SOX9 gene shows association with adolescent idiopathic scoliosis predisposition in Northwest Indians

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is a common structural deformity of the spine affecting adolescent individuals globally. The disorder is polygenic and is accompanied by the association of various genetic loci. Genetic studies in Chinese and Japanese populations have shown the association of genetic variants of SOX9 with AIS curve severity. However, no genetic study evaluating the association of SRY-Box Transcription Factor 9 (SOX9) variants with AIS predisposition has been conducted in any Indian population. Thus, we aimed to investigate the association of the genetic variants of the SOX9 along with 0.88 Mb upstream region with AIS susceptibility in the population of Northwest India.

METHODS

In total, 113 AIS cases and 500 non-AIS controls were recruited from the population of Northwest India in the study and screened for 155 genetic variants across the SOX9 gene and 0.88 Mb upstream region of the gene using Global Screening Array-24 v3.0 chip (Illumina). The statistical significance of the Bonferroni threshold was set at 0.000322.

RESULT

The results showed the association of 11 newly identified variants; rs9302936, rs7210997, rs77736349, rs12940821, rs9302937, rs77447012, rs8071904, rs74898711, rs9900249, rs2430514, and rs1042667 with the AIS susceptibility in the studied population. Only one variant, rs2430514, was inversely associated with AIS in the population, while the ten variants were associated with the AIS risk. Moreover, 47 variants clustered in the gene desert region of the SOX9 gene were associated at a p-value ≤ 0.05.

CONCLUSION

The present study is the first to demonstrate the association of SOX9 enhancer locus variants with AIS in any South Asian Indian population. The results are interesting as rs1042667, a 3' untranslated region (UTR) variant in the exon 3 and upstream variants of the SOX9 gene, were associated with AIS susceptibility in the Northwest Indian population. This provides evidence that the variants in the enhancer region of SOX9 might regulate its gene expression, thus leading to AIS pathology and might act as an important gene for AIS susceptibility.

Time dependent impact of reactive oxidants on seminal attributes, mitochondrial membrane potential, lipid peroxidation and capacitation-like changes of Karan-Fries bulls during cryopreservation

BACKGROUND

Cryopreservation of semen is a valuable technique; however, it is also known to be detrimental to the structure of spermatozoa and fertility due to cryo-injury and subsequent generation of reactive oxidants.

OBJECTIVE

To determine the time-dependent impact of reactive oxidants on seminal attributes, mitochondrial membrane potential (MMP), lipid peroxidation status (LPO) and early capacitation like changes.

MATERIALS AND METHODS

Semen samples were collected by artificial vagina technique from six Karan-Fries (KF) bulls and subsequently examined at 0 h (before cryopreservation) and at 24 hours, 15 days and 2-months of storage for various seminal attributes, MMP, and early capacitation-like changes. Simultaneously, LPO (TBARS) was determined in fresh and post-thaw seminal plasma.

RESULTS

A sharp decrease (P < 0.01) in semen quality was observed only after 24 h of cryopreservation except for viability and acrosomal integrity. Sperm viability and acrosome integrity reduced significantly up to 2 months of cryopreservation. The lipid peroxidation status was found to be lower in fresh seminal plasma (2.6 ±0.2 vs. 3.5 ± 0.3 units/mL) as compared to post-thaw. Furthermore, the active MMP of fresh semen showed a significant (P < 0.01) decrease after 24 hours (77.9 ± 0.4 vs. 54.5 ±0.3%) of cryopreservation, while there was a non-significant decrease in active MMP after 15 d and 2-months (53.7 ± 0.1 and 52.8 ± 0.2%). Moreover, significant (P. < 0.01) early capacitation-like changes were found in post-thaw spermatozoa (25.7 ± 0.1 vs. 9.1 ± 0.2%) as compared to fresh ejaculate.

CONCLUSION

Spermatozoa incur the majority of damages during the early phase of cryopreservation, however the damage associated by different stressors cannot be neglected. doi.org/10.54680/fr22410110212.

Autosomal Dominant Polycystic Kidney Disease: Presence of Hypomorphic Alleles in PKD1 Gene

Autosomal dominant polycystic kidney disease is characterized by multiple cysts in both kidneys manifesting in adult life. In general, the disorder is caused by a pathogenic variant in one allele of PKD1 or PKD2 genes, while the other allele is normal. Pathogenic variants in both the alleles are rare and have variable phenotypes, from lethal or perinatal presentation to a mild form in later adulthood, depending on the type of variant. Here, we describe a proband with two variants (p.Thr1773Ile and p.Ala1871Thr in trans) in PKD1 gene, who presented with disease at age 24 years. Both the parents and one brother had a variant in one allele, the other being wild type only and had normal ultrasound findings. Segregation studies suggest that both the variants may act as “hypomorphic” or “incompletely penetrant” alleles and acting together resulted in haploinsufficiency of protein PC1 in renal cells, leading to cystogenesis in the proband. The consequences of the presence of two hypomorphic variants have been poorly documented in literature. We reviewed the few published cases having two hypomorphic variants and the data conform to the conclusions that we reached by study of the family described. It is emphasized that to resolve the significance of suspected hypomorphic variants, segregation studies in the parents and siblings are essential.

