CircTAOK1 regulates high glucose induced inflammation, oxidative stress, ECM accumulation, and apoptosis in diabetic nephropathy via targeting miR-142-3p/SOX6 axis

BACKGROUND

Diabetic nephropathy (DN) is a complication caused by diabetes. Circular RNAs (circRNAs) are a kind of RNA with a closed circular structure, which has high stability and is involved in many disease-related processes. The mechanism of circRNA TAO kinase 1 (circTAOK1) in the pathogenesis and development of DN is unclear.

METHODS

CircTAOK1, microRNA (miR)-142-3p, and sex-determining region Y-box transcription factor 6 (SOX6) mRNA levels were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK8) and 5-ethynyl-2'-deoxyuridine (EdU) assays were used to analyze cell proliferation. Cell cycle distribution was detected by flow cytometry. Western blot assay was performed to test B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax), cleaved-caspase 3, and fibronectin (FN), collagen I (Col I), and collagen IV (Col IV) protein levels. ELISA assay was used to measure interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor (TNF-α) levels. The reactive oxygen species (ROS) and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) activity were assessed by the corresponding kits. And the correlation between miR-142-3p and circTAOK1 or SOX6 was confirmed by dual luciferase reporter assay, RNA immunoprecipitation assay and RNA pull down assay.

RESULTS

CircTAOK1 and SOX6 expression levels were up-regulated, while miR-142-3p expression was down-regulated in DN serum and HG-treated HK-2 cells. Knockdown of circTAOK1 could inhibit cell injury of HG-induced HK-2 cells. The inhibitory effect of circTAOK1 knockdown on HG-induced HK-2 cell injury was restored by miR-142-3p downregulation. CircTAOK1 acted as a sponge for miR-142-3p, and SOX6 was targeted by miR-142-3p. The overexpression of SOX6 could recover the effect of miR-142-3p overexpression on HG-induced HK-2 cell injury. CircTAOK1 regulated the expression of SOX6 by targeting miR-142-3p.

CONCLUSION

CircTAOK1 knockdown inhibited HG-induced HK-2 cell damage in DN by the miR-142-3p/SOX6 axis.

EGR1/LINC00839/SOX5 axis modulates migration, invasion and Gemcitabine resistance of bladder cancer cells

BACKGROUND

Bladder cancer is one of the most common malignant tumors of the urinary system, and its incidence is increasing worldwide. However, the underlying mechanisms that trigger migration, invasion and chemotherapy resistance are unclear.

RESULTS

Bioinformatics analysis of bladder cancer cohort indicated that LINC00839 is deregulated in bladder cancer. LINC00839 was validated and highly expressed in bladder cancer patients and cell lines. In addition, LINC00839 induced the migration, invasion and Gemcitabine resistance of bladder cancer cells. We identified that the transcription factor EGR1 directly repressed LINC00839 and thereby suppressed the migration and invasion of bladder cancer cells. Furthermore, LINC00839 interacted with miR-142, which subsequently regulated the expression of SOX5, a well-studied oncogene and targeted by miR-142. In addition, EGR1 served as a suppressive transcription factor of SOX5. Therefore, EGR1 directly or indirectly regulates SOX5 via LINC00839/miR-142 axis. LINC00839 induced Gemcitabine resistance by promoting autophagy.

CONCLUSIONS

EGR1, LINC00839/miR-142 and SOX5 form a coherent feed-forward loop that modulates the migration, invasion and Gemcitabine resistance of bladder cancer.

Regulatory mechanisms of SoxD transcription factors and their influences on male fertility

Members of the SRY-related box (SOX) subfamily D (SoxD) of transcription factors are well conserved among vertebrate species and play important roles in different stages of male reproductive development. In mammals, the SoxD subfamily contains three members: SOX5, SOX6 and SOX13. Here, we describe their implications in testicular development and spermatogenesis, contributing to fertility. We also cover the mechanisms of action of SoxD transcription factors in gene regulation throughout male development. The specificity of activation of target genes by SoxD members depends, in part, on their post-translational modifications and interactions with other partners. Sperm production in adult males requires the coordination in the regulation of gene expression by different members of the SoxD subfamily of transcription factors in the testis. Specifically, the regulation of genes promoting adequate spermatogenesis by SoxD members is discussed in comparison between species.

Lamb-Shaffer syndrome: 20 Spanish patients and literature review expands the view of neurodevelopmental disorders caused by SOX5 haploinsufficiency

Lamb-Shaffer Syndrome (LSS; OMIM #616803; ORPHA #313892; ORPHA #313884) is an infrequent genetic disorder that affects multiple aspects of human development especially those related to the development of the nervous system. LSS is caused by variants in the SOX5 gene. At the molecular level, SOX5 gene encodes for a transcription factor containing a High Mobility Group (HMG) DNA-Binding domain with relevant functions in brain development in different vertebrate species. Clinical features of Lamb-Shaffer syndrome may include intellectual disability, delayed speech and language development, attention deficits, hyperactivity, autism spectrum disorder, visual problems and seizures. Additionally, patients with the syndrome may present distinct facial dimorphism such as a wide mouth with full lips, small chin, broad nasal bridge, and deep-set eyes. Other physical features that have been reported in some patients include short stature, scoliosis, and joint hypermobility. Here, we report the clinical and molecular characterization of a Spanish LSS cohort of new 20 patients and review all the patients published so far which amount for 111 patients. The most frequent features included developmental delay, intellectual disability, visual problems, poor speech development and facial dysmorphic features. Strikingly, pain insensitivity and hypermetropia seems to be more frequent than previously reported, based on the frequency seen in the Spanish cohort. Eighty-three variants have been reported so far, single nucleotide variants (SNV) and copy number variants represent 47% and 53%, respectively, from the total of variants reported. Similarly to previous reports, the majority of the SNVs variants of the novel patients reported herein fall in the HMG domain of the protein. However, new variants, affecting other functional domains, were also detected. In conclusion, LLS is a rare genetic disorder mostly characterized by a wide range of developmental and neurological symptoms. Early diagnosis would allow to start of care programs, clinical follow up, prospective studies and appropriate genetic counseling, to promote clinical and social improvement to have profound lifelong benefits for patients and their families. Further research is needed to better understand the underlying mechanisms of the syndrome related to SOX5 haploinsufficiency.

Sox6 impairs the adipogenic commitment of mesenchymal stem cells by targeting lysyl oxidase and preadipocyte factor 1

The commitment of mesenchymal stem cells (MSCs) to preadipocytes and the termination of differentiation to adipocytes are critical for maintaining systemic energy homeostasis. However, our knowledge of the molecular mechanisms governing the commitment of MSCs to preadipocytes and the subsequent termination of their differentiation into adipocytes remain limited. Additionally, the role of Sox6 sex-determining region Y (SRY)-box6 (Sox6), a transcription factor that regulates gene transcription, is reportedly involved in various cellular processes, including adipogenesis; however, its function in regulating preadipocyte development and the factors involved in the termination of adipogenic differentiation remain unexplored. Therefore, we investigated the role of Sox6 in regulating the differentiation of adipocytes by monitoring the effects of its overexpression in C3H10T1/2 cells (in vitro) and C57BL/6J mouse (in vivo) models of adipogenesis. We observed lower Sox6 expression in the adipose tissue of obese mice than that in control mice. Sox6 overexpression inhibited the differentiation of MSC by directly binding to the lysyl oxidase (Lox) and preadipocyte factor 1 (Pref1) promoters, which was potentiated by histone deacetylase-1(HDAC1). Our findings suggest that Sox6 is a key regulator of MSC commitment to adipocytes; therefore, targeting the Sox6-mediated regulation of this process could offer potential therapeutic avenues for addressing obesity and related metabolic disorders.

Genome-wide CRISPR activation screening in senescent cells reveals SOX5 as a driver and therapeutic target of rejuvenation

Our understanding of the molecular basis for cellular senescence remains incomplete, limiting the development of strategies to ameliorate age-related pathologies by preventing stem cell senescence. Here, we performed a genome-wide CRISPR activation (CRISPRa) screening using a human mesenchymal precursor cell (hMPC) model of the progeroid syndrome. We evaluated targets whose activation antagonizes cellular senescence, among which SOX5 outperformed as a top hit. Through decoding the epigenomic landscapes remodeled by overexpressing SOX5, we uncovered its role in resetting the transcription network for geroprotective genes, including HMGB2. Mechanistically, SOX5 binding elevated the enhancer activity of HMGB2 with increased levels of H3K27ac and H3K4me1, raising HMGB2 expression so as to promote rejuvenation. Furthermore, gene therapy with lentiviruses carrying SOX5 or HMGB2 rejuvenated cartilage and alleviated osteoarthritis in aged mice. Our study generated a comprehensive list of rejuvenators, pinpointing SOX5 as a potent driver for rejuvenation both in vitro and in vivo.

