Background: Male factor is the major contributor in roughly half of infertility cases. Genetic factors account for 10–15% of male infertility. Microdeletions of azoospermia factors (AZF) on the Yq region are the second most frequent spermatogenesis disorder among infertile men after Klinefelter syndrome. We detected in our previous study a frequency of 37.5% AZF microdeletions which investigated mainly the AZFb and AZFc. We attempted in this study for the first time to evaluate the frequencies of all AZF sub-regions microdeletions and to analyze reproductive hormonal profiles in idiopathic cases of azoospermic and oligozoospermic men from Sudan.Methods: A group of 51 medically fit infertile men were subjected to semen analysis. Four couples have participated in this study as a control group. Semen analysis was performed according to WHO criteria by professionals at Elsir Abu-Elhassan Fertility Centre where samples have been collected. We detected 12 STSs markers of Y chromosome AZF microdeletions using a multiplex polymerase chain reaction. Analysis of reproductive hormone levels including Follicle Stimulating, Luteinizing, and Prolactin hormones was performed using ELISA. Comparisons between outcome groups were performed using Student’s t-test Chi-square test or Fisher’s exact test.Results: AZF microdeletion was identified in 16 out of 25 Azoospermic and 14 out of 26 of the Oligozoospermic. Microdeletion in the AZFa region was the most frequent among the 30 patients (N = 11) followed by AZFc, AZFd (N = 4 for each) and AZFb (N = 3). Among the Oligozoospermic participants, the most frequent deletions detected were in the AZFa region (N = 10 out of 14) and was significantly associated with Oligozoospermic phenotype, Fisher's Exact Test (2-sided)p = 0.009. Among the Azoospermic patients, the deletion of the AZFc region was the most frequent (N = 9 out of 16) and was significantly associated with Azoospermia phenotype Fisher's Exact Testp = 0.026. There was a significant difference in Y chromosome microdeletion frequency between the two groups. The hormonal analysis showed that the mean levels of PRL, LH, and FSH in Azoospermic patients were slightly higher than those in oligozoospermic. A weak negative correlation between prolactin higher level and Azoospermic patients was detected. (AZFa r = 0.665 and 0.602,p = 0.000 and 0.0004, AZFb r = 0.636 and 0.409,p = 0.000 and 0.025, and AZFd r = 0.398 and 0.442,p = 0.029 and 0.015). The correlation was positive for AZFa and negative for AZFb and AZFd.Conclusions: We concluded in this study that the incidences of microdeletions of the Y chromosome confined to AZF a, b, c and d regions is 58.8% in infertile subjects with 31.4% were Azoospermic and 27.5% were Oligozoospermic. This might provide a piece of evidence that these specified regions of the Y chromosome are essential for controlling spermatogenesis. These findings will be useful for genetic counseling within infertility clinics in Sudan and to adopt appropriate methods for assisted reproduction.
17 February 2022 in Molecular Genetics and Metabolism Reports
Fabry disease (FD) is a rare genetic lysosomal storage disorder, resulting from partial or complete lack of alpha-galactosidase A (α-GAL) enzyme, leading to systemic accumulation of substrate glycosphingolipids with a broad range of tissue damage. Current in vivo models are laborious, expensive, and fail to adequately mirror the complex FD physiopathology. To address these issues, we developed an innovative FD model in zebrafish.
Fabry disease (FD) is an X-linked inborn metabolic disorder due to partial or complete lysosomal α-galactosidase A deficiency. FD is characterized by progressive renal insufficiency and cardio- and cerebrovascular involvement. Restricted access on Gb3-independent tissue injury experimental models has limited the understanding of FD pathophysiology and delayed the development of new therapies. Accumulating glycosphingolipids, mainly Gb3 and lysoGb3, are Fabry specific markers used in clinical follow up. However, recent studies suggest there is a need for additional markers to monitor FD clinical course or response to treatment. We used a gla-knockout zebrafish (ZF) to investigate alternative biomarkers in Gb3-free-conditions. RNA sequencing was used to identify transcriptomic signatures in kidney tissues discriminating gla-mutant (M) from wild type (WT) ZF. Gene Ontology (GO) and KEGG pathways analysis showed upregulation of immune system activation and downregulation of oxidative phosphorylation pathways in kidneys from M ZF. In addition, upregulation of the Ca2+ signaling pathway was also detectable in M ZF kidneys. Importantly, disruption of mitochondrial and lysosome-related pathways observed in M ZF was validated by immunohistochemistry. Thus, this ZF model expands the pathophysiological understanding of FD, the Gb3-independent effects of gla mutations could be used to explore new therapeutic targets for FD.
Fabry nephropathy is a major cause of kidney failure in Fabry disease, caused by pathogenic GLA variants that reduce α-galactosidase A activity and lead to globotriaosylceramide (Gb3) accumulation. In recent years, rapid advances in experimental modeling and emerging therapeutic strategies have dramatically reshaped understanding and treatment prospects for Fabry nephropathy. Experimental models – including cellular systems, patient-derived kidney organoids, and animal models such as zebrafish, Drosophila, mice and rats – have been pivotal in elucidating classic Gb3-dependent and novel Gb3-independent pathogenic mechanisms. These insights challenge the traditional Gb3-centric paradigm by highlighting other contributors, such as its metabolite lyso-Gb3, as well as α-synuclein accumulation and endothelial dysfunction. Despite established therapies for Fabry nephropathy, such as enzyme replacement and pharmacological chaperones, disease progression remains a clinical challenge, underscoring the urgent need for deeper mechanistic understanding and precision medicine approaches. This timely Review summarizes diverse model systems' unique strengths, limitations and translational potential to guide future research and therapeutic development for this complex disease.