Cisplatin-loaded mesoporous polydopamine nanoparticles capped with MnO2 and coated with platelet membrane provide synergistic anti-tumor therapy.

A multifunctional nanoplatform was constructed in this work, with the goal of ameliorating the challenges faced with traditional cancer chemotherapy. Cisplatin (CP) was loaded into mesoporous polydopamine (mPDA) nanoparticles (NPs) with a drug loading of 15.8 ± 0.1 %, and MnO2 used as pore sealing agent. Finally, the NPs were wrapped with platelet membrane (PLTM). P-selectin on the PLTM can bind to CD44, which is highly expressed on the tumor cell membrane, so as to improve the targeting performance of the NPs. In addition, the CD47 on the PLTM can prevent the NPs from being phagocytosed by macrophages, which is conducive to immune escape. The final PLTM-CP@mPDA/MnO2 NPs were found to have a particle size of approximately 198 nm. MnO2 is degraded into Mn2+ in the tumor microenvironment, leading to CP release from the pores in the mPDA. CP both acts as a chemotherapy agent and can also increase the concentration of H2O2 in cells. Mn2+ can catalyze the conversion of H2O2 to OH, resulting in oxidative damage and chemodynamic therapy. In addition, Mn2+ can be used as a contrast agent in magnetic resonance imaging (MRI). In vitro and in vivo experiments were performed to explore the therapeutic effect of the NPs. When the concentration of CP is 30 µg/mL, the NPs cause approximately 50 % cell death. It was found that the PLTM-CP@mPDA/MnO2 NPs are targeted to cancerous cells, and in the tumor site cause extensive apoptosis. Tumor growth is thereby repressed. No negative off-target side effects were noted. MRI could be used to confirm the presence of the NPs in the tumor site. Overall, the nano-platform developed here provides cooperative chemotherapy and chemodynamic therapy, and can potentially be used for effective cancer treatment which could be monitored by MRI.

Deleveraging and decapacity: A comparative analysis of corporate capital allocation based on asset reversibility.

China's stimulus policies have caused overleveraging and overcapacity for the sustainable development of most industries (particularly high-pollution and energy-intensive industries). Thus, deleveraging and decapacity have become the two best options for the above industries to achieve long-term sustainable development. Based on China's A-share listed companies from 2009 to 2019, this study investigated the effect of deleveraging and decapacity on corporate capital allocation using fixed effects, propensity score matching (PSM) and difference-in-differences (DID). A homogeneity analysis of geographical and firm characteristics was also conducted. The results show that: (1) Deleveraging and decapacity can significantly increase financial capital allocation by 3.67%, and decapacity can increase investment-related capital allocation by 0.63%. This indicates asset allocation optimization for sustainable development. (2) High asset reversibility can weaken the effect of deleveraging on financial capital allocation while strengthening the effect of decapacity on capital investment. (3) The impact of deleveraging and decapacity may vary among companies due to heterogeneous asset reversibility resulting from geographical locations and technological intensities. Given the current global energy crisis, optimizing capital allocation has become essential in addressing resource shortages and achieving long-term sustainable development. This study may provide a reference for alleviating corporate capital misallocation.

MFG-E8 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells through GSK3ß/ß-catenin signaling pathway.