CircWHSC1 serves as a prognostic biomarker and promotes malignant progression of non-small-cell lung cancer via miR-590-5p/SOX5 axis

Dysregulated circWHSC1 has been shown to play potential roles in diverse cancer types, including ovarian cancer, endometrial cancer and hepatocellular carcinoma (HCC). The objective of this study was to investigate its expression, underlying role and regulatory mechanism in non-small-cell lung cancer (NSCLC). The expression of circWHSC1 was determined by real-time PCR. After knockdown of circWHSC1 expression in NSCLC cells, the proliferation, migration, and invasion were detected using CCK-8, colony formation, and Transwell assays, and the effects of circWHSC1 on NSCLC tumorigenesis in vivo was also investigated. With the help of luciferase reporter and pull-down assays, we further explored the downstream mechanism of circWHSC1 in NSCLC cells. CircWHSC1 was highly expressed in NSCLC tissues and cell lines. The inhibition of circWHSC1 suppressed the malignant properties of NSCLC cells, as evidenced by the reduction of proliferation, migration and invasion. CircWHSC1 sponged miR-590-5p and functioned as an oncogene in NSCLC by increasing sex determining region Y-boxprotein 5 (SOX5) expression. CircWHSC1 may contribute to the oncogenicity of NSCLC via the regulation of miR-590-5p/SOX5 axis, which might be a novel therapeutic target in NSCLC.

Unveiling the prognostic significance of SOX5 in esophageal squamous cell carcinoma: a comprehensive bioinformatic and experimental analysis

BACKGROUND

This study aimed to investigate the expression and prognostic significance of SOX5 in esophageal squamous cell carcinoma (ESCC).

METHODS

Gene Expression Omnibus (GEO) data were analyzed to assess SOX5 expression in ESCC and normal tissues. Survival analysis was performed to evaluate its prognostic significance. Pathway enrichment analysis was conducted to identify pathways associated with low SOX5 expression. Methylation status of CpG sites in ESCC cases was examined, and SOX5 expression was evaluated. Differential expression and ChIP-seq data analyses were used to identify genes significantly correlated with SOX5 and to obtain target genes. A protein-protein interaction (PPI) network was constructed using hub genes, and their association with immune cell infiltration was determined. In vitro ESCC cell experiments validated the findings.

RESULTS

SOX5 was significantly downregulated in ESCC samples compared to normal samples. Its downregulation was associated with shorter survival in ESCC patients. Pathway enrichment analysis revealed enrichment in regulated necrosis, NLRP3 inflammasome, formation of the cornified envelope, and PD-1 signaling. Methylation status of two CpG sites negatively correlated with SOX5 expression. Differential expression analysis identified 122 genes significantly correlated with SOX5, and 28 target genes were obtained from ChIP-seq analysis. Target genes were enriched in DNA replication, cell cycle, spindle, and ATPase activity. Five hub genes were identified, and the PPI network showed significant associations with immune cell infiltration. In vitro experiments confirmed SOX5 downregulation, upregulation of hub genes, and their functional effects on ESCC cell apoptosis and proliferation.

CONCLUSIONS

These findings enhance understanding of SOX5 in ESCC and potential therapeutic strategies.

SOX5: Lamb-Shaffer syndrome-A case series further expanding the phenotypic spectrum

To delineate further the clinical phenotype of Lamb-Shaffer Syndrome (LSS) 16 unpublished patients with heterozygous variation in SOX5 were identified either through the UK Decipher database or the study team was contacted by clinicians directly. Clinical phenotyping tables were completed for each patient by their responsible clinical geneticist. Photos and clinical features were compared to assess key phenotypes and genotype-phenotype correlation. We report 16 SOX5 variants all of which meet American College of Medical Genetics/Association for Clinical Genomic Science ACMG/ACGS criteria class IV or V. 7/16 have intragenic deletions of SOX5 and 9/16 have single nucleotide variants (including both truncating and missense variants). The cohort includes two sets of monozygotic twins and parental gonadal mosaicism is noted in one family. This cohort of 16 patients is compared with the 71 previously reported cases and corroborates previous phenotypic findings. As expected, the most common findings include global developmental delay with prominent speech delay, mild to moderate intellectual disability, behavioral abnormalities and sometimes subtle characteristic facial features. We expand in more detail on the behavioral phenotype and observe that there is a greater tendency toward lower growth parameters and microcephaly in patients with single nucleotide variants. This cohort provides further evidence of gonadal mosaicism in SOX5 variants; this should be considered when providing genetic counseling for couples with one affected child and an apparently de novo variant.

Higher TYROBP and lower SOX6 as predictive biomarkers for poor prognosis of clear cell renal cell carcinoma: A pilot study

BACKGROUND

Clear cell renal carcinoma (ccRCC) is the most common subtype of renal cancer, accounting for approximately 75% of all histological types of renal cancer, and is the leading cause of death from renal cancer. However, the molecular mechanism of tyrosine kinase binding protein (TYROBP) and sex-determining region Y Box-6 (SOX6) in the ccRCC was not precise.

METHODS

Bioinformatics analysis was performed to explore the hub role of TYROBP and SOX6 on the ccRCC. A total of 6 patients with clear cell renal cell carcinoma (ccRCC) were recruited. HE staining was performed to observe the pathology result of ccRCC. Immunohistochemistry and Immunofluorescence assay was made to detect the protein expression of TYROBP. Total RNA was extracted using TRIzol to examine the mRNA expression of TYROBP via the Real time quantitative polymerase chain reaction. The strong correlation between the expression of TYROBP and the survival time of ccRCC patients was performed by the BP neural network and support vector machine.

RESULTS

Compared with the control group, the expression of SOX6 was downregulated in the samples with ccRCC. However, the expression of TYROBP was higher in the samples with ccRCC than in the control group. Compared with the patients with high SOX6 expression, the patients with low SOX6 expression have a poor survival prognosis (HR=0.39, P < .05). However, the patients with high TYROBP expression have a shorter survival time than the patients with low TYROBP expression (HR=1.66, P < .05). The genes related with TYROBP and SOX6 are mainly enriched in the regulation of cell activation, leukocyte activation, negative regulation of cell activation, myeloid leukocyte activation, positive regulation of response to external stimulus, immune response-regulating signaling pathway. The interaction between TYROBP, SOX6, and kidney neoplasms was drawn, and the inference score of TYROBP and SOX6 on the kidney neoplasms was high.

CONCLUSION

In conclusion, TYROBP is highly expressed in renal clear cell carcinoma, and when this molecule is highly expressed, the survival prognosis of renal carcinoma is poor. TYROBP and SOX6 may be potential targets for diagnosing and treating renal clear cell carcinoma.

LINC00520 up-regulates SOX5 to promote cell proliferation and invasion by miR-4516 in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common human cancers. Long non-coding RNA (lncRNA) has been demonstrated to play an important role in regulating tumor development. The current study aims to explore the specific role of LINC00520 during HCC progression. The present study identified that LINC00520 was upregulated in HCC tissues and indicated poor patient survival. Overexpression of LINC00520 promoted HCC cell proliferation, migration and invasion, while LINC00520 downregulation led to the opposite effects. Besides, LINC00520 knockdown was found to inhibit tumor growth in vivo. Furthermore, LINC00520 acted as a sponge of miR-4516 to regulate SRY-related high mobility group box 5 (SOX5). In addition, the inhibition of miR-4516 partly reversed the inhibitory effect of LINC00520 silencing on HCC cell proliferation, migration and invasion. In conclusion, the inhibition of LINC00520 suppressed HCC cell proliferation, migration and invasion through mediating miR-4516/SOX5 axis. Therefore, our study provides a basis for the development of treatment strategies for HCC.

Pluripotent stem cell derived dopaminergic subpopulations model the selective neuron degeneration in Parkinson's disease

In Parkinson’s disease (PD), substantia nigra (SN) dopaminergic (DA) neurons degenerate, while related ventral tegmental area (VTA) DA neurons remain relatively unaffected. Here, we present a methodology that directs the differentiation of mouse and human pluripotent stem cells toward either SN- or VTA-like DA lineage and models their distinct vulnerabilities. We show that the level of WNT activity is critical for the induction of the SN- and VTA-lineage transcription factors Sox6 and Otx2, respectively. Both WNT signaling modulation and forced expression of these transcription factors can drive DA neurons toward the SN- or VTA-like fate. Importantly, the SN-like lineage enriched DA cultures recapitulate the selective sensitivity to mitochondrial toxins as observed in PD, while VTA-like neuron-enriched cultures are more resistant. Furthermore, a proteomics approach led to the identification of compounds that alter SN neuronal survival, demonstrating the utility of our strategy for disease modeling and drug discovery.

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Derivation of distinct dopaminergic subpopulations from pluripotent stem cells

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Wnt signaling inhibitors promote SN dopaminergic neuron specification

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Modeling selective vulnerability of SN dopaminergic neurons in vitro

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Proteomics reveals pathways that promote SN dopaminergic neuron survival

Sox6 expression distinguishes dorsally and ventrally biased dopamine neurons in the substantia nigra with distinctive properties and embryonic origins

Dopamine (DA) neurons in the ventral tier of the substantia nigra pars compacta (SNc) degenerate prominently in Parkinson's disease, while those in the dorsal tier are relatively spared. Defining the molecular, functional, and developmental characteristics of each SNc tier is crucial to understand their distinct susceptibility. We demonstrate that Sox6 expression distinguishes ventrally and dorsally biased DA neuron populations in the SNc. The Sox6+ population in the ventral SNc includes an Aldh1a1+ subset and is enriched in gene pathways that underpin vulnerability. Sox6+ neurons project to the dorsal striatum and show activity correlated with acceleration. Sox6- neurons project to the medial, ventral, and caudal striatum and respond to rewards. Moreover, we show that this adult division is encoded early in development. Overall, our work demonstrates a dual origin of the SNc that results in DA neuron cohorts with distinct molecular profiles, projections, and functions.

