Betaine alleviates alcohol-induced osteonecrosis of the femoral head via mTOR signaling pathway regulation

Altered gut microbe metabolites in patients with alcohol‑induced osteonecrosis of the femoral head: An integrated omics analysis

Excessive alcohol consumption is considered to be a major risk factor of alcohol-induced osteonecrosis of the femoral head (AONFH). The gut microbiota (GM) has been reported to aid in the regulation of human physiology and its composition can be altered by alcohol consumption. The aim of the present study was to improve the understanding of the GM and its metabolites in patients with AONFH. Metabolomic sequencing and 16S rDNA analysis of fecal samples were performed using liquid chromatography-mass spectrometry to characterize the GM of patients with AONFH and healthy normal controls (NCs). Metagenomic sequencing of fecal samples was performed to identify whether GM changes on the species level were associated with the expression of gut bacteria genes or their associated functions in patients with AONFH. The abundance of 58 genera was found to differ between the NC group and the AONFH group. Specifically, Klebsiella, Holdemanella, Citrobacter and Lentilactobacillus were significantly more abundant in the AONFH group compared with those in the NC group. Metagenomic sequencing demonstrated that the majority of the bacterial species that exhibited significantly different abundance in patients with AONFH belonged to the genus Pseudomonas. Fecal metabolomic analysis demonstrated that several metabolites were present at significantly different concentrations in the AONFH group compared with those in the NC group. These metabolites were products of vitamin B6 metabolism, retinol metabolism, pentose and glucuronate interconversions and glycerophospholipid metabolism. In addition, these changes in metabolite levels were observed to be associated with the altered abundance of specific bacterial species, such as Basidiobolus, Mortierella, Phanerochaete and Ceratobasidium. According to the results of the present study, a comprehensive landscape of the GM and metabolites in patients with AONFH was revealed, suggesting the existence of interplay between the gut microbiome and metabolome in AONFH pathogenesis.

Chromolaena odorata (L.) R. M. King and H. Robinson Leaves Aqueous Extract Improves the Femoral Head in Ethanol-Induced Osteonecrosis in Rats

Chronic alcohol consumption damages bone formation and causes bone pathology, including osteonecrosis of the femoral head. The aim of this work was to evaluate the effects of the leaf aqueous extract of Chromolaena odorata (C. odorata) on the femoral head in ethanol-induced osteonecrosis in rats. Animals received alcohol (40°) at 3 g/kg for 12 weeks. A group of animals were sacrificed to attest to the instalment of osteonecrosis by using histopathological analysis. The remaining animals received alcohol concomitantly with the plant extract (150, 300, or 600 mg/kg) or diclofenac (1 mg/kg) for 28 additional days. At the end of the experimental period, biochemical parameters including total cholesterol, triglycerides, calcium, alkaline phosphatase (ALP), reduced glutathione (GSH), malondialdehyde (MDA), nitrite, superoxide dismutase (SOD), and catalase activities were measured. Histopathological and histomorphometry analyses of femurs were also assessed. The administration of alcohol, irrespective of the experimental period, induced a significant increase in total cholesterol (p < 0.05) and triglyceride (p < 0.01) and a decrease in ALP (p < 0.05) and calcium (p < 0.05-p < 0.001) levels. Intoxicated animals showed an alteration in oxidative stress parameters accompanied by a significant drop in bone cortical thickness and density with necrosis and marked bone resorption. The concomitant administration of the plant with ethanol reversed the alcohol-induced bone defect, characterized by the improvement of the lipid profile (p < 0.001), bone calcium concentration (p < 0.05), bone ALP activity (p < 0.001), oxidative stress parameters, improved cortical bone thickness (p < 0.01), and bone density (p < 0.05). These results are supported by the absence of bone resorption with an obvious effect at a dose of 300 mg/kg. The pharmacological effect of the extract on ethanol-induced osteonecrosis of the femoral head is probably due to its osteogenic, hypolipidemic, and antioxidant properties, justifying its use in Cameroonian folk medicine for articulation and bone pain management.

Amino Acid Composition of a Chum Salmon (Oncorhynchus keta) Skin Gelatin Hydrolysate and Its Antiapoptotic Effects on Etoposide-Induced Osteoblasts

