Objective:To explore the effects of parathyroid hormone(PTH)on the osteogenic differentiation of osteoblasts by reg-ulating macrophage polarization in inflammatory microenvironment.Methods:Macrophages were pretreated with lipopolysaccharide(LPS)for 2 h to establish an inflammatory microenvironment model,and then treated with PTH for 24 h.Macrophages and osteo-blasts were co-cultured in Transwell cells.Alkaline phosphatase staining,alizarin red staining,RT-qPCR and Western blot were applied to detect osteogenic differentiation.The expression of SOCS1/JAK2/STAT3 protein in macrophages was detected by West-ern blot.The change of STAT3 expression was detected after adding AG490.The expression of miR-155-5p,SOCS1,IL-1β,IL-6 and i-NOS was detected by ELISA and RT-qPCR.Results:LPS induced M1-type polarization of macrophages and inhibited the osteogenic differentiation of osteoblasts.PTH inhibited the polarization of M1-type macrophages and promoted the osteogenic differ-entiation of osteoblasts in inflammatory microenvironment(P＜0.05).PTH down-regulated the expression of miR-155-5p,IL-1β,IL-6,i-NOS,p-JAK2/JAK2 and p-STAT3/STAT3 in macrophages under inflammatory microenvironment(P＜0.05),and up-reg-ulated SOCS1(P＜0.05).AG490 further inhibited p-STAT3/STAT3 expression.Conclusion:PTH inhibits the polarization of M1-type macrophages and promotes osteogenic differentiation of osteoblasts by down-regulating miR-155-5p and then targeting SOCS1/JAK2/STAT3 signaling pathway in inflammatory microenvironment.

Immune checkpoint inhibitors (ICIs) are widely used in the treatment of various malignant tumors. While achieving therapeutic benefits, immune-related adverse events (irAEs) caused by ICIs have also drawn clinical attention. irAEs can affect almost all organs in the body, and the diversity of clinical manifestations increases the difficulty for clinicians and pharmacists to diagnose and intervene. Therefore, finding reliable biomarkers that can accurately predict and diagnose irAEs has significant clinical value. This article reviews the research progress of biomarkers of ICIs-related adverse events, providing a reference for the safe application of these drugs in clinical treatment.

Objective:To explore the effects of parathyroid hormone(PTH)on the osteogenic differentiation of osteoblasts by reg-ulating macrophage polarization in inflammatory microenvironment.Methods:Macrophages were pretreated with lipopolysaccharide(LPS)for 2 h to establish an inflammatory microenvironment model,and then treated with PTH for 24 h.Macrophages and osteo-blasts were co-cultured in Transwell cells.Alkaline phosphatase staining,alizarin red staining,RT-qPCR and Western blot were applied to detect osteogenic differentiation.The expression of SOCS1/JAK2/STAT3 protein in macrophages was detected by West-ern blot.The change of STAT3 expression was detected after adding AG490.The expression of miR-155-5p,SOCS1,IL-1β,IL-6 and i-NOS was detected by ELISA and RT-qPCR.Results:LPS induced M1-type polarization of macrophages and inhibited the osteogenic differentiation of osteoblasts.PTH inhibited the polarization of M1-type macrophages and promoted the osteogenic differ-entiation of osteoblasts in inflammatory microenvironment(P＜0.05).PTH down-regulated the expression of miR-155-5p,IL-1β,IL-6,i-NOS,p-JAK2/JAK2 and p-STAT3/STAT3 in macrophages under inflammatory microenvironment(P＜0.05),and up-reg-ulated SOCS1(P＜0.05).AG490 further inhibited p-STAT3/STAT3 expression.Conclusion:PTH inhibits the polarization of M1-type macrophages and promotes osteogenic differentiation of osteoblasts by down-regulating miR-155-5p and then targeting SOCS1/JAK2/STAT3 signaling pathway in inflammatory microenvironment.

Immune checkpoint inhibitors (ICIs) are widely used in the treatment of various malignant tumors. While achieving therapeutic benefits, immune-related adverse events (irAEs) caused by ICIs have also drawn clinical attention. irAEs can affect almost all organs in the body, and the diversity of clinical manifestations increases the difficulty for clinicians and pharmacists to diagnose and intervene. Therefore, finding reliable biomarkers that can accurately predict and diagnose irAEs has significant clinical value. This article reviews the research progress of biomarkers of ICIs-related adverse events, providing a reference for the safe application of these drugs in clinical treatment.

BACKGROUND:Bone defects are caused by many factors,such as inflammation,tumor,trauma or bone diseases.Erythropoietin can promote the differentiation of mesenchymal stem cells into osteoblasts and osteoclasts and act on vascular endothelial cells to induce angiogenesis and accelerate the repair of bone and cartilage defects.Erythropoietin is a growth factor with potential application in bone tissue engineering construction. OBJECTIVE:To expound the application and potential mechanism of erythropoietin in bone tissue engineering. METHODS:The first author searched the related articles published in CNKI,WanFang,VIP,and PubMed databases from 2004 to 2022 by computer.Search terms were"erythropoietin,bone defect,bone regeneration,angiogenesis,osteogenesis,osteoblast,osteoclast,bone tissue engineering"in Chinese and English.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Erythropoietin can directly act on osteoblasts and osteoclasts in the bone marrow microenvironment by promoting the differentiation of mesenchymal stem cells into osteoblasts,osteoclasts,adipocytes,nerve cells and stromal cells.The activation of Wnt/β-catenin,hypoxia-inducible factor 1α/vascular endothelial growth factor,p38 MAPK and EphrinB2/EphB4 signaling pathways mediates the osteogenic differentiation of mesenchymal stem cells.(2)Erythropoietin can not only regulate the production of erythrocytes to alter the oxygen-carrying capacity of blood but also stimulate vascular endothelial cells to promote angiogenesis.The new blood vessels can carry oxygen,nutrients,growth factors,and bone progenitor cells necessary for osteogenesis to the osteogenic site,thereby promoting bone formation and fracture healing.(3)Currently,erythropoietin is being used as a growth factor with osteogenic and angiogenic effects in various types of scaffold materials such as chitosan,polycaprolactone,bioceramics,and nanofibers through various drug delivery methods.Erythropoietin,along with other growth factors such as bone morphogenetic protein-2 and bone morphogenetic protein-9,has been applied to the surface of scaffold materials to participate in the repair of bone defects.Erythropoietin has demonstrated excellent practicality in the construction of new tissue-engineered bone and has potential clinical application value.

