From gains to gaps? How Selective Androgen Receptor Modulator (SARM) YK11 impact hippocampal function: In silico, in vivo, and ex vivo perspectives.

Selective Androgen Receptor Modulators (SARMs), particularly (17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic-acid-methyl-ester (YK11), are increasingly popular among athletes seeking enhanced performance. Serving as an Androgen Receptor (AR) agonist, YK11 stimulates muscle growth while inhibiting myostatin. Our study delved into the impact of YK11 on the rat hippocampus, analyzing potential alterations in neurochemical mechanisms and investigating its synergistic effects with exercise (EXE), based on the strong relationship between SARM users and regular exercise. Utilizing Physiologically Based Pharmacokinetic (PBPK) modeling, we demonstrated YK11 remarkable brain permeability, with molecular docking analysis revealing YK11 inhibitory effects on 5-alpha-reductase type II (5αR2), suggesting high cell bioavailability. Throughout a 5-week experiment, we divided the animals into the following groups: Control, YK11 (0.35 g/kg), EXE (swimming exercise), and EXE + YK11. Our findings showed that YK11 displayed a high binding affinity with AR in the hippocampus, influencing neurochemical function and modulating aversive memory consolidation, including the downregulation of the BDNF/TrkB/CREB signaling, irrespective of EXE combination. In the hippocampus, YK11 increased pro-inflammatory IL-1ß and IL-6 cytokines, while reducing anti-inflammatory IL-10 levels. However, the EXE + YK11 group counteracted IL-6 effects and elevated IL-10. Analysis of apoptotic proteins revealed heightened p38 MAPK activity in response to YK11-induced inflammation, initiating the apoptotic cascade involving Bax/Bcl-2/cleaved caspase-3. Notably, the EXE + YK11 group mitigated alterations in Bcl-2 and cleaved caspase-3 proteins. In conclusion, our findings suggest that YK11, at anabolic doses, significantly alters hippocampal neurochemistry, leading to impairments in memory consolidation. This underscore concerns about the misuse risks of SARMs among athletes and challenges common perceptions of their minimal side effects.

The Molecular Basis of 5α-Reductase Type 2 Deficiency.

The 5α-reductase type 2 enzyme catalyzes the conversion of testosterone into dihydrotestosterone, playing a crucial role in male development. This enzyme is encoded by the SRD5A2 gene, which maps to chromosome 2 (2p23), consists of 5 exons and 4 introns, and encodes a 254 amino acid protein. Disruptions in this gene are the molecular etiology of a subgroup of differences of sex development (DSD) in 46,XY patients. Affected individuals present a large range of external genitalia undervirilization, ranging from almost typically female external genitalia to predominantly typically male external genitalia with minimal undervirilization, including isolated micropenis. This is an updated review of the implication of the SRD5A2 gene in 5α-reductase type 2 enzyme deficiency. For that, we identified 451 cases from 48 countries of this particular 46,XY DSD from the literature with reported variants in the SRD5A2 gene. Herein, we present the SRD5A2 mutational profile, the SRD5A2 polymorphisms, and the functional studies related to SRD5A2 variants to detail the molecular etiology of this condition.

Fetal Genotype-Phenotype Sex Discordance: A Case of 5-Alpha-Reductase Deficiency.

OBJECTIVE: To describe the prenatal and postnatal diagnostic workup leading to the diagnosis of 5-alpha-reductase type 2 deficiency (5AR2D) in a case of 46,XY disorder of sex development (DSD). CASE REPORT: A first-trimester noninvasive prenatal test (NIPT) on maternal blood revealed a male fetus with a low risk of aneuploidy. However, a female fetus was identified at the second-trimester scan. A repeat sample revealed similar results and ruled out the possibility of both a sample swap or a vanishing twin. At birth, phenotypically female external genitalia were evident, with testes noted in the labioscrotal area. Neonatal blood confirmed a 46,XY complement and a 46,XY DSD genetic panel revealed a 5AR2D. CONCLUSION: Our case and others described in the literature demonstrate that fetal sex discordance detected by a combination of NIPT and subsequent ultrasound examination can be associated with several biological conditions, with DSD being the most significant.