A gelatin hydrolysate with a hydrolysis degree of 13.7% was generated using the skin gelatin of chum salmon (Oncorhynchus keta) and papain-catalyzed enzymatic hydrolysis. The results of analysis demonstrated that four amino acids, namely Ala, Gly, Pro, and 4-Hyp, were the most abundant in the obtained gelatin hydrolysate with measured molar percentages ranging from 7.2% to 35.4%; more importantly, the four amino acids accounted for 2/3 of the total measured amino acids. However, two amino acids, Cys and Tyr, were not detected in the generated gelatin hydrolysate. The experimental results indicated that the gelatin hydrolysate at a dose of 50 µg/mL could combat etoposide-induced apoptosis in human fetal osteoblasts (hFOB 1.19 cells), causing a decrease in the total apoptotic cells from 31.6% to 13.6% (via apoptotic prevention) or 13.3% to 11.8% (via apoptotic reversal). Meanwhile, the osteoblasts exposed to the gelatin hydrolysate showed expression changes for 157 genes (expression folds > 1.5-fold), among which JNKK, JNK1, and JNK3 were from the JNK family with a 1.5-2.7-fold downregulated expression. Furthermore, the protein expressions of JNKK, JNK1, JNK3, and Bax in the treated osteoblasts showed a 1.25-1.41 fold down-regulation, whereas JNK2 expression was not detected in the osteoblasts. It is thus suggested that gelatin hydrolysate is rich in the four amino acids and has an in vitro antiapoptotic effect on etoposide-stimulated osteoblasts via mitochondrial-mediated JNKK/JNK(1,3)/Bax downregulation.

Betaine regulates adipogenic and osteogenic differentiation of hAD-MSCs

BACKGROUND

With an ageing population, the incidence of bone loss and obesity are increasing. Numerous studies emphasized the multidirectional differentiation ability of mesenchymal stem cells (MSCs), and reported betaine modulated the osteogenic differentiation and adipogenic differentiation of MSCs in vitro. We wondered how betaine affected the differentiation of hAD-MSCs and hUC-MSCs.

METHODS AND RESULTS

ALP staining and alizarin red S (ARS) staining were proved 10 mM betaine significantly increased the number of ALP-positive cells and plaque calcified extracellular matrices, accompanying by the up-regulation of OPN, Runx-2 and OCN. Oil red O staining demonstrated the number and size of lipid droplets were reduced, the expression of adipogenic master genes such as PPARγ, CEBPα and FASN were down-regulated simultaneously. For further investigating the mechanism of betaine on hAD-MSCs, RNA-seq was performed in none-differentiation medium. The Gene Ontology (GO) analysis showed fat cell differentiation and bone mineralization function terms were enriched, and KEGG showed PI3K-Akt signaling pathway, cytokine-cytokine receptor interaction and ECM-receptor interaction pathways were enriched in betaine treated hAD-MSCs, demonstrated betaine had a positive inducing effect on osteogenic of hAD-MSCs in the non-differentiation medium in vitro, which is opposite to the effect on adipogenic differentiation.

CONCLUSIONS

Our study demonstrated that betaine promoted osteogenic and compromised adipogenic differentiation of hUC-MSCs and hAD-MSCs upon low concentration administration. PI3K-Akt signaling pathway, cytokine-cytokine receptor interaction and ECM-receptor interaction were significantly enriched under betaine-treated. We showed hAD-MSCs were more sensitive to betaine stimulation and have a better differentiation ability than hUC-MSCs. Our results contributed to the exploration of betaine as an aiding agent for MSCs therapy.

A multi-organ analysis of the role of mTOR in fetal alcohol spectrum disorders

Alcohol exposure during gestation can lead to fetal alcohol spectrum disorders (FASD), an array of cognitive and physical developmental impairments. Over the past two and a half decades, Mammalian Target of Rapamycin (mTOR) has emerged at the nexus of many fields of study, and has recently been implicated in FASD etiology. mTOR plays an integral role in modulating anabolic and catabolic activities, including protein synthesis and autophagy. These processes are vital for proper development and can have long lasting effects following alcohol exposure, such as impaired hippocampal and synapse formation, reduced brain size, as well as cognitive, behavioral, and memory impairments. We highlight recent advances in the field of FASD, primarily with regard to animal model discoveries and discuss the interaction between alcohol and mTOR in the context of various tissues, including brain, placenta, bone, and muscle, with respect to developmental alcohol exposure paradigms. The current review focuses on novel FASD research within the context of the mTOR signaling and sheds light on mechanistic etiologies at various biological levels including molecular, cellular, and functional, across multiple stages of development and illuminates the dichotomy between the different mTOR complexes and their unique signaling roles.

Betaine promotes osteogenic differentiation in immortalized human dental pulp-derived cells

Objectives

This study aimed to evaluate the effect of betaine (BET) on immortalized human dental pulp stem cell (ihDP) osteogenic differentiation.

Materials and methods

hDPs were immortalized using SV40 T-antigen transfection. Characterization, multilineage differentiation, proliferation, cell cycle, colony-forming unit, and cellular senescence were evaluated (n = 4). The effect of BET on ihDP response was assessed (n = 4). Osteogenic differentiation was detected using ALP, ARS staining, and RT-qPCR (n = 4). To investigate the involvement of calcium signaling, the cells were pretreated with either 8-(NN-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8) or thapsigargin before BET treatment (n = 6).

