Germ Cell Degeneration Research Articles

The effects of testicular stromal stem cells on surgically injured testicular tissue in rats.

This study investigated the effects of transplanted testicular stromal stem cells (tSSCs) on surgically damaged testis tissue. Ten-week-old male Wistar albino rats were divided into three groups: control (n = 6), damage (DG) (n = 6) and testicular stromal stem cell (TSSC) (n = 6) groups. Surgically induced damage was inflicted on the left testes of both the DG and TSSC groups, with no intervention on the right testes. In the TSSC group, damaged testes were treated with transplanted tSSCs, followed by orchiectomy after 15 days. Testes tissues were stained with haematoxylin-eosin (H&E), and recovery rates of functional structures were assessed by modified Johnsen scoring. The effects of tSSCs on testicular tissue were demonstrated by immunohistochemistry using BAX, BCL-2 and caspase 3. Serum testosterone levels were analysed using the enzyme-linked immunosorbent assay (ELISA) method. Surgical damage caused germ cell degeneration in some seminiferous tubules and a decrease in interstitial areas. With tSSC treatment, improvements in testicular architecture were identified through spermatogenesis in the seminiferous tubules and normal histological structures in the interstitial areas. Correspondingly, in the modified Johnsen score, the DG group showed a significant difference compared to the other groups (p = 0.001). High expressions of BAX, BCL-2 and caspase-3 in the DG group revealed prominent features of apoptosis. With the injection of tSSCs, these expressions significantly normalized according to H score analysis (all p = 0.004). Although serum testosterone levels in the tSSC group were higher compared to the control and DG groups, this difference was not statistically significant (p = 0.119). This study suggests transplanting tSSCs could accelerate tissue healing after testicular sperm extraction (TESE) surgery for azoospermia patients, potentially paving the way for a new and important clinical treatment.

The Role of Retinoic Acid in Spermatogenesis and Its Application in Male Reproduction.

Spermatogenesis in mammalian testes is essential for male fertility, ensuring a continuous supply of mature sperm. The testicular microenvironment finely tunes this process, with retinoic acid, an active metabolite of vitamin A, serving a pivotal role. Retinoic acid is critical for various stages, including the differentiation of spermatogonia, meiosis in spermatogenic cells, and the production of mature spermatozoa. Vitamin A deficiency halts spermatogenesis, leading to the degeneration of numerous germ cells, a condition reversible with retinoic acid supplementation. Although retinoic acid can restore fertility in some males with reproductive disorders, it does not work universally. Furthermore, high doses may adversely affect reproduction. The inconsistent outcomes of retinoid treatments in addressing infertility are linked to the incomplete understanding of the molecular mechanisms through which retinoid signaling governs spermatogenesis. In addition to the treatment of male reproductive disorders, the role of retinoic acid in spermatogenesis also provides new ideas for the development of male non-hormone contraceptives. This paper will explore three facets: the synthesis and breakdown of retinoic acid in the testes, its role in spermatogenesis, and its application in male reproduction. Our discussion aims to provide a comprehensive reference for studying the regulatory effects of retinoic acid signaling on spermatogenesis and offer insights into its use in treating male reproductive issues.

Effects of pharmacological doses of niacin on subacute glucocorticoid-induced testicular damage in rats.

Glucocorticoid excess adversely affects male reproduction. This study evaluates effects of pharmacological doses of niacin on testicular structure and function in dexamethasone-treated rats. Adult rats (48) were randomly assigned to 6 equal groups: (1) Negative control (NC): normal rats; (2) Positive control (PC): dexamethasone at 7 mg/kg/day by intraperitoneal injections for 7 days; groups 3-6 (N50, N100, N200, and N400): dexamethasone and concomitant treatment with niacin at 50, 100, 200, and 400 mg/kg/day by oral gavages. Testicular weight and volume of PC rats were significantly lower than the NC group (p < .05). Testicular volume of rats in the N50 and N200 groups was statistically similar to the NC group. Significant decreases in serum testosterone with a slight LH increase were detected in the PC group. Nacin at 50 mg/kg reversed serum testosterone to NC levels and increased serum LH concentration. Niacin only slightly increased epididymal spermatozoa number while all groups of niacin-treated rats had significantly higher percentages of motile spermatozoa compared with the PC group. Hypospermatogenesis, germ cell degeneration and depletion, epithelial vacuolization, and degenerated Leydig cells were observed in PC rats. Lesions were relatively milder in niacin-treated rats. Johnsen scores were also significantly higher in niacin-treated rats. Niacin reduced apoptosis as shown by TUNEL assay. In conclusion, niacin administration at pharmacological doses dose-dependently ameliorates the destructive effects of dexamethasone on sperm motility, Johnsen score, and testicular cell apoptosis in rats with the latter can be considered a decisive mechanism for its positive effects on testis.

