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Lead (Pb) exposure during perinatal development alters testosterone (T) concentrations and delays puberty in children and laboratory rodents. In addition, exposure to the metal during adult life decreases T and libido in men and affects male reproductive behaviour (MRB) in rats. MRB is regulated by various brain nuclei including the medial preoptic area (MPOa) and the medial amygdala (MeA), in which T and oestradiol (E 2 ) act through their respective androgen (AR) and oestrogen (ER) receptors. However, the mechanism by which MRB is affected by Pb exposure is not known. The objectives of the present study were to evaluate whether perinatal Pb exposure affects MRB and the number of cells immunoreactive to AR and ERα in the MPOa and the MeA. Male Wistar rats exposed to Pb (320 ppm) in drinking water from the beginning of pregnancy until weaning were used. The experimental group experienced significant alterations in MRB, an important decrease in T and E 2 concentrations, and a significant increase in Pb concentrations in the blood, MPOa (hypothalamus) and MeA. In addition, in the studied areas the number of cells immunoreactive to AR and ERα, or detected using the Nissl technique, decreased significantly. These results show that perinatal exposure to Pb alters MRB. This event may be related to a decrease in both the concentrations of sex hormones and the number of cells that express their receptors as well as in the neuronal Nissl staining population. This ultimately affects the quality of life of the individual., (© 2024 Company of the International Journal of Experimental Pathology (CIJEP).)

Background: Congenital hypothyroidism (CH) is a pathology that affects various organs, including the testicles. The mechanisms by which this condition alters fertility is unknown. This study aimed at determining if experimental CH affects gonocyte differentiation and arrests meiosis; and the possible role of the Sertoli cell (SC) in this condition., Material and Methods: Two groups of rats consisting of Control group and Methimazole (MMI) induced CH rats were formed. The induction of CH was achieved by the administration of MMI starting on day 16 postcoitum and continued until euthanized. Euthanasia was performed at 5, 8, 10, 16 and 64 days of age. Following this, the testicular tissue of each animal was extracted and processed for histopathological and ultrastructural analysis. In addition, the tissue was used for the determination of proteins and their transcriptions, events which are characteristics of gonocyte differentiation. The SC functionality proteins was determined immunohistochemically, while sperm parameters of the cauda epididymis were verified., Results: CH caused a delay in the gonocyte differentiation, and arrested meiosis and spermiogenesis. These events had long-term repercussions on the quality of the seminiferous epithelium. The results show that CH induces alterations in the functional state of SCs that may have led to the deficiency in the synthesis and/or in the release of molecules necessary for gonocyte differentiation; as well as disorders in the process of meiosis that resulted in sperm absence., Conclusion: These results suggest that CH affects gonocyte differentiation and arrests meiosis, possibly through altering the functional status of SCs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Gómez-Zúñiga, Landero-Huerta, Rojas-Castañeda, Sánchez-Huerta, Contreras-García, Reynoso-Robles, Arteaga-Silva and Vigueras-Villaseñor.)

Pre- and/or post-natal administrations of di(2-ethylhexyl) phthalate (DEHP) in experimental animals cause alterations in the spermatogenesis. However, the mechanism by which DEHP affects fertility is unknown and could be through alterations in the survival and differentiation of the gonocytes. The aim of the present study was to evaluate the effect of a single administration of DEHP in newborn mice on gonocytic proliferation, differentiation and survival and its long-term effects on seminiferous epithelium and sperm quality. BALB/c mice distributed into Control and DEHP groups were used. Each animal in the DEHP group was given a single dose of 500 mg/Kg at birth. The animals were analyzed at 1, 2, 4, 6, 8, 10 and 70 days postpartum (dpp). Testicular tissues were processed for morphological analysis to determine the different types of gonocytes, differentiation index, seminiferous epithelial alterations, and immunoreactivity to Stra8, Pcna and Vimentin proteins. Long-term evaluation of the seminiferous epithelium and sperm quality were carried out at 70 dpp. The DEHP animal group presented gonocytic degeneration with delayed differentiation, causing a reduction in the population of spermatogonia (Stra8 +) in the cellular proliferation (Pcna+) and disorganization of Vimentin filaments. These events had long-term repercussions on the quality of the seminiferous epithelium and semen. Our study demonstrates that at birth, there is a period that the testes are extremely sensitive to DEHP exposure, which leads to gonocytic degeneration and delay in their differentiation. This situation can have long-term repercussions or permanent effects on the quality of the seminiferous epithelium and sperm parameters., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier B.V. All rights reserved.)

