There is increasing interest in depleting or repolarizing tumor-associated macrophages (TAMs) to generate a proinflammatory effect. However, TAMs usually display an immunosuppressive M2-like phenotype in the tumor microenvironment. Apparently, developing a macrophage-targeting delivery system with immunomodulatory agents is urgent. In this study, an efficient siRNA and CpG ODNs delivery system (CpG-siRNA-tFNA) was prepared with nucleic acid stepwise self-assembled. The tFNA composed of CpG ODNs and siRNA showed a higher stability and an enhanced cellular uptake efficiency. Moreover, the CpG-siRNA-tFNA effectively reprogrammed TAMs toward M1 phenotype polarization with increased proinflammatory cytokine secretion and NF-κB signal pathway activation, which triggers dramatic antitumor immune responses. Additionally, the CpG-siRNA-tFNA exhibited superior antitumor efficacy in a breast cancer xenograft mouse model without obvious systemic side effects. Taken together, CpG-siRNA-tFNA displayed greatly antitumor effect by facilitating TAM polarization toward M1 phenotypes in favor of immunotherapy. Hence, we have developed an efficient therapeutic strategy with immunomodulatory agents for clinical applications.

Objective To investigate the role of miR-100-5p in the pathogenesis of non-traumatic osteonecrosis of the femoral head (NONFH). Methods The miRNA expression in patients with NONFH was detected by real-time quantitative PCR, the high expression of miR-100-5p in femoral head tissues of the patients determined. Rat bone marrow mesenchymal stem cells (rBMSCs) were cultured and divided into 5 groups: blank control group, dexamethasone treatment group (treated with dexamethasone for 3 days), miR-NC group (transfected with miR-NC), agomiR-100-5p group (overexpression of miR-100-5p), and antagomiR-100-5p group (transfected with miR-100-5p antagonist). The mRNA expression levels of miR-100-5p, alkaline phosphatase (ALP), Runt-associated transcription factor 2 (RUNX2), and collagen type I (Col1) were detected by real-time quantitative PCR. The protein expressions of ALP, RUNX2, Col1, and bone morphogenetic protein receptor 2 (BMPR2) were detected by Western blotting. The effect of miR-100-5p on the migration ability of rBMSCs was evaluated by scratch healing assay. And the effect of miR-100-5p on osteogenic differentiation ability of rBMSCs was investigated by alizarin red staining. Results miR-100-5p was significantly upregulated in the femoral head bone tissue of NONFH patients compared with normal femoral head bone tissue. Compared with those in the normal rBMSCs, the expression of miR-100-5p in rBMSCs treated with 20 μmol/L of dexamethasone was up-regulated. The upregulation of miR-100-5p in rBMSCs reduced the expressions of ALP, RUNX2, Col1, and BMPR2, and inhibited the osteogenic differentiation and migration abilities of rBMSCs. Conclusion The expression of miR-100-5p is elevated in bone tissues of NONFH patients and in rBMSCs treated with 20 μmol/L of dexamethasone. The up-regulated miR-100-5p may be involved in the pathogenesis of NONFH by inhibiting the migration and osteogenic differentiation of rBMSCs.