Molecular genetic analysis of AKR1C2-4 and HSD17B6 genes in subjects 46,XY with hypospadias.

BACKGROUND: The formation of the male urethra depends to enzyme-mediated testosterone (T) conversion into 5α-dihydrotestosterone (DHT). Two metabolic pathways could be operating in the fetal testis to synthesize androgens: 1) the "classic" route (T→DHT) mediated by SRD5A2 and 2) a "backdoor" pathway in which DHT is synthesized by aldo-keto reductase family 1, member C2 (AKR1C2), AKR1C3, and AKR1C4 enzymes without formation of a T intermediate. OBJECTIVE: We studied four genes of the "backdoor" pathway in karyotypic males with hypospadias to ascertain whether gene defects in AKRs impair urethral DHT formation that result in hypospadias. DESIGN AND PATIENTS: The coding regions of the AKR1C2-4 and HSD17B6 genes were analyzed by PCR-SSCP and sequencing in a cohort of 25 Mexican patients (0.3-9 year-old-children) with 46,XY-hypospadias. Chi-squared tests was performed to evaluate the distribution of genotypes, alleles, and the Hardy-Weinberg (H-W) equilibrium. The effect of the genetic variants was investigated by in silico studies. RESULTS: Screening studies revealed distinct genotypic patterns at different exons of AKR1C2-4 whereas HSD17B6 presented a wild-type sequence. The DNA analyses detected two synonymous variants (c.327C>T, c.666T>C/unreported) in AKR1C2. The AKR1C3 had two variants (c.15C>G, c.230A>G), two unreported variants (c.538T>C, c.596G>A), and one silent variant (c.312G>A). Two variants (c.434C>G, c.931C>G) were identified in AKR1C4. All variants were in H-W equilibrium without structural changes. DISCUSSION: Hypospadias have been associated with defects that alter androgen biosynthesis in the human fetal testis, specifically 5α-DHT. We selected four candidate genes involved in the "backdoor" pathway for the formation of 5α-DHT. Molecular assays of the AKR1C2, AKR1C3, and AKR1C4 genes revealed a total of nine genetic single nucleotide variants. Several variants in the AKR1C genes have been associated with a variety of human pathologies. However, our studies suggest that active steroid biosynthesis via AKR1C might not be involved in hypospadias. Additionally, genetic research suggests a low involvement in the "backdoor" 5α-DHT pathway during human sexual development, specifically, the differentiation of male external genitalia. CONCLUSION: These results indicate that substitutions in AKR1C2-4 are polymorphisms and all genetic variants lacks deleterious significant association with hypospadias. The data suggest that inactivating mutations in the AKR1C2-4 and HSD17B6 genes are an infrequent cause of hypospadias, which might weaken the contribution of the "backdoor" pathway to embryonic urethral masculinization.

Mutational analysis of SRD5A2: From gene to functional kinetics in individuals with steroid 5α-reductase 2 deficiency.

Human steroid 5α-reductase 2 (SRD5A2) plays a determinative role in the masculinization of external genitalia. To date, approximately 114 different mutations of the SRD5A2 gene have been reported; however, little information is available about their impact on catalytic function or their three-dimensional (3D) structures. We determined the effect of point mutations on the testosterone-depend kinetic constants (Km,app and Vmax,app) and structural characteristics of SRD5A2 from Mexican patients with 46,XY-steroid 5α-reductase 2 deficiency. PCR-SSCP assays identified ten distinct gene variants and sequencing analysis identified missense mutations [p.V3I, p.S14R, p.A52T, p.F118L, p.R145W, p.R171S, p.L226P, p.F229S, p.S245Y, and p.A248V]. Mutations were re-created by site-directed mutagenesis and expressed in HEK293 cells. Functional studies demonstrated that 8 variants led to partial (Km,app = 0.16-2.6 µM; Vmax,app = 224-2640 pmol/mg P/min) or complete losses of activity compared to the wild-type enzyme (Km,app = 0.7 µM; Vmax,app = 4044 pmol/mg P/min). All the mutations were assessed using multiple software tools and the results predicted that all of the mutations were associated with disease or damage. Mapping mutations on the model of a 3D structure of SRD5A2 demonstrated alterations in contact sites with their proximal amino acids. Our data show that mutations affect the catalytic efficiency (Vmax/Km) or result in residual enzymatic activity, which could be due to erroneous interactions between amino acid residues, the substrate testosterone, or NADPH.