The articular cartilage preservative effects of genistein in an experimental model of knees osteoarthritis

The study aimed to investigate the preservative effects of genistein on articular cartilage in an experimental model of knee osteoarthritis in rats. Thirty male Wistar rats were assigned to 3 equal groups: sham group, osteoarthritis control group (OAG), and genistein-treated osteoarthritis group (GTG). Intra-articular injections of monosodium iodoacetate were used for osteoarthritis induction. After 2 weeks of rest for the induction of the inflammatory process, genistein (30 mg/kg/day) vs. saline gavage was administered for 8 weeks. The expression of matrix metalloproteinase (MMP)-8 and MMP-13, Sox5/Sox6, Indian hedgehog (IHH), and Col2 were evaluated in medial femoral condyle sections by immunohistochemical staining. The number of chondrocytes and cartilage thicknesses were also measured and compared among the groups. No significant change in cartilage thickness was observed in GTG compared with OAG (p = 0.188). Chondrocyte count was significantly higher in the articular cartilage of GTG compared with OAG (p = 0.006). Induction of osteoarthritis significantly increased the expression of MMP-8, MMP-13, and IHH, but decreased Col2, Sox5, and Sox6 expression (p < 0.001); these were partially prevented in the GTG. Our findings support the effectiveness of genistein treatment in the prevention of articular cartilage damage in the experimental model of knee osteoarthritis. The proposed mechanism of action is through the suppression of the MMP, IHH, and Col2 pathways, besides the induction of Sox5 and Sox6 expression. Novelty: Genistein prevents articular cartilage damage in the experimental model of knee osteoarthritis. The osteoprotective effect is manifested by the modulation of expression of MMP, Sox, IHH, and Col2 proteins.

Circular RNA circ_0000712 regulates high glucose-induced apoptosis, inflammation, oxidative stress, and fibrosis in (DN) by targeting the miR-879-5p/SOX6 axis

Diabetic nephropathy (DN), a frequent diabetes complication, has complex pathogenesis. Circular RNAs (circRNAs) circ_0000712 has been reported to be upregulated in kidney tissues and high glucose (HG)-inducted Mesangial cells (MCs). This study is designed to explore the role and mechanism of circ_0000712 in the HG-inducted MCs injury in DN. Circ_0000712, microRNA-879-5p (miR-879-5p), and SRY-Box Transcription Factor 6 (SOX6) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell apoptosis was examined by flow cytometry assay. Protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), fibronectin (FN), collagen type I (Col. I), collagen type IV (Col. IV), and SOX6 were assessed by western blot assay. Levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) generation, Lactate Dehydrogenase (LDH) activity, and Superoxide Dismutase (SOD) activity were detected by the corresponding kits. The binding relationship between miR-879-5p and circ_0000712 or SOX6 was predicted by starBase and Targetscan, and then verified by a dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays. Circ_0000712 and SOX6 were highly expressed, and miR-879-5p was decreased in db/db DN mice and HG-inducted SV40-MES13 cells. Furthermore, circ_0000712 deficiency repressed HG-caused apoptosis, inflammation, oxidative stress, and fibrosis in SV40-MES13 cells. Mechanically, circ_0000712 could regulate SOX6 expression by sponging miR-879-5p. Circ_0000712 knockdown could hinder HG-inducted SV40-MES13 cell injury through targeting the miR-879-5p/SOX6 axis, implying a possible circRNA-targeted therapy for DN.

Novel NFκB Inhibitor SC75741 Mitigates Chondrocyte Degradation and Prevents Activated Fibroblast Transformation by Modulating miR-21/GDF-5/SOX5 Signaling

Osteoarthritis (OA) is a common articular disease manifested by the destruction of cartilage and compromised chondrogenesis in the aging population, with chronic inflammation of synovium, which drives OA progression. Importantly, the activated synovial fibroblast (AF) within the synovium facilitates OA through modulating key molecules, including regulatory microRNAs (miR's). To understand OA associated pathways, in vitro co-culture system, and in vivo papain-induced OA model were applied for this study. The expression of key inflammatory markers both in tissue and blood plasma were examined by qRT-PCR, western blot, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assays. Herein, our result demonstrated, AF-activated human chondrocytes (AC) exhibit elevated NFκB, TNF-α, IL-6, and miR-21 expression as compared to healthy chondrocytes (HC). Importantly, AC induced the apoptosis of HC and inhibited the expression of chondrogenesis inducers, SOX5, TGF-β1, and GDF-5. NFκB is a key inflammatory transcription factor elevated in OA. Therefore, SC75741 (an NFκB inhibitor) therapeutic effect was explored. SC75741 inhibits inflammatory profile, protects AC-educated HC from apoptosis, and inhibits miR-21 expression, which results in the induced expression of GDF-5, SOX5, TGF-β1, BMPR2, and COL4A1. Moreover, ectopic miR-21 expression in fibroblast-like activated chondrocytes promoted osteoblast-mediated differentiation of osteoclasts in RW264.7 cells. Interestingly, in vivo study demonstrated SC75741 protective role, in controlling the destruction of the articular joint, through NFκB, TNF-α, IL-6, and miR-21 inhibition, and inducing GDF-5, SOX5, TGF-β1, BMPR2, and COL4A1 expression. Our study demonstrated the role of NFκB/miR-21 axis in OA progression, and SC75741's therapeutic potential as a small-molecule inhibitor of miR-21/NFκB-driven OA progression.

LncRNA UCC promotes epithelial-mesenchymal transition via the miR-143-3p/SOX5 axis in non-small-cell lung cancer

Long non-coding RNAs (lncRNAs) have been found to play regulatory roles in cancers; for example, UCC was reported to promote colorectal cancer progression. However, the function of UCC in non-small-cell lung cancer (NSCLC) remains unclear. Therefore, mRNA and protein levels were assessed using qPCR and western blots. Cell viability was assessed by colony-formation assays. The interaction between lncRNAs and miRNAs was detected by dual-luciferase reporter and RIP assays. The tumorigenesis of NSCLC cells in vivo was determined by xenograft assays. LncRNA UCC was highly expressed in both NSCLC tissues and cells. Knockdown of UCC expression suppressed the proliferation of NSCLC cells. In addition, a dual-luciferase reporter system and RIP assays showed that UCC specifically bound to miR-143-3p and acted as a sponge of miR-143-3p in NSCLC cells. The miR-143-3p inhibitor rescued the inhibitory effect of sh-UCC on the proliferation of NSCLC cells. Moreover, miR-143-3p and UCC showed opposite effects on the expression of SOX5, which promoted EMT in NSCLC cells. In addition, in a mouse model, knockdown of UCC expression alleviated EMT and NSCLC progression in vivo, which was consistent with the in vitro results. In the current study, we found that UCC induced the proliferation and migration of NSCLC cells both in vitro and in vivo by inducing the expression of SOX5 via miR-143-3p and subsequently promoted EMT in NSCLC.

[Variant analysis of SOX5 gene in a Lamb-Shaffer syndrome family]

OBJECTIVE

To explore the genetic basis for a case of Lamb-Shaffer syndrome.

METHODS

Genomic DNA was extracted from peripheral blood samples and subjected to whole exome sequencing(WES). Suspected variant was verified by Sanger sequencing.

RESULTS

The patients was found to harbor a heterozygous c.1495delA(p.Thr499Glnfs*5) frameshift variant of the SOX5 gene by WES. Sanger sequencing confirmed that the same variant was a de novo variant. Based on the American College of Medical Genetics and Genomics guidelines, c.1495delA(p.Thr499Glnfs*5) variant of the SOX5 gene was predicted to be pathogenic (PVS1+PS2+PM2).

CONCLUSION

The c.1495delA(p.Thr499Glnfs*5) variant of the SOX5 gene probably underlies the Lamb-Shaffer syndrome in this patient.

Blockage of miR-485-5p on Cortical Neuronal Apoptosis Induced by Oxygen and Glucose Deprivation/Reoxygenation Through Inactivating MAPK Pathway

This study is designed to explore the role of miR-485-5p in hypoxia/reoxygenation-induced neuronal injury in primary rat cortical neurons. Hypoxia/reoxygenation model was established through oxygen and glucose deprivation/reoxygenation (OGD/R). RN-c cells were transfected with miR-485-5p mimics, miR-485-5p inhibitors, si-SOX6, pCNDA3.1-SOX6 or miR-485-5p + pCDNA3.1-SOX6, in which cell viability, apoptosis, lactate dehydrogenase (LDH) release rate were assessed. Western blot detected the protein expressions of apoptotic-related proteins (caspase3, Bcl-2, Bax) and the phosphorylated level of ERK1/2. The potential binding sites between miR-485-5p and SOX6 were predicted by STARBASE and identified using dual luciferase reporter gene assay. OGD/R-treated RN-c cell presented increases in apoptosis and LDH release rate as well as a decrease in cell viability. miR-485-5p was downregulated while SOX6 was upregulated in OGD/R-treated RN-c cells. Overexpression of miR-485-5p or SOX6 knockdown rescued cell viability and Bcl-2 expression, while attenuated apoptosis, LDH release rate, expression of SOX6 and the phosphorylated level of ERK1/2. Consistently, miR-485-5p inhibition led to the reverse pattern. Co-transfection of miR-485-5p and SOX6 reversed the protective effect of miR-485-5p on OGD/R-induced neuronal apoptosis. miR-485-5p can directly target SOX6. Together, miR-485-5p inhibited SOX6 to alleviate OGD/R-induced apoptosis. Collectively, miR-485-5p protects primary cortical neurons against hypoxia injury through downregulating SOX6 and inhibiting MAPK pathway.

