Next Generation Sequencing expression profiling of mitochondrial subunits in men with Klinefelter syndrome

Humanin gene expression in subjects with Parkinson's disease

BACKGROUND

Bradykinesia, tremor, rigidity and postural instability are the hallmark of Parkinson's disease (PD). Non-motor symptoms including cognitive, behavioral, and neuropsychiatric changes, sensory and sleep disturbances that may precede the motor symptoms by years. The peculiar pathological features of PD are decreased dopaminergic neurons and dopamine levels in the substantia nigra pars compacta and pontine locus coeruleus. Humanin is produced by a small gene peptide, which is located in the mitochondria genome. Inflammation, oxidative stress, mitochondrial dysfunction and altered transcription have been recognized as causative factors of PD. This evidence has prompted many researchers to focus on studying the functions of DNA and mitochondria. The purpose of the present study was to evaluate Humanin mRNA levels in peripheral blood mononuclear cells (PBMCs) of PD subjects, compared with those in PBMCs of normal control (NC) subjects.

METHODS AND RESULTS

A total of 220 participants, including 154 PD patients (57 females and 97 males; mean age 71.54 years, SD 7.8) and 66 CN (28 females and 38 males; mean age 70.54 years, SD 9.45) were enrolled for the qRT-PCR analysis. Increased Humanin mRNA levels were found in PD samples, compared to controls.

CONCLUSION

In conclusion, the present data confirm the tendency of mitochondria to overexpress mRNA in PD, which could be a cellular attempt to reduce apoptotic damage in PD subjects. Humanin might be useful as a marker for a better diagnosis of PD, and we cannot exclude that in the future it might also play a role on prognosis and in the possible therapies for PD.

Rapidly Progressing to ESRD in an Individual with Coexisting ADPKD and Masked Klinefelter and Gitelman Syndromes

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenetic hereditary renal disease, promoting end-stage renal disease (ESRD). Klinefelter syndrome (KS) is a consequence of an extra copy of the X chromosome in males. Main symptoms in KS include hypogonadism, tall stature, azoospermia, and a risk of cardiovascular diseases, among others. Gitelman syndrome (GS) is an autosomal recessive disorder caused by SLC12A3 variants, and is associated with hypokalemia, hypomagnesemia, hypocalciuria, normal or low blood pressure, and salt loss. The three disorders have distinct and well-delineated clinical, biochemical, and genetic findings. We here report a male patient with ADPKD who developed early chronic renal failure leading to ESRD, presenting with an intracranial aneurysm and infertility. NGS identified two de novo PKD1 variants, one known (likely pathogenic), and a previously unreported variant of uncertain significance, together with two SLC12A3 pathogenic variants. In addition, cytogenetic analysis showed a 47, XXY karyotype. We investigated the putative impact of this rare association by analyzing possible clinical, biochemical, and/or genetic interactions and by comparing the evolution of renal size and function in the proband with three age-matched ADPKD (by variants in PKD1) cohorts. We hypothesize that the coexistence of these three genetic disorders may act as modifiers with possible synergistic actions that could lead, in our patient, to a rapid ADPKD progression.

In-vivo skeletal muscle mitochondrial function in Klinefelter syndrome

Klinefelter syndrome (XXY) occurs in 1 in 600 males, resulting in testosterone deficiency and a high prevalence of insulin resistance. Testosterone deficiency in men is a known cause of insulin resistance, and mitochondrial dysfunction is hypothesized to mediate this relationship. The aim of this cross-sectional study was to evaluate muscle mitochondrial function in XXY compared with male controls. Twenty-seven boys with XXY (age 14.7±1.8 years) were compared with 87 controls (age 16.9±0.9). In-vivo calf muscle mitochondrial function was assessed via phosphorus magnetic resonance spectroscopy (³¹P-MRS) following 90 s of isometric 70% maximal exercise. Multiple linear regression was used to compare ³¹P-MRS outcomes (ADP and phosphocreatine (PCr) time constants, rate of oxidative phosphorylation (Oxphos), and Q_max or the maximal mitochondrial function relative to mitochondrial density) between groups after adjusting for age differences. There were no statistically significant differences in the mitochondrial outcomes of ADP, Oxphos, PCr, and Q_max between the groups. There were also no differences in a sensitivity analysis within the XXY group by testosterone treatment status. In this study, in-vivo postexercise skeletal muscle mitochondrial function does not appear to be impaired in adolescents with XXY compared with controls and is not significantly different by testosterone treatment status in XXY.

mRNA expression profiling of mitochondrial subunits in subjects with Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) is a common adult-onset neurodegenerative disorder caused by a progressive loss of dopaminergic neurons due to the accumulation of α-synuclein in the substantia nigra. Mitochondria are known to play a key role in cell respiratory function and bioenergetics. Indeed, mitochondrial dysfunction causes insufficient energy production required to satisfy the needs of several organs, especially the nervous system. However, the profiling of messenger RNA (mRNA) expression of mitochondrial subunits in PD has not been systematically investigated yet.