5α-Reductase type 2 deficiency in families from an isolated Andean population in Venezuela.

5α-Reductase type 2 deficiency causes a 46,XY disorder of sex development (DSD) characterized by ambiguous external genitalia, rudimentary prostate, and normal internal genitalia. The disease prevalence worldwide is low, but in a small and isolated village of the Venezuelan Andes, a higher incidence has been found. DNA analysis of the SRD5A2 gene was performed in three inbred affected individuals clinically diagnosed with DSD. The entire coding regions, the p.L89V polymorphism (rs523349) and five intragenic SNPs (rs2300702, rs2268797, rs2268796, rs4952220, rs12470196) used to construct haplotypes were analyzed by Sanger sequencing. To assess the probable ethnic origin of the mutation in this geographic isolate, a population structure analysis was performed. Homozygosis for the p.N193S mutation was found in all patients, with a mutation carrier frequency of 1:80 chromosomes (0.0125) in the geographic focus, suggesting a founder phenomenon. The results of the population structure analysis suggested a mutation origin closer to the Spanish populations, according to the clusters grouping. The genotype-phenotype correlation in the patients was not absolute, being hypospadias and cryptorchidism the main traits that differentiate affected individuals.

Nandrolone decanoate and resistance exercise affect prostate morphology and hormone receptor interface in adult rats with implications for the aging process.

BACKGROUND: Nandrolone decanoate (ND) is an anabolic-androgenic steroid, and its indiscriminate use leads to subclinical alterations in the hypothalamic-pituitary-gonadal axis and androgen-dependent organs. OBJECTIVES: To evaluate the effects of ND, either alone or in combination with resistance exercise (RE), on the levels of sex hormones, converting enzymes, and steroid receptors and the morphology of the ventral prostate (VP) in adult and aged rats. METHODS: Forty Sprague-Dawley adult and aged rats were divided into four groups each, sedentary and trained with and without ND. The groups received treatments over 8 weeks. Adult animals were sacrificed immediately following treatment completion, while the aged groups were left untreated until 300 days of age. RESULTS: Adult and aged animals showed reductions in testosterone levels following the different treatments, and 17ß-estradiol levels were decreased in the ND-treated groups. The level of 5α-reductase type 2 (5αR2) and aromatase was increased significantly in the prostates of adult animals that performed RE. However, aromatase levels were decreased in the prostates of aged animals that performed RE and were treated with ND, while 5αR2 levels were reduced in aged animals that performed RE without ND treatment. When sex receptors levels were examined, the aged and trained animals presented low androgen receptor (AR) levels. Estrogen receptors (ERs) levels were increased in the prostates of adult animals that received ND. ERß levels were reduced after treatments in aged animals. The heights of the prostatic epithelium were reduced in all adult treated animals, coinciding with increases in PCNA and PAR4 levels. DISCUSSION: ND and RE alter the levels of hormone, converting enzymes, and sex steroid receptors and the morphology of the VP. These effects were observed in both adult and aged rats. CONCLUSION: ND, either with or without RE, during post-puberty stage is able to interfere with the morphophysiology of the prostate.

Gender identity in patients with 5-alpha reductase deficiency raised as females.