Single-nucleotide polymorphism rs10036727 in the SLIT3 gene is associated with osteoporosis at the femoral neck in older Mexican postmenopausal women

AIMS

Osteoporosis (OP) remains a major public health problem worldwide. The most serious complications of this disease are fragility fractures, which increase morbidity and mortality. Management of OP represents an economic burden for health systems. Therefore, it is necessary to develop new screening strategies to identify the population at risk and implement preventive measures. We previously identified the SNPs rs3801387 in WNT16, rs7108738 in SOX6, rs10036727 in SLIT3 and rs7584262 in PKDCC as associated with bone mineral density in postmenopausal women through a genome-wide association study. The aim of this study was to validate those SNPs in two independent cohorts of non-related postmenopausal women.

MATERIALS AND METHODS

We included 1160 women classifying them as normal, osteopenic or osteoporotic and a group with hip fragility fracture. Genotyping was performed using predesigned TaqMan assays.

RESULTS

The variants rs10036727 and rs7108738 showed a significant association with BMD at the femoral neck. SLIT3 has been previously proposed as a potential biomarker and therapeutic resource.

CONCLUSIONS

Our results provide new evidence regarding a possible involvement of SLIT3 in bone metabolisms and encourage the development of more studies in different populations to support these observations.

Emerging roles of Sox6 in the renal and cardiovascular system

The function of Sex-determining Region Y (SRY)-related high-mobility-group box (Sox) family of transcription factors in cell fate decisions during embryonic development are well-established. Accumulating evidence indicates that the Sox family of transcription factors are fundamental in adult tissue homeostasis, regeneration, and physiology. The SoxD subfamily of genes are expressed in various cell types of different organs during embryogenesis and adulthood and have been involved in cell-fate determination, cellular proliferation and survival, differentiation, and terminal maturation in a number of cell lineages. The dysregulation in the function of SoxD proteins (i.e. Sox5, Sox6, Sox13, and Sox23) have been implicated in different disease conditions such as chondrodysplasia, cancer, diabetes, hypertension, autoimmune diseases, osteoarthritis among others. In this minireview, we present recent developments related to the transcription factor Sox6, which is involved in a number of diseases such as diabetic nephropathy, adipogenesis, cardiomyopathy, inflammatory bowel disease, and cancer. Sox6 has been implicated in the regulation of renin expression and JG cell recruitment in mice during sodium depletion and dehydration. We provide a current perspective of Sox6 research developments in last five years, and the implications of Sox6 functions in cardiovascular physiology and disease conditions.

Transactivation of SOX5 by Brachyury promotes breast cancer bone metastasis

The bone marrow has been long known to host a unique environment amenable to colonization by metastasizing tumor cells. Yet, the underlying molecular interactions which give rise to the high incidence of bone metastasis (BM) in breast cancer patients have long remained uncharacterized. In our study, in vitro and in vivo assays demonstrated that Brachyury (Bry) could promote breast cancer BM. Bry drives epithelial–mesenchymal transition (EMT) and promotes breast cancer aggressiveness. As an EMT driver, SOX5 involves in breast cancer metastasis and the specific function in BM. Chromatin immunoprecipitation (ChIP) assays revealed SOX5 is a direct downstream target gene of Bry. ChIP analysis and reporter assays identified two Bry-binding motifs; one consistent with the classic conserved binding sequence and the other a new motif sequence. This study demonstrates for the first time that Bry promotes breast cancer cells BM through activating SOX5. In clinical practice, targeting the Bry-Sox5-EMT pathway is evolving into a promising avenue for the prevention of bone metastatic relapse, therapeutic resistance and other aspects of breast cancer progression.

Brachyury directly regulates the expression of SOX5 by binding to two motifs in its promoter region. The Bry-SOX5-EMT pathway may represent a potential target to develop treatments to prevent and treat bone metastasis from breast cancer.

Circ_WBSCR17 aggravates inflammatory responses and fibrosis by targeting miR-185-5p/SOX6 regulatory axis in high glucose-induced human kidney tubular cells

BACKGROUND

Diabetic nephropathy (DN), a severe microvascular complication of diabetes, has complex pathogenesis. Circular RNAs (circRNAs) exert broad biological functions on human diseases. This study intended to explore the role and mechanism of circ_WBSCR17 in DN.

METHODS

DN mice models were constructed using streptozotocin injection, and DN cell models were assembled using high glucose (HG) treatment in human kidney 2 cells (HK-2). The expression of circ_WBSCR17, miR-185-5p and SRY-Box Transcription Factor 6 (SOX6) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of SOX6 and fibrosis markers were examined by western blot. The release of inflammatory cytokines, cell proliferation and apoptosis, were assessed by enzyme-linked immunosorbent assay (ELISA), cell counting kit-8 (CCK-8) assay and flow cytometry assay, respectively. The predicted interaction between miR-185-5p and circ_WBSCR17 or SOX6 was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

RESULT

Circ_WBSCR17 was highly expressed in DN mice models and HG-induced HK-2 cells. Circ_WBSCR17 knockdown or SOX6 knockdown promoted cell proliferation and blocked cell apoptosis, inflammatory responses and fibrosis, while circ_WBSCR17 overexpression or SOX6 overexpression conveyed the opposite effects. MiR-185-5p was a target of circ_WBSCR17 and directly bound to SOX6. MiR-185-5p could reverse the role of circ_WBSCR17 or SOX6. Moreover, the expression of SOX6 was modulated by circ_WBSCR17 through intermediating miR-185-5p.

CONCLUSION

Circ_WBSCR17 triggered the dysfunction of HG-induced HK-2 cells, including inflammatory responses and fibrosis, which was accomplished via the miR-185-5p/SOX6 regulatory axis.

Identification of HMG-box family establishes the significance of SOX6 in the malignant progression of glioblastoma

Glioblastoma multiforme (GBM) is the most malignant neuroepithelial primary brain tumor and its mean survival time is 15 months after diagnosis. This study undertook to investigate the genome-wide and transcriptome-wide analyses of human high mobility group box (HMG-box) TF (transcript factor) families / HOX, TOX, FOX, HMG and SOX gene families, and their relationships to GBM. According to the TCGA-GBM profile analysis, differentially expressed HOX, FOX, HMG and SOX gene families (62 DEmRNA) were found in this study. We also analyzed DEmRNA (HMG-box related genes) co-expressed eight DElncRNA in GBM, and constructed a ceRNA network analysis as well. We constructed 50 DElncRNA-DEmiRNA-DEmRNA (HMG-box related genes) pairs between GBM and normal tissues. Then, risk genes SOX6 and SOX21 expression were correlated with immune infiltration levels in GBM. SOX6 also had a strong association with MAPT, GSK3B, FYN and DPYSL4, suggesting that they might be functional members in GBM.

RETRACTED: LncRNA DANCR silence inhibits SOX5-medicated progression and autophagy in osteosarcoma via regulating miR-216a-5p

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Authors and Editor-in-Chief. The authors of this article have informed the editors that the human anti-LC3 antibody used in this work recognized multiple antigens in murine tissues, leading them to believe that the antibody is contaminated. This possible contamination further leads them to determine that the data generated using these antibodies, and any conclusions based on that data, cannot be considered accurate. Furthermore, the authors also report that subsequent work has revealed that the DANCR/miR-216a-5p axis plays a role in the regulation of beta-oxidation and downstream non-programmed cell death and homeostasis. They therefore have requested to retract this article as unreliable. The authors have not provided the relevant raw data for the editors' review, or the subsequent reported role of DANCR in beta-oxidation. Therefore, given the authors' loss of confidence in these findings, the Editor-in-Chief supports the decision to retract the article.

Pentoxifylline alleviated cardiac injury via modulating the cardiac expression of lncRNA-00654-miR-133a-SOX5 mRNA in the rat model of ischemia-reperfusion

Pentoxifylline (PTX) protects from many cardiovascular complications. It plays a critical role in stem cell proliferation and differentiation. Here, the effect of PTX administration on cardiac ischemia and dysfunction was explored. PTX in 3 doses (20, 30, and 40 mg/kg), was administered in vivo 5 min before a 45 min occlusion of the left anterior descending artery, followed by a 120 min reperfusion in male Wistar rats. The left ventricular end-diastolic pressure and dP/dt_max were assessed. Blood and cardiac tissue samples were collected for measuring the levels of cardiac enzymes and the expression of lncRNA-00654-miR-133a-SOX5. Samples of left ventricles were collected and processed for light microscopic, immunohistochemical staining for c-kit (a marker for cardiac progenitor cells) and transmission electron microscopic examination. PTX administration showed improvements in cardiac function tests, enzymes, and myocytes. Microscopic features showed minimal cardiac edema, hemorrhage, cellular inflammatory infiltration and fibrosis in addition to increased c-kit + cells in cardiac tissue samples. Notably, this treatment also produced a dose-dependent decrease in lncRNA-00654 with an increase in SOX5 mRNA and miRNA-133a-3p expressions. In conclusion, PTX has the potential to alleviate cardiac injury and increase the number of c-kit + cells following ischemia-reperfusion in the rat model via modulation of lncRNA-00654 and miR-133a-SOX5 mRNA expressions.

