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Bone is one of the most sophisticated and dynamic tissues in the human body, and is characterized by its remarkable potential for regeneration. In most cases, bone has the capacity to be restored to its original form with homeostatic functionality after injury without any remaining scarring. Throughout the fascinating processes of bone regeneration, a plethora of cell lineages and signaling molecules, together with the extracellular matrix, are precisely regulated at multiple length and time scales. However, conditions, such as delayed unions (or nonunion) and critical-sized bone defects, represent thorny challenges for orthopedic surgeons. During recent decades, a variety of novel biomaterials have been designed to mimic the organic and inorganic structure of the bone microenvironment, which have tremendously promoted and accelerated bone healing throughout different stages of bone regeneration. Advances in tissue engineering endowed bone scaffolds with phenomenal osteoconductivity, osteoinductivity, vascularization and neurotization effects as well as alluring properties, such as antibacterial effects. According to the dimensional structure and functional mechanism, these biomaterials are categorized as zero-dimensional, one-dimensional, two-dimensional, three-dimensional, and four-dimensional biomaterials. In this review, we comprehensively summarized the astounding advances in emerging biomaterials for bone regeneration by categorizing them as zero-dimensional to four-dimensional biomaterials, which were further elucidated by typical examples. Hopefully, this review will provide some inspiration for the future design of biomaterials for bone tissue engineering.
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Materiais Biocompatíveis , Regeneração Óssea , Nanoestruturas , Engenharia Tecidual/métodos , Animais , Humanos , Camundongos , Alicerces TeciduaisRESUMO
Glucocorticoid (GC) administration is one of the main causes of osteonecrosis of the femoral head (ONFH). Inflammation, especially the TLR4/NF-κB pathway, has been demonstrated to play a pivotal role in the pathogenesis of GC-induced ONFH. Calycosin, the main bioactive extract of Astragali Radix, could substantially regulate the TLR4/NF-κB pathway. Therefore, in this study, we hypothesized that calycosin could exert beneficial effects in GC-induced ONFH. In vitro, effects of calycosin on the osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs) were determined using Alizarin red staining, alkaline phosphatase activity examination, and osteogenic-related gene assay. Meanwhile, inflammatory cytokines were detected by enzyme-linked immunosorbent assay. In vivo, 60 male Sprague-Dawley rats were randomly separated into three groups: the control group, the methylprednisolone (MPS) group, and the MPS + calycosin group. The results showed that calycosin could significantly promote dynamic bone formation and retard TLR4/NF-κB pathway. in vivo investigations indicated that calycosin could decrease the morbidity of ONFH and alleviate pathological manifestations within the femoral head. Meanwhile, calycosin could protect osseous blood supply and facilitate dynamic bone formation. The findings collectively demonstrated that calycosin could ameliorate GC-induced ONFH in rat and might become a potential candidate for pharmaceutical prevention of this intractable disease.
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Characteristic pathological changes in osteonecrosis of the femoral head (ONFH) include reduced osteogenic differentiation of bone mesenchymal stem cells (BMSCs), impaired osseous circulation and increased intramedullary adipocytes deposition. Osthole is a bioactive derivative from coumarin with a wide range of pharmacotherapeutic effects. The aim of this study was to unveil the potential protective role of osthole in alcohol-induced ONFH. In vitro, ethanol (50 mmol/L) remarkably decreased the proliferation and osteogenic differentiation of BMSCs and impaired the proliferation and tube formation capacity of human umbilical vein endothelial cell (HUVECs), whereas it substantially promoted the adipogenic differentiation of BMSCs. However, osthole could reverse the effects of ethanol on osteogenesis via modulating Wnt/ß-catenin pathway, stimulate vasculogenesis and counteract adipogenesis. In vivo, the protective role of osthole was confirmed in the well-constructed rat model of ethanol-induced ONFH, demonstrated by a cascade of radiographical and pathological investigations including micro-CT scanning, haematoxylin-eosin staining, TdT-mediated dUTP nick end labelling, immunohistochemical staining and fluorochrome labelling. Taken together, for the first time, osthole was demonstrated to rescue the ethanol-induced ONFH via promoting bone formation, driving vascularization and retarding adipogenesis.