Fracture nonunion and bone defects are challenging for orthopedic surgeons. Milk fat globule-epidermal growth factor 8 (MFG-E8), a glycoprotein possibly secreted by macrophages in a fracture hematoma, participates in bone development. However, the role of MFG-E8 in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is unclear. We investigated the osteogenic effect of MFG-E8 in vitro and in vivo. The CCK-8 assay was used to assess the effect of recombinant human MFG-E8 (rhMFG-E8) on the viability of hBMSCs. Osteogenesis was investigated using RT-PCR, Western blotting, and immunofluorescence. Alkaline phosphatase (ALP) and Alizarin red staining were used to evaluate ALP activity and mineralization, respectively. An enzyme-linked immunosorbent assay was conducted to evaluate the secretory MFG-E8 concentration. Knockdown and overexpression of MFG-E8 in hBMSCs were established via siRNA and lentivirus vector transfection, respectively. Exogenous rhMFG-E8 was used to verify the in vivo therapeutic effect in a tibia bone defect model based on radiographic analysis and histological evaluation. Endogenous and secretory MFG-E8 levels increased significantly during the early osteogenic differentiation of hBMSCs. Knockdown of MFG-E8 inhibited the osteogenic differentiation of hBMSCs. Overexpression of MFG-E8 and rhMFG-E8 protein increased the expression of osteogenesis-related genes and proteins and enhanced calcium deposition. The active ß-catenin to total ß-catenin ratio and the p-GSK3ß protein level were increased by MFG-E8. The MFG-E8-induced enhanced osteogenic differentiation of hBMSCs was partially attenuated by a GSK3ß/ß-catenin signaling inhibitor. Recombinant MFG-E8 accelerated bone healing in a rat tibial-defect model. In conclusion, MFG-E8 promotes the osteogenic differentiation of hBMSCs by regulating the GSK3ß/ß-catenin signaling pathway and so, is a potential therapeutic target.

Engineered Sensory Nerve Guides Self-Adaptive Bone Healing via NGF-TrkA Signaling Pathway.

The upstream role of sensory innervation during bone homeostasis is widely underestimated in bone repairing strategies. Herein, a neuromodulation approach is proposed to orchestrate bone defect healing by constructing engineered sensory nerves (eSN) in situ to leverage the adaptation feature of SN during tissue formation. NGF liberated from ECM-constructed eSN effectively promotes sensory neuron differentiation and enhances CGRP secretion, which lead to improved RAOECs mobility and osteogenic differentiation of BMSC. In turn, such eSN effectively drives ossification in vivo via NGF-TrkA signaling pathway, which substantially accelerates critical size bone defect healing. More importantly, eSN also adaptively suppresses excessive bone formation and promotes bone remodeling by activating osteoclasts via CGRP-dependent mechanism when combined with BMP-2 delivery, which ingeniously alleviates side effects of BMP-2. In sum, this eSN approach offers a valuable avenue to harness the adaptive role of neural system to optimize bone homeostasis under various clinical scenario.

Controllable synthesis of variable-sized magnetic nanocrystals self-assembled into porous nanostructures for enhanced cancer chemo-ferroptosis therapy and MR imaging.

Magnetic-based nanomaterials are promising for cancer diagnosis and treatment. Herein, we develop a self-assembled approach for the preparation of a porous magnetic nanosystem, DOX/Mn(0.25)-Fe3O4-III NPs, which can simultaneously achieve chemotherapy, ferroptosis therapy and MRI to improve the therapeutic efficacy. By tuning its porous structures, whole particle sizes and compositions, this nanosystem possesses both a high drug loading capacity and excellent Fenton reaction activity. Owing to the synergetic catalysis effect of iron and manganese ions, the Fenton catalytic activity of Mn(0.25)-Fe3O4-III NPs (K cat = 1.2209 × 10-2 min-1) was six times higher than that of pure porous Fe3O4 NPs (K cat = 1.9476 × 10-3 min-1), making them greatly advantageous in ferroptosis-inducing cancer therapy. Moreover, we found out that these Mn(0.25)-Fe3O4-III NPs show a pH-dependent Fenton reaction activity. At acidic tumorous pH, this nanosystem could catalyze H2O2 to produce the cytotoxic ˙OH to kill cancer cells, while in neutral physiological conditions it decomposed H2O2 into biosafe species (H2O and O2). In vivo studies demonstrated that DOX/Mn(0.25)-Fe3O4-III NPs exhibited a significant synergistic anticancer effect of combining chemotherapy and ferroptosis therapy and effective T2-weighted MRI with minimal side effects. Therefore, this porous magnetic nanoplatform has a great potential for combined diagnosis and therapy in future clinical applications.

Aucubin promotes bone-fracture healing via the dual effects of anti-oxidative damage and enhancing osteoblastogenesis of hBM-MSCs.