SOXopathies: Growing Family of Developmental Disorders Due to SOX Mutations

The SRY-related (SOX) transcription factor family pivotally contributes to determining cell fate and identity in many lineages. Since the original discovery that SRY deletions cause sex reversal, mutations in half of the 20 human SOX genes have been associated with rare congenital disorders, henceforward called SOXopathies. Mutations are generally de novo, heterozygous, and inactivating, revealing gene haploinsufficiency, but other types, including duplications, have been reported too. Missense variants primarily target the HMG domain, the SOX hallmark that mediates DNA binding and bending, nuclear trafficking, and protein-protein interactions. We here review key clinical and molecular features of SOXopathies and discuss the prospect that the disease family likely involves more SOX genes and larger clinical and genetic spectrums than currently appreciated.

SP1-mediated upregulation of lncRNA ILF3-AS1 functions a ceRNA for miR-212 to contribute to osteosarcoma progression via modulation of SOX5

Long noncoding RNA ILF3-AS1 (ILF3-AS1) has been reported to be abnormally expressed in several tumors. However, its expression pattern and function in osteosarcoma have not been investigated. In this study, we showed that ILF3-AS1 expression was significantly up-regulated in both osteosarcoma tissues and cell lines. We first reported that ILF3-AS1 upregulation was induced by nuclear transcription factor SP1. Clinical assays revealed that higher expression of ILF3-AS1 was associated with advanced clinical stage, distant metastasis and shorter overall survival. in multivariate analysis, ILF3-AS1 expression level was found to be an independent prognostic factor for osteosarcoma patients. Functional investigations showed that knockdown of ILF3-AS1 suppressed the proliferation, migration and invasion of osteosarcoma cells, and promoted apoptosis. Bioinformatic software predicted that miR-212 both targeted the 3'-UTR of ILF3-AS1 and SOX5, which was confirmed using luciferase reporter assay, RT-PCR and Western blot. Taken together, ILF3-AS1 displayed its tumor-promotive roles in the progression of osteosarcoma through miR-212/SOX5 axis. Our findings help to elucidate the tumorigenesis of osteosarcoma, and future study will provide a novel therapeutic target for osteosarcoma.

Position effect, cryptic complexity, and direct gene disruption as disease mechanisms in de novo apparently balanced translocation cases

The majority of apparently balanced translocation (ABT) carriers are phenotypically normal. However, several mechanisms were proposed to underlie phenotypes in affected ABT cases. In the current study, whole-genome mate-pair sequencing (WG-MPS) followed by Sanger sequencing was applied to further characterize de novo ABTs in three affected individuals. WG-MPS precisely mapped all ABT breakpoints and revealed three possible underlying molecular mechanisms. Firstly, in a t(X;1) carrier with hearing loss, a highly skewed X-inactivation pattern was observed and the der(X) breakpoint mapped ~87kb upstream an X-linked deafness gene namely POU3F4, thus suggesting an underlying long-range position effect mechanism. Secondly, cryptic complexity and a chromothripsis rearrangement was identified in a t(6;7;8;12) carrier with intellectual disability. Two translocations and a heterozygous deletion disrupted SOX5; a dominant nervous system development gene previously reported in similar patients. Finally, a direct gene disruption mechanism was proposed in a t(4;9) carrier with dysmorphic facial features and speech delay. In this case, the der(9) breakpoint directly disrupted NFIB, a gene involved in lung maturation and development of the pons with important functions in main speech processes. To conclude, in contrast to familial ABT cases with identical rearrangements and discordant phenotypes, where translocations are considered coincidental, translocations seem to be associated with phenotype presentation in affected de novo ABT cases. In addition, this study highlights the importance of investigating both coding and non-coding regions to decipher the underlying pathogenic mechanisms in these patients, and supports the potential introduction of low coverage WG-MPS in the clinical investigation of de novo ABTs.

Genome-wide meta-analysis of 158,000 individuals of European ancestry identifies three loci associated with chronic back pain

Back pain is the #1 cause of years lived with disability worldwide, yet surprisingly little is known regarding the biology underlying this symptom. We conducted a genome-wide association study (GWAS) meta-analysis of chronic back pain (CBP). Adults of European ancestry were included from 15 cohorts in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and from the UK Biobank interim data release. CBP cases were defined as those reporting back pain present for ≥3-6 months; non-cases were included as comparisons ("controls"). Each cohort conducted genotyping using commercially available arrays followed by imputation. GWAS used logistic regression models with additive genetic effects, adjusting for age, sex, study-specific covariates, and population substructure. The threshold for genome-wide significance in the fixed-effect inverse-variance weighted meta-analysis was p<5×10(-8). Suggestive (p<5×10(-7)) and genome-wide significant (p<5×10(-8)) variants were carried forward for replication or further investigation in the remaining UK Biobank participants not included in the discovery sample. The discovery sample comprised 158,025 individuals, including 29,531 CBP cases. A genome-wide significant association was found for the intronic variant rs12310519 in SOX5 (OR 1.08, p = 7.2×10(-10)). This was subsequently replicated in 283,752 UK Biobank participants not included in the discovery sample, including 50,915 cases (OR 1.06, p = 5.3×10(-11)), and exceeded genome-wide significance in joint meta-analysis (OR 1.07, p = 4.5×10(-19)). We found suggestive associations at three other loci in the discovery sample, two of which exceeded genome-wide significance in joint meta-analysis: an intergenic variant, rs7833174, located between CCDC26 and GSDMC (OR 1.05, p = 4.4×10(-13)), and an intronic variant, rs4384683, in DCC (OR 0.97, p = 2.4×10(-10)). In this first reported meta-analysis of GWAS for CBP, we identified and replicated a genetic locus associated with CBP (SOX5). We also identified 2 other loci that reached genome-wide significance in a 2-stage joint meta-analysis (CCDC26/GSDMC and DCC).

TNF-α-Induced SOX5 Upregulation Is Involved in the Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells Through KLF4 Signal Pathway

Postmenopausal osteoporosis (PMOP) is a common systemic skeletal disease characterized by reduced bone mass and microarchitecture deterioration. Although differentially expressed SOX5 has been found in bone marrow from ovariectomized mice, its role in osteogenic differentiation in human mesenchymal stem cells (hMSCs) from bone marrow in PMOP remains unknown. In this study, we investigated the biological function of SOX5 and explore its molecular mechanism in hMSCs from patients with PMOP. Our findings showed that the mRNA and protein expression levels of SOX5 were upregulated in hMSCs isolated from bone marrow samples of PMOP patients. We also found that SOX5 overexpression decreased the alkaline phosphatase (ALP) activity and the gene expression of osteoblast markers including Collagen I, Runx2 and Osterix, which were increased by SOX5 knockdown using RNA interference. Furthermore, TNF-α notably upregulated the SOX5 mRNA expression level, and SOX5 knockdown reversed the effect of TNF-α on osteogenic differentiation of hMSCs. In addition, SOX5 overexpression increased Kruppel-like factor 4 (KLF4) gene expression, which was decreased by SOX5 silencing. KLF4 knockdown abrogated the suppressive effect of SOX5 overexpression on osteogenic differentiation of hMSCs. Taken together, our results indicated that TNF-α-induced SOX5 upregulation inhibited osteogenic differentiation of hMSCs through KLF4 signal pathway, suggesting that SOX5 might be a novel therapeutic target for PMOP treatment.

Distinct interactions of Sox5 and Sox10 in fate specification of pigment cells in medaka and zebrafish

Mechanisms generating diverse cell types from multipotent progenitors are fundamental for normal development. Pigment cells are derived from multipotent neural crest cells and their diversity in teleosts provides an excellent model for studying mechanisms controlling fate specification of distinct cell types. Zebrafish have three types of pigment cells (melanocytes, iridophores and xanthophores) while medaka have four (three shared with zebrafish, plus leucophores), raising questions about how conserved mechanisms of fate specification of each pigment cell type are in these fish. We have previously shown that the Sry-related transcription factor Sox10 is crucial for fate specification of pigment cells in zebrafish, and that Sox5 promotes xanthophores and represses leucophores in a shared xanthophore/leucophore progenitor in medaka. Employing TILLING, TALEN and CRISPR/Cas9 technologies, we generated medaka and zebrafish sox5 and sox10 mutants and conducted comparative analyses of their compound mutant phenotypes. We show that specification of all pigment cells, except leucophores, is dependent on Sox10. Loss of Sox5 in Sox10-defective fish partially rescued the formation of all pigment cells in zebrafish, and melanocytes and iridophores in medaka, suggesting that Sox5 represses Sox10-dependent formation of these pigment cells, similar to their interaction in mammalian melanocyte specification. In contrast, in medaka, loss of Sox10 acts cooperatively with Sox5, enhancing both xanthophore reduction and leucophore increase in sox5 mutants. Misexpression of Sox5 in the xanthophore/leucophore progenitors increased xanthophores and reduced leucophores in medaka. Thus, the mode of Sox5 function in xanthophore specification differs between medaka (promoting) and zebrafish (repressing), which is also the case in adult fish. Our findings reveal surprising diversity in even the mode of the interactions between Sox5 and Sox10 governing specification of pigment cell types in medaka and zebrafish, and suggest that this is related to the evolution of a fourth pigment cell type.