LoCa LoPa myelopathy: is prevention better than cure?

Manifestations of primary hypoparathyroidism are produced by neuromuscular irritability or by extraosseous calcifications. We present a patient of primary hypoparathyroidism who had extensive calcification of brain parenchyma, and was suffering from chronic, generalised and progressive stiffness of body due to cervical compressive myelopathy, caused by calcification of posterior longitudinal ligament and ligamentum flavum. By presenting this case we wanted to emphasize the usefulness of meticulous clinical examination to differentiate the stiffness caused by myelopathy from that which is caused by possible coexisting extrapyramidal disorder. This case presentation also builds the hypothesis that early diagnosis and institution of early and appropriate treatment has potential to prevent the complications arising from extraosseous calcifications in patients with primary hypoparathyroidism.

Effects of FSH and LH on steroid production by buffalo (Bubalus bubalis) granulosa cells cultured in vitro under serum-free conditions

The objective of this study was to examine the effects of FSH and LH on oestradiol-17β and progesterone production by buffalo granulosa cells cultured under serum-free conditions. Granulosa cells (3 × 10(5) ) from small (≤ 5 mm diameter) follicles were cultured for up to 4 days in 48-well plates coated with 3.3 μg/cm(2) fibronectin in Dulbecco's modified Eagle's medium (DMEM) : nutrient mixture F-12 Ham (1 : 1 ratio) supplemented with 10(-7) m androstenedione, 5 μg/ml human apo-transferrin and 0.1% bovine serum albumin, in the presence or absence of FSH or LH (0, 1, 2, 4, 8, 16, 32 or 64 ng/ml each). Basal oestradiol-17β production by granulosa cells from small follicles reduced (p < 0.01) from days 1 to 2 of culture and became undetectable by day 3 and basal progesterone production increased (p < 0.05) from day 1 through day 4 of the culture. Although there was no effect of FSH on day 1 of the culture, FSH at 2, 4, 8 and 16 ng/ml increased (p < 0.05) oestradiol-17β production by granulosa cells from small follicles on day 2. Progesterone secretion was increased (p < 0.05) by all doses of FSH on all days of culture. All doses of LH had no effect on oestradiol-17β or progesterone production by granulosa cells from small follicles on any day of the culture. The results of this study demonstrate a serum-free culture system for buffalo granulosa cells and stimulatory effect of FSH but not LH on steroid hormone production by buffalo granulosa cells under these conditions.

"Toxic" beef bone soup

Hypercalcaemia is most commonly caused by primary hyperparathyroidism or malignancy. Vitamin D intoxication, also a cause of hypercalcaemia, is mostly caused by excessive administration of vitamin D-containing medications and excessive intake of foods fortified with vitamin D. We present a young cricketer, with recurrent vomiting due to hypercalcaemia and hypervitaminosis D, who used to drink large volumes of soup prepared by boiling long beef bones, for many months. This case presentation highlights the importance of in-depth dietary history for arriving at proper diagnosis.

Telomeres, histone code, and DNA damage response

Genomic stability is maintained by telomeres, the end terminal structures that protect chromosomes from fusion or degradation. Shortening or loss of telomeric repeats or altered telomere chromatin structure is correlated with telomere dysfunction such as chromosome end-to-end associations that could lead to genomic instability and gene amplification. The structure at the end of telomeres is such that its DNA differs from DNA double strand breaks (DSBs) to avoid nonhomologous end-joining (NHEJ), which is accomplished by forming a unique higher order nucleoprotein structure. Telomeres are attached to the nuclear matrix and have a unique chromatin structure. Whether this special structure is maintained by specific chromatin changes is yet to be thoroughly investigated. Chromatin modifications implicated in transcriptional regulation are thought to be the result of a code on the histone proteins (histone code). This code, involving phosphorylation, acetylation, methylation, ubiquitylation, and sumoylation of histones, is believed to regulate chromatin accessibility either by disrupting chromatin contacts or by recruiting non-histone proteins to chromatin. The histone code in which distinct histone tail-protein interactions promote engagement may be the deciding factor for choosing specific DSB repair pathways. Recent evidence suggests that such mechanisms are involved in DNA damage detection and repair. Altered telomere chromatin structure has been linked to defective DNA damage response (DDR), and eukaryotic cells have evolved DDR mechanisms utilizing proficient DNA repair and cell cycle checkpoints in order to maintain genomic stability. Recent studies suggest that chromatin modifying factors play a critical role in the maintenance of genomic stability. This review will summarize the role of DNA damage repair proteins specifically ataxia-telangiectasia mutated (ATM) and its effectors and the telomere complex in maintaining genome stability.