Cryptorchidism (CO) is a risk factor for the development of testicular germ-cell tumors (TGCT). This is supported by reports showing the persistence of gonocytes in CO patients. These cells are proposed to be related to the development of germ-cell neoplasia in situ (GCNIS), which is considered the precursor stage/lesion of TGCT. Therefore, it is proposed that some patients with CO could express some molecular markers related to TGCT. In this study, we analyzed testicular tissue samples from CO, TGCT, and controls. We determined the expression of POU5F1, PLAP, and KIT by immunohistochemistry and that of the hsa-miR-371-373 cluster, hsa-miR-367, and LATS2 , PTEN , and IGFR1 genes by RT-qPCR. We then carried out a bioinformatic analysis to identify other possible candidate genes as tumor biomarkers. We found that 16.7% (2/12) of the CO patients presented increased expression of POU5F1, KIT, PLAP, hsa-miR-371-373, and hsa-miR-367 and decreased expression of LATS2 and IGF1R . Finally, the genes ARID4B , GALNT3 , and KPNA6 were identified as other possible candidate tumor biomarkers. This is the first report describing the expression of the hsa-miR-371-373 cluster, hsa-miR-367, LATS2 , and IGF1R in the testicular tissues of two CO patients with cells immune-positive to POU5F1, PLAP, and KIT, which is similar to what is observed in TGCT.

Some pediatric patients with cryptorchidism preserve cells with gonocyte characteristics beyond their differentiation period, which could support the theory of the gonocyte as a target for malignancy in the development of testicular neoplasia. One of the key molecules in gonocyte malignancy is represented by microRNAs (miRNAs). The goal of this review is to give an overview of miRNAs, a class of small non-coding RNAs that participate in the regulation of gene expression. We also aim to review the crucial role of several miRNAs that have been further described in the regulation of gonocyte differentiation to spermatogonia, which, when transformed, could give rise to germ cell neoplasia in situ, a precursor lesion to testicular germ cell tumors. Finally, the potential use of miRNAs as diagnostic and prognostic biomarkers in testicular neoplasia is addressed, due to their specificity and sensitivity compared to conventional markers, as well as their applications in therapeutics.

Chronic lead (Pb) exposure affects the circadian physiological processes regulated by suprachiasmatic nucleus (SCN), which is synchronized (entrainment) by light. Disorders in the entrainment capacity of an organism alter its performance to interact with the environment, thus affecting its health status. The objectives of the present study were to evaluate whether chronic early Pb exposure affects the entrainment of the circadian rhythm of locomotor activity by light and to explore the possible mechanisms involved. Adult male Wistar rats, control and chronically exposed to Pb (320 ppm) in drinking water from gestation to adult age, were used. Assessment of the metal level showed a significant increase of Pb in the blood, hypothalamus and prefrontal cortex of the experimental rats. Continuous registrations of locomotor activity (12 h:12 h light-dark cycle) depicted that Pb induces important delay of this activity when the light was turned off. The Pb exposed animals entrained faster with a photoperiod delay of 6 h, (lights on at 13:00 h), and maintained the significant delay in the onset of activity at lights out. In continuous darkness, the animals were exposed to a light pulse at circadian time 23. This resulted in a significant decrease of photo-stimulated neurons (immunoreactivity to c-Fos) in the SCN of the metal-exposed animals. These results show that chronic early Pb exposure alters the photic entrainment of the rhythm of locomotor activity, which is evidenced by a significant decrease in both the number of photo-stimulated neurons and neuronal population (Nissl stain) of the SCN., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: This study aimed to correlate the presence of microlithiasis (ML) in cryptorchidism (CO) patients with the functionality of Sertoli cells and the arrest of gonocyte differentiation., Methods: Testicular biopsies were obtained from 21 inguinal CO pediatric patients and were classified in two groups as follows: patients with ML and those without ML. In both groups, the number of Sertoli cells/seminiferous cords and their functionality were determined, considering the concentrations of inhibin B. In addition, the area and the histological alterations of seminiferous epithelium were evaluated. The arrest of gonocyte differentiation was determined by immunoreactivity to SALL4, AP2ɣ, PLAP and POU5F1., Results: We found a statistical correlation between the presence of ML with the alterations in the functionality of Sertoli cells without reflecting in the differentiation of the gonocytes., Conclusion: The study of this population suggests that the association between CO and ML shows a malfunction of the Sertoli cells without necessarily causing arrest in the differentiation of gonocytes in these patients., Competing Interests: Declaration of Competig Interest None., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: Cryptorchidism is the most common genitourinary birth defect in live newborn males and is considered as an important risk factor for testicular germ cell tumors and infertility. The Androgen Receptor gene is important in this pathology due to its participation, mainly, in the inguinoscrotal phase of testicular descent. We determine the length of the CAG tract in the Androgen Receptor ( AR ) gene in Mexican patients with nonsyndromic cryptorchidism., Methods: One hundred and 15 males were included; of these, 62 had nonsyndromic cryptorchidism and 53 were healthy volunteers. DNA was extracted from a peripheral blood samples, subsequently, the CAG tract in exon 1 of AR gene was amplified by PCR and sequenced., Results: Mexican patients with nonsyndromic cryptorchidism presented 25.03 ± 2.58 repeats of CAG tract in the AR gene compared to 22.72 ± 3.17 repeats of CAG tract in Mexican healthy individuals (p≤0.0001; t value of 4.3). Furthermore, the deletion of codon 57 that corresponds to the deletion of a leucine residue at position 57 (Del L57) in the AR gene was found for the first time in a nonsyndromic cryptorchidism patient. This molecular alteration has been related previously to testicular germ cell tumor (TGCT)., Conclusions: The CAG tract in the AR gene is longer in patients with nonsyndromic cryptorchidism than in healthy individuals, supporting the association between this polymorphism of the AR gene and nonsyndromic cryptorchidism in the Mexican population., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Allelic variants in genes implicated in the development of testicular germ cell tumor (TGCT) could be present in patients with cryptorchidism (CO). Currently; the mechanisms explaining this relationship are still unknown. In this study the common clinical features in patients with CO and TGCT and 6 variants of KIT and AR genes associated to TGCT were analyzed. Population analyzed included 328 individuals: 91 patients with CO; 79 with TGCT, 13 of them with previous CO diagnosis, and 158 healthy males. Of the 13 patients with TGCT and history of CO, one patient (7.7%) presented the heterozygous form of the variant rs121913507 and two patients (15.4%) presented homozygote genotype for the variant rs121913506 in KIT gene. Interestingly, the heterozygous form for the variant rs121913506 of KIT gene was identifying in all of 13 patients. The rs201934623, rs774171864, and rs12014709 variants of the AR gene did not show any clinical association. Our results strongly support that genetic component in CO could be conditioning for the development of TGCT. Notably, KIT gene variants might be determinants in the pathological association between TGCT and CO., (Copyright © 2020 Landero-Huerta, Vigueras-Villaseñor, Yokoyama-Rebollar, García-Andrade, Rojas-Castañeda, Herrera-Montalvo, Díaz-Chávez, Pérez-Añorve, Aréchaga-Ocampo and Chávez-Saldaña.)