How individual cell fates become specified from multipotent progenitors is a fundamental question in developmental and stem cell biology. Body pigment cells derive from a multipotent progenitor, but while in zebrafish there are three types of pigment cells (melanocytes, iridophores and xanthophores), in medaka these progenitors form four (as zebrafish, plus leucophores). Here, we address whether mechanisms generating each cell-type are conserved between the two species. We focus on two key regulatory proteins, Sox5 and Sox10, which we previously showed were involved in pigment cell development in medaka and zebrafish, respectively. We compare experimentally how the two proteins interact in regulating development of each of the pigment cell lineages in these fish. We show that development of all pigment cells, except leucophores, is dependent on Sox10, and that Sox5 modulates Sox10 activity antagonistically in all pigment cells in zebrafish, and melanocytes and iridophores in medaka. Surprisingly, in medaka, Sox5 acts co-operatively with Sox10 to promote xanthophore fate and to repress leucophore fate. Our findings reveal surprising diversity how Sox5 and Sox10 interact to govern pigment cell development in medaka and zebrafish, and suggest that this likely relates to the evolution of the novel leucophore pigment cell type in medaka.

Nfix Induces a Switch in Sox6 Transcriptional Activity to Regulate MyHC-I Expression in Fetal Muscle

Sox6 belongs to the Sox gene family and plays a pivotal role in fiber type differentiation, suppressing transcription of slow-fiber-specific genes during fetal development. Here, we show that Sox6 plays opposite roles in MyHC-I regulation, acting as a positive and negative regulator of MyHC-I expression during embryonic and fetal myogenesis, respectively. During embryonic myogenesis, Sox6 positively regulates MyHC-I via transcriptional activation of Mef2C, whereas during fetal myogenesis, Sox6 requires and cooperates with the transcription factor Nfix in repressing MyHC-I expression. Mechanistically, Nfix is necessary for Sox6 binding to the MyHC-I promoter and thus for Sox6 repressive function, revealing a key role for Nfix in driving Sox6 activity. This feature is evolutionarily conserved, since the orthologs Nfixa and Sox6 contribute to repression of the slow-twitch phenotype in zebrafish embryos. These data demonstrate functional cooperation between Sox6 and Nfix in regulating MyHC-I expression during prenatal muscle development.

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Sox6 has opposite roles in MyHC-I regulation during embryonic and fetal myogenesis

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In embryonic muscle, Sox6 enhances MyHC-I expression via regulation of Mef2C

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In fetal muscle, Nfix is required for Sox6-mediated repression of MyHC-I

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The Sox6 and Nfixa orthologs cooperate in repressing smyhc1 in zebrafish

Comparison of Four Protocols to Generate Chondrocyte-Like Cells from Human Induced Pluripotent Stem Cells (hiPSCs)

Stem cells (SCs) are a promising approach to regenerative medicine, with the potential to treat numerous orthopedic disorders, including osteo-degenerative diseases. The development of human-induced pluripotent stem cells (hiPSCs) has increased the potential of SCs for new treatments. However, current methods of differentiating hiPSCs into chondrocyte-like cells are suboptimal and better methods are needed. The aim of the present study was to assess four different chondrogenic differentiation protocols to identify the most efficient method of generating hiPSC-derived chondrocytes. For this study, hiPSCs were obtained from primary human dermal fibroblasts (PHDFs) and differentiated into chondrocyte-like cells using four different protocols: 1) monolayer culture with defined growth factors (GF); 2) embryoid bodies (EBs) in a chondrogenic medium with TGF-β3 cells; 3) EBs in chondrogenic medium conditioned with human chondrocytes (HC-402-05a cell line) and 4) EBs in chondrogenic medium conditioned with human chondrocytes and supplemented with TGF-β3. The cells obtained through these four protocols were evaluated and compared at the mRNA and protein levels. Although chondrogenic differentiation of hiPSCs was successfully achieved with all of these protocols, the two fastest and most cost-effective methods were the monolayer culture with GFs and the medium conditioned with human chondrocytes. Both of these methods are superior to other available techniques. The main advantage of the conditioned medium is that the technique is relatively simple and inexpensive while the directed method (i.e., monolayer culture with GFs) is faster than any protocol described to date because it is does not require additional steps such as EB formation.

MiR-146b is down-regulated during the chondrogenic differentiation of human bone marrow derived skeletal stem cells and up-regulated in osteoarthritis

Articular cartilage injury can result in chondrocyte loss and diminishment of specialised extracellular matrix, which can progress to an osteoarthritic (OA) phenotype. Stem cells have emerged as a favourable approach for articular cartilage regeneration. Identification of miRNAs which influence stem cell fate offers new approaches for application of miRNAs to regenerate articular cartilage. Skeletal stem cells (SSCs) isolated from human bone marrow were cultured as high density micromass' using TGF-β3 to induce chondrogenesis. qPCR and TaqMan qPCR were used to assess chondrogenic gene and miRNA expression. Target prediction algorithms identified potential targets of miR-146b. Transient transfection with miR-146b mimic and western blotting was used to analyse SOX5. Human OA articular chondrocytes were examined for miR-146b expression. Chondrogenic differentiation of human bone marrow derived SSCs resulted in significant down-regulation of miR-146b. Gain of miR-146b function resulted in down-regulation of SOX5. MiR-146b expression was up-regulated in OA chondrocytes. These findings demonstrate the functional role of miR-146b in the chondrogenic differentiation of human bone marrow derived SSCs. MiR-146b may play a role in the pathophysiology of OA. Application of miR-146b combined with stem cell therapy could enhance regeneration of cartilaginous tissue and serve as a potential therapeutic target in the treatment of OA.

SOX6 gene polymorphism (rs16933090) and markers of subclinical atherosclerosis in patients with type 2 diabetes mellitus

BACKGROUND

The present study was designed to investigate the association between the polymorphism of the SOX6 gene (rs16933090) and subclinical markers of carotid atherosclerosis, such as carotid intima media thickness (CIMT), the number of affected segments of carotid arteries and the sum of plaque thickness in patients with type 2 diabetes mellitus (T2DM). The second aim of the study was to demonstrate an association between the rs16933090 and subclinical markers of coronary artery disease in the same subset of patients with T2DM.

METHODS

A total of 595 T2DM subjects were enrolled in the cross-sectional study. Markers of carotid atherosclerosis were assessed by ultrasonography. Additionally, in a subset of subjects with T2DM a coronary computed tomography angiography (CCTA) was performed for diagnostic purposes. Genotyping of SOX6 gene (rs16933090) was performed using KASPar assays.

RESULTS

In our study we demonstrated the effect of the rs16933090 on coronary calcium score obtained at CCTA, whereas we did not demonstrate any association between the tested polymorphism (rs16933090) and the presence of more than 50% stenotic lesions in coronary arteries, the sum of plaque thickness, the number of involved carotid segments, high-sensitivity C-reactive protein, the presence of carotid plaques, and the presence of unstable carotid plaques.

CONCLUSIONS

In our study, we demonstrated the effect of the rs16933090 on coronary calcium score obtained at CCTA, whereas we did not demonstrate an important effect of the rs16933090 on either subclinical markers of carotid atherosclerosis or the presence of more than 50% stenotic lesions in coronary arteries in Caucasians with T2DM. We presume that the rs16933090 plays a minor role in the development of subclinical atherosclerosis in subjects with T2DM.

Transcriptome Dynamics and Potential Roles of Sox6 in the Postnatal Heart

The postnatal heart undergoes highly coordinated developmental processes culminating in the complex physiologic properties of the adult heart. The molecular mechanisms of postnatal heart development remain largely unexplored despite their important clinical implications. To gain an integrated view of the dynamic changes in gene expression during postnatal heart development at the organ level, time-series transcriptome analyses of the postnatal hearts of neonatal through adult mice (P1, P7, P14, P30, and P60) were performed using a newly developed bioinformatics pipeline. We identified functional gene clusters by principal component analysis with self-organizing map clustering which revealed organized, discrete gene expression patterns corresponding to biological functions associated with the neonatal, juvenile and adult stages of postnatal heart development. Using weighted gene co-expression network analysis with bootstrap inference for each of these functional gene clusters, highly robust hub genes were identified which likely play key roles in regulating expression of co-expressed, functionally linked genes. Additionally, motivated by the role of the transcription factor Sox6 in the functional maturation of skeletal muscle, the role of Sox6 in the postnatal maturation of cardiac muscle was investigated. Differentially expressed transcriptome analyses between Sox6 knockout (KO) and control hearts uncovered significant upregulation of genes involved in cell proliferation at postnatal day 7 (P7) in the Sox6 KO heart. This result was validated by detecting mitotically active cells in the P7 Sox6 KO heart. The current report provides a framework for the complex molecular processes of postnatal heart development, thus enabling systematic dissection of the developmental regression observed in the stressed and failing adult heart.

Altered mRNA Splicing, Chondrocyte Gene Expression and Abnormal Skeletal Development due to SF3B4 Mutations in Rodriguez Acrofacial Dysostosis

The acrofacial dysostoses (AFD) are a genetically heterogeneous group of inherited disorders with craniofacial and limb abnormalities. Rodriguez syndrome is a severe, usually perinatal lethal AFD, characterized by severe retrognathia, oligodactyly and lower limb abnormalities. Rodriguez syndrome has been proposed to be a severe form of Nager syndrome, a non-lethal AFD that results from mutations in SF3B4, a component of the U2 small nuclear ribonucleoprotein particle (U2 snRNP). Furthermore, a case with a phenotype intermediate between Rodriguez and Nager syndromes has been shown to have an SF3B4 mutation. We identified heterozygosity for SF3B4 mutations in Rodriguez syndrome, confirming that the phenotype is a dominant disorder that is allelic with Nager syndrome. The mutations led to reduced SF3B4 synthesis and defects in mRNA splicing, primarily exon skipping. The mutations also led to reduced expression in growth plate chondrocytes of target genes, including the DLX5, DLX6, SOX9, and SOX6 transcription factor genes, which are known to be important for skeletal development. These data provide mechanistic insight toward understanding how SF3B4 mutations lead to the skeletal abnormalities observed in the acrofacial dysostoses.

