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Amyotrophic lateral sclerosis (ALS) is irreversible and fatal within 3-5 years, with limited options for treatment. It is imperative to develop a symptom-based treatment that may increase the survival of ALS patients and improve their quality of life. Inflammation status, especially elevated interleukin 1β (IL1β), has been reported to play a critical role in ALS progression. Our study determined that neutralizing circulating IL1β slows down the progression of ALS in an ALS mouse model.The ALS mouse model was developed by microinjection of lentivirus-carrying OPTNThe model revealed that neuroinflammation contributes to ALS progression. ALS mice exhibited elevated neuroinflammation and IL1β secretion. After anti-IL1β treatment, ALS mice revealed decreased neural cell death and astrogliosis and gained improved muscle strength and motor ability.Blocking IL1β is a promising strategy to slow down the progression of ALS.

Osteoporosis is one of the most common metabolic bone diseases affecting millions of people. We previously found that harmine prevents bone loss in ovariectomized mice via increasing preosteoclast platelet‐derived growth factor‐BB (PDGF‐BB) production and type H vessel formation. However, the molecular mechanisms by which harmine promotes preosteoclast PDGF‐BB generation are still unclear. In this study, we revealed that inhibitor of DNA binding‐2 (Id2) and activator protein‐1 (AP‐1) were important factors implicated in harmine‐enhanced preosteoclast PDGF‐BB production. Exposure of RANKL‐induced Primary bone marrow macrophages (BMMs), isolated from tibiae and femora of mice, to harmine increased the protein levels of Id2 and AP‐1. Knockdown of Id2 by Id2‐siRNA reduced the number of preosteoclasts as well as secretion of PDGF‐BB in RANKL‐stimulated BMMs administrated with harmine. Inhibition of c‐Fos or c‐Jun (components of AP‐1) both reversed the stimulatory effect of harmine on preosteoclast PDGF‐BB production. Dual‐luciferase reporter assay analyses determined that PDGF‐BB was the direct target of AP‐1 which was up‐regulated by harmine treatment. In conclusion, our data demonstrated a novel mechanism involving in the production of PDGF‐BB increased by harmine, which may provide potential therapeutic targets for bone loss diseases.

Two-dimensional (2D) nanomaterials are attracting more and more interest in regenerative medicine due to their unique properties; however 2D biomimetic calcium mineral has not yet been developed and demonstrated application for bone tissue engineering. Here we described a novel calcium phosphate material with a 2D nanostructure that was synthesized using collagen and sodium alginate as the template. In vitro performance of the nanocrystalline material was evaluated, and we found that 2D CaP nanoparticles (NPs) enhanced the in vitro osteogenic differentiation of rat mesenchymal stem cells (rMSCs) through a macrophage-mediated signal pathway, when co-cultured with RAW 264.7 cells, rather than direct NP/stem cell interaction. A 2D topology structured surface was constructed by encapsulating the CaP nanomaterials in a gelatin hydrogel, which was demonstrated to be able to mediate in vivo ossification through a macrophage polarization related pathway in a femur defect rat model, and allowed the optimal therapeutic outcome compared to normal CaP counterparts. Our current work may have enlightened a new mechanism regarding NP-induced stem cell differentiation through immunoregulation, and the 2D CaP encapsulated hydrogel scaffold may serve as a potential alternative to autograft bone for orthopedic applications.