BACKGROUND: Aucubin (AU), an iridoid glucoside isolated from many traditional herbal medicines, has anti-osteoporosis and anti-apoptosis bioactivities. However, the effect of AU on the treatment of bone-fracture remains unknown. In the present study, the aims were to investigate the roles and mechanisms of AU not only on osteoblastogenesis of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) and anti-oxidative stress injury in vitro, but also on bone-fracture regeneration by a rat tibial fracture model in vivo. METHODS: CCK-8 assay was used to assess the effect of AU on the viability and proliferation of hBM-MSCs. The expression of specific genes and proteins on osteogenesis, apoptosis and signaling pathways was measured by qRT-PCR, western blotting and immunofluorescence analysis. ALP staining and quantitative analysis were performed to evaluate ALP activity. ARS and quantitative analysis were performed to evaluate calcium deposition. DCFH-DA staining was used to assess the level of reactive oxygen species (ROS). A rat tibial fracture model was established to validate the therapeutic effect of AU in vivo. Micro-CT with quantitative analysis and histological evaluation were used to assess the therapeutic effect of AU locally injection at the fracture site. RESULTS: Our results revealed that AU did not affect the viability and proliferation of hBM-MSCs. Compared with control group, western blotting, PCR, ALP activity and calcium deposition proved that AU-treated groups promoted osteogenesis of hBM-MSCs. The ratio of phospho-Smad1/5/9 to total Smad also significantly increased after treatment of AU. AU-induced expression of BMP2 signaling target genes BMP2 and p-Smad1/5/9 as well as of osteogenic markers COL1A1 and RUNX2 was downregulated after treating with noggin and LDN193189. Furthermore, AU promoted the translocation of Nrf2 from cytoplasm to nucleus and the expression level of HO1 and NQO1 after oxidative damage. In a rat tibial fracture model, local injection of AU promoted bone regeneration. CONCLUSIONS: Our study demonstrates the dual effects of AU in not only promoting bone-fracture healing by regulating osteogenesis of hBM-MSCs partly via canonical BMP2/Smads signaling pathway but also suppressing oxidative stress damage partly via Nrf2/HO1 signaling pathway.

One-Pot Synthesis of Ag/Quaternary Ammonium Salt Co-Decorated Mesoporous Silica Nanoparticles for Synergistic Treatment of Cancer and Bacterial Infections.

Developing drug delivery nanosystems with both anticancer and antibacterial effects is of great clinical value. Herein, we report a facile approach to synthesize Ag and quaternary ammonium salt (QAS) co-decorated mesoporous silica nanoparticles (MSNs), namely, Ag/QAS-MSNs, for synergistic treatment of cancer and bacterial infections. In vitro studies demonstrated that Ag/QAS-MSNs not only had a strong antibacterial activity against the bacterial pathogens but also could efficiently induce cancer cell death through an apoptotic pathway. Moreover, in vivo combination therapy with Ag and QAS in Ag/QAS-MSNs was also tested in a nude mouse tumor model, and a significant synergistic anticancer effect, which is superior to that obtained by therapy with Ag-MSNs or QAS-MSNs alone, was achieved. Such excellent anticancer and antibacterial activity of Ag/QAS-MSNs could be attributed to the synergistic effect of Ag ions and QAS. Thus, Ag/QAS-MSNs have a promising future as potent anticancer agents with high antibacterial performance.

Role of Lysosomal Acidification Dysfunction in Mesenchymal Stem Cell Senescence.

Mesenchymal stem cell (MSC) transplantation has been widely used as a potential treatment for a variety of diseases. However, the contradiction between the low survival rate of transplanted cells and the beneficial therapeutic effects has affected its clinical use. Lysosomes as organelles at the center of cellular recycling and metabolic signaling, play essential roles in MSC homeostasis. In the first part of this review, we summarize the role of lysosomal acidification dysfunction in MSC senescence. In the second part, we summarize some of the potential strategies targeting lysosomal proteins to enhance the therapeutic effect of MSCs.

Whole life exposure to low dose cadmium alters diet-induced NAFLD.