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Adipogenia/efeitos dos fármacos , Cumarínicos/farmacologia , Necrose da Cabeça do Fêmur/tratamento farmacológico , Osteonecrose/tratamento farmacológico , Animais , Diferenciação Celular/efeitos dos fármacos , Etanol/toxicidade , Cabeça do Fêmur/crescimento & desenvolvimento , Necrose da Cabeça do Fêmur/induzido quimicamente , Necrose da Cabeça do Fêmur/genética , Necrose da Cabeça do Fêmur/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteocalcina/genética , Osteogênese/efeitos dos fármacos , Osteonecrose/induzido quimicamente , Osteonecrose/genética , Osteonecrose/patologia , Ratos , Ratos Sprague-Dawley , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/genéticaRESUMO
The rising concerns of the recurrence and bone deficiency in surgical treatment of malignant bone tumors have raised an urgent need of the advance of multifunctional therapeutic platforms for efficient tumor therapy and bone regeneration. Herein, the construction of a multifunctional biomaterial system is reported by the integration of 2D Nb2 C MXene wrapped with S-nitrosothiol (RSNO)-grafted mesoporous silica with 3D-printing bioactive glass (BG) scaffolds (MBS). The near infrared (NIR)-triggered photonic hyperthermia of MXene in the NIR-II biowindow and precisely controlled nitric oxide (NO) release are coordinated for multitarget ablation of bone tumors to enhance localized osteosarcoma treatment. The in situ formed phosphorus and calcium components degraded from BG scaffold promote bone-regeneration bioactivity, augmented by sufficient blood supply triggered by on-demand NO release. The tunable NO generation plays a crucial role in sequential adjuvant tumor ablation, combinatory promotion of coupled vascularization, and bone regeneration. This study demonstrates a combinatory osteosarcoma ablation and a full osseous regeneration as enabled by the implantation of MBS. The design of multifunctional scaffolds with the specific features of controllable NO release, highly efficient photothermal conversion, and stimulatory bone regeneration provides an intriguing biomaterial platform for the diversified treatment of bone tumors.
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Regeneração Óssea , Óxido Nítrico , Osteossarcoma , Impressão Tridimensional , Dióxido de Silício , Alicerces Teciduais , Humanos , Recidiva Local de Neoplasia , Osteossarcoma/terapia , Impressão Tridimensional/instrumentação , Dióxido de Silício/química , Engenharia Tecidual , Alicerces Teciduais/química , Alicerces Teciduais/normasRESUMO
BACKGROUND: Charcot neuroarthropathy is a systemic disease that generates pathological changes in the musculoskeletal system, causing instability, dislocations, and deformities. Charcot neuroarthropathy of the knee, due to either diabetes mellitus or syringomyelia, is anecdotally reported with the epidemic of the diseases. However, idiopathic sensory peripheral neuropathy can inflict osteoarticular structures directly, inducing a dysfunctional Charcot neuroarthropathy. An early diagnosis and effective relief of the symptomatic deformity is essential for the treatment. CASE PRESENTATION: We report the case of a patient with idiopathic sensory peripheral neuropathy who presented with a swelling right knee, as well as distorted and painless gait disorder, diagnosed as Charcot neuroarthropathy of the knee. Partial weight bearing with a hinged knee brace was used to correct the abnormal alignment and gait posture, and bisphosphonates were prescribed to decrease pathological bone resorption. Although the alignment and Knee Society Score got a gradual deterioration, the combination of orthosis and pharmacy could alleviate the symptom to a certain extent. CONCLUSION: The diagnosis of Charcot neuroarthropathy of the knee is rare that requiring early diagnosis. The presence of features, including painlessness, numbness, and deformed arthropathy following chronic-onset algesthesia loss should be taken carefully.
