commonly experienced in patients with advanced kidney disease and associated with poor outcomes. The purpose of this review was to discuss the prevalence, assessment methods and contributing factors of fatigue in patients with end-stage renal disease (ESRD), and also examined possible interventions to improve fatigue and concludes by defining some future research directions.