Changes in testicular function following specific deprivation of LH in the adult male rabbit

Immunological significance of prognostic alternative splicing signature in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) ranks the sixth prevalent tumors with high mortality globally. Alternative splicing (AS) drives protein diversity, the imbalance of which might act an important factor in tumorigenesis. This study aimed to construct of AS-based prognostic signature and elucidate the role in tumor immune microenvironment (TIME) and immunotherapy in HCC.

METHODS

Univariate Cox regression analysis was performed to determine the prognosis-related AS events and gene set enrichment analysis (GSEA) was employed for functional annotation, followed by the development of prognostic signatures using univariate Cox, LASSO and multivariate Cox regression. K-M survival analysis, proportional hazards model, and ROC curves were conducted to validate prognostic value. ESTIMATE R package, ssGSEA algorithm and CIBERSORT method and TIMER database exploration were performed to uncover the context of TIME in HCC. Quantitative real-time polymerase chain reaction was implemented to detect ZDHHC16 mRNA expression. Cytoscape software 3.8.0 were employed to visualize AS-splicing factors (SFs) regulatory networks.

RESULTS

A total of 3294 AS events associated with survival of HCC patients were screened. Based on splicing subtypes, eight AS prognostic signature with robust prognostic predictive accuracy were constructed. Furthermore, quantitative prognostic nomogram was developed and exhibited robust validity in prognostic prediction. Besides, the consolidated signature was significantly correlated with TIME diversity and ICB-related genes. ZDHHC16 presented promising prospect as prognostic factor in HCC. Finally, the splicing regulatory network uncovered the potential functions of splicing factors (SFs).

CONCLUSION

Herein, exploration of AS patterns may provide novel and robust indicators (i.e., risk signature, prognostic nomogram, etc.,) for prognostic prediction of HCC. The AS-SF networks could open up new approach for investigation of potential regulatory mechanisms. And pivotal players of AS events in context of TIME and immunotherapy efficiency were revealed, contributing to clinical decision-making and personalized prognosis monitoring of HCC.

Semi-mechanistic pharmacodynamic modeling for degarelix, a novel gonadotropin releasing hormone (GnRH) blocker

An integrated semi-mechanistic pharmacodynamic (PD) model describing the relationship between luteinizing hormone (LH) and testosterone (T) after short-term administration of degarelix was developed. Data from three clinical studies involving, intravenous (IV) and subcutaneous (SC) dosing, in healthy male subjects were available. Degarelix pharmacokinetic (PK) data from all studies were modeled simultaneously. One intravenous study was used to develop the PD model and the two other studies (IV and SC dosing) were used to qualify the model. Degarelix PK follows a two-compartment model and exhibits flip-flop kinetics after subcutaneous dosing. Based on physiological mechanism, the gonadotropin releasing hormone (GnRH) time course was described using a pulsatile release model. A precursor-dependent pool model was used to describe the kinetics of LH in the pituitary and plasma compartment. In males, LH regulates T production in leydig cells. Degarelix inhibits the release of LH from the pool compartment to the plasma compartment leading to decreased T production. The plasma half-life of LH (2.6-3.3 hr) and T (2.7 hr) match well with the literature reports. The proposed PD model reasonably described the time course of LH and T including the LH rebound for short-term studies. The model predicted the time course of LH and T for the second IV and SC dosing studies very well. However, the long term simulations from the final model did not match with literature reports. A modification is suggested based on the physiological understanding of the system. The proposed novel modification to precursor models can be of general use for predicting long term responses.

Induction of Antifertility with Lupeol Acetate in Male Albino Rats

The present study was undertaken to evaluate the antifertility activity of the active principle, i.e. lupeol acetate, isolated from benzene extract of Alstonia scholaris in male albino rats. The treatment with lupeol acetate at the dose level of 10 mg/rat/day did not cause any significant change in the body weights, but significant reduction in the weight of reproductive organs, i.e. testes, epididymides, seminal vesicle and ventral prostate, was observed. Testicular sperm count, epididymal sperm count and motility were found significantly declined when compared with controls, which resulted in reduction of male fertility by 100%. Arrest of spermatogenesis was noted at various stages with production of primary spermatocytes (preleptotene and pachytene), secondary spermatocytes and step-19 spermatids were decreased by 52.36, 54.91, 55.67 and 69.65%, respectively. The seminiferous tubules appeared reduced in size by 24.62%. Cross-sectional surface area of Sertoli cells as well as their counts were found to be significantly depleted. Leydig cell nuclear area and number of mature Leydig cells were decreased by 27.65 and 35.47%. Biochemical parameters of tissues i.e. protein, sialic acid, glycogen and cholesterol content of testes and seminal vesicular fructose also showed significant reduction.