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Doença de Charcot-Marie-Tooth/diagnóstico por imagem , Doença de Charcot-Marie-Tooth/etiologia , Articulação do Joelho/diagnóstico por imagem , Doenças do Sistema Nervoso Periférico/complicações , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Adulto , Humanos , MasculinoRESUMO
A series of novel tetrandrine (Tet) derivatives were synthesized through Suzuki -Miyaura reaction and evaluated for their cytotoxicity against human non-small cell lung carcinoma (NSCLC) A549 cells. Interestingly, most of derivatives showed similar cytotoxicity to Tet against NSCLC A549 cells, and particularly, compounds Y5, Y6, Y9 and Y11 showed the most significant cytotoxic effects with IC50 values ranging from 3.87 to 4.66 mM. The present study is expected to contribute to the future design of more effective anticancer agents in lung cancer chemotherapy.
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Antineoplásicos Fitogênicos/farmacologia , Benzilisoquinolinas/química , Benzilisoquinolinas/farmacologia , Células A549 , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Carcinoma Pulmonar de Células não Pequenas , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura MolecularRESUMO
Natural fracture healing is most efficient when the fine-tuned mechanical force and proper micromotion are applied. To mimick this micromotion at the fracture gap, a near-infrared-II (NIR-II)-activated hydrogel was fabricated by integrating two-dimensional (2D) monolayer Nb2C nanosheets into a thermally responsive poly(N-isopropylacrylamide) (NIPAM) hydrogel system. NIR-II-triggered deformation of the NIPAM/Nb2C hydrogel was designed to generate precise micromotion for co-culturing cells. It was validated that micromotion at 1/300 Hz, triggering a 2.37-fold change in the cell length/diameter ratio, is the most favorable condition for the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Moreover, mRNA sequencing and verification revealed that micromotion-induced augmentation was mediated by Piezo1 activation. Suppression of Piezo1 interrupts the mechano-sensitivity and abrogates osteogenic differentiation. Calvarial and femoral shaft defect models were established to explore the biocompatibility and osteoinductivity of the Micromotion Biomaterial. A series of research methods, including radiography, micro-CT scanning, and immunohistochemical staining have been performed to evaluate biosafety and osteogenic efficacy. The in vivo results revealed that tunable micromotion strengthens the natural fracture healing process through the sequential activation of endochondral ossification, promotion of neovascularization, initiation of mineral deposition, and combinatory acceleration of full-thickness osseous regeneration. This study demonstrated that Micromotion Biomaterials with controllable mechanophysical characteristics could promote the osteogenic differentiation of BMSCs and facilitate full osseous regeneration. The design of NIPAM/Nb2C hydrogel with highly efficient photothermal conversion, specific features of precisely controlled micromotion, and bionic-mimicking bone-repair capabilities could spark a new era in the field of regenerative medicine.
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Geometry and angles play crucial roles in cellular processes; however, its mechanisms of regulation remain unclear. In this study, a series of three dimensional (3D)-printed microfibers with different geometries is constructed using a near-field electrostatic printing technique to investigate the regulatory mechanisms of geometry on stem cell function and bone regeneration. The scaffolds precisely mimicked cell dimensions with high porosity and interoperability. Compared with other spatial topography angles, microfibers with a 90° topology can significantly promote the expression of osteogenic gene proteins in bone marrow-derived mesenchymal stem cells (BMSCs). The effects of different spatial structures on the expression profiles of BMSCs differentiation genes are correlated and validated using microRNA sequencing. Enrichment analysis shows that the 90° microfibers promoted osteogenesis in BMSCs by significantly upregulating miR-222-5p/cbfb/Runx2 expression. The ability of the geometric architecture to promote bone regeneration, as assessed using the cranial defect model, demonstrates that the 90° fiber scaffolds significantly promote new bone regeneration and neovascular neural network formation. This study is the first to elucidate the relationship between angular geometry and cellular gene expression, contributing significantly to the understanding of how geometric architecture can promote stem cell differentiation, proliferation, and function for structural bone regeneration.