Background Nontraumatic osteonecrosis of the femoral head (NONFH) is a common, progressive, and refractory orthopaedic disease. Decreased osteogenesis and angiogenesis are considered the main factors in the pathogenesis of NONFH. We aimed to figure out whether exosomes and exosomal miRNA from necrotic bone tissues of patients with NONFH are involved in the pathogenesis of NONFH and reveal the underlying mechanisms. Methods RT-PCR and western blotting (WB) were used to detect the expression of osteogenic, adipogenic, and angiogenic markers. ALP staining and Alizarin Red S (ARS) staining were used to evaluate osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Oil Red O staining was performed to assess the adipocyte deposition. A tube formation assay was used to study angiogenesis of human umbilical vascular endothelial cells (HUVECs). H&E staining and immunohistochemistry (IHC) staining were used to detect the effect of the NONFH exosomes in vivo. MicroRNA sequencing was conducted to identify potential regulators in the NONFH exosomes. The target relationship between miR-100-5p and BMPR2 was predicted and confirmed by a dual luciferase reporter assay and WB. Results The NONFH exosomes reduced the osteogenic differentiation of hBMSCs and angiogenesis of HUVECs. In addition, the injection of the NONFH exosomes caused thinning and disruption of bone trabeculae in the femoral heads of rats. MiR-100-5p expression was upregulated in the NONFH exosomes and inhibited the osteogenesis of hBMSCs and angiogenesis of HUVECs by targeting BMPR2 and suppressing the BMPR2/SMAD1/5/9 signalling pathway. Silencing miR-100-5p expression rescued the reduction in osteogenesis and angiogenesis caused by the NONFH exosomes by activating the BMPR2/SMAD1/5/9 signalling pathway. Conclusion The NONFH exosomal miR-100-5p can lead to NONFH-like damage by targeting BMPR2 and suppressing the BMPR2/SMAD1/5/9 signalling pathway, which may be involved in the pathophysiological mechanisms of nontraumatic osteonecrosis of the femoral head (NONFH).

Age-related loss of skeletal muscle mass and function, termed sarcopenia, could impair the quality of life in the elderly. The mechanisms involved in skeletal muscle aging are intricate and largely unknown. However, more and more evidence demonstrated that mitochondrial dysfunction and apoptosis also play an important role in skeletal muscle aging. Recent studies have shown that mitochondrial calcium uniporter (MCU)-mediated mitochondrial calcium affects skeletal muscle mass and function by affecting mitochondrial function. During aging, we observed downregulated expression of mitochondrial calcium uptake family member3 (MICU3) in skeletal muscle, a regulator of MCU, which resulted in a significant reduction in mitochondrial calcium uptake. However, the role of MICU3 in skeletal muscle aging remains poorly understood. Therefore, we investigated the effect of MICU3 on the skeletal muscle of aged mice and senescent C2C12 cells induced by D-gal. Downregulation of MICU3 was associated with decreased myogenesis but increased oxidative stress and apoptosis. Reconstitution of MICU3 enhanced antioxidants, prevented the accumulation of mitochondrial ROS, decreased apoptosis, and increased myogenesis. These findings indicate that MICU3 might promote mitochondrial Ca2+ homeostasis and function, attenuate oxidative stress and apoptosis, and restore skeletal muscle mass and function. Therefore, MICU3 may be a potential therapeutic target in skeletal muscle aging.

BackgroundThe main pathogenesis of steroid-induced avascular necrosis of the femoral head (SANFH) is closely connected with osteogenesis and adipogenesis. MicroRNAs have been proved to play prominent roles in the initiation and progression of SANFH. The present study investigated the effects of silencing miR-199a-3p on the prevention and early treatment of SANFH. MethodsRT-PCR was used to detect the expression of miR-199a-3p. Western blotting was used to detect protein expression. Alkaline phosphatase (ALP) activity, alizarin red S staining, and oil red O staining were used to study the effect of miR-199a-3p on the osteogenic and adipogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs) and MC3T3-E1 cells. A dual-luciferase reporter assay was used to confirm the target relation of miR-199a-3p and integrin β8 (ITGB8). Animal study was used to explore the effect of silencing miR-199a-3p in vivo.ResultsMiR-199a-3p expression was upregulated in necrotic bone tissues and rBMSCs and MC3T3-E1 cells treated with 20 UM dexamethasone. Western blotting and a dual luciferase assay were employed to verify that miR-199a-3p directly targets ITGB8. Silencing of miR-199a-3p also promoted osteogenesis and inhibited adipogenesis of rBMSCs and MC3T3-E1 cells in the presence or absence of glucocorticoids. In addition, the silence of miR-199A-3p prevent SANFH by promoting osteogenesis in rats.ConclusionThe upregulation of miR-199a-3p induced by GCs could reciprocally regulate the adipo-osteogenic differentiation of rBMSCs and MC3T3-E1 cells by targeting ITGB8. The miR-199a-3p-ITGB8-FAK-Erk1/2-RUNX2 axis is a potential signaling mechanism, and inhibition of miR-199a-3p expression could promote osteogenesis and inhibit adipogenesis to alleviate the occurrence of SANFH.