Nonalcoholic fatty liver disease (NAFLD) is a major global public health concern affecting more than 25% of the world's population. Although obesity and diabetes are major risk factors for NAFLD, they cannot account for all cases, indicating the importance of other factors such as environmental exposures. Cadmium (Cd) exposure is implicated in the development of NAFLD; however, the influence of early life, in utero Cd exposure on the development of diet-induced NAFLD is poorly understood. Therefore, we developed an in vivo, multiple-hit model to study the effect of whole-life, low dose Cd exposure on high fat diet (HFD)-induced NAFLD. Adult male and female C57BL/6 J mice fed normal diets (ND) were exposed to 0, 0.5 or 5 ppm Cd-containing drinking water for 14 weeks before breeding. At weaning, offspring were fed ND or HFD and continued on the same drinking water regimen as their parents for 24 weeks. Cd exposure at different concentrations differentially altered HFD-associated adverse health effects, including liver injury. HFD-induced increased body weight, decreased glucose tolerance. Liver injury and lipid deposition were exacerbated by 5 ppm Cd exposure but attenuated by 0.5 ppm Cd exposure. Further, HFD blunted the response of metallothionein, a major Cd detoxification protein, in mice exposed to 5 ppm Cd but enhanced the response in mice exposed to 0.5 ppm Cd, suggesting a possible mechanism for Cd alteration of HFD-induced NAFLD. These results confirm the multi-hit nature of NAFLD and show whole life, low dose Cd exposure alters HFD-induced NAFLD with outcomes dependent on Cd concentration.

Effects of whole-life exposure to low-dose cadmium with post-weaning high-fat diet on offspring testes in a male mouse model.

Although several studies have reported testicular impairments caused by cadmium (Cd) or obesity alone, the combined effect of Cd and obesity on the testes and its underlying mechanism remains unclear. We examined the combined effect of whole-life exposure to low-dose Cd started at preconception and post-weaning high-fat diet (HFD) on the testes of offspring mice. At weaning, male offspring parented with and without exposure to low-dose Cd were continued on the same drinking water regimen as their parents and fed with either a normal diet (ND) or HFD for 10 or 24 weeks. Whole-life exposure to Cd resulted in its accumulation in testes, and HFD induced obesity and lipid metabolism disorder. Exposure to Cd or HFD alone significantly decreased Johnsen scores, disrupted testicular structure, and increased germ cell apoptosis at both 10 and 24 weeks. However, co-exposure to Cd and HFD did not induce the toxic effects that were induced by either alone, as revealed by preserved testicular structure and spermatogenesis, lack of significant apoptosis, and increased cell proliferation. Mechanistically, the combined effects of low-dose Cd and HFD consumption were associated with the activation of the JAK/STAT pathway. These findings suggest that co-exposure to low-dose Cd and HFD did not cause Cd- or HFD-induced testicular injury, probably because of the activation of the JAK/STAT pathway to prevent germ cell apoptosis.

Sex differences in the effects of whole-life, low-dose cadmium exposure on postweaning high-fat diet-induced cardiac pathogeneses.