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Regeneração Óssea , Osteogênese , Regeneração Óssea/genética , Osteogênese/genética , Diferenciação Celular/genética , Células-Tronco , Expressão GênicaRESUMO
AIMS: Alcoholism is a well-known detrimental factor in fracture healing. However, the underlying mechanism of alcohol-inhibited fracture healing remains poorly understood. METHODS: MicroRNA (miR) sequencing was performed on bone mesenchymal stem cells (BMSCs). The effects of alcohol and miR-19a-3p on vascularization and osteogenic differentiation were analyzed in vitro using BMSCs and human umbilical vein endothelial cells (HUVECs). An in vivo alcohol-fed mouse model of femur fracture healing was also established, and radiological and histomorphometric analyses were used to evaluate the role of miR-19a-3p. The binding of miR-19a-3p to forkhead box F2 (FOXF2) was analyzed using a luciferase reporter assay. RESULTS: miR-19a-3p was identified as one of the key regulators in the osteogenic differentiation of BMSCs, and was found to be downregulated in the alcohol-fed mouse model of fracture healing. In vitro, miR-19a-3p expression was downregulated after ethanol administration in both BMSCs and HUVECs. Vascularization and osteogenic differentiation were independently suppressed by ethanol and reversed by miR-19a-3p. In addition, the luciferase reporter assay showed that FOXF2 is the direct binding target of miR-19a-3p. In vivo, miR-19a-3p agomir stimulated callus transformation and improved the alcohol-impaired fracture healing. CONCLUSION: This study is the first to demonstrate that the miR-19a-3p/FOXF2 axis has a pivotal role in alcohol-impaired fracture healing, and may be a potential therapeutic target. Cite this article: Bone Joint Res 2022;11(6):386-397.
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Effective antitumor therapeutics with distinctive bactericidal and osteogenic properties are in high demand for comprehensive osteosarcoma treatment. Here, a "scaffold engineering" strategy that integrates highly active single-atomic iron catalysts (FeSAC) into a 3D printed bioactive glass (BG) scaffold is reported. Based on the atomically dispersed iron species within the catalysts, the engineered FeSAC displays prominent Fenton catalytic activity to generate toxic hydroxyl radicals (â¢OH) in response to the microenvironment specific to osteosarcoma. In addition, the constructed FeSAC-BG scaffold can serve as a sophisticated biomaterial platform for efficient osteosarcoma ablation, with concomitant bacterial sterilization via localized hyperthermia-reinforced nanocatalytic therapeutics. The destruction of the osteosarcoma, as well as the bacterial foci, can be achieved, further preventing susceptible chronic osteomyelitis during osteogenesis. In particular, the engineered FeSAC-BG scaffold is identified with advances in accelerated osteoconduction and osteoinduction, ultimately contributing to the sophisticated therapeutics and management of osteosarcoma. This work broadens the biomedical potential of single-atom catalysts and offers a comprehensive clinically feasible strategy for overall osteosarcoma therapeutics, bacterial inhibition, and tissue regeneration.