Protective effect of exogenous melatonin on testicular histopathology and histomorphometry of adult rats with domperidone-induced hyperprolactinemia

Hyperprolactinemia is a pathological condition resulting from increased prolactin that directly affects reproduction, as this condition inhibits the release of LH, FSH and gonadal steroidogenesis, bringing several negative clinical associations in reproduction. In contrast, melatonin (MEL) plays an important role in the regulation of steroidogenesis and modulates damages to the process of spermatogenesis. The objective was to analyze the protective effects of exogenous melatonin on the testis of hyperprolactinemic adult rats. Forty-eight male rats were used, divided into two treatment periods: 30 and 60 days, each treatment was subdivided into three groups: Control, Hyper (hyperprolactinemia), and Hyper+MEL (hyperprolactinemia and melatonin). Treatment with melatonin was 200 μg/100 g, subcutaneously. Induction of hyperprolactinemia was obtained with a dose of 4 mg/kg of domperidone, subcutaneously. The results of the histopathology demonstrated that the animals in the Hyper group presented degeneration of germ cells when compared to the control. In addition, the degenerations were presented in smaller quantities in the Hyper+MEL, in both treatment periods, evidencing the benefits of the melatonin in gonadal regeneration. The Hyper group of both treatment periods showed a decrease in tubular diameter, epithelium height, and tubular area, in addition to a decrease in Sertoli cells, when compared to the control and the Hyper+MEL group. In conclusion, the hyperprolactinemia can affect the germinal epithelium and testicular microstructure; the exogenous melatonin has a protective effect against hyperprolactinemia, reducing testicular damage.

Protective effects of CAPE against testicular damage in streptozotocin-induced diabetic rats

Objective: The aim of this study was to investigate the protective effect of CAPE on oxidative stress and apoptosis against streptozotocin (STZ)-induced damage in rat testis after diabetes. Materials and methods: The rats were randomly divided into 4 groups: Control animals, Control animals given CAPE, STZ-induced diabetic animals, and STZ-induced diabetic rats given CAPE. Diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg). Testicular damage was examined by using hematoxylin and eosin staining and apoptosis was determined by Caspase-3. Potential disorders associated with seminiferous tubular sperm formation were evaluated using the Johnsen score and seminiferous tubule diameters were measured using the Leica Q Win Plus Image Analysis System. Results: Diabetic rats showed an increase in degenerated germ cells along with a decrease in seminiferous tubule diameter. Also, Caspase-3 positive cells were significantly increased in diabetic rats compared to control rats. On the other hand, CAPE significantly reduced the damage and germ cell apoptosis in diabetic rat testis. In testis tissues samples. CAPE treatment significantly decreased the elevated tissue malondialdehyde levels, while increasing the reduced superoxide dismutase enzyme activity. Conclusion: These results suggest that CAPE administered intraperitoneally for 20 days to diabetic rats is a potentially beneficial agent that can be used to reduce testicular damage.

Zinc protects against lead-induced testicular damage via modulation of steroidogenic and xanthine oxidase/uric acid/caspase 3-mediated apoptotic signaling in male Wistar rats