Results

ihDPs retained similar phenotypic characteristics presented in hDPs but exhibited an increase in cell proliferation and extended culture to passage 25. An increased proportion of cells in S and G2/M phases without senescence was observed in ihDPs. BET (50 mM) treatment significantly increased mineral deposition at 14 days and upregulated ALP, MSX2, BMP2, and RUNX2 expression. TMB-8 pretreatment reduced the effect of BET-induced ihDP osteogenic differentiation, whereas thapsigargin promoted osteogenic differentiation in ihDPs synergistically with BET.

Conclusion

ihDPs showed superior proliferation ability and a longer life span, which could serve as a promising cell for regenerative dentistry. BET promoted odonto/osteogenic differentiation via intracellular calcium regulation.

Identification and characterization of extrachromosomal circular DNA in alcohol induced osteonecrosis of femoral head

Alcohol-induced osteonecrosis of the femoral head (AIONFH) is a complicated refractory bone disease seen in the clinic. The pathogenesis of AIONFH is still controversial. Extrachromosomal circular DNA (eccDNA) elements have been indicated ubiquitously exist in eukaryotic genomes. However, the characteristics and biological functions of eccDNAs remain unclear in AIONFH. In this study, eccDNAs from AIONFH samples (n = 7) and fracture of femoral neck samples as a control (n = 7) were purified by removing linear DNA and rolling circle amplification. High-throughput sequencing and bioinformatics analysis were performed to study the characterization and biofunction of eccDNAs. We identified more than 600,000 unique eccDNAs. The number of detected eccDNAs in AIONFH was less than that in the control, and eccDNA formation may be related to transcription or other characteristics of coding genes. The eccDNA lengths are mainly distributed between 0.1 kb and 1 kb, with a major peak in 0.358 kb. The bioinformatic analysis showed that 25 significant genes were detected, including MAP3K1, ADCY1, CACNA1S, and MACF1, which contributed to regulating bone formation. GO and KEGG analyses suggested that the related genes derived from exons mainly affected metabolic processes and signal transduction, and bone metabolism-related pathways, such as the MAPK pathway and TGF-β pathway, were enriched. EccDNAs in AIONFH are common and may play an important role in pathogenesis by regulating bone metabolism.

Single-cell transcriptome analysis reveals aberrant stromal cells and heterogeneous endothelial cells in alcohol-induced osteonecrosis of the femoral head

Alcohol-induced osteonecrosis of the femoral head (ONFH) is a disabling disease with a high incidence and elusive pathogenesis. Here, we used single-cell RNA sequencing to explore the transcriptomic landscape of mid- and advanced-stage alcohol-induced ONFH. Cells derived from age-matched hip osteoarthritis and femoral neck fracture samples were used as control. Our bioinformatics analysis revealed the disorder of osteogenic-adipogenic differentiation of stromal cells in ONFH and altered regulons such as MEF2C and JUND. In addition, we reported that one of the endothelial cell clusters with ACKR1 expression exhibited strong chemotaxis and a weak angiogenic ability and expanded with disease progression. Furthermore, ligand-receptor-based cell-cell interaction analysis indicated that ACKR1+ endothelial cells might specifically communicate with stromal cells through the VISFATIN and SELE pathways, thus influencing stromal cell differentiation in ONFH. Overall, our data revealed single cell transcriptome characteristics in alcohol-induced ONFH, which may contribute to the further investigation of ONFH pathogenesis.

Single-cell RNA-seq of bone from patients with osteonecrosis of the femoral head (ONFH) highlights the relevance of stromal and endothelial cells to disease pathogenesis, and provides a resource for developing cell type-specific therapeutic strategies.

Calycosin modulates inflammation via suppressing TLR4/NF-κB pathway and promotes bone formation to ameliorate glucocorticoid-induced osteonecrosis of the femoral head in rat

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.

Impact of Alcohol on Bone Health, Homeostasis and Fracture repair

Purpose of review

Alcohol use continues to rise globally. We review the current literature on the effect of alcohol on bone health, homeostasis and fracture repair to highlight what has been learned in people and animal models of alcohol consumption.

Recent findings

Recently, forkhead box O (FoxO) has been found to be upregulated and activated in mesenchymal stem cells (MSC) exposed to alcohol. FoxO has also been found to modulate Wnt/β-catenin signaling, which is necessary for MSC differentiation. Recent evidence suggests alcohol activates FoxO signaling, which may be dysregulating Wnt/β-catenin signaling in MSCs cultured in alcohol.

Summary

This review highlights the negative health effects learned from people and chronic and episodic binge alcohol consumption animal models. Studies using chronic alcohol exposure or alcohol exposure then bone fracture repair model have explored several different cellular and molecular signaling pathways important for bone homeostasis and fracture repair, and offer potential for future experiments to explore additional signaling pathways that may be dysregulated by alcohol exposure.