Objective: To investigate the effect of G protein-coupled receptor 108(GPR108) gene knockout on systemic inflammation in lipopolysaccharide(LPS)-induced sepsis mice. Methods: Male C57BL/6 mice and GPR108 gene knockout mice were randomly divided into 4 groups: WT group, WT-LPS group, KO group, KO-LPS group. The physiological characteristics of mice in different groups were observed, and the morphological changes of liver and lung tissues were observed. Macrophages were extracted from bone marrow and subjected to flow cytometry to detect their M1 polarization status. The expression levels of IL-6 in liver and lung tissues, macrophages, and serum were also measured. Results: KO-LPS group mice showed significant liver and lung tissue damage, with a significantly greater number of bone marrow-derived macrophages polarizing towards M1 in the KO-LPS group compared to the WT-LPS group. Additionally, at the tissue, cellular, and serum levels, the expression of IL-6 in the KO-LPS group mice was significantly higher than that in the WT-LPS group mice(P<0.05). Conclusion During the systemic inflammatory infection induced by LPS in mice, the lack of GPR108 exacerbates the systemic inflammatory response. GPR108 has an inhibitory effect on the inflammatory response in mice with LPS-induced sepsis.

Objective To investigate the role and mechanism of urate in chronic kidney disease complicated with renal interstitial fibrosis(CKD-RIF).Methods Mice were continuously fed with a diet containing 0.2％adenine for a duration of 9 weeks to establish mice models with CKD-RIF.By the end of the 9-week experimental periods,collected blood samples from the posterior orbital venous plexus of mice to measure renal functions and serum urate concentrations prior to euthanizing the mice.Hematoxylin-eosin(HE)staining and periodic acid-Schiff staining(PAS)were used to investigate the pathological alternations in kidney tissues.Masson's trichrome staining was used to observe the extent of renal fibrosis.Urate staining was used to detect urate deposition in renal tissues.Western blot and immunohistochemistry were used to detect the expression of target molecules.Scratch tests were used to ex-amine the migration abilities of cells treated with different concentrations of uric acid.Results The kidney function analysis showed that a significant increase in the levels of serum urea nitrogen(P=0.006 4),creatinine(P=0.008 0)and urate(P=0.000 7)in the CKD-RIF mice compared with the normal control group.The results of HE staining and PAS staining showed a significance of renal tubule injury and infiltration of inflammatory cells in the model group.Masson's trichrome staining showed that a marked increase in collagen deposition in the model group.The results of urate staining showed a significant presence of urate crystals in kidney tissue of the model group when compared to the control group.Animal tissue immunoblotting and immunohistochemistry analysis showed a significant increase in the expression levels of vimentin,α-SMA and TGF-β1 in the model group in comparison to the control group.Conversely,in the model group,E-cadherin levels exhibited a dramatic reduction compared to the control group.The findings from the scratching tests showed that uric acid significantly enhanced cell migration.Western blot analysis showed a dramatic increase in the expression levels of vimentin and α-SMA,while E-cadherin exhibited significant decrease in the cells subjected to uric acid treatment.Conclusion Urate stimulates the secre-tion of TGF-β1 by renal tubule epithelial cells and induces epithelial-mesenchymal transdifferentiation,thereby ex-acerbating renal interstitial fibrosis in CKD.

Objective To explore the effects of disuse-induced architectural changes in the osteocytic lacunar-canalicular system(LCS)on the fluid dynamic microenvironment of osteocytes under mechanical stimulus.Methods First,taking the axially loaded mice tibia as the object,a multi-scale model of'whole bone-single osteocyte LCS'was established.Subsequently,pressure gradients and other results obtained from the whole-bone poroelastic finite element model were used as boundary conditions for the single-osteocyte LCS model to calculate the flow velocity and shear stress around osteocytes.Finally,a design of experiment(DOE)method was used to determine the individual and interactive effects of the LCS architectural parameters(lacunar volume,lacunar shape,and canalicular diameter)on the osteocytic fluid dynamic microenvironment within the LCS.Results When the lacunar volume,lacunar shape,and canalicular diameter changed from normal to disused,the flow velocity increased by 5.3%,39.3%,and 37.0%,respectively.The DOE results showed that the lacunar shape and canalicular diameter had a significant effect on fluid velocity and shear stress(P<0.05),with a contribution ratio of 0.38∶0.62,whereas the lacunar volume and interaction of architectural parameters had no significant effects.Conclusions Disuse-induced changes in canalicular diameter and lacunar shape were the main factors affecting the osteocytic fluid dynamic environment within the LCS under mechanical stimulus.Appropriate exercise methods are expected to prevent disuse-induced bone loss caused by space weightlessness and other conditions.