We previously showed the development of cardiac remodeling (hypertrophy or fibrosis) in mice with either post-weaning high-fat diet (HFD, 60% kcal fat) feeding or exposure to chronic low-dose cadmium. Here, we determined whether whole-life exposure to environmentally relevant, low-dose cadmium affects the susceptibility of offspring to post-weaning HFD-induced cardiac pathologies and function. Besides, we also determined whether these effects are sex-dependent. Male and female mice were exposed to cadmium-containing (0, 0.5, or 5 parts per million [ppm]) drinking water before breeding; the pregnant mice and dams with offspring continually drank the same cadmium-containing water. After weaning, the offspring were continued on the same regime as their parents and fed either a HFD or normal fat diet for 24 weeks. Cardiac function was examined with echocardiography. Cardiac tissues were used for the histopathological and biochemical (gene and protein expression by real-time PCR and Western blotting) assays. Results showed a dose-dependent cadmium accumulation in the hearts of male and female mice along with decreased cardiac zinc and copper levels only in female offspring. Exposure to 5 ppm, but not 0.5 ppm, cadmium significantly enhanced HFD cardiac effects only in female mice, shown by worsened cardiac systolic and diastolic dysfunction (ejection fraction, mitral E-to-annular e' ratio), increased fibrosis (collagen, fibronectin, collagen1A1), hypertrophy (cardiomyocyte size, atrial natriuretic peptide, ß-myosin heavy chain), and inflammation (intercellular adhesion molecule-1, tumor necrosis factor-α, plasminogen activator inhibitor type 1), compared to the HFD group. These synergistic effects were associated with activation of the p38 mitogen-activated protein kinases (MAPK) signaling pathway and increased oxidative stress, shown by 3-nitrotyrosine and malondialdehyde, along with decreased metallothionein expression. These results suggest that whole-life 5 ppm cadmium exposure significantly increases the susceptibility of female offspring to HFD-induced cardiac remodeling and dysfunction. The underlying mechanism and potential intervention will be further explored in the future.

Early-Life Exposure to Low-Dose Cadmium Accelerates Diethylnitrosamine and Diet-Induced Liver Cancer.

Maternal exposure to cadmium causes obesity and metabolic changes in the offspring, including nonalcoholic fatty liver disease-like pathology. However, whether maternal cadmium exposure accelerates liver cancer in the offspring is unknown. This study investigated the impact of early-life exposure to cadmium on the incidence and potential mechanisms of hepatocellular carcinoma (HCC) in offspring subjected to postweaning HCC induction. HCC in C57BL/6J mice was induced by diethylnitrosamine (DEN) injection at weaning, followed by a long-term high-fat choline-deficient (HFCD) diet. Before weaning, liver cadmium levels were significantly higher in mice with early-life cadmium exposure than in those without cadmium exposure. However, by 26 and 29 weeks of age, hepatic cadmium fell to control levels, while a significant decrease was observed in copper and iron in the liver. Both male and female cadmium-exposed mice showed increased body weight compared to non-cadmium-treated mice. For females, early-life cadmium exposure also worsened insulin intolerance but did not significantly promote DEN/HFCD diet-induced liver tumors. In contrast, in male mice, early-life cadmium exposure enhanced liver cancer induction by DEN/HFCD with high incidence and larger liver tumors. The liver peritumor tissue of early-life cadmium-exposed mice exhibited greater inflammation and disruption of fatty acid metabolism, accompanied by higher malondialdehyde and lower esterified triglyceride levels compared to mice without cadmium exposure. These findings suggest that early-life exposure to low-dose cadmium accelerates liver cancer development induced by a DEN/HFCD in male mice, probably due to chronic lipotoxicity and inflammation caused by increased uptake but decreased consumption of fatty acids.

Establishment of an immortalized cell line derived from the pupal ovary of Mythimna separata (Lepidoptera: Noctuidae) and identification of the cell source.

Determining the source of primary cells is conductive to enriching sufficient cells with immortal potential thereby improving the success rate of establishing cell lines. However, most of the existing insect cell lines are established by mixing and fragmentation of explants. At present, the origin of cell lines can only be determined according to the cultured tissues, so it is impossible to determine which cell types they come from. In this study, a new cell line designated IOZCAS-Myse-1 was generated from pupal ovaries of the migratory pest Mythimna separata by explant tissues to derive adherent cultures. This paper mainly shows the further descriptive information on the origin of primary cells in the process of ovarian tissue isolation and culture. Phospho-histone H3 antibody-labeled cells with mitotic activity showed that the rapidly developing somatic cells in vivo gradually stopped proliferation when cultured ex vivo. The primary cells dissociated outside the tissue originated from the lumen cells, rather than the germ cells or the follicular epithelium cells. The results suggest that the newly established cell line IOZCAS-Myse-1 had two possible sources. One is the mutation of lumen cells in the vitellarium, and the other is the stem cells with differentiation potential in the germarium of the ovarioles. Moreover, the newly established cell line is sensitive to the infection of Autographa californica multiple nucleopolyhedrovirus, responds to 20-hydroxyecdysone and has weak encapsulation ability. Therefore, the new cell line can be a useful platform for replication of viral insecticides, screening of hormone-based insecticides and immunology research.