The acrofacial dysostoses (AFD) are inherited disorders with abnormalities of the facial and limb bones. Rodriguez syndrome is a severe type of AFD that is usually lethal in the immediate perinatal period. Rodriguez syndrome has been proposed to be a severe form of Nager syndrome, a non-lethal AFD that results from mutations in SF3B4, a component of mRNA splicing machinery needed for proper maturation of primary transcripts. Furthermore, a case with a phenotype intermediate between Rodriguez and Nager syndromes has been shown to have an SF3B4 mutation. We found that mutations in SF3B4 produce Rodriguez syndrome, further demonstrating that it is allelic with Nager syndrome. The consequences of the mutations include abnormal splicing and reduced expression in growth plate chondrocytes of genes that are important for proper development of the skeleton, providing mechanistic insight toward understanding how SF3B4 mutations lead to the skeletal abnormalities observed in the acrofacial dysostoses.

MiR-132-3p Regulates the Osteogenic Differentiation of Thoracic Ligamentum Flavum Cells by Inhibiting Multiple Osteogenesis-Related Genes

Ossification of the ligamentum flavum (OLF) is a disorder of heterotopic ossification of spinal ligaments and is the main cause of thoracic spinal canal stenosis. Previous studies suggested that miR-132-3p negatively regulates osteoblast differentiation. However, whether miR-132-3p is involved in the process of OLF has not been investigated. In this study, we investigated the effect of miR-132-3p and its target genes forkhead box O1 (FOXO1), growth differentiation factor 5 (GDF5) and SRY-box 6 (SOX6) on the osteogenic differentiation of ligamentum flavum (LF) cells. We demonstrated that miR-132-3p was down-regulated during the osteogenic differentiation of LF cells and negatively regulated the osteoblast differentiation. Further, miR-132-3p targeted FOXO1, GDF5 and SOX6 and down-regulated the protein expression of these genes. Meanwhile, FOXO1, GDF5 and SOX6 were up-regulated after osteogenic differentiation and the down-regulation of endogenous FOXO1, GDF5 or SOX6 suppressed the osteogenic differentiation of LF cells. In addition, we also found FOXO1, GDF5 and SOX6 expression in the ossification front of OLF samples. Overall, these results suggest that miR-132-3p inhibits the osteogenic differentiation of LF cells by targeting FOXO1, GDF5 and SOX6.

MicroRNA-21a-5p Functions on the Regulation of Melanogenesis by Targeting Sox5 in Mouse Skin Melanocytes

MicroRNAs (miRNAs) play an important role in regulating almost all biological processes. miRNAs bind to the 3′ untranslated region (UTR) of mRNAs by sequence matching. In a previous study, we demonstrated that miR-21 was differently expressed in alpaca skin with different hair color. However, the molecular and cellular mechanisms for miR-21 to regulate the coat color are not yet completely understood. In this study, we transfected miR-21a-5p into mouse melanocytes and demonstrated its function on melanogenesis of miR-21a-5p by targeting Sox5, which inhibits melanogenesis in mouse melanocytes. The results suggested that miR-21a-5p targeted Sox5 gene based on the binding site in 3′ UTR of Sox5 and overexpression of miR-21a-5p significantly down-regulated Sox5 mRNA and protein expression. Meanwhile, mRNA and protein expression of microphthalmia transcription factor (MITF) and Tyrosinase (TYR) were up-regulated, which subsequently make the melanin production in melanocytes increased. The results suggest that miR-21a-5p regulates melanogenesis via MITF by targeting Sox5.

[Microdeletion 12p12 involving SOX5 gene: a new syndrome with developmental delay]

INTRODUCTION

The SOX5 gene encodes a transcription factor involved in the regulation of chondrogenesis and the development of the nervous system.

CASE REPORT

We report a 10 years-old girl with developmental delay, behavior problems and dysmorphic features of this new syndrome with developmental delay. She had a 12p12 deletion involving SOX5.

CONCLUSIONS

We review the reported cases, intragenic SOX5 deletions and larger 12p12 deletions encompassing SOX5. We analyze the genotype-phenotype associations and the genes involved in our patient.

Sox5 functions as a fate switch in medaka pigment cell development

Mechanisms generating diverse cell types from multipotent progenitors are crucial for normal development. Neural crest cells (NCCs) are multipotent stem cells that give rise to numerous cell-types, including pigment cells. Medaka has four types of NCC-derived pigment cells (xanthophores, leucophores, melanophores and iridophores), making medaka pigment cell development an excellent model for studying the mechanisms controlling specification of distinct cell types from a multipotent progenitor. Medaka many leucophores-3 (ml-3) mutant embryos exhibit a unique phenotype characterized by excessive formation of leucophores and absence of xanthophores. We show that ml-3 encodes sox5, which is expressed in premigratory NCCs and differentiating xanthophores. Cell transplantation studies reveal a cell-autonomous role of sox5 in the xanthophore lineage. pax7a is expressed in NCCs and required for both xanthophore and leucophore lineages; we demonstrate that Sox5 functions downstream of Pax7a. We propose a model in which multipotent NCCs first give rise to pax7a-positive partially fate-restricted intermediate progenitors for xanthophores and leucophores; some of these progenitors then express sox5, and as a result of Sox5 action develop into xanthophores. Our results provide the first demonstration that Sox5 can function as a molecular switch driving specification of a specific cell-fate (xanthophore) from a partially-restricted, but still multipotent, progenitor (the shared xanthophore-leucophore progenitor).

How individual cell fates are specified from multipotent progenitor cells is a fundamental question in developmental and stem cell biology. Accumulating evidence indicates that stem cells develop into each of their final, diverse cell-types after progression through one or more partially-restricted intermediates, but the molecular mechanisms underlying final fate choice are largely unknown. Neural crest cells (NCCs) give rise to diverse cell-types including multiple pigment cells and thus are a favored model for understanding the mechanism of fate specification. We have investigated how a specific fate choice is made from partially-restricted pigment cell progenitors in medaka. We show that Sry-related transcription factor Sox5 is required for fate determination between yellow xanthophore and white leucophore, and its loss causes excessive formation of leucophores and absence of xanthophores. We demonstrate that Sox5 functions cell-autonomously in the xanthophore lineage in medaka. Furthermore, pax7a is expressed in the partially-restricted progenitor cells shared with xanthophore and leucophore lineages, and Sox5 acts in some of these cells to promote xanthophore lineage. Our work reveals the role of Sox5 as a molecular switch determining xanthophore versus leucophore fate choice from the shared progenitor, and identifies an important mechanism regulating pigment cell fate choice from NCCs.

Regulation of Sox6 by cyclin dependent kinase 5 in brain

Cyclin dependent kinase 5 (Cdk5) is a proline-directed Ser/Thr kinase involved in various biological functions during normal brain development and neurodegeneration. In brain, Cdk5 activity is specific to post-mitotic neurons, due to neuronal specific expression of its activator p35. The biological functions of Cdk5 have been ascribed to its cytoplasmic substrates, however not much is known in nucleus. Here, we show that nuclear transcription factor Sox6 is a direct nuclear target of Cdk5. Sox6 is expressed in Tuj1 positive neurons, suggesting that Sox6 is expressed in differentiating neurons. The expression of Sox6 is high in mitotic nuclei during embryonic day 12 (E12) and gradually decreases during development into adult. On the other hand, Cdk5 expression gradually increases during its development. We show that Sox6 is expressed in mitotic nuclei in embryonic day 12 (E12) and in migrating neurons of E16. Sox6 is phosphorylated in vivo. Sox6 was detected by phospho-Ser/Thr and phospho-Ser/Thr-Pro and MPM-2 (Mitotic protein #2) antibodies in brain. Furthermore, calf intestinal alkaline phosphatase (CIAP) digestion resulted in faster migration of Sox6 band. The GST-Sox6 was phosphorylated by Cdk5/p35. The mass spectrometry analysis revealed that Sox6 is phosphorylated at T119PER motif. We show that Sox6 steady state levels are regulated by Cdk5. Cdk5 knockout mice die in utero and Sox6 protein expression is remarkably high in Cdk5-/- brain, however, there is no change in mRNA expression, suggesting a post-translational regulation of Sox6 by Cdk5. Transfection of primary cortical neurons with WT Cdk5 reduced Sox6 levels, while dominant negative (DN) Cdk5 and p35 increased Sox6 levels. Thus, our results indicate that Cdk5 regulates Sox6 steady state protein level that has an important role in brain development and function.