Radioresistance of tumor cells gives rise to local recurrence and disease progression in many patients. MicroRNAs (miRNAs) are master regulators of gene expression that control oncogenic pathways to modulate the radiotherapy response of cells. In the present study, differential expression profiling assays identified 16 deregulated miRNAs in acquired radioresistant breast cancer cells, of which miR-122 was observed to be up-regulated. Functional analysis revealed that miR-122 has a role as a tumor suppressor in parental cells by decreasing survival and promoting radiosensitivity. However, in radioresistant cells, miR-122 functions as an oncomiR by promoting survival. The transcriptomic landscape resulting from knockdown of miR-122 in radioresistant cells showed modulation of the ZNF611, ZNF304, RIPK1, HRAS, DUSP8 and TNFRSF21 genes. Moreover, miR-122 and the set of affected genes were prognostic factors in breast cancer patients treated with radiotherapy. Our data indicate that up-regulation of miR-122 promotes cell survival in acquired radioresistant breast cancer and also suggest that miR-122 differentially controls the response to radiotherapy by a dual function as a tumor suppressor an and oncomiR dependent on cell phenotype., (© 2019 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Cryptorchidism is a frequent genitourinary malformation considered as an important risk factor for infertility and testicular malignancy. The aetiology of cryptorchidism is multifactorial in which certain SNPs, capable of inhibiting the development of the gubernaculum, are implicated. We analysed 16 SNPs by allelic discrimination and automated sequencing in 85 patients and 99 healthy people, with the objective to identify the association between these variants and isolated cryptorchidism. In two different patients with unilateral cryptorchidism, we found the variants rs121912556 and p.R105R of INSL3 gene in a heterozygous form associated with cryptorchidism, so we could considered them as risk factors for cryptorchidism. On the other hand, SNPs rs10421916 of INSL3 gene, as well as the variants rs1555633 and rs7325513 in the RXFP2 gene, and rs3779456 variant of the HOXA10 gene were statistically significant, when the patients and controls were compared and could be considered as protective factors since are predominantly present in controls. The genotype-phenotype correlation did not show statistical significance. With these results, we could conclude that these polymorphisms can be considered as important variants in our population and would contribute in the future knowledge of the aetiology and physiopathology of cryptorchidism., (© 2017 Blackwell Verlag GmbH.)

Testicular germ cell cancer (TGCT) is the most common malignancy among young adult males, which has become important due to its increased incidence and mortality in the population worldwide. The etiology is multifactorial. Recent studies have shown some associations between the development of isolated TGCT and certain risk factors, such as exposure to endocrine disruptors, cryptorchidism, and family history of cancer, in order to identify the key pieces in carcinogenesis. Some of the most important findings in recent years is the association of different genes, such as c-KIT / KITLG , expression of the miR-371-373 cluster and protein expression as c-KIT and POU5F1 in the development of this neoplasia, and the identification of new molecular markers as TGFBR3 gene, identifying aberrant methylation patterns in promoter regions of several genes, expression of miR-1297 which regulates PTEN and protein expression as DMTR1. In the future, a multidisciplinary research strategy could provide valuable new insights into the etiology of TGCTs, which support clinical diagnosis of TGCT in the next years to increase survival in this kind of patients.