MicroRNA‑206 contributes to the progression of steroid‑induced avascular necrosis of the femoral head by inducing osteoblast apoptosis by suppressing programmed cell death 4

Brain-body mechanisms contribute to sexual dimorphism in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common form of human motor neuron disease. It is characterized by the progressive degeneration of upper and lower motor neurons, leading to generalized motor weakness and, ultimately, respiratory paralysis and death within 3-5 years. The disease is shaped by genetics, age, sex and environmental stressors, but no cure or routine biomarkers exist for the disease. Male individuals have a higher propensity to develop ALS, and a different manifestation of the disease phenotype, than female individuals. However, the mechanisms underlying these sex differences remain a mystery. In this Review, we summarize the epidemiology of ALS, examine the sexually dimorphic presentation of the disease and highlight the genetic variants and molecular pathways that might contribute to sex differences in humans and animal models of ALS. We advance the idea that sexual dimorphism in ALS arises from the interactions between the CNS and peripheral organs, involving vascular, metabolic, endocrine, musculoskeletal and immune systems, which are strikingly different between male and female individuals. Finally, we review the response to treatments in ALS and discuss the potential to implement future personalized therapeutic strategies for the disease.

Knowledge mapping of programmed cell death in osteonecrosis of femoral head: a bibliometric analysis (2000-2022)

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a common, refractory and disabling disease of orthopedic department, which is one of the common causes of hip pain and dysfunction. Recent studies have shown that much progress has been made in the research of programmed cell death (PCD) in ONFH. However, there is no bibliometric analysis in this research field. This study aims to provide a comprehensive overview of the knowledge structure and research hot spots of PCD in ONFH through bibliometrics.

METHOD

The literature search related to ONFH and PCD was conducted on the Web of Science Core Collection (WoSCC) database from 2002 to 2021. The VOSviewers, "bibliometrix" R package and CiteSpace were used to conduct this bibliometric analysis.

RESULTS

In total, 346 articles from 27 countries led by China and USA and Japan were included. The number of publications related to PCD in ONFH is increasing year by year. Shanghai Jiao Tong University, Xi An Jiao Tong University, Wuhan University and Huazhong University of Science and Technology are the main research institutions. Molecular Medicine Reports is the most popular journal in the field of PCD in ONFH, and Clinical Orthopaedics and Related Research is the most cocited journal. These publications come from 1882 authors among which Peng Hao, Sun Wei, Zhang Chang-Qing, Zhang Jian and Wang Kun-zheng had published the most papers and Ronald S Weinstein was cocited most often. Apoptosis, osteonecrosis, osteonecrosis of the femoral head, glucocorticoid and femoral head appeared are the main topics the field of PCD in ONFH. Autophagy was most likely to be the current research hot spot for PCD in ONFH.

CONCLUSION

This is the first bibliometric study that comprehensively summarizes the research trends and developments of PCD in ONFH. This information identified recent research frontiers and hot directions, which will provide a reference for scholars studying PCD in ONFH.

Interplay Between Non-Coding RNAs and Programmed Cell Death Proteins

Programmed cell death (PDCD) family of proteins includes at least 12 members, function of seven of them being more investigated. These members are PDCD1, PDCD2, PDCD4, PDCD5, PDCD6, PDCD7 and PDCD10. Consistent with the important roles of these proteins in the regulation of apoptosis, dysregulation of PDCDs is associated with diverse disorders ranging from intervertebral disc degeneration, amyotrophic lateral sclerosis, immune thrombocytopenia, type 1 diabetes, congenital hypothyroidism, Alzheimer’s disease to different types of cancers. More recently, the interaction between non-coding RNAs and different members of PDCD family is being discovered. In the current study, we described the functional interactions between PDCDs and two classes of non-coding RNAs, namely microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). miR-21 and miR-183 are two miRNAs whose interactions with PDCDs have been assessed in different contexts. The lncRNAs interaction with PDCDs is mainly assessed in the context of neoplasia indicating the role of MALAT1, MEG3, SNHG14 and LINC00473 in this process.

Noncoding RNAs in Steroid-Induced Osteonecrosis of the Femoral Head

Steroid-induced osteonecrosis of the femoral head (ONFH) is a severe orthopedic disease caused by the long-term administration of glucocorticoids. The main pathological feature of ONFH is the gradually progressive necrosis of bone cells and the bone marrow, ultimately resulting in structural changes or even complete collapse of the femoral head. However, the exact pathogenic mechanism of ONFH remains unknown. Noncoding RNAs (ncRNAs) have emerged as very powerful regulators of gene expression, functioning at both transcriptional and posttranscriptional levels in the pathogenesis of ONFH. Here, we review the current knowledge of the role of ncRNAs, including microRNAs, long noncoding RNAs, and circular RNAs, in the pathogenesis of steroid-induced ONFH. Further focus and validation of these associations can provide new insight into the pathogenic mechanisms at the molecular level to suggest targets for treatment and prevention.