Aim This study evaluated the effect of lead, with or without zinc co-administration, on steroidogenic and xanthine oxidase (XO)/uric acid (UA)/caspase 3-mediated apoptotic signaling in the testis. Materials and methods Forty male Wistar rats were divided into four groups at random; vehicle-treated control, zinc-treated, lead-treated, and lead + zinc-treated groups. Results Lead exposure significantly lowered overall weight gain, testicular, epididymal, seminal vesicle, and prostate weights. Also, lead decreased sperm count, viability and motility but increased the fraction of sperm with aberrant morphology. In addition, lead caused a marked rise in the level of UA and XO activity but a decrease in nuclear factor erythroid 2-related factor 2 (Nrf2), reduced glutathione (GSH) as well as total antioxidant capacity (TAC) levels, and superoxide dismutase (SOD) and catalase activities. Furthermore, lead increased the testicular levels of nuclear factor kappa B (NFkB), interleukin-1beta (IL-1β), and tumour necrotic factor-alpha (TNF-α), which were associated with an increase in testicular caspase 3 activity and DNA fragmentation as well as a decline in circulating gonadotropin releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and testicular 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD). These were associated with lead-induced degenerative changes in testicular tissues evidenced by shrunken seminiferous tubules, degeneration and sloughing of germ cells. Co-administration of zinc prevented lead-induced testicular injury by ameliorating oxidative stress, apoptosis, and inflammation through downregulation of XO/UA/caspase 3 pathway and upregulation of testicular 3β-HSD/17β-HSD. Conclusion This study demonstrated that zinc protected against lead-induced testicular toxicity via the downregulation of XO/UA/caspase 3 signaling.

Reproductive findings in male animals exposed to selective survival of motor neuron 2 (SMN2) gene splicing-modifying agents

Risdiplam is a daily, orally dosed, survival of motor neuron 2 (SMN2) mRNA splicing-modifying agent approved for the treatment of spinal muscular atrophy (SMA). RG7800 is a closely related SMN2 mRNA-splicing compound. Effects on secondary mRNA splice targets such as Forkhead Box M1 (FOXM1) and MAP kinase-activating death domain protein (MADD), which have been implicated in cell-cycle regulation, were observed in non-clinical studies with both risdiplam and RG7800. Potential effects of risdiplam on male fertility via FOXM1 and MADD are important as these secondary splice targets exist in humans. This publication reports the findings from 14 in vivo studies that investigated the reproductive tissues of male animals in various stages of development. Exposure to risdiplam or RG7800 induced changes within the germ cells in the testes of male cynomolgus monkeys and rats. Germ-cell changes included both cell-cycle gene changes (alteration of mRNA-splicing variants) and seminiferous tubule degeneration. In monkeys treated with RG7800, there was no evidence of damage to spermatogonia. Observed testicular changes were stage-specific with spermatocytes in the pachytene stage of meiosis and were fully reversible in monkeys following a sufficient recovery period of eight weeks following cessation of RG7800. In rats, seminiferous tubule degeneration was present, and full reversibility of germ-cell degeneration in the testes was observed among half of the rats that were exposed to risdiplam or RG7800 and then allowed to recover. With these results, coupled with histopathological findings, the effects on the male reproductive system are expected to be reversible in humans for these types of SMN2 mRNA-splicing modifiers.

Zika Virus Infection Damages the Testes in Pubertal Common Squirrel Monkeys (Saimiri collinsi).

During the Zika virus (ZIKV) outbreak and after evidence of its sexual transmission was obtained, concerns arose about the impact of the adverse effects of ZIKV infection on human fertility. In this study, we evaluated the clinical-laboratory aspects and testicular histopathological patterns of pubertal squirrel monkeys (Saimiri collinsi) infected with ZIKV, analyzing the effects at different stages of infection. The susceptibility of S. collinsi to ZIKV infection was confirmed by laboratory tests, which detected viremia (mean 1.63 × 106 RNA copies/µL) and IgM antibody induction. Reduced fecal testosterone levels, severe testicular atrophy and prolonged orchitis were observed throughout the experiment by ultrasound. At 21 dpi, testicular damage associated with ZIKV was confirmed by histopathological and immunohistochemical (IHC) analyses. Tubular retraction, the degeneration and necrosis of somatic and germ cells in the seminiferous tubules, the proliferation of interstitial cells and an inflammatory infiltrate were observed. ZIKV antigen was identified in the same cells where tissue injuries were observed. In conclusion, squirrel monkeys were found to be susceptible to the Asian variant of ZIKV, and this model enabled the identification of multifocal lesions in the seminiferous tubules of the infected group evaluated. These findings may suggest an impact of ZIKV infection on male fertility.