Senile osteoporosis (OP) is often concomitant with decreased autophagic activity. OPTN (optineurin), a macroautophagy/autophagy (hereinafter referred to as autophagy) receptor, is found to play a pivotal role in selective autophagy, coupling autophagy with bone metabolism. However, its role in osteogenesis is still mysterious. Herein, we identified Optn as a critical molecule of cell fate decision for bone marrow mesenchymal stem cells (MSCs), whose expression decreased in aged mice. Aged mice revealed osteoporotic bone loss, elevated senescence of MSCs, decreased osteogenesis, and enhanced adipogenesis, as well as optn(–)(/ –) mice. Importantly, restoring Optn by transplanting wild-type MSCs to optn(–)(/ –) mice or infecting optn(–)(/ –) mice with Optn-containing lentivirus rescued bone loss. The introduction of a loss-of-function mutant of Optn(K193R) failed to reestablish a bone-fat balance. We further identified FABP3 (fatty acid binding protein 3, muscle and heart) as a novel selective autophagy substrate of OPTN. FABP3 promoted adipogenesis and inhibited osteogenesis of MSCs. Knockdown of FABP3 alleviated bone loss in optn(–)(/ –) mice and aged mice. Our study revealed that reduced OPTN expression during aging might lead to OP due to a lack of FABP3 degradation via selective autophagy. FABP3 accumulation impaired osteogenesis of MSCs, leading to the occurrence of OP. Thus, reactivating OPTN or inhibiting FABP3 would open a new avenue to treat senile OP. Abbreviations: ADIPOQ: adiponectin, C1Q and collagen domain containing; ALPL: alkaline phosphatase, liver/bone/kidney; BGLAP/OC/osteocalcin: bone gamma carboxyglutamate protein; BFR/BS: bone formation rate/bone surface; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CDKN1A/p21: cyclin-dependent kinase inhibitor 1A; CDKN2A/p16: cyclin dependent kinase inhibitor 2A; CDKN2B/p15: cyclin dependent kinase inhibitor 2B; CEBPA: CCAAT/enhancer binding protein (C/EBP), alpha; COL1A1: collagen, type I, alpha 1; Ct. BV/TV: cortical bone volume fraction; Ct. Th: cortical thickness; Es. Pm: endocortical perimeter; FABP4/Ap2: fatty acid binding protein 4, adipocyte; H2AX: H2A.X variant histone; HE: hematoxylin and eosin; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MAR: mineral apposition rate; MSCs: bone marrow mesenchymal stem cells; NBR1: NBR1, autophagy cargo receptor; OP: osteoporosis; OPTN: optineurin; PDB: Paget disease of bone; PPARG: peroxisome proliferator activated receptor gamma; Ps. Pm: periosteal perimeter; qRT-PCR: quantitative real-time PCR; γH2AX: Phosphorylation of the Serine residue of H2AX; ROS: reactive oxygen species; RUNX2: runt related transcription factor 2; SA-GLB1: senescence-associated (SA)-GLB1 (galactosidase, beta 1); SP7/Osx/Osterix: Sp7 transcription factor 7; SQSTM1/p62: sequestosome 1; TAX1BP1: Tax1 (human T cell leukemia virus type I) binding protein 1; Tb. BV/TV: trabecular bone volume fraction; Tb. N: trabecular number; Tb. Sp: trabecular separation; Tb. Th: trabecular thickness; μCT: micro computed tomography.

Healing of the chronic diabetic ulceration and large burns remains a clinical challenge. Therapeutic fasting has been shown to improve health. Our study tested whether fasting facilitates diabetic and burn wound healing and explored the underlying mechanism. Methods: The effects of fasting on diabetic and burn wound healing were evaluated by analyzing the rates of wound closure, re-epithelialization, scar formation, collagen deposition, skin cell proliferation and neovascularization using histological analyses and immunostaining. In vitro functional assays were conducted to assess fasting and refeeding on the angiogenic activities of endothelial cells. Transcriptome sequencing was employed to identify the differentially expressed genes in endothelial cells after fasting treatment and the role of the candidate genes in the fasting-induced promotion of angiogenesis was demonstrated. Results: Two times of 24-h fasting in a week after but especially before wound injury efficiently induced faster wound closure, better epidermal and dermal regeneration, less scar formation and higher level of angiogenesis in mice with diabetic or burn wounds. In vitro, fasting alone by serum deprivation did not increase, but rather reduced the abilities of endothelial cell to proliferate, migrate and form vessel-like tubes. However, subsequent refeeding did not merely rescue, but further augmented the angiogenic activities of endothelial cells. Transcriptome sequencing revealed that fasting itself, but not the following refeeding, induced a prominent upregulation of a variety of pro-angiogenic genes, including SMOC1 (SPARC related modular calcium binding 1) and SCG2 (secretogranin II). Immunofluorescent staining confirmed the increase of SMOC1 and SCG2 expression in both diabetic and burn wounds after fasting treatment. When the expression of SMOC1 or SCG2 was down-regulated, the fasting/refeeding-induced pro-angiogenic effects were markedly attenuated. Conclusion: This study suggests that fasting combined with refeeding, but not fasting solely, enhance endothelial angiogenesis through the activation of SMOC1 and SCG2, thus facilitating neovascularization and rapid wound healing.