Iodine Immobilized Metal-Organic Framework for NIR-Triggered Antibacterial Therapy on Orthopedic Implants.

Iodine has been known as an effective disinfectant with broad-spectrum antimicrobial potency yet without drug resistance risk when used in clinic. However, the exploration of iodine for antibacterial therapy in orthopedics remains sparse due to its volatile nature and poor solubility. Herein, leveraging the superior absorption capability of metal-organic frameworks (MOFs) and their inherent photocatalytic properties, iodine-loaded MOF surface is presented to realize responsive iodine release along with intracellular reactive oxygen species(ROS) oxidation under near-infrared (NIR) exposure to achieve synergistic antibacterial effect. Iodine is successfully loaded using vapor deposition process onto zeolitic imidazolate framework-8(ZIF-8), which is immobilized onto micro arc oxidized titanium via a hydrothermal approach. The combination of NIR-triggered iodine release and ZIF-8 mediated ROS oxidative stress substantially augments the antibacterial efficacy of this approach both in vitro and in vivo. Furthermore, this composite coating also supported osteogenic differentiation of bone marrow stromal cells, as well as improved osseointegration of coated implants using an intramedullary rat model, suggesting improvement of antibacterial efficacy does not impair osteogenic potential of the implants. Altogether, immobilization of iodine via MOF on orthopedic implants with synergistic antibacterial effect can be a promising strategy to combat bacterial infections.

Glycyrrhizic Acid Promotes Osteogenic Differentiation of Human Bone Marrow Stromal Cells by Activating the Wnt/ß-Catenin Signaling Pathway.

Glycyrrhizic acid (GA) is a major triterpene glycoside isolated from liquorice root that has been shown to inhibit osteoclastogenesis. However, there have been no reports regarding the effect of GA on osteogenic differentiation. Therefore, this study was performed to explore the effects and mechanism of action of GA on osteogenesis. A CCK-8 array was used to assess cell viability. The osteogenic capability was investigated by real-time quantitative PCR, western blotting and immunofluorescence analyses. ALP staining and ARS were used to evaluate ALP activity and mineralization, respectively. GA-GelMA hydrogels were designed to verify the therapeutic effects of GA in vivo by radiographic analysis and histological evaluation. Our results show that GA had no significant influence on the viability or proliferation of human bone marrow stromal cells (hBMSCs). GA promoted osteogenic differentiation and enhanced calcium deposition. Furthermore, ratio of active ß-catenin and total ß-catenin protein increased after treatment with GA. Wnt/catenin signaling inhibitor partially attenuated the effects of GA on osteogenic differentiation. In a mouse femoral fracture model, GA-GelMA hydrogels accelerated bone healing. Our results show that GA promotes the osteogenic differentiation of hBMSCs by modulating the Wnt/ß-catenin signaling pathway. GA-GelMA hydrogels promoted bone fracture healing. GA has potential as a cost-effective treatment of bone defects.

Low-dose IL-34 has no effect on osteoclastogenesis but promotes osteogenesis of hBMSCs partly via activation of the PI3K/AKT and ERK signaling pathways.