Association of osteoporosis susceptibility genes with bone mineral density and bone metabolism related markers in Koreans: the Chungju Metabolic Disease Cohort (CMC) study

In this study, we evaluated the association between bone mineral density (BMD) and 10 single-nucleotide polymorphisms (SNPs) within eight osteoporosis susceptibility genes that were previously identified in genome-wide association studies (GWASs). A total of 494 men and 493 postmenopausal women participating in the Chungju Metabolic Disease cohort study in Korea were included. The following 10 SNPs were genotyped: ZBTB40 rs6426749, MEF2C rs1366594, ESR1 rs2941740, TNFRSF11B rs3134070, TNFRSF11B rs2073617, SOX6 rs711785, LRP5 rs599083, TNFSF11 rs227438, TNFSF11 rs9594782, and FOXL1 rs10048146; and the association between these SNPs and bone metabolism-related markers was assessed. Two SNPs, TNFSF11 rs2277438 and FOXL1 rs1004816, were associated with lumbar spine BMD. TNFSF11 rs2277438 in men and SOX6 rs7117858 and FOXL1 rs10048146 in postmenopausal women were found to be associated with lumbar BMD. ZBTB40 rs6426749, MEF2C rs1366594, and LRP5 rs599083 showed significant associations with femur neck BMD. These three SNPs in men and MEF2C rs1366594 and ESR1 rs2941740 in postmenopausal women were associated with femur neck BMD. A significant association between MEF2C rs1366594 and serum calcium levels was observed in men. Serum phosphorus levels were related to SOX6 rs7117858. Serum PTH levels were significantly associated with TNFRSF11B rs3134070 in men, and SOX6 rs711858 in postmenopausal women. In conclusion, our study independently confirmed associations between several SNPs: ZBTB40, MEF2C, ESR1, SOX6, LRP5, TNFSF11, and FOXL1 and bone marrow density in the Korean population.

Sox6 up-regulation by macrophage migration inhibitory factor promotes survival and maintenance of mouse neural stem/progenitor cells

Macrophage migration inhibitory factor (MIF) has important roles in supporting the proliferation and/or survival of murine neural stem/progenitor cells (NSPCs), but downstream effectors remain unknown. We show here that MIF robustly increases the expression of Sox6 in NSPCs in vitro. During neural development, Sox6 is expressed in the ventricular zone of the ganglionic eminence (GE) of mouse brains at embryonic day 14.5 (E14.5), cultured NSPCs from E14.5 GE, and NSPCs in the subventricular zone (SVZ) around the lateral ventricle (LV) of the adult mouse forebrain. Retroviral overexpression of Sox6 in NSPCs increases the number of primary and secondary neurospheres and inhibits cell differentiation. This effect is accompanied with increased expression of Hes1 and Bcl-2 and Akt phosphorylation, thus suggesting a role for Sox6 in promoting cell survival and/or self-renewal ability. Constitutive activation of the transcription factor Stat3 results in up-regulation of Sox6 expression and chromatin immunoprecipitation analysis showed that MIF increases Stat3 binding to the Sox6 promoter in NSPCs, indicating that Stat3 stimulates Sox6 expression downstream of MIF. Finally, the ability of MIF to increase the number of primary and secondary neurospheres is inhibited by Sox6 gene silencing. Collectively, our data identify Sox6 as an important downstream effector of MIF signaling in stemness maintenance of NSPCs.

MiR-499 regulates cell proliferation and apoptosis during late-stage cardiac differentiation via Sox6 and cyclin D1

Background

MiR-499 is a cardiac-abundant miRNA. However, the biological functions of miR-499 in differentiated cardiomyocytes or in the cardiomyocyte differentiation process is not very clear. Sox6 is believed to be one of its targets, and is also believed to play a role in cardiac differentiation. Therefore, our aim was to investigate the association between Sox6 and miR-499 during cardiac differentiation.

Methodology/Principal Findings

Using a well-established invitro cardiomyocyte differentiation system, mouse P19CL6 cells, we found that miR-499 was highly expressed in the late stage of cardiac differentiation. In cells stably transfected with miR-499 (P-499 cells), it was found that miR-499 could promote the differentiation into cardiomyocytes at the early stage of cardiac differentiation. Notably, cell viability assay, EdU incorporation assay, and cell cycle profile analysis all showed that the P-499 cells displayed the distinctive feature of hyperplastic growth. Further investigation confirmed that miR-499 could promote neonatal rat cardiomyocyte proliferation. MiR-499 knock-down enhanced apoptosis in the late differentiation stage in P19CL6 cells, but overexpression of miR-499 resulted in a decrease in the apoptosis rate. Sox6 was identified as a direct target of miR-499 and its expression was detected from day 8 or day 10 of cardiac differentiation of P19CL6 cells. Sox6 played a role in cell viability, inhibited cell proliferation and promoted cell apoptosis in P19CL6 cells and cardiomyocytes. The overexpression of Sox6 could reverse the proliferation and anti-apoptosis effects of miR-499. It was also found that miR-499 might exert its function by regulating cyclin D1 via its influence on Sox6.

Conclusions/Significance

miR-499 probably regulates the proliferation and apoptosis of P19CL6 cells in the late stage of cardiac differentiation via its effects on Sox6 and cyclin D1.

A comparison of brain gene expression levels in domesticated and wild animals

Domestication has led to similar changes in morphology and behavior in several animal species, raising the question whether similarities between different domestication events also exist at the molecular level. We used mRNA sequencing to analyze genome-wide gene expression patterns in brain frontal cortex in three pairs of domesticated and wild species (dogs and wolves, pigs and wild boars, and domesticated and wild rabbits). We compared the expression differences with those between domesticated guinea pigs and a distant wild relative (Cavia aperea) as well as between two lines of rats selected for tameness or aggression towards humans. There were few gene expression differences between domesticated and wild dogs, pigs, and rabbits (30-75 genes (less than 1%) of expressed genes were differentially expressed), while guinea pigs and C. aperea differed more strongly. Almost no overlap was found between the genes with differential expression in the different domestication events. In addition, joint analyses of all domesticated and wild samples provided only suggestive evidence for the existence of a small group of genes that changed their expression in a similar fashion in different domesticated species. The most extreme of these shared expression changes include up-regulation in domesticates of SOX6 and PROM1, two modulators of brain development. There was almost no overlap between gene expression in domesticated animals and the tame and aggressive rats. However, two of the genes with the strongest expression differences between the rats (DLL3 and DHDH) were located in a genomic region associated with tameness and aggression, suggesting a role in influencing tameness. In summary, the majority of brain gene expression changes in domesticated animals are specific to the given domestication event, suggesting that the causative variants of behavioral domestication traits may likewise be different.

The Rose-comb mutation in chickens constitutes a structural rearrangement causing both altered comb morphology and defective sperm motility

Rose-comb, a classical monogenic trait of chickens, is characterized by a drastically altered comb morphology compared to the single-combed wild-type. Here we show that Rose-comb is caused by a 7.4 Mb inversion on chromosome 7 and that a second Rose-comb allele arose by unequal crossing over between a Rose-comb and wild-type chromosome. The comb phenotype is caused by the relocalization of the MNR2 homeodomain protein gene leading to transient ectopic expression of MNR2 during comb development. We also provide a molecular explanation for the first example of epistatic interaction reported by Bateson and Punnett 104 years ago, namely that walnut-comb is caused by the combined effects of the Rose-comb and Pea-comb alleles. Transient ectopic expression of MNR2 and SOX5 (causing the Pea-comb phenotype) occurs in the same population of mesenchymal cells and with at least partially overlapping expression in individual cells in the comb primordium. Rose-comb has pleiotropic effects, as homozygosity in males has been associated with poor sperm motility. We postulate that this is caused by the disruption of the CCDC108 gene located at one of the inversion breakpoints. CCDC108 is a poorly characterized protein, but it contains a MSP (major sperm protein) domain and is expressed in testis. The study illustrates several characteristic features of the genetic diversity present in domestic animals, including the evolution of alleles by two or more consecutive mutations and the fact that structural changes have contributed to fast phenotypic evolution.

Genetic variants in the SOX6 gene are associated with bone mineral density in both Caucasian and Chinese populations

SUMMARY

Given the biological function of SOX6 and recent genome-wide association finding, we performed a fine-mapping association analyses to investigate the relationship between SOX6 and BMD both in Caucasian and Chinese populations. We identified many single-nucleotide polymorphisms (SNPs) within or near the SOX6 gene to be significantly associated with hip bone mineral density (BMD).

INTRODUCTION

SOX6 gene is an essential transcription factor in chondrogenesis and cartilage formation. Recent genome-wide association studies (GWAS) detected a SNP (rs7117858) located at the downstream of SOX6 significantly associated with hip BMD.

METHODS

Given the biological function of SOX6 and the GWAS finding, we considered SOX6 as a new candidate for BMD and osteoporosis. Therefore, in this study, we performed a fine-mapping association analyses to investigate the relationship between SNPs within and near the SOX6 gene and BMD at both hip and spine. A total of 301 SNPs were tested in two independent US Caucasian populations (2,286 and 1,000 unrelated subjects, respectively) and a Chinese population (1,627 unrelated Han subjects).

RESULTS

We confirmed that the previously reported rs7117858-A was associated with reduced hip BMD, with combined P value of 2.45 × 10(-4). Besides this SNP, we identified another 19 SNPs within or near the SOX6 gene to be significantly associated with hip BMD after false discovery rate adjustment. The most significant SNP was rs1347677 located at the intron 3 (P = 3.15 × 10(-7)). Seven additional SNPs in high linkage disequilibrium with rs1347677 were also significantly associated with hip BMD. SNPs in SOX6 showed significant skeletal site specificity since no SNP was detected to be associated with spine BMD.

CONCLUSION

Our study identified many SNPs in the SOX6 gene associated with hip BMD even across different ethnicities, which further highlighted the importance of the SOX6 gene influencing BMD variation and provided more information to the understanding of the genetic architecture of osteoporosis.