The etiology of epilepsy remains undefined in two-thirds of patients. Here, we identified a de novo variant of ATP1A2 (c.2426 T G, p.Leu809Arg), which encodes the α2 subunit of Na

A differentiation switch of bone marrow mesenchymal stem/stromal cells (BMSCs) from osteoblasts to adipocytes contributes to age‐ and menopause‐associated bone loss and marrow adiposity. Here it is found that osteocytes, the most abundant bone cells, promote adipogenesis and inhibit osteogenesis of BMSCs by secreting neuropeptide Y (NPY), whose expression increases with aging and osteoporosis. Deletion of NPY in osteocytes generates a high bone mass phenotype, and attenuates aging‐ and ovariectomy (OVX)‐induced bone‐fat imbalance in mice. Osteocyte NPY production is under the control of autonomic nervous system (ANS) and osteocyte NPY deletion blocks the ANS‐induced regulation of BMSC fate and bone‐fat balance. γ‐Oryzanol, a clinically used ANS regulator, significantly increases bone formation and reverses aging‐ and OVX‐induced osteocyte NPY overproduction and marrow adiposity in control mice, but not in mice lacking osteocyte NPY. The study suggests a new mode of neuronal control of bone metabolism through the ANS‐induced regulation of osteocyte NPY., Normally, norepinephrine (NE) and acetylcholine (ACh) production is maintained at a balanced level in bone, so that osteocytes cannot generate excessive neuropeptide Y (NPY) to favor bone marrow mesenchymal stem/stromal cell adipogenesis rather than osteogenesis. With aging/estrogen deficiency, sympathetic overactivity, and decreased parasympathetic activity cause NE overproduction and ACh reduction, resulting in excess osteocyte NPY generation and subsequent bone‐fat imbalance.

The etiology of epilepsy remains undefined in two-thirds of patients. Here, we identified a de novo mutation of ATP1A2 (c.2426 T>G, p.Leu809Arg), which encodes the α2 subunit of Na+/K+-ATPase, from a family with idiopathic epilepsy. This mutation caused seizures in the study patients. We generated the point mutation mouse model Atp1a2L809R, which recapitulated the epilepsy observed in the study patients. In Atp1a2L809R/WT mice, convulsions were observed and cognitive and memory function was impaired. This mutation affected the potassium binding function of the protein, disabling its ion transport ability, thereby increasing the frequency of nerve impulses. Our work revealed that ATP1A2L809R mutations cause a predisposition to epilepsy. Moreover, we first provide a point mutation mouse model for epilepsy research and drug screening.

Osteoporosis and osteoporotic fractures severely compromise quality of life in elderly people and lead to early death. Human umbilical cord mesenchymal stromal cell (MSC)-derived extracellular vesicles (hucMSC-EVs) possess considerable therapeutic effects in tissue repair and regeneration. Thus, in the present study, we investigated the effects of hucMSC-EVs on primary and secondary osteoporosis and explored the underlying mechanisms. Methods: hucMSCs were isolated and cultured. EVs were obtained from the conditioned medium of hucMSCs and determined by using transmission electron microscopy, dynamic light scattering and Western Blot analyses. The effects of hucMSC-EVs on ovariectomy-induced postmenopausal osteoporosis and tail suspension-induced hindlimb disuse osteoporosis in mouse models were assessed by using microcomputed tomography, biomechanical, histochemical and immunohistochemical, as well as histomorphometric analyses. Proteomic analysis was applied between hucMSC-EVs and hucMSCs to screen the candidate proteins that mediate hucMSC-EVs function. The effects of hucMSC-EVs on osteogenic and adipogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs), and osteoclastogenesis of the macrophage cell line RAW264.7 in vitro were determined by using cytochemical staining and quantitative real-time PCR analysis. Subsequently, the roles of the key protein in hucMSC-EVs-induced regulation on BMSCs and RAW264.7 cells were evaluated. Results: hucMSCs were able to differentiate into osteoblasts, adipocytes or chondrocytes and positively expressed CD29, CD44, CD73 and CD90, but negatively expressed CD34 and CD45. The morphological assessment revealed the typical cup- or sphere-shaped morphology of hucMSC-EVs with diameters predominantly ranging from 60 nm to 150 nm and expressed CD9, CD63, CD81 and TSG101. The systemic administration of hucMSC-EVs prevented bone loss and maintained bone strength in osteoporotic mice by enhancing bone formation, reducing marrow fat accumulation and decreasing bone resorption. Proteomic analysis showed that the potently pro-osteogenic protein, CLEC11A (C-type lectin domain family 11, member A) was very highly enriched in hucMSC-EVs. In addition, hucMSC-EVs enhanced the shift from adipogenic to osteogenic differentiation of BMSCs via delivering CLEC11A in vitro. Moreover, CLEC11A was required for the inhibitory effects of hucMSC-EVs on osteoclast formation. Conclusion: Our results suggest that hucMSC-EVs serve as a critical regulator of bone metabolism by transferring CLEC11A and may represent a potential agent for prevention and treatment of osteoporosis.