Objective To establish and validate a biomechanical modeling method based on micro-magnetic resonance imaging(μMRI)and microstructure segmentation for noninvasively assessing microstructure behavior of the proximal femur.Methods Firstly,μMRI images were obtained from the femoral samples,and bone microstructures were segmented through regionized image processing to create the μMRI finite element model(μMRI model).Finite element analysis was performed utilizing a lateral fall posture simulation,and stress and strain were calculated.Secondly,the accuracy of μMRI image segmentation of bone microstructure was verified using micro-computed tomography(μCT),and the accuracy of μMRI model calculation result was verified using a finite element model constructed based on μCT(μCT model).Finally,the accuracy of bone surface strain calculated by μMRI model was verified through in vitro mechanical loading experiments simulating lateral falls and strain gauge measurements.Results The bone microstructure parameters BV/TV calculated by μMRI model and μCT model were significantly correlated(r=0.89,P<0.05).The maximum and minimum principal stress/principal strain percentiles calculated by μMRI model and μCT model were highly correlated(R2>0.9).The strain calculated by μMRI-FEM was highly correlated with the strain measured by mechanical experiments(R2=0.82).Conclusions The micro finite element model based on μMRI segmentation of bone microstructure can accurately characterize the micro-mechanical behavior of the proximal femur.This study provides an important tool for non-invasive assessment of hip femur microstructure degeneration and osteoporosis fracture risk in vivo.

Methods: Forty-two female volunteers (aged 62.3±6.3 years) underwent spine examination with both MRI (including a phantom) and dual-energy X-ray absorptiometry (DXA) following ethical approval. MRI phantom-based F- and W-scoreS1 were defined by normalizing S1 vertebral signal intensities (SIs) by coconut oil and water SIs of the phantom on T1- and T2-weighted imaging, respectively. Using receiver operating characteristic analysis, the diagnostic performances of the new scores for evaluating osteoporosis and vertebral fractures were investigated against standard areal bone mineral density measured with DXA (DXA-aBMD). Results: The F-scoreS1 and W-scoreS1 were greater (4.11 and 2.43, respectively) in patients with osteoporosis than those without osteoporosis (3.25 and 1.92, respectively) and achieved areas under the curve (AUCs) of 0.82 and 0.76 (p<0.05), respectively, for osteoporosis detection. Similarly, the mean F-scoreS1 and W-scoreS1 were higher (4.11 and 2.63, respectively) in patients with vertebral fractures than in those without fractures (3.30 and 1.82, respectively) and had greater AUCs (0.90 for W-scoreS1 and 0.74 for F-scoreS1) than DXA-aBMD (AUC, 0.26; p<0.03). In addition, the F- and W-scoreS1 demonstrated a strong correlation (r=0.65, p<0.001). Conclusions The new S1 vertebral-based MRI scores were developed to detect osteoporotic changes and demonstrated improvements over DXA-aBMD in differentiating patients with vertebral fractures.

Background/Aims: Roxadustat, an oral medication for treating renal anemia, is a hypoxia-inducible factor prolyl hydroxylase inhibitor used for regulating iron metabolism and promoting erythropoiesis. To investigate the efficacy and safety of roxadustat in patients undergoing peritoneal dialysis (PD) with erythropoietin hyporesponsiveness. Methods: Single-center, retrospective study, 81 PD patients (with erythropoietin hyporesponsiveness) were divided into the roxadustat group (n = 61) and erythropoiesis-stimulating agents (ESAs) group (n = 20). Hemoglobin (Hb), total cholesterol, intact parathyroid hormone (iPTH), brain natriuretic peptide (BNP), related indicators of cardiac function and high-sensitivity C-reactive protein (hs-CRP) were collected. Additionally, adverse events were also recorded. The follow-up period was 16 weeks. Results: The two groups exhibited similar baseline demographic and clinical characteristics. At baseline, the roxadustat group had a mean Hb level of 89.8 ± 18.9 g/L, while the ESAs group had a mean Hb level of 95.2 ± 16.0 g/L. By week 16, the Hb levels had increased to 118 ± 19.8 g/L (p < 0.05) in the roxadustat group and 101 ± 19.3 g/L (p > 0.05) in the ESAs group. The efficacy of roxadustat in improving anemia was not influenced by baseline levels of hs-CRP and iPTH. Cholesterol was decreased in the roxadustat group without statin use. An increase in left ventricular ejection fraction and stabilization of BNP were observed in the roxadustat group. Conclusions For PD patients with erythropoietin hyporesponsiveness, roxadustat can significantly improve renal anemia. The efficacy of roxadustat in improving renal anemia was not affected by baseline levels of hs-CRP0 and iPTH.