BACKGROUND AND OBJECTIVE: 5-Alpha reductase type 2 deficiency (5-ARD) is a rare disorder of sex development. The lack of 5-alpha reductase, an enzyme that converts testosterone into dihydrotestosterone, results in external genitalia that may appear female, or predominantly male, albeit undervirilized, or, more often, ambiguous. METHODS: This study describes a series of patients with 5-ARD raised as female, focusing on aspects related to gender identity. Following a retrospective chart review, patients with 5-ARD were invited to return to the clinic to enable their gender identity to be assessed using an 11-item structured in-house questionnaire. The Golombok-Rust Inventory of Sexual Satisfaction was applied to patients who had initiated their sexual life. RESULTS: Six patients aged >15 years with 5-ARD and raised as female were included. Most patients were diagnosed late: two before and four after puberty. The mean length of the phallus was 2.8 cm (0.5-5.0). Reasons for seeing a doctor included genital appearance (n = 3), amenorrhea/absence of breast development (n = 2), and changes in gender role attitudes (n = 1). According to the gender identity assessment, 4 patients identified as female, 1 as male, and 1 as both genders. Only the patient identified as male requested gender re-assignment. Of the two patients who had initiated their sexual life, sexual satisfaction was found to be good in one and poor in the other due to vaginal discomfort during intercourse. CONCLUSION: In the present series, the majority of undervirilized patients with a diagnosis of 5-ARD raised as female were in complete conformation with being female and described themselves as heterosexual. The more virilized patients were those least in conformity with their female-assigned gender.

5-α-Reductase type 2 deficiency: is there a genotype-phenotype correlation? A review.

5-α-Reductase type 2 enzyme catalyzes the conversion of testosterone into dihydrotestosterone, a potent androgen responsible for male sexual development during the fetal period and later during puberty. Its deficiency causes an autosomal recessive disorder of sex development characterized by a wide range of under-virilization of external genitalia in patients with a 46,XY karyotype. Mutations in the SRD5A2 gene cause 5-α-Reductase deficiency; although it is an infrequent disorder, it has been reported worldwide, with mutational heterogeneity. Furthermore, it has been proposed that there is no genotype-phenotype correlation, even in patients carrying the same mutation. The aim of this review was to perform an extensive search in various databases and to select those articles with a comprehensive genotype and phenotype description of the patients, classifying their phenotypes using the external masculinization score (EMS). Thus, it was possible to objectively compare the eventual genotype-phenotype correlation between them. The analysis showed that for most of the studied mutations no correlation can be established, although the specific location of the mutation in the protein has an effect on the severity of the phenotype. Nevertheless, even in patients carrying the same homozygous mutation, a variable phenotype was observed, suggesting that additional genetic factors might be influencing it. Due to the clinical variability of the disorder, an accurate diagnosis and adequate medical management might be difficult to carry out, as is highlighted in the review.

The herbicide atrazine affects sperm quality and the expression of antioxidant and spermatogenesis genes in zebrafish testes.

The herbicide atrazine (ATZ) is used worldwide in the control of annual grasses and broad-leaved weeds. The present study evaluated sperm quality parameters in zebrafish Danio rerio after 11-day exposure to nominal ATZ concentrations of 2, 10, and 100 µg L-1. All ATZ concentrations caused a decrease in motility, mitochondrial functionality, and membrane integrity, as measured using conventional microscopy or fluorescence microscopy with specific probes. The DNA integrity of sperm was not affected. The levels of expression of genes related to spermatogenesis, antioxidant defenses, and DNA repair were also investigated using RT-qPCR. The ATZ caused transcriptional repression of the spermatogenesis-related genes SRD5A2 and CFTR, the antioxidant defense genes SOD2 and GPX4B, and the DNA repair gene XPC. This is the first study to show that environmentally relevant concentrations of ATZ significantly affect the sperm quality in fish, possibly resulting in reduced fertility rates. In addition, we showed that the repression of genes related to spermatogenesis and cellular defense could be part of the mechanisms involved in the ATZ toxicity in the testes of male fish.