BACKGROUND: Inflammatory microenvironment is significant to the differentiation and function of mesenchymal stem cells (MSCs). It evidentially influences the osteoblastogenesis of MSCs. IL-34, a newly discovered cytokine, playing a key role in metabolism. However, the research on its functional role in the osteogenesis of MSCs was rarely reported. Here, we described the regulatory effects of low-dose IL-34 on both osteoblastogenesis and osteoclastogenesis. METHODS: We performed the osteogenic effects of hBMSCs by exogenous and overexpressed IL-34 in vitro, so were the osteoclastogenesis effects of mBMMs by extracellular IL-34. CCK-8 was used to assess the effect of IL-34 on the viability of hBMSCs and mBMMs. ALP, ARS, and TRAP staining was used to evaluate ALP activity, mineral deposition, and osteoclastogenesis, respectively. qRT-PCR and Western blotting analysis were performed to detect the expression of target genes and proteins. ELISA was used to evaluate the concentrations of IL-34. In vivo, a rat tibial osteotomy model and an OVX model were established. Radiographic analysis and histological evaluation were performed to confirm the therapeutic effects of IL-34 in fracture healing and osteoporosis. Statistical differences were evaluated by two-tailed Student's t test, one-way ANOVA with Bonferroni's post hoc test, and two-way ANOVA with Bonferroni multiple comparisons post hoc test in the comparison of 2 groups, more than 2 groups, and different time points of treated groups, respectively. RESULTS: Promoted osteoblastogenesis of hBMSCs was observed after treated by exogenous or overexpressed IL-34 in vitro, confirmed by increased mineral deposits and ALP activity. Furthermore, exogenous or overexpressed IL-34 enhanced the expression of p-AKT and p-ERK. The specific AKT and ERK signaling pathway inhibitors suppressed the enhancement of osteoblastogenesis induced by IL-34. In a rat tibial osteotomy model, imaging and histological analyses testified the local injection of exogenous IL-34 improved bone healing. However, the additional IL-34 has no influence on both osteoclastogenesis of mBMMs in vitro and osteoporosis of OVX model of rat in vivo. CONCLUSIONS: Collectively, our study demonstrate that low-dose IL-34 regulates osteogenesis of hBMSCs partly via the PIK/AKT and ERK signaling pathway and enhances fracture healing, with neither promoting nor preventing osteoclastogenesis in vitro and osteoporosis in vivo.

Drought tolerance in Brassica napus is accompanied with enhanced antioxidative protection, photosynthetic and hormonal regulation at seedling stage.

Climate change, food insecurity, water scarcity, and population growth are some of today's world's frightening problems. Drought stress exerts a constant threat to field crops and is often seen as a major constraint on global agricultural productivity; its intensity and frequency are expected to increase in the near future. The present study investigated the effects of drought stress (15% w/v polyethylene glycol PEG-6000) on physiological and biochemical changes in five Brassica napus cultivars (ZD630, ZD622, ZD619, GY605, and ZS11). For drought stress induction, 3-week-old rapeseed oil seedlings were treated with PEG-6000 in full strength Hoagland nutrient solution for 7 days. PEG treatment significantly decreased the plant growth and photosynthetic efficiency, including primary photochemistry (Fv/Fm) of PSII, intercellular CO2 , net photosynthesis, chlorophyll contents, and water-use efficiency of all studied B. napus cultivars; however, pronounced growth retardations were observed in cultivar GY605. Drought-stressed B. napus cultivars also experienced a sharp rise in H2 O2 generation and malondialdehyde (MDA) content. Additionally, the accumulation of ROS was accompanied by increased activity of enzymatic antioxidants (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase), although the increase was more obvious in ZD622 and ZS11. Drought stress also caused an increased endogenous hormonal biosynthesis (abscisic acid, jasmonic acid, salicylic acid) and accumulation of total soluble proteins and proline content, but the extent varies in B. napus cultivars. These results suggest that B. napus cultivars have an efficient drought stress tolerance mechanism, as shown by improved antioxidant enzyme activities, photosynthetic and hormonal regulation.

The Role of Forkhead Box Family in Bone Metabolism and Diseases.

Forkhead box (Fox) family, an evolutionarily conserved family of transcription factors carrying the "Forkhead" motif, plays an indispensable role in human health and disease. Fox family genes are involved in cell differentiation, proliferation and apoptosis, embryonic development, aging, glucose and lipid metabolism, and immune regulation. The regulatory role of the Fox family in the context of bone metabolism and orthopedic diseases is an emerging research hotspot. In this review, we highlight the major molecular mechanisms underlying the regulatory role of Fox factors in bone metabolism, bone development, bone homeostasis, and bone diseases associated with inhibition or upregulation of Fox factors. In addition, we discuss the emerging evidence in the realm of Fox factor-based therapeutics.

