Bone remodeling, crucial for maintaining the balance between bone resorption and formation, relies on the coordinated activity of osteoclasts and osteoblasts. During osteoclastogenesis, hematopoietic stem cells (HSCs) differentiate into the osteoclast lineage through the signaling pathways OPG/RANK/RANKL. On the other hand, during osteoblastogenesis, mesenchymal stem cells (MSCs) differentiate into the osteoblast lineage through activation of the signaling pathways TGF-β/BMP/Wnt. Recent studies have shown that bone remodeling is regulated by post-transcriptional mechanisms including microRNAs (miRNAs). miRNAs are small, single-stranded, noncoding RNAs approximately 22 nucleotides in length. miRNAs can regulate virtually all cellular processes through binding to miRNA-response elements (MRE) at the 3’ untranslated region (3′UTR) of the target mRNA. miRNAs are involved in controlling gene expression during osteogenic differentiation through the regulation of key signaling cascades during bone formation and resorption. Alterations of miRNA expression could favor the development of bone disorders, including osteoporosis. This review provides a general description of the miRNAs involved in bone remodeling and their significance in osteoporosis development.

To identify genetic variants influencing bone mineral density (BMD) in the Mexican-Mestizo population, we performed a GWAS for femoral neck (FN) and lumbar spine (LS) in Mexican-Mestizo postmenopausal women. In the discovery sample, 300,000 SNPs were genotyped in a cohort of 411 postmenopausal women and seven SNPs were analyzed in the replication cohort (n=420). The combined results of a meta-analysis from the discovery and replication samples identified two loci, RMND1 (rs6904364, P=2.77×10−4) and CCDC170 (rs17081341, P=1.62×10−5), associated with FN BMD. We also compared our results with those of the Genetic Factors for Osteoporosis (GEFOS) Consortium meta-analysis. The comparison revealed two loci previously reported in the GEFOS meta-analysis: SOX6 (rs7128738) and PKDCC (rs11887431) associated with FN and LS BMD, respectively, in our study population. Interestingly, rs17081341 rare in Caucasians (minor allele frequency < 0.03) was found in high frequency in our population, which suggests that this association could be specific to non-Caucasian populations. In conclusion, the first pilot Mexican GWA study of BMD confirmed previously identified loci and also demonstrated the importance of studying variability in diverse populations and/or specific populations.

Objective: Bone is a tissue that is constantly remodeled to adjust the microarchitecture and maintain the mechanical needs of bone through the balance of bone resorption and formation processes. Alterations in these processes can lead to the development of different diseases, such as osteoarthritis and osteoporosis. In recent years, it has been shown that acupuncture is an effective treatment for pain, physical dysfunctions, and the immune system, so the stimulation of acupuncture points could affect genes associated with inflammatory processes and, therefore, osteoarthritis and osteoporosis. To analyze changes in gene expression post-acupuncture in data from a group of individuals with osteoarthritis that also manifests in osteoporosis. Methods: Through using microarray technology and bioinformatics analysis, potential genes associated with osteoarthritis after acupuncture treatment are identified and compared with genes implicated in osteoporosis. The genes identified in each disease were evaluated through a Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analysis, where the results allowed the generation of an in-silico model that shows interaction networks between signaling pathways and genes involved in both diseases. Results: In this interaction, 37 differentially expressed genes were identified in patients with osteoarthritis before and after acupuncture treatment, and 665 differentially expressed genes were involved in osteoporosis. In the osteoarthritis group, 15 signaling pathways involved in this disease were obtained, and for osteoporosis, 13 signaling pathways associated with immunological processes that participate in bone metabolism were obtained osteoarthritis and osteoporosis are two age-associated diseases that are characterized by alterations in the bone remodeling mechanism induced by changes in gene expression profiles. Conclusions: Treatment with acupuncture can modify various cytokines involved in diseases related to the immune system so that it can have beneficial effects on osteoarthritis and osteoporosis. In addition, bioinformatics analysis allows us to know those signaling pathways through which they could have acupuncture effects.

Osteoporosis (OP) is a disease affecting bone metabolism, characterized by low bone mineral density and the deterioration of the bone microarchitecture, leading to increased bone fragility and risk of fracture. OP mainly results from alterations in the balance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Currently, there are several molecular mechanisms underlying the development of OP that are not entirely clear. One such mechanism is the role of long non-coding RNAs, which are key regulators of gene expression through various mechanisms. In the last decade, it has been shown that these molecules participate in multiple biological processes and play essential roles in the pathogenesis of different diseases. In this review, we address recent advances on the relationship of long non-coding RNAs with OP, mainly over their regulatory functions during osteoclastogenesis and osteogenesis. Furthermore, we analyze their potential application as clinical or therapeutic resources focused on OP.

Oxidative stress is essential in developing multiple bone metabolism diseases, including osteoporosis. Single-nucleotide variants (SNVs) have been associated with oxidative stress, promoting an imbalance between the production of reactive oxygen species and the ability to neutralize them, and it has been reported that antioxidant nutrient intake can influence bone mineral density (BMD). This work reports the association between oxidative stress-related SNVs (GPX1-rs1050450, rs17650792, SOD2-rs4880, and CAT-rs769217), BMD, and antioxidant nutrient intake. The study included 1269 Mexican women from the Health Workers Cohort Study. Genotyping was performed using predesigned TaqMan assays. Dietary data were collected using a 116-item semi-quantitative food frequency questionnaire. A dietary antioxidant quality score (DAQS) was used to estimate antioxidant–nutrient intake. Association analysis was estimated via linear, logistic, or quantile regression models. The results showed an association of the rs1050450-A and rs17650792-A alleles with femoral neck BMD (p = 0.038 and p = 0.017, respectively) and the SNV rs4880-A allele with total hip BMD (p = 0.026) in respondents aged 45 years or older. In addition, antioxidant–nutrient intake was associated with the rs4880-GG genotype, being significant for fiber (p = 0.007), riboflavin (p = 0.005), vitamin B6 (p = 0.034), and vitamin D (p = 0.002). The study showed an association between oxidative stress-related SNVs, BMD, and antioxidant–nutrient intake in Mexican women. Therefore, treatments for low BMD could be developed based on antioxidant supplementation.

Background: Rejection continues to be the main cause of renal graft loss. Currently, the gold standard for diagnosis is an allograft biopsy; however, because it is time-consuming, costly, and invasive, the pursuit of novel biomarkers has gained interest. Variation in the expressions of miRNAs is currently considered a probable biomarker for the diagnosis of acute rejection. This study aimed to determine whether miR-150-5p in serum is related to microvascular damage in patients with acute antibody-mediated rejection (ABMR). Methods: A total of 27 patients who underwent renal transplantation (RT) with and without ABMR were included in the study. We performed the quantification of hsa-miR-150-5p, hsa-miR-155, hsa-miR-21, hsa-miR-126, and hsa-miR-1 in plasma by RT-qPCR. The expressions between the groups and their correlations with the histological characteristics of the patients with ABMR were also investigated. Results: miR-150-5p significantly increased in the plasma of patients with rejection (p < 0.05), and the changes in miR-150-5p were directly correlated with microvascular inflammation in the allograft biopsies. Clinical utility was determined by ROC analysis with an area under the curve of 0.873. Conclusions: Our results show that the patients with RT with ABMR exhibited increased expression of miR-150-5p compared to patients without rejection, which could have clinical consequences, as well as probable utility in the diagnosis of ABMR, and bioinformatics may help in unraveling the molecular mechanisms underlying ABMR conditions.