MATERIAL AND METHODS

We explored the mRNA expression of mitochondrial DNA (mtDNA) encoded respiratory chain (RC) subunits in 43 PD patients and 43 normal controls (NC). Next generation sequencing analysis (NGS) was used and quantitative real-time polymerase chain reaction (qRT-PCR) assay was used for confirmation of the NGS results.

RESULTS

All tested mitochondrial RC subunits were significantly over-expressed in subjects with PD compared to NC. In qRT-PCR the mean expression of all mitochondrial subunits had an expression level of at least 7 times compared to NC.

CONCLUSIONS

The over-expression of mitochondrial subunits in PD subjects with respect to NC might be secondary to a degeneration-related alteration of the mitochondrial structure and/or dynamics, or to the occurrence of a compensatory mechanism. The study of specific mRNA by peripheral blood mononuclear cells may provide a further diagnostic frame for early detection PD patients.

SOX13 gene downregulation in peripheral blood mononuclear cells of patients with Klinefelter syndrome

Klinefelter syndrome (KS) is the most common sex chromosome disorder in men. It is characterized by germ cell loss and other variable clinical features, including autoimmunity. The sex-determining region of Y (SRY)-box 13 (Sox13) gene is expressed in mouse spermatogonia. In addition, it has been identified as islet cell autoantigen 12 (ICA12), which is involved in the pathogenesis of autoimmune diseases, including type 1 diabetes mellitus (DM) and primary biliary cirrhosis. Sox13 expression has never been investigated in patients with KS. In this age-matched, case-control study performed on ten patients with KS and ten controls, we found that SOX13 is significantly downregulated in peripheral blood mononuclear cells of patients with KS compared to controls. This finding might be consistent with the germ cell loss typical of patients with KS. However, the role of Sox13 in the pathogenesis of germ cell loss and humoral autoimmunity in patients with KS deserves to be further explored.

GPR56 gene down-regulation in patients with Klinefelter Syndrome: a candidate for infertility?

BACKGROUND

The etiology of azoospermia in patients with Klinefelter Syndrome (KS) is still unknown. The protein codified by the G protein-couple receptor 56 (GPR56) belongs to the adhesion family of G protein-coupled receptors (GPRs). Its mutations are involved in the pathogenesis of intellectual disability and, according to animal studies, infertility. As the expression of GPR56 in patients with KS has not been investigated so far, this study was undertaken with the purpose of evaluating its expression in peripheral blood mononuclear cells (PBMCs) of patients with KS and normal controls.

METHODS

This age-matched case-control study was performed in 10 patients with KS and 10 controls. Patients and controls underwent to blood sampling for next-generation sequencing (NGS) analysis, and differentially expressed mRNAs were identified using DESeq2 v.1.12. QRT-PCR was used to validate the results obtained by NGS analysis. TaqMan Gene Expression Assay primers were used to carry out the real-time PCR analysis for GPR56.

RESULTS

GPR56 was down-regulated by -2081-fold (q-value <0.05) in PBMCs of patients with KS compared to controls. NGS data were confirmed by QRT-PCR.

CONCLUSIONS

The possible contribution of the GPR56 gene down-regulation in the pathogenesis of spermatogenic failure in patients with KS is worthy to be further explored.

Integration and reanalysis of transcriptomics and methylomics data derived from blood and testis tissue of men with 47,XXY Klinefelter syndrome indicates the primary involvement of Sertoli cells in the testicular pathogenesis

Klinefelter syndrome (KS; 47,XXY) is the most common sex chromosomal anomaly and causes a multitude of symptoms. Often the most noticeable symptom is infertility caused by azoospermia with testicular histology showing hyalinization of tubules, germ cells loss, and Leydig cell hyperplasia. The germ cell loss begins early in life leading to partial hyalinization of the testis at puberty, but the mechanistic drivers behind this remain poorly understood. In this systematic review, we summarize the current knowledge on developmental changes in the cellularity of KS gonads supplemented by a comparative analysis of the fetal and adult gonadal transcriptome, and blood transcriptome and methylome of men with KS. We identified a high fraction of upregulated genes that escape X-chromosome inactivation, thus supporting previous hypotheses that these are the main drivers of the testicular phenotype in KS. Enrichment analysis showed overrepresentation of genes from the X- and Y-chromosome and testicular transcription factors. Furthermore, by re-evaluation of recent single cell RNA-sequencing data originating from adult KS testis, we found novel evidence that the Sertoli cell is the most affected cell type. Our results are consistent with disturbed cross-talk between somatic and germ cells in the KS testis, and with X-escapee genes acting as mediators.