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Regeneração Óssea , Osteossarcoma , Ferro , Osteogênese , Impressão Tridimensional , Alicerces TeciduaisRESUMO
Early surgical resection and chemotherapy of bone cancer are commonly used in the treatment of bone tumor, but it is still highly challenging to prevent recurrence and fill the bone defect caused by the resection site. In this work, we report a rational integration of photonic-responsive two-dimensional (2D) ultrathin niobium carbide (Nb2C) MXene nanosheets (NSs) into the 3D-printed bone-mimetic scaffolds (NBGS) for osteosarcoma treatment. The integrated 2D Nb2C-MXene NSs feature specific photonic response in the second near-infrared (NIR-II) biowindow with high tissue-penetrating depth, making it highly efficient in killing bone cancer cells. Importantly, Nb-based species released by the biodegradation of Nb2C MXene can obviously promote the neogenesis and migration of blood vessels in the defect site, which can transport more oxygen, vitamins and energy around the bone defect for the reparative process, and gather more immune cells around the defect site to accelerate the degradation of NBGS. The degradation of NBGS provides sufficient space for the bone remodeling. Besides, calcium and phosphate released during the degradation of the scaffold can promote the mineralization of new bone tissue. The intrinsic multifunctionality of killing bone tumor cell and promoting angiogenesis and bone regeneration makes the engineered Nb2C MXene-integrated composite scaffolds a distinctive implanting biomaterial on the efficient treatment of bone tumor.
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Due to the native skin limitations and the complexity of reconstructive microsurgery, advanced biomaterials are urgently required to promote wound healing for severe skin defects caused by accidents and disasters. Accumulating evidence has supported that substance P (SP) has a potential effect on skin regeneration. However, SP application is seriously impeded by its poor stability and oxidative reactions occurring during production, transportation, and storage. An SP-conjugated chitosan hydrochloride hydrogel (CSCl-SP) fabricated in this study demonstrated an enhanced capacity to repair full-thickness skin defects. CSCl-SP provided a stable in vitro delivery system for SP. The dissolution of CSCl-SP promoted the proliferation, migration, and tube formation, as well as angiogenesis-related gene and protein expression in human umbilical vein endothelial cells. CSCI-SP also stimulated the proliferation, migration, and production of anabolic growth factor in human fibroblasts. Moreover, CSCl-SP significantly promoted the neurite outgrowth in Neuro-2A cells. In vivo, CSCl-SP dramatically strengthened the vascularization, extracellular matrix deposition and remodeling, and nerve regeneration, thereby promoting efficient recovery of the full-thickness skin defect. Thus, synchronized multifunction of the CSCl-SP hydrogel makes it a promising and smart material for intractable skin defects.
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Quitosana , Hidrogéis , Matriz Extracelular , Humanos , Regeneração Nervosa , Pele , Substância P , CicatrizaçãoRESUMO
OBJECTIVES: Alcohol consumption is one of the leading factors contributing to premature osteopenia. MicroRNA (miRNA) coordinates a cascade of anabolic and catabolic processes in bone homeostasis and dynamic vascularization. The aim was to investigate the protective role of miR-4286 in alcohol-induced bone loss and its mechanism. MATERIALS AND METHODS: The effect of miR-4286 and alcohol on bone mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) was explored via multiple in vitro assays, including cell proliferation, QPCR, Western blot, osteogenesis, angiogenesis etc miR-4286 directly regulated HDAC3 was investigated by luciferase reporter assay, and the function of HDAC3 was also explored in vitro. Moreover, alcohol-induced bone loss in mice was established to reveal the preventive effect of miR-4286 by radiographical and histopathological assays. RESULTS: In vitro, ethanol dramatically inhibited the proliferation and osteogenesis of BMSCs, and substantially impaired the proliferation and vasculogenesis of HUVECs. However, a forced overexpression of miR-4286 within BMSCs and HUVECs could largely abolish inhibitory effects by alcohol. Furthermore, alcohol-induced inhibition on osteogenic and vasculogenic functions was mediated by histone deacetylase 3 (HDAC3), and dual-luciferase reporter assay showed that HDAC3 was the direct binding target of miR-4286. In vivo, micro-CT scanning and histology assessment revealed that miR-4286 could prevent alcohol-induced bone loss. CONCLUSIONS: We firstly demonstrated that miR-4286 might function via intimate osteogenesis-angiogenesis pathway to alleviate alcohol-induced osteopenia via targeting HDAC3.