Pisidium Guajava Ameliorates Testicular Distortions Triggered by Aluminium Chloride in Adult Male Wistar Rats

Introduction: Aluminium (Al) is a trivalent cation that does not undergo redox changes. Extensive experimental shreds of evidence demonstrate in-vitro and in-vivo, that high Al concentrations cause oxidative stress; an imbalance between free radical generation and the antioxidant defense system. Oxidative stress induced by Aluminium is one of the major contributing factors to male reproductive disorders. Psidium guajava, the guava tree is widely distributed as a native plant in Latin America and Sub-Saharan Africa, with its leaves being deployed in folk medicine to manage several diseased conditions such as; diarrhoea, stomach ache, and hepatic problems. The study was conducted to evaluate the effects of an aqueous extract of Pisidium guajava on Aluminium (AlCl3) induced testicular damage. Materials and Methods: Thirty adult male Wistar rats were divided randomly into six (6) groups of five (5) animals each and used for this study. Group A was orally administered with 0.5 ml of normal saline from the 1st to the 14th day. Group B got 0.5 ml of 100mg/kg body weight of aluminium chloride (AlCl3) only, from the 1st to 14th day. Group C got 0.5 mls of 250mg/kg body weight of Psidium gaujava leaf extract from the 1st to 14th day, Group D got 0.5 mls of 500 mg/kg body weight of Psidium guajava from the 1st to 14th day. Group E got 0.5 mls of 100mg/kg body weight of aluminum chloride from the 1st to 14th day, and 0.5 mls of 250 mg/kg body weight of Psidium guajava leaf extract from the 15th to 28th day. Group F got 0.5mls of 100 mg/kg body weight of aluminum chloride from the 1st to the 14th day, and 0.5mls of 500 mg/kg body weight of Psidium guajava leaf extract from the 15th to the 28th day. Administration was via the oral gavage. Results: Oral administration of aluminum chloride adversely compromised the testicular histomorphology of Wistar rats, causing testicular atrophy associated with degeneration of germ cells within the seminiferous tubules, and enlarged lumen with fewer spermatids compared with the non-treated animals. Conclusion: Guava leaf extract reversed the damage caused by aluminum chloride, restoring the distorted seminiferous tubules and presenting the lumen with densely packed primary spermatocytes.

Histomorphological and histomorphometric changes in the testes of male Wistar rats following prepubertal exposure to caffeine

This experiment was designed to study the effects of caffeine on the histomorphology of the testes of prepubertal male Wistar rats. Prepubertal Wistar rats (25-28 days old), weighing between 50-60 g were randomly divided into three treatment groups (B, C and D) and control (A) of ten rats each. Group A rats received distilled water while Groups B, C, and D rats were respectively given daily dose of 50 mg/kg, 100 mg/kg, and 200 mg/kg of caffeine dissolved in distilled water for 14 days by gavage. Five rats from each group were sacrificed 24 hours after the last caffeine administration while the remaining rats were monitored for another three weeks for them to attain sexual maturity. The rats were sacrificed under diethyl ether anesthesia and the testes were fixed by immersion in Bouin’s fluid. The tissues were processed for histomorphological and histomorphometric assessment. Data obtained were analyzed using one way ANOVA followed by Dunnett post hoc test for comparison with control. Alpha level was set at 0.05. Results showed that treatment with caffeine caused a significant decrease in testicular weight and a marked cellular degeneration and depletion of germ cells in the testes of rats in group D. The height of the germinal epithelium was significantly reduced when compared with control. This study concluded that prepubertal exposure of Wistar rats to caffeine reduced testicular growth and deleteriously alters testicular morphology.

Increased DNA strand breaks in spermatozoa of Pxt1 knockout mice.