Non-traumatic osteonecrosis of the femoral head (ONFH) is clinically a devastating and progressive disease without an effective treatment. Mesenchymal stem cells (MSCs) transplantation has been used to treat ONFH in early stage, but the failure rate of this therapy is high due to the reduced osteogenic differentiation and migration of the transplanted MSCs related with pathological bone tissues. However, the mechanism responsible for this decrease is still unclear. Therefore, we assume that the implanted MSCs might be influenced by signals delivered from pathological bone tissue, where the exosomes might play a critical role in this delivery. This study showed that exosomes from ONFH bone tissues (ONFH-exos) were able to induce GC-induced ONFH-like damage, in vivo and impair osteogenic differentiation and migration of MSCs, in vitro. Then, we analyzed the differentially expressed proteins (DEPs) in ONFH-exos using proteomic technology and identified 842 differentially expressed proteins (DEPs). On the basis of gene ontology (GO) enrichment analysis of DEPs, fold-changes and previous report, cell adhesion-related CD41 (integrin α2b) was selected for further investigation. Our study showed that the CD41 (integrin α2b) was distinctly decreased in ONFH-exos, compared to NOR-exos, and downregulation of CD41 could impair osteogenic differentiation and migration of the MSCs, where CD41-integrin β3-FAK-Akt-Runx2 pathway was involved. Finally, our study further suggested that CD41-affluent NOR-exos could restore the glucocorticoid-induced decline of osteogenic differentiation and migration in MSCs, and prevent GC-induced ONFH-like damage in rat models. Taken together, our study results revealed that in the progress of ONFH, exosomes from the pathological bone brought about the failure of MSCs repairing the necrotic bone for lack of some critical proteins, like integrin CD41, and prompted the progression of experimentally induced ONFH-like status in the rat. CD41 could be considered as the target of early diagnosis and therapy in ONFH.

Objective To investigate the effect of progranulin (PGRN) on osteoporosis in ovariectomized mice. Methods PGRN-knockout (PGRN-/-) and wild-type mice were ovariectomized to induce postmenopausal osteoporosis models. Next, the bone tissues in all mice were scanned by Micro-CT and three-dimensional reconstruction was performed to detect the micro-structure, followed by trabecula data analysis. The morphology and osteoclasts in the bone tissues of PGRN-/- and wild-type mice were observed by HE staining and TRAP staining, respectively. The expression of receptor activator for nuclear factor-κB ligand (RANKL), tumor necrosis factor α (TNF-α) and P65 were detected by immunohistochemistry. The expression of TRAP mRNA in the mice was measured using fluorescence quantitative PCR and the protein expression of MMP9, MMP14, P65 was detected by Western blot analysis. Results Bone mineral density (BMD), bone volume fraction (BV/TV), trabecular number (Tb.N) and trabecular thickness (Tb.Th) in the PGRN-/- group were significantly higher than those in the wild-type group, while the trabecular separation (Tb.S) in the PGRN-/- group was in the contrary. The degree of osteoporosis was less severe and number of osteoclasts in the PGRN-/- mice were reduced, likewise, RANKL, TNF-α, MMP9, MMP14 and P65 as well as TRAP mRNA were down-regulated in the PGRN-/- group compared with the wild-type group. Conclusion PGRN aggravates the postmenopausal osteoporosis in ovariectomized mice.