Contraceptive vaccines

The world's population is growing at a tremendous rate, affecting growth and development. Apart from this population growth, unintended pregnancies resulting in elective abortions continue to be a major public health issue. In over half of these unintended pregnancies, the women have used some type of contraception. Thus, there is an urgent need for a better method of contraception that is acceptable, effective and available. The contraceptive choices available to women at this time include steroid contraceptives, intrauterine devices, barrier methods, spermicides, natural family planning, male and female sterilisation, and recently available emergency contraceptives. Contraceptive vaccines (CVs) may provide viable and valuable alternatives that can fulfill most, if not all, properties of an ideal contraceptive. Since both the developed and most of the developing nations have an infrastructure for mass immunisation, the development of vaccines for contraception is an exciting proposition. The molecules that are being explored for CV development either target gamete production (gonadotropin releasing hormone, follicle-stimulating hormone and luteinising hormone), gamete function (zona pellucida [ZP] proteins and sperm antigens) or gamete outcome (human chorionic gonadotropin [hCG]). Disadvantages of CVs targeting gamete production are that they affect sex steroids and/or show only a partial effect in reducing fertility. CVs targeting gamete function are better choices. Vaccines based on ZP proteins are quite efficacious in producing contraceptive effects. However, they invariably induce oophoritis affecting sex steroids. Sperm antigens constitute the most promising and exciting targets for CVs. Several sperm-specific antigens have been delineated in several laboratories and are being actively explored for CV development. Antisperm antibody-mediated immunoinfertility provides a naturally occurring model to indicate how an antisperm vaccine will work in humans. Vaccines targeting gamete outcome primarily focus on the hCG molecule. The hCG vaccine is the first vaccine to undergo phase I and II clinical trials in humans. Both the efficacy and the lack of immunotoxicity have been reasonably well demonstrated for this vaccine. The present studies focus on increasing the immunogenicity and efficacy of this birth control vaccine.

A Sertoli cell-selective knockout of the androgen receptor causes spermatogenic arrest in meiosis

Androgens control spermatogenesis, but germ cells themselves do not express a functional androgen receptor (AR). Androgen regulation is thought to be mediated by Sertoli and peritubular myoid cells, but their relative roles and the mechanisms involved remain largely unknown. Using Cre/loxP technology, we have generated mice with a ubiquitous knockout of the AR as well as mice with a selective AR knockout in Sertoli cells (SC) only. Mice with a floxed exon 2 of the AR gene were crossed with mice expressing Cre recombinase ubiquitously or selectively in SC (under control of the anti-Müllerian hormone gene promoter). AR knockout males displayed a complete androgen insensitivity phenotype. Testes were located abdominally, and germ cell development was severely disrupted. In contrast, SC AR knockout males showed normal testis descent and development of the male urogenital tract. Expression of the homeobox gene Pem, which is androgen-regulated in SC, was severely decreased. Testis weight was reduced to 28% of that in WT littermates. Stereological analysis indicated that the number of SC was unchanged, whereas numbers of spermatocytes, round spermatids, and elongated spermatids were reduced to 64%, 3%, and 0% respectively of WT. These changes were associated with increased germ cell apoptosis and grossly reduced expression of genes specific for late spermatocyte or spermatid development. It is concluded that cell-autonomous action of the AR in SC is an absolute requirement for androgen maintenance of complete spermatogenesis, and that spermatocyte/spermatid development/survival critically depends on androgens.

Seasonal timing of sperm production in roe deer: interrelationship among changes in ejaculate parameters, morphology and function of testis and accessory glands

Roe deer are seasonal breeders with a short rutting season from mid-July to mid-August. The seasonality of reproductive activity in males is associated with cyclic changes between growth and involution of both testes and the accessory sex glands. This study characterizes morphological and functional parameters of these organs prior to, during and after breeding season in live adult roe deer bucks. Size and morphology of the reproductive tract was monitored monthly by transcutaneous (testes, epididymis) and transrectal (accessory glands) ultrasonography. Semen was collected by electroejaculation. Concentration, motility and morphological integrity of spermatozoa as well as the content of proteins and testosterone in semen plasma were evaluated. Proportions of haploid, diploid and tetraploid cells were estimated by flow cytometry in testicular tissue biopsies. Serum testosterone was measured by enzyme immunoassay. Most parts of the male reproductive tract showed distinct circannual changes in size and texture. These changes were most pronounced in the testes, seminal vesicles, and prostate. All reproductive organs were highly developed during the rut only. The volume of ejaculates, total sperm number and percentages of motile and intact spermatozoa also showed a maximum during this period and corresponded with high proportions of haploid cells in the testis. The highest percentages of tetraploid cells were found in the prerutting period. The production of motile and intact spermatozoa correlated with both the protein content of semen plasma and the concentration of testosterone in semen plasma and blood serum. These results suggest the importance of combined actions of the testes and accessory sex glands and the crucial role of testosterone in facilitating the optimal timing of intensified semen production to ensure sufficient numbers of normal spermatozoa in seasonal breeders.