Objective Senile osteoporosis is one of the most common age-related diseases worldwide. Accumulating evidences have indicated that young blood can reverse age-related impairments. Extracellular vesicles (EVs) exert therapeutic effects in a variety of diseases by delivering bioactive molecules such as microRNAs (miRNAs). The aim of the study is to evaluate the therapeutic potential of EVs from human umbilical cord blood plasma (UCB-EVs) on senile osteoporosis and to preliminarily clarify the underlying mechanism. Methods UCB-EVs were injected into the tail vein of aged (16 months old) male C57BL/6 mice. Microcomputed tomography was performed to evaluate bone mass and microarchitecture of mice. The osteogenic and osteoclastic activities were determined by quantitative real-time PCR (qRT-PCR), histological examination and western blot analysis. In vitro, qRT-PCR assay was undertaken to explore the enrichment levels of a number of miRNAs that have positive effects in reducing bone loss. The efficacy of UCB-EVs on osteoblastic differentiation of bone marrow mesenchymal stromal cells (BMSCs) and osteoclastogenesis of RAW264.7 cells were assessed by cytochemical staining. Gene and protein expression changes were detected by qRT-PCR and western blotting respectively. Meanwhile, the roles of the selected miRNA in the regulatory effects of UCB-EVs on BMSCs and RAW264.7 cells were evaluated by using specific miRNA inhibitor. Results The intravenous injection of UCB-EVs for two months attenuated bone loss in old mice, as defined by increased trabecular and cortical bone mass, enhanced osteoblast formation and reduced osteoclast formation compared to the control mice. In vitro, UCB-EVs could promote the osteogenic differentiation of BMSCs and inhibit the osteoclastogenesis of RAW264.7 cells. Moreover, it was confirmed that miR-3960 was highly enriched in UCB-EVs and miR-3960 inhibitor reversed the stimulatory effect of UCB-EVs on osteoblastic differentiation of BMSCs. Conclusion Our findings indicate that UCB-EVs ameliorate age-related bone loss by stimulating bone formation and inhibiting bone resorption, and miR-3960 mediated the osteogenic effect of UCB-EVs on BMSCs. Thus, UCB-EVs may represent a promising agent for prevention of senile osteoporosis.

Adipocyte differentiation of bone marrow mesenchymal stem/stromal cells (BMSCs) instead of osteoblast formation contributes to age- and menopause-related marrow adiposity and osteoporosis. Vascular calcification often occurs with osteoporosis, a contradictory association called “calcification paradox”. Here we show that extracellular vesicles derived from aged bone matrix (AB-EVs) during bone resorption favor BMSC adipogenesis rather than osteogenesis and augment calcification of vascular smooth muscle cells. Intravenous or intramedullary injection of AB-EVs promotes bone-fat imbalance and exacerbates Vitamin D3 (VD3)-induced vascular calcification in young or old mice. Alendronate (ALE), a bone resorption inhibitor, down-regulates AB-EVs release and attenuates aging- and ovariectomy-induced bone-fat imbalance. In the VD3-treated aged mice, ALE suppresses the ovariectomy-induced aggravation of vascular calcification. MiR-483-5p and miR-2861 are enriched in AB-EVs and essential for the AB-EVs-induced bone-fat imbalance and exacerbation of vascular calcification. Our study uncovers the role of AB-EVs as a messenger for calcification paradox by transferring miR-483-5p and miR-2861.