The Pxt1 gene encodes a male germ cell-specific protein and its overexpression results in male germ cell degeneration and male infertility in transgenic mice. The analysis of the function of Pxt1 during mouse spermatogenesis. The phenotype of Pxt1 knockout mice was characterised by testicular histology, assessment of semen parameters including sperm motility, and DNA fragmentation by flow cytometry. Gene expression was analysed using RT-PCR. Fertility of mutants was checked by standard breeding and competition breeding tests. In Pxt1 -/- mice, a strong increase in the sperm DNA fragmentation index (DFI) was observed, while other sperm parameters were comparable to those of control animals. Despite enhanced DFI, mutants were fertile and able to mate in competition with wild type males. Pxt1 induces cell death; thus, the higher sperm DFI of mice with targeted deletion of Pxt1 suggests some function for this gene in the elimination of male germ cells with chromatin damage. Ablation of mouse Pxt1 results in enhanced DFI. In humans, the homologous PXT1 gene shares 74% similarity with the mouse gene; thus, it can be considered a candidate for mutation screening in patients with increased DFI.

The peptide fraction of Bothrops jararaca snake venom induces toxicological effects on the male reproductive system after local envenomation in mice

Bothrops envenomation is complex and provokes prominent local tissue damage and systemic disturbances, but little is known about their effects on the male reproductive system. After intratesticular injection, the bioactive peptide fraction (Bj-PF) obtained from Bothrops jararaca snake venom changes the structure of different stages of the seminiferous epithelium cycle in adult mice. For the first time, we investigated whether local envenomation of Bj-PF induces toxicological effects on the male reproductive system, particularly on the seminiferous epithelium and Sertoli cells. Male adult mice were treated with 0.24 mg.kg−1 by intramuscular (i.m.) injection for 24 h. The testes samples were collected for morphological and morphometric evaluation. The toxicological effects of Bj-PF were also analyzed on mitochondrial metabolism and nitrite (NO2) production in 15P-1 Sertoli cell culture. Bj-PF changed the structure and function of the seminiferous epithelium, particularly the disruption of the epithelium and the presence of degenerated germ cells in the adluminal compartment, but there were no alterations in the basal compartment. Bj-PF increased the thickness of the seminiferous epithelium and decreased the lumen diameter of the tubule. Semiquantitative histological assessment of the degree of tubule degeneration revealed that Bj-PF also increased the number of hypospermatogenic tubules compared to control. Bj-PF reduced NO2 levels in 15P-1 Sertoli cells without changing the mitochondrial metabolism. Overall, the fact that Bj-PF alters the structure and function of the seminiferous epithelium suggests that bioactive peptides found in B. jararaca snake venom can have toxicological effects on the reproductive systems of affected male mice, providing new insight into the biological characteristics of snake venom and therapeutic strategies for envenomation inflammation.

Histo-architecture of the male reproductive system of freshwater African catfish Clarias gariepinus (Burchell, 1822) : An impact of Hexaconazole

Endocrine disrupting chemicals (EDCs), which are include industrial and agricultural chemicals with a wide range of toxicological properties. Among them conazole is one of the potential class of EDCs. Due to the various use of conazoles, it ultimately concentrates into the water bodies. So, aquatic ecosystem contaminates have wide range of agricultural effluents which ultimately affect the aquatic organism especially fishes. Therefore, the present study was conducted to investigate the effects of Hexaconazole, on male gonad of African catfish Clarias gariepinus by using a histopathological study. To perform the experiment, fishes were divided into three groups: control group, low dose (5 mg/lit) and high dose (8 mg/lit) groups. Each group was exposed to respective doses of Hexaconazole for five days and in last sacrificed for the histopathological study. It was observed that, the fishes which were expose to low and high dose of Hexaconazole showed severe damage to the testes, which includes disorganization of spermatogenic cyst, degeneration of germ cells, hypertrophy of Sertoli cells, and degeneration of seminiferous tubules, vacuolization in seminiferous tubules, clumping of spermatogenic cells etc. Thus, it can be concluded that, exposure to Hexaconazole causes significant alterations in the histological structure of the testes which may impair the normal reproductive functions in male C. gariepinus and these alterations were directly related to the concentration of Hexaconazole.

Functions of somatic cells for spermatogenesis in stallions.