Comparison between two inhibin B ELISA assays in 46,XY testicular disorders of sex development (DSD) with normal testosterone secretion.

BACKGROUND: Inhibin B is a hormone produced by the Sertoli cells that can provide important information for the investigation of disorders of sex development (DSD) with 46,XY karyotype. The aim of this study is to compare two enzyme-linked immunosorbent assay (ELISA) assays for dosage of serum inhibin B in patients with 46,XY DSD with normal testosterone secretion. METHODS: Twenty-nine patients with 46,XY DSD and normal testosterone secretion (partial androgen insensitivity syndrome [PAIS] [n=8]; 5α-reductase deficiency [n=7] and idiopathic 46,XY DSD [n=14]) were included. Molecular analysis of the AR and SRD5A2 genes were performed in all patients and the NR5A1 gene analysis in the idiopathic group. Measurements of inhibin B were performed by two second-generation ELISA assays (Beckman-Coulter and AnshLabs). Assays were compared using the interclass correlation coefficient (ICC) and the Bland-Altman method. RESULTS: ICC was 0.915 [95% confidence interval (CI): 0.828-0.959], however, a discrepancy was observed between trials, which is more evident among higher values when analyzed by the Bland-Altman method. CONCLUSIONS: It is recommended to perform the inhibin B measurement always using the same ELISA kit when several evaluations are required for a specific patient.

Respuesta ultrarrapida de tecnologia sanitária: ácido cólico / Ultrarapid response of sanitary technology: colic acid

INTRODUCCIÓN: El término colestasis comprende todas las situaciones en las cuales existe un impedimento en el flujo normal de bilis desde el polo canalicular del hepatocito hasta el duodeno, lo que produce alteraciones morfológicas, fisiológicas y clínicas. De acuerdo a su mecanismo de producción se clasifican en colestasis intra y extrahepáticas, la cual es universalmente aceptada y fue establecida por la Asociación Internacional para el Estudio del Hígado (1994), ya que provee un esquema práctico, con importantes implicaciones diagnósticas y terapéuticas. Los mecanismos involucrados en las colestasis intrahepáticas familiares suceden por: 1. alteración del transporte canalicular de los componentes normales de la bilis: debido a mutaciones en los genes que codifican estos transportadores. 2. defectos en la síntesis de ácidos biliares: a consecuencia de diferentes deficiencias enzimáticas específicas, debidas a mutaciones1 . El trastorno de la síntesis de ácidos biliares (en inglés

Genotyping the High Altitude Mestizo Ecuadorian Population Affected with Prostate Cancer.

Prostate cancer (PC) is the second most commonly diagnosed type of cancer in males with 1,114,072 new cases in 2015. The MTHFR enzyme acts in the folate metabolism, which is essential in methylation and synthesis of nucleic acids. MTHFR C677T alters homocysteine levels and folate assimilation associated with DNA damage. Androgens play essential roles in prostate growth. The SRD5A2 enzyme metabolizes testosterone and the V89L polymorphism reduces in vivo SRD5A2 activity. The androgen receptor gene codes for a three-domain protein that contains two polymorphic trinucleotide repeats (CAG, GGC). Therefore, it is essential to know how PC risk is associated with clinical features and polymorphisms in high altitude Ecuadorian mestizo populations. We analyzed 480 healthy and 326 affected men from our three retrospective case-control studies. We found significant association between MTHFR C/T (odds ratio [OR] = 2.2; P = 0.009), MTHFR C/T+T/T (OR = 2.22; P = 0.009), and PC. The SRD5A2 A49T substitution was associated with higher pTNM stage (OR = 2.88; P = 0.039) and elevated Gleason grade (OR = 3.15; P = 0.004). Additionally, patients with ≤21 CAG repeats have an increased risk of developing PC (OR = 2.99; P < 0.001). In conclusion, genotype polymorphism studies are important to characterize genetic variations in high altitude mestizo populations.