In elderly people particularly in postmenopausal women, inadequate bone formation by osteoblasts originating from bone marrow mesenchymal stem cells (BMSCs) for compensation of bone resorption by osteoclasts is a major reason for osteoporosis. Enhancing osteoblastic differentiation of BMSCs is a feasible therapeutic strategy for osteoporosis. Here, bone marrow stromal cell (ST)-derived exosomes (STExos) are found to remarkably enhance osteoblastic differentiation of BMSCs in vitro. However, intravenous injection of STExos is inefficient in ameliorating osteoporotic phenotypes in an ovariectomy (OVX)-induced postmenopausal osteoporosis mouse model, which may be because STExos are predominantly accumulated in the liver and lungs, but not in bone. Hereby, the STExo surface is conjugated with a BMSC-specific aptamer, which delivers STExos into BMSCs within bone marrow. Intravenous injection of the STExo-Aptamer complex enhances bone mass in OVX mice and accelerates bone healing in a femur fracture mouse model. These results demonstrate the efficiency of BMSC-specific aptamer-functionalized STExos in targeting bone to promote bone regeneration, providing a novel promising approach for the treatment of osteoporosis and fracture.

Alzheimer's disease (AD) is currently ranked as the third leading cause of death for eldly people, just behind heart disease and cancer. Autophagy is declined with aging. Our study determined the biphasic changes of miR-331-3p and miR-9-5p associated with AD progression in APPswe/PS1dE9 mouse model and demonstrated inhibiting miR-331-3p and miR-9-5p treatment prevented AD progression by promoting the autophagic clearance of amyloid beta (Aβ). Methods: The biphasic changes of microRNAs were obtained from RNA-seq data and verified by qRT-PCR in early-stage (6 months) and late-stage (12 months) APPswe/PS1dE9 mice (hereinafter referred to as AD mice). The AD progression was determined by analyzing Aβ levels, neuron numbers (MAP2+) and activated microglia (CD68+IBA1+) in brain tissues using immunohistological and immunofluorescent staining. MRNA and protein levels of autophagic-associated genes (Becn1, Sqstm1, LC3b) were tested to determine the autophagic activity. Morris water maze and object location test were employed to evaluate the memory and learning after antagomirs treatments in AD mice and the Aβ in the brain tissues were determined. Results: MiR-331-3p and miR-9-5p are down-regulated in early-stage of AD mice, whereas up-regulated in late-stage of AD mice. We demonstrated that miR-331-3p and miR-9-5p target autophagy receptors Sequestosome 1 (Sqstm1) and Optineurin (Optn), respectively. Overexpression of miR-331-3p and miR-9-5p in SH-SY5Y cell line impaired autophagic activity and promoted amyloid plaques formation. Moreover, AD mice had enhanced Aβ clearance, improved cognition and mobility when treated with miR-331-3p and miR-9-5p antagomirs at late-stage. Conclusion: Our study suggests that using miR-331-3p and miR-9-5p, along with autophagic activity and amyloid plaques may distinguish early versus late stage of AD for more accurate and timely diagnosis. Additionally, we further provide a possible new therapeutic strategy for AD patients by inhibiting miR-331-3p and miR-9-5p and enhancing autophagy.

Osteosarcoma is a common malignant bone cancer easily to metastasize. Much safer and more efficient strategies are still needed to suppress osteosarcoma growth and lung metastasis. We recently presented a pure physical method to fabricate Angstrom-scale silver particles (AgAPs) and determined the anti-tumor efficacy of fructose-coated AgAPs (F-AgAPs) against lung and pancreatic cancer. Our study utilized an optimized method to obtain smaller F-AgAPs and aimed to assess whether F-AgAPs can be used as an efficient and safe agent for osteosarcoma therapy. We also investigated whether the induction of apoptosis by altering glucose metabolic phenotype contributes to the F-AgAPs-induced anti-osteosarcoma effects. Methods: A modified method was developed to prepare smaller F-AgAPs. The anti-tumor, anti-metastatic and pro-survival efficacy of F-AgAPs and their toxicities on healthy tissues were compared with that of cisplatin (a first-line chemotherapeutic drug for osteosarcoma therapy) in subcutaneous or orthotopic osteosarcoma-bearing nude mice. The pharmacokinetics, biodistribution and excretion of F-AgAPs were evaluated by testing the levels of silver in serum, tissues, urine and feces of mice. A series of assays in vitro were conducted to assess whether the induction of apoptosis mediates the killing effects of F-AgAPs on osteosarcoma cells and whether the alteration of glucose metabolic phenotype contributes to F-AgAPs-induced apoptosis. Results: The newly obtained F-AgAPs (9.38 ± 4.11 nm) had good stability in different biological media or aqueous solutions and were more effective than cisplatin in inhibiting tumor growth, improving survival, attenuating osteolysis and preventing lung metastasis in osteosarcoma-bearing nude mice after intravenous injection, but were well tolerated in normal tissues. One week after injection, about 68% of F-AgAPs were excreted through feces. F-AgAPs induced reactive oxygen species (ROS)-dependent apoptosis of osteosarcoma cells but not normal cells, owing to their ability to selectively shift glucose metabolism of osteosarcoma cells from glycolysis to mitochondrial oxidation by inhibiting pyruvate dehydrogenase kinase (PDK). Conclusion: Our study suggests the promising prospect of F-AgAPs as a powerful selective anticancer agent for osteosarcoma therapy.