Spermatogenesis and testis development are highly structured physiological processes responsible for post-pubertal fertility in stallions. Spermatogenesis comprises spermatocytogenesis, meiosis, and spermiogenesis. Although germ cell degeneration is a continuous process, its effects are more pronounced during spermatocytogenesis and meiosis. The productivity and efficiency of spermatogenesis are directly linked to pubertal development, degenerated germ cell populations, aging, nutrition, and season of the year in stallions. The multiplex interplay of germ cells with somatic cells, endocrine and paracrine factors, growth factors, and signaling molecules contributes to the regulation of spermatogenesis. A cell-to-cell communication within the testes of these factors is a fundamental requirement of normal spermatogenesis. A noteworthy development has been made recently on discovering the effects of different somatic cells including Leydig, Sertoli, and peritubular myoid cells on manipulation the fate of spermatogonial stem cells. In this review, we discuss the self-renewal, differentiation, and apoptotic roles of somatic cells and the relationship between somatic and germ cells during normal spermatogenesis. We also summarize the roles of different growth factors, their paracrine/endocrine/autocrine pathways, and the different cytokines associated with spermatogenesis. Furthermore, we highlight important matters for further studies on the regulation of spermatogenesis. This review presents an insight into the mechanism of spermatogenesis, and helpful in developing better understanding of the functions of somatic cells, particularly in stallions and would offer new research goals for developing curative techniques to address infertility/subfertility in stallions.

Abstract 3592: Targeting SWI/SNF ATPases in enhancer-addicted human cancers

Abstract In mammalian cells, DNA is wrapped around histone octamers (collectively referred to as nucleosomes) which form a physical barrier to all DNA-based processes. The switch/sucrose non-fermentable (SWI/SNF) is a multi-subunit chromatin remodeling complex that uses energy from ATP hydrolysis to reposition or eject nucleosomes at non-coding regulatory elements, thereby enabling access to the underlying DNA for transcriptional activation. Notably, the SWI/SNF complex plays a crucial role in chromatin remodeling and is recurrently altered in over 20% of human cancers, with the revised complex in cancer cells enabling central oncogenic gene programs. Yet, no studies have assessed the therapeutic efficacy of complete SWI/SNF inactivation across human cancers. Here, we developed a proteolysis targeting chimera (PROTAC) degrader of ATPase subunits of the SWI/SNF complex, SMARCA2 and SMARCA4. In a panel with over 90 normal and cancer cell lines from 18 different lineages, we found MYC-driven multiple myeloma and androgen receptor (AR)/forkhead box A1 (FOXA1)-positive prostate and breast cancers to be preferentially sensitive to dual SMARCA2 and SMARCA4 degradation relative to benign prostate as well as other cancer cell lines, including cancer cell lines with inactivating SMARCA4 mutations. We found complete SWI/SNF ATPase degradation to instantaneously compact the cis-regulatory elements that are bound and activated by transcription factors that drive cancer proliferation, namely MYC, IRF4, TCF3, AR, FOXA1, and ERG. This ensued in parallel untethering of these oncogenic drivers from the chromatin, with subsequent chemical decommissioning of their core enhancer circuitry and attenuation of downstream gene programs. Furthermore, using chromatin conformation assays we found SWI/SNF inactivation to disrupt super-enhancer and promoter DNA looping interactions that wire supra-physiologic expression of the MYC, AR, ERG, IRF4, and TCF3 oncogenes themselves, thereby tempering their expression in cancer cells. Treatment with the SMARCA2/4 degrader alone induced potent inhibition of tumor growth in cell line-derived xenograft models of multiple myeloma, as well as prostate cancer, and synergized with AR antagonists, inducing disease remission in several drug-resistant disease models. Notably, no major toxicities were seen in mice upon prolonged treatment with the SMARCA2/4 degrader, including no indications of thrombocytopenia, gastrointestinal goblet cell depletion, or germ cell degeneration—all being major toxicities associated with the BRD4-targeting therapeutics. To our knowledge, this study is the first preclinical proof of concept that targeted obstruction of chromatin accessibility at non-coding regulatory elements can be a potent therapeutic strategy in enhancer-addicted tumors, warranting the safety and efficacy assessments of SWI/SNF inhibitors and degraders in human clinical trials. Citation Format: Abhijit Parolia, Lanbo Xiao, Yuanyuan Qiao, Pushpinder Bawa, Sanjana Eyunni, Eleanor Young, Rahul Mannan, Sandra E. Carson, Yu Chang, Yuping Zhang, James George, Mustapha Jaber, Fengyun Su, Rui Wang, Sanjita Sasmal, Leena Khare, Subhendu Mukerjee, Chandrasekhar AbbinenI, Kiran Aithal, Xuhong Cao, Yuzhuo Wang, Susanta Samajdar, Murali Ramachandra, Arul M. Chinnaiyan. Targeting SWI/SNF ATPases in enhancer-addicted human cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3592.