Current advances in antifertility vaccines for fertility control and noncontraceptive applications

The search for effective antifertility vaccines has been actively pursued for decades in clinical applications as contraceptives or in the treatment of hormone-dependent conditions. More recently, innovations have seen immunocontraception being employed successfully in veterinary and farming applications, as well as in population control of a number of different wildlife species. Although the basic principle behind these vaccines is the same, design considerations and criteria for commercialization are very different. This review will examine current advances in this field and evaluate the future scope of antifertility vaccines.

Immunobiology of a synthetic luteinizing hormone receptor peptide 21-41

Immunization of adult male rabbits with a synthetic luteinizing hormone-receptor peptide (LH-RP; representing amino-acids 21-41 of the extracellular domain of the rat LH receptor) resulted in production of high-titer antibodies capable of interacting with particulate and cell-based LH receptors. The antibody produced was able to inhibit binding of 125I-labeled human chorionic gonadotropin (hCG) to a particulate sheep luteal LH receptor preparation by 40%-50%. Maximal inhibitory activity was correlated with high antibody titer. Immunocytometry revealed that the antibody could directly bind to cells having LH receptors, such as rat granulosa and Leydig cells. The antibodies recognized a 77-kilodalton membrane protein in Western blots of mouse testicular extracts. Interaction of endogenous Leydig cell LH receptor with the LH-RP antibody resulted in both hormone agonist and antagonistic activities. The hormone-mimicking activity (increase in serum testosterone over control) was confined only to the early phase of immunization when the antibody titer was low. Blockade of LH receptor during the later part of immunization resulted in a significant reduction in serum testosterone over controls and inhibition of spermatogenesis. DNA flow cytometry showed that a specific and significant inhibition of meiosis (transformation of primary spermatocytes to round and elongated spermatids P < .01) and spermiogenesis (transformation of round spermatids to elongated spermatids P < .0001) occurred following blockade of LH function.

Calculation of spermatogenic transformations based on dual-flow cytometric analysis of testicular tissue in seasonal breeders

The percentages of somatic and spermatogenic cells were quantified at different time intervals in testes of three seasonal breeders: roe deer, brown hare and mink. The haploid, diploid and tetraploid cells were monitored by one-parameter flow cytometry. Somatic and spermatogenic cells were distinguished by dual-parameter flow cytometry after DNA staining and selective labelling of the somatic cells with an antivimentin antibody. The portions of spermatogenic diploid and tetraploid cells were used to calculate total germ cell transformation (haploid:diploid cell ratio) as well as meiotic transformation (haploid:tetraploid cell ratio). During the breeding season the means of both ratios were 10.27 and 38.42 in roe deer, 7.55 and 15.81 in brown hare, and 11.25 and 53.47 in mink. The equivalent quotients calculated on the base of total diploid and tetraploid cells were considerably lower: 4.41 and 7.79, 5.13 and 7.86, 5.68 and 13.75, respectively. Portions as well as proportions of germinative and somatic cells changed during the annual cycle. The results demonstrate that the distinction of somatic and germinative cells in flow cytometric studies of spermatogenesis is a prerequisite for exact calculations of mitotic and meiotic processes and their alterations under different conditions.

Quantification of somatic and spermatogenic cell proliferation in the testes of ruminants, using a proliferation marker and flow cytometry analysis

We compared 2 methods for the quantification of proliferation in somatic and spermatogenic compartments of post mortem-collected testes in cattle and roe deer. Proliferation was evaluated by estimation of the tissue polypeptid specific antigen (TPS) using an ELISA. This proliferation-specific marker was detected in homogenized cells after selective enrichment of different cell types by density gradient centrifugation. The haploid, diploid and tetraploid cells were monitored by one-parameter flow cytometry and analyzed for mitotic cell cycle. Somatic and spermatogenic cells were discriminated by dual-parameter flow cytometry after DNA staining with propidium iodide and selective labelling of stromatic cells with a vimentin antibody. The TPS was related to the ploidy of cells and their somatic or spermatogenic type. High concentrations of TPS were found in both species. The TPS values varied with different contents of spermatogenic and somatic cells in the fractions of the density gradient. The TPS was positively correlated with spermatogenic cells in the G2/M phase of mitotic cycle (r = 0.474; P < 0.01) and negatively correlated with somatic cells (r = -0.676; P < 0.0001) in roe deer (n = 40). Discrimination of germinative and stromatic cells in the G2-M phase showed their varying proliferation during the annual cycle in roe deer. The quantification of tetraploid spermatogenic cells allowed the calculation of an exact meiotic transformation (ratio haploid:tetraploid cells). In conclusion, TPS indicates proliferation in the germinative compartment of the testes. However, this marker provides only relative values, without information on the number and type of proliferating cells. Dual-parameter flow cytometry using specific staining for vimentin proves to be a better method for studying changing mitotic and meiotic steps during the involution and recrudescence of testes in seasonally breeding ruminants, as it relates proliferative processes directly to both spermatogenic and somatic cells.