Osteonecrosis of the femoral head (ONFH) frequently occurs after glucocorticoid (GC) treatment. Extracellular vesicles (EVs) are important nano-sized paracrine mediators of intercellular crosstalk. This study aimed to determine whether EVs from human urine-derived stem cells (USC-EVs) could protect against GC-induced ONFH and focused on the impacts of USC-EVs on angiogenesis and apoptosis to explore the mechanism by which USC-EVs attenuated GC-induced ONFH. The results in vivo showed that the intravenous administration of USC-EVs at the early stage of GC exposure could rescue angiogenesis impairment, reduce apoptosis of trabecular bone and marrow cells, prevent trabecular bone destruction and improve bone microarchitecture in the femoral heads of rats. In vitro, USC-EVs reversed the GC-induced suppression of endothelial angiogenesis and activation of apoptosis. Deleted in malignant brain tumors 1 (DMBT1) and tissue inhibitor of metalloproteinases 1 (TIMP1) proteins were enriched in USC-EVs and essential for the USC-EVs-induced pro-angiogenic and anti-apoptotic effects in GC-treated cells, respectively. Knockdown of TIMP1 attenuated the protective effects of USC-EVs against GC-induced ONFH. Our study suggests that USC-EVs are a promising nano-sized agent for the prevention of GC-induced ONFH by delivering pro-angiogenic DMBT1 and anti-apoptotic TIMP1. Statement of Significance This study demonstrates that the intravenous injection of extracellular vesicles from human urine-derived stem cells (USC-EVs) at the early stage of glucocorticoid (GC) exposure efficiently protects the rats from the GC-induced osteonecrosis of the femoral head (ONFH). Moreover, this study identifies that the promotion of angiogenesis and inhibition of apoptosis by transferring pro-angiogenic DMBT1 and anti-apoptotic TIMP1 proteins contribute importantly to the USC-EVs-induced protective effects against GC-induced ONFH. This study suggests the promising prospect of USC-EVs as a new nano-sized agent for protecting against GC-induced ONFH, and the potential of DMBT1 and TIMP1 as the molecular targets for further augmenting the protective function of USC-EVs.

Osteoporosis is a frequent complication of chronic inflammatory diseases and increases in the pro-inflammatory cytokines make an important contribution to bone loss by promoting bone resorption and impairing bone formation. Omentin-1 is a newly identified adipocytokine that has anti-inflammatory effects, but little is known about the role of omentin-1 in inflammatory osteoporosis. Here we generated global omentin-1 knockout (omentin-1−/−) mice and demonstrated that depletion of omentin-1 induces inflammatory bone loss-like phenotypes in mice, as defined by abnormally elevated pro-inflammatory cytokines, increased osteoclast formation and bone tissue destruction, as well as impaired osteogenic activities. Using an inflammatory cell model induced by tumor necrosis factor-α (TNF-α), we determined that recombinant omentin-1 reduces the production of pro-inflammatory factors in the TNF-α-activated macrophages, and suppresses their anti-osteoblastic and pro-osteoclastic abilities. In the magnesium silicate-induced inflammatory osteoporosis mouse model, the systemic administration of adenoviral-delivered omentin-1 significantly protects from osteoporotic bone loss and inflammation. Our study suggests that omentin-1 can be used as a promising therapeutic agent for the prevention or treatment of inflammatory bone diseases by downregulating the pro-inflammatory cytokines., Osteoporosis: Fat-secreted protein guards against bone loss in mice An anti-inflammatory molecule produced by fat tissue helps protect against bone loss in mouse model of osteoporosis. Researchers from China’s Central South University in Changsha, led by Hui Xie, examined whether omentin-1, a protein secreted by fat tissue recently implicated in the development of obesity and diabetes, might play a role in osteoporosis as well. In mice engineered to lack omentin-1, they observed more bone tissue destruction and increased numbers of bone-resorbing osteoclast cells than in normal, healthy animals. The researchers also administered exogenous omentin-1 to mice either with an overactive inflammatory molecule or experimentally induced to develop osteoporosis. In both cases, they found that the protein suppressed inflammation and guarded against bone loss. Omentin-1 thus provides promising therapeutic agent for preventing or treating inflammatory bone diseases such as osteoporosis.