Abstract 5469: Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer

Abstract The switch/sucrose non-fermentable (SWI/SNF) complex plays a crucial role in chromatin remodeling and is recurrently altered in over 20% of human cancers. Here, we developed a proteolysis targeting chimera (PROTAC) degrader of ATPase subunits of the SWI/SNF complex, SMARCA2 and SMARCA4. Intriguingly, we found androgen receptor (AR)/forkhead box A1 (FOXA1)-positive prostate cancer to be exquisitely sensitive to dual SMARCA2 and SMARCA4 degradation relative to benign prostate as well as other cancer cell lines, including those with inactivating SMARCA4 mutations. Mechanistically, SWI/SNF inhibition rapidly compacts the cis-regulatory elements that are bound and activated by transcription factors that drive cancer proliferation, namely AR, FOXA1, ERG, and MYC. This ensues in chromatin untethering of these oncogenic drivers, chemical decommissioning of their core enhancer circuitry, and attenuation of downstream gene programs. Furthermore, we found SWI/SNF inhibition to disrupt super-enhancer and promoter DNA looping interactions that wire supra-physiologic expression of the AR, FOXA1, and MYC oncogenes, thereby tempering their expression in cancer cells. Monotherapy with the SMARCA2/4 degrader induced potent inhibition of tumor growth in cell line-derived xenograft models of prostate cancer and remarkably synergized with AR antagonists, inducing disease remission in models of castration-resistant prostate cancer. We also found the combinatorial treatment to significantly inhibit the growth of enzalutamide resistant disease using in vitro as well as patient-derived xenograft models. Notably, no major toxicities were seen in mice upon prolonged treatment with the SMARCA2/4 degrader, including no indications of thrombocytopenia, gastrointestinal goblet cell depletion, or germ cell degeneration. Taken together, these results suggest that impeding enhancer accessibility through SWI/SNF ATPase inactivation represents a novel therapeutic approach in enhancer addicted human cancers. Citation Format: Lanbo Xiao, Abhijit Parolia, Yuanyuan Qiao, Pushpinder Bawa Pushpinder, Sanjana Eyunni, Rahul Mannan, Sandra E. Carson, Yu Chang, Xiaoju Wang, Yuping Zhang, Josh Vo, Steven Kregel, Stephanie A. Simko, Andrew D. Delekta, Mustapha Jaber, Heng Zheng, Ingrid Apel, Lisa McMurry, Fengyun Su, Rui Wang, Sylvia Wang, Sanjita Sasmal, Leena K. Satyam, Subhendu Mukherjee, Chandrasekhar AbbinenI, Kiran Aithal, Mital S. Bhakta, Jay Ghurye, Xuhong Cao, Nora M. Navone, Alexey Nesvizhskii, Rohit Mehra, Ulka Vaishampayan, Marco Blanchette, Yuzhuo Wang, Susanta Samajdar, Murali Ramachandra, Arul M. Chinnaiyan. Targeting SWI/SNF ATPases in enhancer-addicted prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5469.

SUPPRESSION OF MALE REPRODUCTIVE FUNCTION BY BROWN HT IN RAT

Objective: Brown HT is an extensively used food color. Our objective was to evaluate the possible toxic effect of Brown HT on male reproductive functions in rats. Methods: Brown HT was administered to male rats orally at 100, 200, and 400 mg/kg body weight/day for a period of 30 days. At the end of this period, different types of parameters related to male reproductive physiology and activities of different antioxidant enzymes were measured by spectrophotometric method using standard protocols. The serum hormonal levels were measured by Chemiluminescence Immuno Assay method using the kit. Results: We have observed significant decrease in mean body weight, gonado somatic index, number of epididymal sperms, percentage of motile sperms, and also decrease in serum level of luteinizing hormone, follicle-stimulating hormone (FSH), and testosterone in a dose dependent manner in Brown HT exposed rats. The activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and glutathione-S-transferase have been decreased and the level of malondialdehyde, a biomarker of lipid peroxidation has been increased significantly in exposed rats. Histopathology of testes also showed degeneration of germ cells in somniferous tubules in Brown HT exposed rats. Conclusion: According to this result, it is concluded that Brown HT suppresses the male reproductive functions probably by producing oxidative stress in testicular tissues and suppressing the hypothalamus-anterior pituitary-testicular axis in rat.