Humanin gene expression in fibroblast of Down syndrome subjects

Down syndrome (DS) is characterized by trisomy of chromosome 21 and peculiar phenotype. Humanin (HN) is a mitochondrial short 24-residue polypeptide whit anti-apoptotic and neuroprotective effects. In this study we evaluated HN protein expression and HN mRNA levels in cultured fibroblasts from DS patients and normal controls. Our results obtained by immunocytochemistry, western-blot and qRT-PCR analysis show a significant HN up-regulation in DS patients. These results confirm previous studies and suggest a role for HN may in the DS phenotype.

Transcriptome analysis of boar spermatozoa with different freezability using RNA-Seq

Semen freezability is associated with genetic markers, and there is a diverse set of sperm transcripts that have been attributed to various cellular functions. RNA-Seq was performed to compare the transcript profiles of spermatozoa from boars with different semen freezability. We examined ejaculates from the Polish large white (PLW) boars that were classified as having good and poor semen freezability (GSF and PSF, respectively; n = 3 boars per group) by assessing post-thaw motility characteristics, mitochondrial membrane potential, plasma membrane and acrosome integrity. Total RNA was isolated from fresh spermatozoa from boars of the GSF and PSF groups and subjected to RNA-Seq (Illumina NextSeq 500 platform). Transcript abundance was assessed with the DESeq2, DESeq, and EdgeR Bioconductor R packages, and varying numbers of differentially expressed gene (DEG) transcripts were detected in the spermatozoa of each boar. Using RNA-Seq, we identified several genes associated with inflammation and apoptosis (FOS, NFATC3, ITGAL, EAF2 and ZDHHC14), spermatogenesis (FGF-14 and BAMBI), autophagy (RAB33B), protein phosphorylation (PTPRU and PTPN2) and energy metabolism (ND6 and ACADM) that were predominantly up-regulated in poor freezability ejaculates. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) validated the transcript expression levels detected by RNA-Seq and thus confirmed the reliability of this technique. Subsequent validation with western blotting showed that the expression of three proteins was in accordance with the transcript abundance. Overall, we demonstrated that the up-regulation of the DEG transcripts in spermatozoa was associated with poor semen freezability. We suggest that spermatozoa transcriptome profiling provides a foundation to further elucidate the relevance of sperm-related transcripts on cryo-survival. The sperm-related transcripts, namely FOS, NFATC3, EAF2, BAMBI, PTPRU, PTPN2, ND6 and ACADM, are potential markers for predicting the freezability of boar semen.

Evidence for long noncoding RNA GAS5 up-regulationin patients with Klinefelter syndrome

Background

Klinefelter syndrome (KS) is characterized by the presence of at least one supernumerary X chromosome. KS typical symptoms include tall stature, gynecomastia, hypogonadism and azoospermia. KS patients show a higher risk of developing metabolic and cardiovascular diseases, inflammatory and autoimmune disorders, osteoporosis and cancer. Long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) has been shown to be involved in several biologic processes, including inflammatory and autoimmune diseases, vascular endothelial cells apoptosis and atherosclerosis, as well as cellular growth and proliferation, cellular development and cell-to-cell signaling and interaction. The lncRNA GAS5 expression profile in KS patients has never been evaluated so far.

Methods

To accomplish this, GAS5 mRNA levels were evaluated by Next Generation Sequencing (NGS) technology and qRT-PCR assay in 10 patients with KS and 10 age-matched controls.

Results

NGS results showed a significantly lncRNAGAS5up-regulation by 5.171-fold in patients with KS. Theresults of qRT-PCR confirmed the NGS data.

Conclusions

These findings showed the occurrence of lncRNA GAS5 over-expression in KS patients. Whether this lncRNA is involved in the pathogenesis of inflammation and autoimmune diseases, atherogenesis or germ cell depletion in KS patients is not known. Further studies are needed.