Osteonecrosis of the femoral head (ONFH) frequently occurs after glucocorticoid (GC) treatment. Extracellular vesicles (EVs) are important nano-sized paracrine mediators of intercellular crosstalk. Herein, we found that intravenous administration of EVs from human urine-derived stem cells (USC-EVs) at the early stage of GC exposure rescues angiogenesis impairment, reduces apoptosis of bone marrow and trabecular bone cells, prevent trabecular bone destruction and improves bone microarchitecture in the femoral heads of rats. In vitro, USC-EVs reverse GC-induced suppression of endothelial angiogenesis and activation of cellular apoptosis. Deleted in malignant brain tumors 1 (DMBT1) and tissue inhibitor of metalloproteinases 1 (TIMP1) are enriched in USC-EVs and essential for USC-EVs-induced pro-angiogenic and anti-apoptotic effects in GC-treated cells, respectively. Knockdown of TIMP1 in USC-EVs attenuates their protective effects against GC-induced ONFH. Our study suggests that USC-EVs are a novel promising nano-sized agent for the prevention of GC-induced ONFH by delivering pro-angiogenic DMBT1 and anti-apoptotic TIMP1.

Osteoporosis is a debilitating bone disease affecting millions of people. Here, we used human urine-derived stem cells (USCs), which were noninvasively harvested from unlimited and easily available urine, as a “factory” to obtain extracellular vesicles (USC-EVs) and demonstrated that the systemic injection of USC-EVs effectively alleviates bone loss and maintains bone strength in osteoporotic mice by enhancing osteoblastic bone formation and suppressing osteoclastic bone resorption. More importantly, the anti-osteoporotic properties of USC-EVs are not notably disrupted by the age, gender, or health condition (with or without osteoporosis) of the USC donor. Mechanistic studies determined that collagen triple-helix repeat containing 1 (CTHRC1) and osteoprotegerin (OPG) proteins are enriched in USC-EVs and required for USC-EV-induced pro-osteogenic and anti-osteoclastic effects. Our results suggest that autologous USC-EVs represent a promising novel therapeutic agent for osteoporosis by promoting osteogenesis and inhibiting osteoclastogenesis by transferring CTHRC1 and OPG.

Chronic non-healing wounds represent one of the most common complications of diabetes and need advanced treatment strategies. Exosomes are key mediators of cell paracrine action and can be directly utilized as therapeutic agents for tissue repair and regeneration. Here, we explored the effects of exosomes from human urine-derived stem cells (USC-Exos) on diabetic wound healing and the underlying mechanism. Methods: USCs were characterized by flow cytometry and multipotent differentiation potential analyses. USC-Exos were isolated from the conditioned media of USCs and identified by transmission electron microscopy and flow cytometry. A series of functional assays in vitro were performed to assess the effects of USC-Exos on the activities of wound healing-related cells. Protein profiles in USC-Exos and USCs were examined to screen the candidate molecules that mediate USC-Exos function. The effects of USC-Exos on wound healing in streptozotocin-induced diabetic mice were tested by measuring wound closure rates, histological and immunofluorescence analyses. Meanwhile, the role of the candidate protein in USC-Exos-induced regulation of angiogenic activities of endothelial cells and diabetic wound healing was assessed. Results: USCs were positive for CD29, CD44, CD73 and CD90, but negative for CD34 and CD45. USCs were able to differentiate into osteoblasts, adipocytes and chondrocytes. USC-Exos exhibited a cup- or sphere-shaped morphology with a mean diameter of 51.57 ± 2.93 nm and positive for CD63 and TSG101. USC-Exos could augment the functional properties of wound healing-related cells including the angiogenic activities of endothelial cells. USC-Exos were enriched in the proteins that are involved in regulation of wound healing-related biological processes. Particularly, a pro-angiogenic protein called deleted in malignant brain tumors 1 (DMBT1) was highly expressed in USC-Exos. Further functional assays showed that DMBT1 protein was required for USC-Exos-induced promotion of angiogenic responses of cultured endothelial cells, as well as angiogenesis and wound healing in diabetic mice. Conclusion: Our findings suggest that USC-Exos may represent a promising strategy for diabetic soft tissue wound healing by promoting angiogenesis via transferring DMBT1 protein.