Objective To compare the effects of cortical bone trajectory ( CBT) and traditional trajectory ( TT)pedicle screw internal fixation on the range of motion (ROM) and rod system stress of normal and osteoporotic(OP) spines. Methods The L3-S1 finite element models of normal and OP spines were established. The screwrod system with two kinds of trajectory was used for internal fixation of the L4-5 segment, so as to simulate sixphysiological loads, namely, flexion, extension, left / right bending, left / right rotation. The effects of two internalfixation methods on ROMs and maximum equivalent stress of screws in normal and OP spines were compared.Results For both bone conditions, CBT and TT significantly reduced ROM of the fixed segment (L4-5) and theentire segment of lower lumbar spine ( L3-S1). However, the ROM decline of CBT group was slightly smaller than that of TT group, and their ROMs were similar under flexion and extension, but the ROM differences were significant under lateral bending and axial rotation. In addition, for both the normal and OP spine models, themaximum equivalent stress of screws in CBT group was significantly higher than that in TT group. Compared withTT group, the screw stress of CBT group in normal spine model under flexion and extension, lateral bending,axial rotation was increased by 27% , 268% and 58% , respectively. However, when CBT technique was used atthe same time, the OP spine model had a smaller screw stress distribution than the normal spine model.Conclusions Compared with TT technique, CBT technique can achieve higher screw stress under OP conditionand reduce screw stress concentration under normal bone condition. In addition, CBT slightly increases ROMs of each segment, which is conducive to recovery of spinal physiological function after surgery. Lateral bending and axial rotation can produce negative mechanical effects, and these two physiological loads should be avoided.

Humans ; COVID-19 Vaccines/therapeutic use* ; HIV-1 ; Immunity, Humoral ; COVID-19/prevention & control* ; SARS-CoV-2

Osteoporosis is characterized by decreased bone strength and increased fracture risk. The most serious consequence of osteoporosis is fracture, which commonly occurs in vertebrae. Accurate assessment of fracture risk at an earlier stage is the key to identify high-risk population and further prevent osteoporotic fracture. Currently, clinical assessment of vertebral fracture risk mainly relies on measurement of bone mineral density (BMD) based on dual energy X-ray absorptiometry ( DXA) or quantitative computed tomography ( QCT). However, they cannot fully reflect bone strength and resistance to fracture, and it is hard to achieve an accurate assessment. Biomechanical CT (BCT) technology, based on CT digital modeling and finite element analysis, aims at non-invasive calculation of individual bone strength, bridging the gap between biomechanics and clinical evaluation of fracture risk. In vitro mechanical experiment of vertebrae has proved that BCT is more accurate than BMD in evaluating vertebral fracture strength. Clinical studies have also shown that BCT is superior to DXA inidentifying existing fractures and predicting new fractures. In this article, the implementation process of the BCT technology was introduced, as well as critical parameters during each step affecting its result . The research progress of the BCT technique for in vitro validation and in vivo assessment of vertebral fracture risk was also summarized, with the aim to promote the application of BCT technology in clinical assessment of vertebral fracture risk for the Chinese people.

Objective: To investigate the role and mechanism of Sigirr deletion in chronic kidney disease complicated with renal interstitial fibrosis (CKD⁃RIF) in mice. Methods: polymerase chain reaction (PCR) was used for identification of gene types of mice. Mice were continuously fed with the foods containing 0. 2% adenine for 12 weeks to establish the CKD⁃RIF models. Then , serum was collected to detect levels of creatinine and nitrogen when mice were killed. H&E staining was used to analyze the pathological changes of kidney tissues. Masson staining was used to observe the degree of renal fibrosis. Immunohistochemistry was used to detect the changes of the interest proteins , such as IL⁃1β , MyD88 , activated NF⁃κB , TGF⁃ β1 , E ⁃cadherin and Vimentin. Results: Serum creatinines and urea nitrogens of mice fed with high adenine (CKD⁃RIF groups) significantly increased , compared with those of the control groups. H&E and Masson staining results showed that there were more infiltrated inflammatory cells and more critical collagen fiber deposition in the renal tissues of the Sigirr - / - mice with CKD⁃RIF. Western blot and Immunohistochemical analysis showed that the expression of IL⁃1β and its downstream MyD88 increased , and the level of phosphorylated NF⁃κB (p⁃P65) significantly increased in the renal tissues of CKD⁃RIF mice compared with the controls. And upregulation of these proteins in renal tissues of Sigirr - / - mice with CKD⁃RIF was more obvious than that of the CKD⁃RIF Sigirr + / + mice. TGF⁃ β1 , as a key cytokine involved in renal interstitial fibrosis , significantly increased ,followed by the increase of vimentin , as well as the decrease of E ⁃cadherin . The results of vimentin and cadherin E detected by Western blot were consistent with those of immunohistochemistry , and α ⁃SMA also increased significantly. Conclusion Adenine diet successfully induces CKD⁃RIF mice models. Sigirr deletion is beneficial to activation of the IL⁃1β mediating NF⁃κB signal pathway ,which promotes TGF⁃ β1 expression in the renal interstitiums to induce renal interstitial fibrosis.