Objective:To investigate the risk factors of bone cement leakage and recompression of injured vertebrae after percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fracture (OVCF).Methods:A case-control study was performed to analyze the clinical data of 297 patients with single-segment OVCF who underwent PKP in First Affiliated Hospital of Soochow University from January 2017 to January 2021, including 67 males and 230 females; aged 60-92 years [(69.5±8.2)years]. According to the occurrence of bone cement leakage, the patients were divided into leakage group ( n=36) and no leakage group ( n=261). According to the occurrence of recompression of injured vertebrae, the patients were divided into recollapse group ( n=40) and no recollapse group ( n=257). The gender, age, fracture segment, type of fracture, fracture severity, cortical disruption, intravertebral cleft, preoperative and postoperative local kyphosis angle, correction value of local kyphosis angle, bone cement injection volume, bone cement distribution, and postoperative anti-osteoporosis treatment were recorded. Univariate analysis was used to analyze the correlation of those factors with bone cement leakage and recompression of injured vertebrae after PKP, followed by multivariate Logistic regression analysis to identify the independent risk factors. Results:Univariate analysis showed that fracture severity, cortical disruption and bone cement injection volume were related to bone cement leakage ( P<0.05 or 0.01). Gender, age, fracture segment, type of fracture, intravertebral cleft, preoperative and postoperative local kyphosis angle, correction value of local kyphosis angle, bone cement distribution, and postoperative anti-osteoporosis treatment were not related to bone cement leakage (all P>0.05). Univariate analysis showed that intravertebral cleft, bone cement distribution, and postoperative anti-osteoporosis treatment were associated with recompression of injured vertebrae (all P<0.01). Gender, age, fracture segment, type of fracture, fracture severity, cortical disruption, preoperative and postoperative local kyphosis angle, correction value of local kyphosis angle, and bone cement injection volume were not related to recompression of injured vertebrae (all P>0.05). Multivariate Logistic regression analysis showed that severe fracture ( OR=4.23, 95% CI 1.52-11.81, P<0.01), cortical disruption ( OR=3.29,95% CI 1.52-7.13, P<0.01), and bone cement injection volume >8 ml ( OR=2.31,95% CI 1.09-4.92, P<0.05) were significantly related to bone cement leakage. Multivariate Logistic regression analysis showed that intravertebral cleft ( OR=2.10, 95% CI 1.03-4.30, P<0.05), solid type of bone cement distribution ( OR=2.56, 95% CI 1.25-5.27, P<0.05) and no anti-osteoporosis treatment after operation ( OR=3.06, 95% CI 1.46-6.40, P<0.01) were significantly related to recompression of injured vertebrae. Conclusions:For OVCF patients, severe fracture, cortical disruption, and bone cement injection volume>8 ml are independent risk factors for bone cement leakage after PKP. Intravertebral cleft, solid type of bone cement distribution, and no anti-osteoporosis treatment after operation are independent risk factors for recompression of injured vertebrae after PKP.

BACKGROUND:Natural colagen is considered to have low immunogenicity and good biocompatibility relatively. OBJECTIVE:To evaluate the immunogenicity of animal-based colagenin vitro. METHODS:Type I colagen was extracted from bovine tendon after immunogenicity removal. The colagen purity was detected by high performance liquid chromatography and residual DNA was measured quantitatively by fluorescence staining. Fifty BALB/c mice were randomly divided into five groups: subcutaneous injection of normal saline solution (negative control), bovine colagen (positive control), 33.4, 66.8, 133.4 mg/kg of bovine tendon colagen, respectively, once a day. After 12 days of continuously subcutaneous injection, lymphocyte proliferation, and cel classification and NK cel kiling function of mice were detected; after 3 weeks of continuous injection, the spleen, liver, spleen and lung tissue of mice were taken for histological examination. RESULTS AND CONCLUSION:Compared with the standard type I colagen, the purity of purified type I bovine colagen reached more than 99%, but the residual DNA was below 1 mg/L which was far less than the residue level of conventional cel-free DNA in the matrix (dry weight: 50-100 μg/g). After 12 days of continuous injection, there were no changes in lymphocyte proliferation, NK cel kiling function and the proportion of lymphocyte subsets. After 3 weeks of injection, the spleen and lymph sheath of mice around the smal artery became thickened in the 66.8 and 133.6 mg/kg bovine tendon colagen groups, which could cause accidental liver injury and lung injury, but the splenic corpuscle germinal center area had no change. These findings indicate that continuously subcutaneous injection of animal-based colagen can cause the lower lymphocyte immune response to the spleen of BALB/c mice, which may cause accidental liver and lung injuries.