A Single Nucleotide Variant in the Promoter Region of 17ß-HSD Type 5 Gene Influences External Genitalia Virilization in Females with 21-Hydroxylase Deficiency.

BACKGROUND: In 21-hydroxylase deficiency (21-OHD), there is an influence of genotype on the severity of external genitalia virilization. However, females carrying mutations predicting a similar impairment of enzymatic activity present a wide variability of genital phenotypes. In such cases, interindividual variability in genes related to the sex steroid hormone pathway could play a role. OBJECTIVE: To evaluate the influence of POR, HSD17B5 and SRD5A2 variants on the severity of external genitalia virilization in 21-OHD females. DESIGN AND PATIENTS: Prader stages were evaluated in 178 females with 21-OHD from a multicenter study. The 21-OHD genotypes were divided into two groups according to their severity: severe and moderate. The influences of the POR p.A503V, HSD17B5 c.-71A>G, HSD17B5 c.-210A>C, and SRD5A2 p.A49T and p.V89L variants on the degree of external genitalia virilization were analyzed. RESULTS: The POR p.A503V, HSD17B5 c.-71A>G, HSD17B5 c.-210A>C, and SRD5A2 p.A49T and p.V89L variants were found in 25, 33, 17, 1, and 31% of the alleles, respectively. In uni- and multilinear regression, HSD17B5 c.-210A>C has a significant influence on the degree of external genitalia virilization. This variant was also identified with a higher frequency in the most severely virilized females. CONCLUSION: We demonstrated that a variant in the promoter region of HSD17B5 related to fetal androgen synthesis influences the genital phenotype in 21-OHD females.

Correlation of androgen receptor and SRD5A2 gene mutations with pediatric hypospadias in 46, XY DSD children.

We performed an exploratory study by analyzing the correlation of 46, XY disorders of sex development (46, XY DSD) with androgen receptor (AR) and steroid 5α-reductase-2 (SRD5A2) gene mutations and a safety analysis of dihydrotestosterone (DHT) gel treatment for pediatric micropenis. We collected samples from 76 pediatric patients with 46, XY DSD and 50 healthy adult men with normal fertility as the control group. The pediatric patients were treated with DHT gel (0.1-0.3 mg/kg/day) for three to six months. The extended penis length, testicular volume, and multiple blood parameters were collected before treatment and one, three, and six months after treatment. Of the 76 cases with 46, XY DSD, 31.58% had hypospadias with micropenis and 6.58% had male pseudohermaphroditism. Through AR gene screening, it was found that 14 patients had AR point mutations and 22 patients had SRD5A2 mutations. After treatment with DHT, the penis length of the patients significantly improved after one, three, and six months of treatment, with longer treatment times resulting in greater improvement. Before treatment with DHT, the average serum DHT value of patients with 46, XY DSD was 24.29 pg/mL. After one, three, and six months of treatment, this value increased to 430.71, 328.9, and 323.6 pg/mL, respectively. We conclude that for pediatric patients who have male hermaphroditism or hypospadias with micropenis, AR and SRD5A2 gene mutation detection should be performed. Local application of DHT gel can promote penis growth effectively without systemic adverse reactions.

The Presence of Clitoromegaly in the Nonclassical Form of 21-Hydroxylase Deficiency Could Be Partially Modulated by the CAG Polymorphic Tract of the Androgen Receptor Gene.