Recently, researchers identified a distinct vessel subtype called type H vessels that couple angiogenesis and osteogenesis. We previously found that type H vessels are reduced in ovariectomy (OVX)-induced osteoporotic mice, and preosteoclasts are able to secrete platelet-derived growth factor-BB (PDGF-BB) to stimulate type H vessel formation and thereby to promote osteogenesis. This study aimed to explore whether harmine, a β-carboline alkaloid, is capable of preventing bone loss in OVX mice by promoting preosteoclast PDGF-BB-induced type H vessel formation. Methods: The impact of harmine on osteoclastogenesis of RANKL-stimulated RAW264.7 cells was verified by gene expression analysis and tartrate-resistant acid phosphatase (TRAP) staining. Enzyme-linked immunosorbent assay (ELISA) was conducted to test PDGF-BB production by preosteoclasts. A series of angiogenesis-related assays in vitro were performed to assess the pro-angiogenic effects of the conditioned media from RANKL-stimulated RAW264.7 cells treated with or without harmine. Meanwhile, the role of PDGF-BB in this process was determined. In vivo, OVX mice were intragastrically administrated with harmine emulsion or an equal volume of vehicle. 2 months later, bone samples were collected for µCT, histological, immunohistochemical and immunofluorescent analyses to evaluate bone mass, osteogenic and osteoclastic activities, as well as the numbers of type H vessels. Bone marrow PDGF-BB concentrations were assessed by ELISA. Results: Exposure of RANKL-stimulated RAW264.7 cells to harmine enhanced the formation of preosteoclasts and the production of PDGF-BB. Harmine augmented the ability of RANKL-stimulated RAW264.7 cells to promote angiogenesis of endothelial cells, whereas the effect was blocked by PDGF-BB inhibition. In vivo, the oral administration of harmine emulsion to OVX mice resulted in enhanced trabecular bone mass and osteogenic responses, increased numbers of preosteoclasts, as well as reduced numbers of osteoclasts and fat cells. Moreover, OVX mice treated with harmine exhibited higher levels of bone marrow PDGF-BB and much more type H vessels in bone. Conclusion: Harmine may exert bone-sparing effects by suppression of osteoclast formation and promotion of preosteoclast PDGF-BB-induced angiogenesis.

Spinocerebellar ataxia type 3 (SCA3) is a degenerative neurological disorders caused by trinucleotide repeat expansion within the ataxin-3 gene. It is characterized by multi-system involvement and diverse clinical phenotypes, which cannot be fully explained the length of the CAG repeats. One possible explanation for the phenotypic heterogeneity could be the presence of mitochondrial DNA mutations that modify disease severity. To explore the role of Mitochondrial DNA(mtDNA) variations in SCA3 pathogenesis, we analyzed polymorphisms of six mitochondrial genes, MT-LT1, MT-ND1, MT-CO2, MT-TK, MT-ATP8 and MT-ATP6, in 102 unrelated SCA3/MJD patients and 100 healthy controls. The results showed that there were 24 variations of those mtDNA genes in the SCA3 patients and only 10 in the unrelated healthy controls. There was no difference of the relative mtDNA copy number variation between the SCA3 patients and healthy controls (93.20 vs. 89.66, P>0.05). In the group of SCA3 patients, the relative mtDNA copy number showed a negative correlation between the number of CAG repeats (r=−0.210, P < 0.05), but did not correlate with the age at diagnosis, the age of onset, disease duration, ICARS scores and SARA scores. Our research demonstrated that the frequency of mutated mtDNA in SCA3 patients was higher than that in the healthy group. The mtDNA relative copy number in SCA3 patients was not significantly different compared to the healthy group. Thus, the copy number might not be treated as a biomedical indicator when measuring the severity of illness in SCA3 patients.