Withanolide B promotes osteogenic differentiation of human bone marrow mesenchymal stem cells via ERK1/2 and Wnt/ß-catenin signaling pathways.

BACKGROUND: The treatment of bone defects has always been a problem for clinicians. In recent years, research on human bone mesenchymal stem cells (hBMSCs) has found that promoting their osteogenic differentiation could be a useful therapeutic strategy for bone healing. Previous studies have been reported that Withania somnifera Dunal inhibits osteoclastogenesis by inhibiting the NF-κB signaling pathway. Withanolide B is an active component of W. somnifera Dunal, but its role in osteogenic differentiation of hBMSCs remains unknown. Here, we performed a preliminary study on the role of Withanolide B in promoting osteogenic differentiation and its possible mechanism. METHODS: We investigated the effect of Withanolide B on osteogenic differentiation of hBMSCs in vitro and in vivo. The effect of Withanolide B on the activity of hBMSCs was verified by CCK-8 assay and quantitative Real-time polymerase chain reaction (qPCR) and Western blotting analysis were used to verify the effect of Withanolide B on osteogenic differentiation-specific genes and proteins. The effect of Withanolide B on ALP activity and mineral deposition was verified by ALP and ARS staining. We then used a rat tibial osteotomy model to observe the effect of Withanolide B on bone healing. RESULTS: Withanolide B is noncytotoxic to hBMSCs and can effectively promote their osteogenic differentiation. Moreover, we found that Withanolide B can regulate the osteogenic differentiation of hBMSCs through the ERK1/2 and Wnt/ß-catenin signaling pathways. When inhibitors of the ERK1/2 and Wnt/ß-catenin signaling pathways were used, the enhancement of osteogenic differentiation induced by Withanolide B was attenuated. Withanolide B also effectively promoted bone healing in the rat tibial osteotomy model. CONCLUSIONS: Our results suggest that Withanolide B can promote the osteogenic differentiation of hBMSCs through the ERK1/2 and Wnt/ß-catenin signaling pathways and can effectively promote bone defect healing.

Endothelial Overexpression of Metallothionein Prevents Diabetes-Induced Impairment in Ischemia Angiogenesis Through Preservation of HIF-1α/SDF-1/VEGF Signaling in Endothelial Progenitor Cells.

Diabetes-induced oxidative stress is one of the major contributors to dysfunction of endothelial progenitor cells (EPCs) and impaired endothelial regeneration. Thus, we tested whether increasing antioxidant protein metallothionein (MT) in EPCs promotes angiogenesis in a hind limb ischemia (HLI) model in endothelial MT transgenic (JTMT) mice with high-fat diet- and streptozocin-induced diabetes. Compared with littermate wild-type (WT) diabetic mice, JTMT diabetic mice had improved blood flow recovery and angiogenesis after HLI. Similarly, transplantation of JTMT bone marrow-derived mononuclear cells (BM-MNCs) stimulated greater blood flow recovery in db/db mice with HLI than did WT BM-MNCs. The improved recovery was associated with augmented EPC mobilization and angiogenic function. Further, cultured EPCs from patients with diabetes exhibited decreased MT expression, increased cell apoptosis, and impaired tube formation, while cultured JTMT EPCs had enhanced cell survival, migration, and tube formation in hypoxic/hyperglycemic conditions compared with WT EPCs. Mechanistically, MT overexpression enhanced hypoxia-inducible factor 1α (HIF-1α), stromal cell-derived factor (SDF-1), and vascular endothelial growth factor (VEGF) expression and reduced oxidative stress in ischemic tissues. MT's pro-EPC effects were abrogated by siRNA knockdown of HIF-1α without affecting its antioxidant action. These results indicate that endothelial MT overexpression is sufficient to protect against diabetes-induced impairment of angiogenesis by promoting EPC function, most likely through upregulation of HIF-1α/SDF-1/VEGF signaling and reducing oxidative stress.