BACKGROUND: In the nonclassical form (NC), good correlation has been observed between genotypes and 17OH-progesterone (17-OHP) levels. However, this correlation was not identified with regard to the severity of hyperandrogenic manifestations, which could depend on interindividual variability in peripheral androgen sensitivity. Androgen action is modulated by the polymorphic CAG tract (nCAG) of the androgen receptor (AR) gene and by polymorphisms in 5α-reductase type 2 (SRD5A2) enzyme, both of which are involved in the severity of hyperandrogenic disorders. OBJECTIVES: To analyze whether nCAG-AR and SRD5A2 polymorphisms influence the severity of the nonclassical phenotype. PATIENTS: NC patients (n = 114) diagnosed by stimulated-17OHP ≥10 ng/mL were divided into groups according to the beginning of hyperandrogenic manifestations (pediatric and adolescent/adult) and CYP21A2 genotypes (C/C: homozygosis for mild mutations; A/C: compound heterozygosis for severe/mild mutations). METHODS: CYP21A2 mutations were screened by allelic-specific PCR, MLPA and/or sequencing. HpaII-digested and HpaII-undigested DNA samples underwent GeneScan analysis to study nCAG, and the SRD5A2 polymorphisms were screened by RLFP. RESULTS: Mean nCAG did not differ among pediatric, adolescent/adult and asymptomatic subjects. In the C/C genotype, we observed a significantly lower frequency of longer CAG alleles in pediatric patients than in adolescent/adults (p = 0.01). In patients carrying the A/C genotype, the frequencies of shorter and longer CAG alleles did not differ between pediatric patients and adolescent/adults (p>0.05). Patients with clitoromegaly had significantly lower weighted CAG biallelic mean than those without it: 19.1±2.7 and 21.6±2.5, respectively (p = 0.007), independent of the CYP21A2 genotype's severity. The SRD5A2 polymorphisms were not associated with the variability of hyperandrogenic NC phenotypes. CONCLUSIONS: In this series, we observed a modulatory effect of the CAG-AR tract on clinical manifestations of the NC form. Although the NC form is a monogenic disorder, our preliminary data suggested that the interindividual variability of the hyperandrogenic phenotype could arise from polygenic interactions.

Opposite effects of dihydrotestosterone and estradiol on apoptosis in the anterior pituitary gland from male rats.

Hormones locally synthesized in the anterior pituitary gland are involved in regulation of pituitary cell renewal. In the pituitary, testosterone (T) may exert its actions per se or by conversion to dihydrotestosterone (DHT) or 17ß-estradiol (E2) by 5α-reductase and aromatase activity, which are expressed in this gland. Previous reports from our laboratory showed that estrogens modulate apoptosis of lactotropes and somatotropes from female rats. Now, we examined the in vitro and in vivo effects of gonadal steroids on apoptosis of anterior pituitary cells from adult male rats. T in vitro did not modify apoptosis in anterior pituitary cells from gonadectomized (GNX) male rats. DHT, a non-aromatizable androgen, exerted direct antiapoptotic action on total anterior pituitary cells and folliculo-stellate cells, but not on lactotropes, somatotropes, or gonadotropes. On the contrary, E2 exerted a rapid apoptotic effect on total cells as well as on lactotropes and somatotropes. Incubation of anterior pituitary cells with T in presence of Finasteride, an inhibitor of 5α-reductase, increased the percentage of TUNEL-positive cells. In vivo administration of DHT to GNX rats reduced apoptosis in the anterior pituitary whereas E2 exerted proapoptotic action and reduced cells in G2/M-phase of the cell cycle. In summary, our results indicate that DHT and E2 have opposite effects on apoptosis in the anterior pituitary gland suggesting that local metabolization of T to these steroids could be involved in pituitary cell turnover in males. Changes in expression and/or activity of 5α-reductase and aromatase may play a role in the development of anterior pituitary tumors.

Associations between the SRD5A2 gene V89L and TA repeat polymorphisms and breast cancer risk: a meta-analysis.