Costus root extract improves testicular toxicity of Bisphenol A in adult male albino rats: histopathological, ultrastructural and biochemical studies

BackgroundBisphenol A (BPA) causes environmental pollution and is used as a natural antioxidant to protect against chemical side-effects. Costus is a well-known medicinal plant containing several biologically active compounds. We investigated the protective effects of costus extract against the toxic effects of BPA in the rat testes.ResultsBiochemical and immunohistochemical investigations revealed that bisphenol reduced the activity of antioxidant enzymes and plasma testosterone levels and significantly increased P53. Co-administration of costus root extract with BPA improved the depletion of antioxidant enzymes, returned testosterone to normal levels, and improved P53 alternations. Histological and ultrastructural examinations showed that BPA reduced body and testicular weights, and the degeneration of seminiferous tubule germ cells, and the use of costus root extract with BPA attenuated these toxic effects.ConclusionsCostus protects rat testes against the toxic effects of BPA.

Dietary Exposure to Lead (pb) Related with Biochemical and Histomorphological Changes in Testes and Kidney of Rabbit

The experiment was conducted to observe the toxic effect of different doses of dietary lead (Pb) on biochemical, gross and histopathological changes in the testes and kidneys of male rabbits. A total number of 36 rabbits (4.5 months of age) were assigned in three dietary treatments with three replicates. Control group T0 received only a basal diet and the other groups T1 and T2 received a basal diet supplemented with Pb at a dose level of 20 and 40 mg/kg bw respectively. By the end of the experiment (4 months), animals were slaughtered and blood and tissue samples were collected for biochemical and histopathological tests. Oral administration of lead caused decreased weight and congestion of the kidney attributed to the glomerular shrinkage and reactive cell infiltration microscopically. Significant decrease in weight, degeneration of germ cells, and vacuolation of the seminiferous tubules were recorded in testes. Serum testosterone level was decreased in lead-treated groups which might be due to the cellular degeneration of Leydig cells. In conclusion, lead acetate had a serious dose-dependent biochemical and histomorphological effect in the male rabbit.

Effect of canola oil on ultrastructure of testis in adult male albino rat

The incidence of infertility is increasing world wild. Among the diet factors, are the quality and quantity of the fat that contributes to spermatogenesis. Canola oil is known to contain oleic acid which is an omega-9 monounsaturated fatty acid, linoleic acid which is an essential omega-6 polyunsaturated fatty acid and alpha-linolenic acid, a plant-based omega-3. Canola oil has the lowest saturated fatty acid content among cooking oil. This study has been designed to investigate the possible effect of Canola oil, the recently used cooking oil, on the testicular structure and ultra-structure. Twelve adult male albino rats (200-250g) were obtained from the animal house in Faculty of Pharmacy, Mansoura University. The animals were housed two in a cage at a constant temperature of 18°C and humidity 45%. Rats were divided into control and treated; treated rats received a diet contains 7ml/100gm canola oil for 39 days. Six rats in each group were weighed and sacrificed at the end of the experiment; testis was dissected and weighed. The specimens were used for paraffin sections and electron microscope examination. The Canola oil-treated group showed irregular seminiferous tubules, germ cells with vacuolated cytoplasm and deeply stained nuclei compared with the control group. The treated testis ultrastructure showed degenerated Sertoli cell with an irregular nucleus, degenerated spermatocytes with the cytoplasm showing phagosomes, lysosomes and increased autophagic vacuoles. Interstitial cells appeared degenerated with vacuolated cytoplasm an. Canola oil is low in saturated fat and high in monounsaturated fat content, making it an ideal healthy cooking oil. This study revealed that Canola oil usage resulted in distorted seminiferous tubules, degenerated germ cells and ultrastructural changes in the treated testis. Canola oil should be used with caution, especially in males, to avoid its hazardous effect on the testis.