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Doenças Ósseas Metabólicas/genética , Histona Desacetilases/genética , MicroRNAs/genética , Neovascularização Fisiológica , Osteogênese , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Doenças Ósseas Metabólicas/etiologia , Linhagem Celular , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Exosomes have a rapid development of bio-nanoparticles for drug delivery and confluent advances in next-generation diagnostics, monitoring the progression of several diseases, and accurate guidance for therapy. Based on their prominent stability, cargo-carriage properties, stable circulating capability, and favorable safety profile, exosomes have great potential to regulate cellular communication by carrying variable cargoes into specific site. However, the specific loading strategies and modification methods for engineered exosomes to enhance the targeting ability are unclear. The clinical application of exosomes is still limited. In this review, we discuss both original and modified exosomes for loading specific therapeutic molecules (proteins, nucleic acids, and small molecules) and the design strategies used to target specific cells. This review can be used as a reference for further loading and modification strategies as well as for the therapeutic applications of exosomes.
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OBJECTIVES: Osteonecrosis of the femoral head (ONFH), largely caused by alcohol abuse, is a refractory bone disease characterized by the impaired capacity of osteogenic differentiation of bone mesenchymal stem cells (BMSCs), as well as the disordered adipocyte accumulation. Chrysophanic acid (CPA) is a natural anthraquinone which has lipid regulation and bone protection capacity. The aim of this study was to reveal the potential function of CPA and the underlying mechanisms for the alcohol-induced ONFH. MATERIALS AND METHODS: The effects of alcohol and CPA on BMSCs were investigated by cell proliferation, induced differentiation assays and immunofluorescent staining. Meanwhile, the function of PI3K/AKT and AMPK pathway was investigated in the process of osteogenic and adipogenic differentiation, respectively. Furthermore, we established the rat model of alcohol-induced ONFH to reveal the pharmacotherapeutic effect of CPA in vivo using radiographical and histopathological methods. RESULTS: In vitro, alcohol significantly inhibited the proliferation and osteogenic differentiation of BMSCs but stimulated the adipogenic differentiation. However, CPA could counteract the anti-osteogenesis of alcohol partly via PI3K/AKT pathway and retard the promotion of alcohol-induced adipogenesis via AMPK pathway. In vivo, radiographical and histopathological findings showed that CPA could alleviate alcohol-induced ONFH and substantially restore the bone volume. CONCLUSIONS: We demonstrated that CPA ameliorated alcohol-induced ONFH possibly via regulating the differentiation tendency of BMSCs. Hence, CPA may become a beneficial herb extract to alleviate alcohol-induced ONFH.
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Antraquinonas/farmacologia , Proliferação de Células/efeitos dos fármacos , Cabeça do Fêmur/patologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteonecrose/patologia , Adipogenia/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Cabeça do Fêmur/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Ratos Sprague-DawleyRESUMO
Osteonecrosis of the femoral head (ONFH) is usually caused by chronic and excessive alcohol dependency, and this condition largely suppresses the osteogenic differentiation of bone mesenchymal stem cells (BMSCs). As a trimethyl derivative of glycine, betaine is an important human nutrient that regulates a series of vital biological processes, including oxidative stress, inflammatory responses, osteoblast differentiation and cellular apoptosis. However, no study has investigated the role of betaine in alcohol-induced ONFH. In this study, we hypothesized that betaine might have protective effects on ethanol-treated BMSCs and decrease the morbidity of alcohol-induced ONFH in a rat model. In vitro, we found that ethanol significantly downregulated the expression of osteocalcin (OCN), collagen 1 (COL1) and RUNX2 via activating the mammalian target of rapamycin (mTOR) signaling cascade. However, the inhibitory effects were rescued by betaine co-treatment at concentrations of 1 mM and 10 mM. In vivo, the typical ONFH pathological changes in a rat model of alcohol-induced ONFH were investigated by using multiple methods, including hematoxylin-eosin staining, micro-CT scans, TdT-mediated dUTP nick end labeling (TUNEL) assays and immunohistochemical staining for OCN and COL1. Osteonecrotic lesions of the femoral head could be alleviated by betaine as evidenced by significant histological and radiological improvements. Collectively, betaine plays a protective role against ethanol-induced suppression of osteogenesis and mineralization of hBMSCs and is thus a potential pharmacotherapy for alcohol-induced ONFH in vivo.