The 5α-reductase type 2 (SRD5A2) gene plays a significant role in the development of breast cancer. The V89L and TA repeat polymorphisms of the SRD5A2 gene have been considered as risk factors for breast cancer. However, the results have been inconsistent. To resolve this conflict, we performed a meta-analysis of studies with V89L (1144 patients and 808 controls) and with TA repeat genotyping (1952 cases and 1008 controls). The associations were evaluated by calculating odds ratios (ORs) and 95% confidence intervals (CIs). The result showed that there was no relationship between the V89L polymorphism of the SRD5A2 gene (V/V versus V/L + L/L genotypes) and breast cancer susceptibility (OR = 1.21; 95%CI = 0.99-1.47; P = 0.28). In addition, there was no difference between patients with breast cancer and healthy people in the distributions of the L allele (OR = 1.06; 95%CI = 0.75-1.49; P = 0.003). Similarly, no significant association between the SRDA5A2 TA repeat polymorphism and breast cancer risk was discovered. The comparison of (TA)0/(TA)0versus (TA)0/(TA)9 + (TA)9/(TA)9 genotypes found no difference in the risk of breast cancer (OR = 0.91; 95%CI = 0.66-1.25; P = 0.05). The OR for the (TA)0 versus (TA)9 allele was 0.89 (95%CI = 0.67-1.19). In conclusion, the V89L and TA repeat polymorphisms of SRD5A2 gene were found to have no significant associations with breast cancer risk.

Hamster SRD5A3 lacks steroid 5α-reductase activity in vitro.

According to current knowledge, two steroid 5α-reductases, designated type 1 (SRD5A1) and type 2 (SRD5A2), are present in all species examined to date. These isozymes play a central role in steroid hormone physiology by catalyzing the reduction of 3-keto-4-ene-steroids into more active 5α-reduced derivatives, including the conversion of testosterone (T) to dihydrotestosterone (DHT). A third 5α-reductase (SRD5A3, -type 3), which is overexpressed in hormone-refractory prostate cancer cells, has been identified; however, its enzymatic characteristics are practically unknown. Here, we isolated a cDNA encoding hamster Srd5a3 (hSrd5a3) and performed functional metabolic assays to investigate its biochemical properties. The cloned cDNA encodes a 330 amino acid protein that is 87% identical to the homologous protein in mice and 78% to that in humans. However, hSrd5a3 exhibits low sequence homology with its counterparts hSrd5a1 (19%) and hSrd5a2 (17%). A fusion protein consisting of hSrd5a3 and green fluorescent protein provided evidence for cytoplasmic localization in transfected mammalian cells. Real-time PCR analysis revealed that, Srd5a3 mRNA was present in nearly all hamster tissues, with high expression in the cerebellum, Harderian gland and testis. Functional assays expressing hSrd5a3 cDNA in HEK-293 cells revealed that this isozyme is unable to reduce T into DHT. Further expression assays confirmed that similar to testosterone, progesterone, androstenedione and corticosterone are not reduced by hSrd5a3 or human SRD5A3. Together, these results indicate that hSrd5a3 lacks the catalytic activity to transform 3-keto-4-ene-compounds; therefore 5α-reductase type 3 may not be involved in 5α-reduction of steroids.

Expression profiles of differentially expressed genes affecting fecundity in goat ovarian tissues.

Although RNA-Seq is an effective method for identifying and exploring novel functional genes in mammals, it has rarely been applied to study fertility-related genes in the goat. In this study, RNA-Seq was used to screen the estrus ovaries of uniparous and multiparous Anhui white goats (AWGs). In total, 15,890 genes were identified and 2201 of these were found to be differentially expressed between the genetic libraries from uniparous and multiparous goats. Compared to the uniparous library, 1583 genes were up-regulated and 618 genes were down-regulated in the multiparous library. The FER1L4 gene showed the level of highest up-regulation in the multiparous library, while SRD5A2 expression showed the greatest down-regulation. In order to determine the functions of FER1L4 and SRD5A2 in goats, the expression profiles of the two genes in different tissues from AWGs and Boer goats at diestrus were analyzed by quantitative PCR. FER1L4 and SRD5A2 showed tissue specific expression patterns and were highly expressed in ovaries from both AWGs and Boer goats. FER1L4 was more highly expressed in ovaries from multiparous than uniparous AWGs. In contrast, SRD5A2 was expressed at a lower level in multiparous AWGs. These results indicated that FER1L4 and SRD5A2 may be associated with the high fecundity of AWGs.