Extracellular vesicles from endothelial progenitor cells prevent steroid-induced osteoporosis by suppressing the ferroptotic pathway in mouse osteoblasts based on bioinformatics evidence

Abnormal antioxidative capabilities were observed in the pathogenesis of steroid-induced osteoporosis (SIOP). Ferroptosis is a recently discovered type of cell death that is characterized by the overproduction of ROS in response to GPX4 and system Xc- downregulation, which is mediated by an Fe2+ fenton reaction. However, investigations focusing on the relationship between ferroptosis and steroid-induced bone disease remain limited. In the present study, high-dose dexamethasone was used to establish a mouse SIOP model, and extracellular vesicles extracted from bone marrow-derived endothelial progenitor cells (EPC-EVs) alleviated the pathological changes in SIOP via microtomography (micro-CT), with elevations in bone volume (BV), bone surface (BS), trabecular thickness (Tb.Th), and trabecular connectivity density (Conn-D) and decreases in trabecular separation (Tb.sp) and the structure model index (SMI). Histopathological analysis, such as haematoxylin and eosin (HE) and Masson staining, showed that EPC-EVs treatment increased the volume and density of the trabecular bone and bone marrow. RNA sequencing (RNA-seq) and bioinformatics analysis revealed subcellular biological alterations upon steroid and EPC-EVs treatment. Compared with the control, high-dose dexamethasone downregulated GPX4 and system XC-, and the Kyoto Encyclopedia of Genes and Genomes (KEGG)-based gene set enrichment analysis suggested that the ferroptotic pathway was activated. In contrast, combination treatment with EPC-EVs partly reversed the KEGG-mapped changes in the ferroptotic pathway at both the gene and mRNA expression levels. In addition, alterations in ferroptotic marker expression, such as SLC3A2, SLC7A11, and GPX4, were further confirmed by RNA-seq. EPC-EVs were able to reverse dexamethasone treatment-induced alterations in cysteine and several oxidative injury markers, such as malondialdehyde (MDA), glutathione (GSH), and glutathione disulphide (GSSG) (as detected by ELISA). In conclusion, EPC-EVs prevented mouse glucocorticoid-induced osteoporosis by suppressing the ferroptotic pathway in osteoblasts, which may provide a basis for novel therapies for SIOP in humans.

Crocin protects against dexamethasone‑induced osteoblast apoptosis by inhibiting the ROS/Ca2+‑mediated mitochondrial pathway

Osteoblast apoptosis has been identified as an important event in the development of glucocorticoid (GC)-induced osteoporosis and osteonecrosis of the femoral head. Crocin, a bioactive ingredient of saffron, has been demonstrated to induce antiapoptotic effects on numerous types of cell in vitro; however, the effects of crocin on the dexamethasone (Dex)-induced apoptosis of osteoblasts remain unclear. In the present study, the protective effects of crocin during Dex-induced apoptosis of MC3T3-E1 osteoblasts, and the underlying mechanisms, were investigated. MTT and Annexin V-FITC/PI flow cytometry assays were performed to evaluate the viability and apoptosis of cells, respectively. The mitochondrial transmembrane potential, reactive oxygen species (ROS), intracellular Ca²⁺ levels and apoptosis-associated protein expression were assessed via flow cytometry, fluorescence microscopy and western blotting. It was demonstrated that crocin pretreatment inhibited Dex-induced apoptosis of osteoblasts in a dose-dependent manner. Crocin reversed Dex-induced decreases in the mitochondrial transmembrane potential, and increases in ROS and intracellular Ca²⁺ levels. Furthermore, crocin upregulated the expression levels of B-cell lymphoma-2 (Bcl-2) and mitochondrial cytochrome c (Cyt C), and downregulated those of cleaved caspase-9, cleaved caspase-3, Bcl-2-associated X protein and cytoplasmic Cyt C. N-acetylcysteine, a ROS inhibitor, and 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, a calcium chelator, attenuated Dex-induced osteoblast apoptosis, whereas H₂O₂ and ionomycin, a calcium ionophore that increases intracellular calcium levels, reversed the antiapoptotic effects of crocin on Dex-treated osteoblasts. These results indicated that crocin may protect osteoblasts from Dex-induced apoptosis by inhibiting the ROS/Ca²⁺-mediated mitochondrial pathway, thus suggesting that crocin has potential value as a treatment for GC-induced bone diseases.

Expression of Bax/Bcl-2, TGF-β1, and Type III Collagen Fiber in Congenital Muscular Torticollis

BACKGROUND This study investigated the expression of Bax/Bcl-2, TGF-β1 and type III collagen fiber in sternocleidomastoid of congenital muscular torticollis (CMT), and explored the possible mechanisms of fibrosis in sternocleidomastoid of CMT. MATERIAL AND METHODS The localization and expression of Bax, Bcl-2, TGF-β1, and type III collagen were detected in the control group and experimental group by using immunohistochemical staining method. The RT-PCR assay was used to measure the expression of TGF-β1 in the control group and experimental group. RESULTS HE staining results showed that the collagen fiber in the experimental group had more abundant hyperplasia compared to the control group (p<0.05). Immunohistochemical staining results showed that the expression of Bax, Bax/Bcl-2, TGF-β1, and type III collagen in the experimental group was significantly increased compared to the control group (p<0.01). There were positive correlations between expression of Bax/Bcl-2 and TGF-b1, and between expression of TGF-β1 and type III collagen fiber (p<0.05, r=0.32 and 0.83, respectively). The RT-PCR results showed that the expression of TGF-β1 mRNA was also significantly elevated in the experimental group compared to the control group (p<0.05). CONCLUSIONS Increased muscular apoptosis may aggravate the formation of muscular fibrosis, which may be involved in the pathogenesis of sternocleidomastoid of CMT.