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Betaína/farmacologia , Etanol/farmacologia , Cabeça do Fêmur/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Colágeno Tipo I/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Cabeça do Fêmur/metabolismo , Necrose da Cabeça do Fêmur/tratamento farmacológico , Necrose da Cabeça do Fêmur/metabolismo , Humanos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteocalcina/efeitos dos fármacos , Osteocalcina/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
M1 muscarinic receptors have long been identified as a potential therapeutic target for the treatment of cognitive impairment in Alzheimer's disease (AD). Our previous study has shown that M1 receptors promote membrane insertion and synaptic delivery of AMPA receptor GluA1 subunit. In this study, we sought to determine whether activation of M1 receptor would rescue the cognitive impairment in AD model mice through modulation of GluA1 subunit. For the mice injected with aggregated ß-amyloid (Aß) fragments to impair learning and memory, activation of M1 receptors could rescue it by reducing the latency to find the platform and spending more time in the target quadrant in the probe test in the Morris water maze. However, such an effect was ablated in mice with Ser845 residue of GluA1 mutated to alanine. Furthermore, the activation of M1 receptors enhanced the expression of GluA1 and its phosphorylation at Ser845 and drove GluA1 to incorporate with PSD95, a postsynaptic marker, in the hippocampi from Aß-injected wild type mice but not from the mutant mice. Moreover, for 9-month-old APP/PS1 transgenic AD model mice, which may resemble the late AD, M1 receptor activation could not improve the cognitive impairment significantly. In addition, the enhancement of GluA1 expression and its phosphorylation at Ser845 were not observed in their hippocampi. Taken together, the study indicated that M1 receptor activation rescued the cognitive deficit through modulating the trafficking of GluA1-containing AMPA receptors and the therapeutics targeting M1 receptors should aim at mild AD or even pre-AD.
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Peptídeos beta-Amiloides/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Agonistas Muscarínicos/farmacologia , Fragmentos de Peptídeos/farmacologia , Receptores de AMPA/metabolismo , Aprendizagem Espacial/efeitos dos fármacos , Memória Espacial/efeitos dos fármacos , Animais , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Camundongos , Agonistas Muscarínicos/uso terapêutico , Fosforilação , Receptor Muscarínico M1/metabolismoRESUMO
BACKGROUND: Hip fracture is one of the major risk factors of global mortality and disability. The aim of this study was to map the pattern of intertrochanteric femoral fractures in China, providing a pilot national dataset and basis for medical policy proposals. METHODS: A multistage probability sampling strategy was applied in the national baseline survey. Thirty provinces in mainland China were included in this survey. A standardized questionnaire survey was conducted to collect information about basic characteristics such as age, working seniority, hospital level, and residence, with two other parts including perioperative and postoperative treatment parameters. Odds ratios and 95% confidence interval were used to determine essential statistical differences. The proportion of the options in each region was compared using the chi-square (χ 2) test. The histogram and choropleth map of the monthly number of admissions were created using Excel 2016 to show the distribution characteristics. RESULTS: In total, 1065 valid responses were included, representing a 96.7% survey capture rate. Perioperative treatment and postoperative care distinctly varied across regions and hospital levels. The monthly number of admissions was relatively lower in the Northern region, with higher proportion of hospitalizations to secondary hospitals compared with the Eastern region. The patients in the Eastern region or tertiary hospitals had shorter preoperative waiting time and hospitalization period. CONCLUSIONS: We found apparent geographic variations in intertrochanteric femoral fractures in this study, and the data can be used for drafting national healthcare plans and medical policies.