Potential role of autophagy in the male reproductive system

Autophagy is a highly controlled cellular mechanism that maintains cellular homeostasis by degrading and recycling cellular components. In recent years, there has been a greater concentration on understanding the role of autophagy in the male reproductive system. This review addresses the potential importance of autophagy in many aspects of male reproductive physiology, such as spermatogenesis, sperm maturation, and testicular function. The role of autophagy in male fertility, sperm quality, and response to environmental stressors is explored. Insights into the molecular mechanisms driving autophagy in male reproductive cells cover the groundwork for future research targeted at understanding the complex relationship between autophagy and male reproductive health.

Introduction

Autophagy, a conserved catabolic mechanism necessary for the maintenance of cellular equilibrium, has emerged as an important factor in a variety of physiological and pathological conditions [1,2]. While autophagy has been extensively investigated in the context of cellular maintenance and stress response, it has recently received a lot of attention for its role in the male reproductive system [3,4]. Understanding the complex connection between autophagy and male reproductive systems holds the prospect of yielding new insights into fertility, sperm production, and testicular health.

Spermatogenesis, the complex process of male germ cell differentiation, entails several carefully regulated events such as mitosis, meiosis, and spermiogenesis [5,6]. Recent research indicates that autophagy is critical in controlling these processes, impacting the destiny of germ cells and total sperm quality [7]. Furthermore, autophagy appears to help remove defective or superfluous organelles, resulting in the generation of functionally competent spermatozoa [8].

Autophagy has a role in cellular remodeling, energy balancing, and environmental cue response in the male reproductive tract, which includes the testes and epididymis [9,10]. The dynamic nature of autophagy enables cells to adapt to changing environments, ensuring optimal function even in stressful situations. Furthermore, autophagy may alter sperm maturation and storage in the epididymis (Figure 1), hence affecting spermatozoa’s functional capability [11,12]. Despite these intriguing correlations, much about autophagy’s potential role in the male reproductive system remains unknown. Understanding the molecular processes and signaling pathways that drive autophagy in male reproductive cells is critical for understanding its impact on fertility, sperm quality, and responses to diverse stresses [13,14]. This review will delve into the available literature, offering a detailed overview of autophagy’s possible significance in male reproductive biology as well as emphasizing future research opportunities in this quickly expanding question.

Figure 1: Autophagy plays an essential role in sperm production and maturation [56].

Apoptosis, also known as programmed cell death, is a controlled process of cell suicide that occurs in response to various stimuli, such as DNA damage, cellular stress, or developmental signals. Apoptosis plays an important role in tissue development, immune response, and the elimination of damaged or infected cells. Unlike necrosis, which is a form of cell death associated with trauma or injury and often results in inflammation, apoptosis is a highly regulated process that does not trigger an inflammatory response [15].

Senescence

Cellular senescence refers to a state of irreversible cell cycle arrest that cells enter into in response to various stressors, such as DNA damage, telomere shortening, or oncogene activation. Senescent cells remain metabolically active but are unable to proliferate. Senescence is believed to be a protective mechanism against the proliferation of damaged or potentially harmful cells, such as those with oncogenic mutations [16]. However, senescent cells can also contribute to age-related diseases and tissue dysfunction through the secretion of pro-inflammatory molecules and the disruption of tissue homeostasis. The relationship between autophagy, apoptosis, and senescence is complex and interconnected. Autophagy can play a dual role in regulating apoptosis and senescence. On one hand, autophagy can promote cell survival by removing damaged components and preventing apoptosis or senescence induction under stress conditions. On the other hand, autophagy can also promote apoptosis or senescence by selectively degrading anti-apoptotic proteins or by regulating signaling pathways involved in cell cycle control [17-19].

Autophagic role during spermatogenesis

The complex interplay between autophagy and male reproductive processes reveals an intriguing view of molecular events that have a substantial impact on fertility, spermatogenesis, and general reproductive health. As indicated by an increasing amount of literature, autophagy emerges as a multidimensional regulator in the male reproductive system, influencing germ cell growth, sperm quality, and reproductive organs’ adaptive responses to various environmental signals (47 & 57). Regarding autophagy in Leydig cells, Leydig cells are a type of cell found in the testes that are responsible for producing testosterone, the primary male sex hormone. Autophagy has been shown to play a crucial role in regulating Leydig cell function and testosterone production. One study, titled “Autophagy in Leydig Cells of the Testis. Autophagy is involved in maintaining Leydig cell homeostasis and testosterone production, and dysregulation of autophagy may contribute to testicular dysfunction and male infertility [20,21].

Autophagosomes play a pivotal role in cellular homeostasis by digesting cellular components and enzymatically regenerating them into essential nutrients such as lipids, sugars, nucleosides, and amino acids. This process facilitates intracellular nutrient recycling and serves as a mechanism for energy replacement [22,23]. The balance of energy is a crucial component in the production of spermatozoa in the testis. A reduction in dietary energy has been linked to diminished testicular weight and a decrease in the number of spermatids within the seminiferous tubules, a phenomenon attributed to the activation of autophagy [24]. Additionally, supplementation with amino acids has proven to be a successful and effective strategy for enhancing spermatozoa quality, a response that is intricately linked to the activation of autophagy [25]. Furthermore, conditions such as elevated scrotal temperature, which induces testicular heat stress, have been shown to promote autophagy, leading to spermatogenic arrest [26]. This emphasizes the intricate relationship between autophagy and various factors influencing male reproductive health. Understanding these connections provides valuable insights into potential interventions to modulate autophagy for optimizing sperm production and quality [27]. Therefore, energy disorders, hyperthermia, and hypoxia all promote autophagy during spermatogenesis. Pharmacological inhibitors are often employed to achieve autophagy inhibition. The physiological function of Sertoli Cells is crucial for the success of spermatogenesis [28]. The number of Sertoli Cells influences the testis size and the number of mature spermatozoa, while they also form the blood-testis barrier, creating a conducive environment for germ cell growth through their close relationship. The blood-testis barrier, determining the polarity of Sertoli Cells, physically divides the seminiferous epithelium into basal and apical sections and is essential for spermatogenesis. Endoplasmic specialization, a testis-specific actin-based hybrid anchoring and tight junction, encompasses both basal and apical endoplasmic specialization [29,30]. The basal endoplasmic specialization forms the blood-testis barrier and links it to the actin cytoskeleton, while the apical endoplasmic specialization is crucial for spermatid development and maturation [31,32]. Autophagy-deficient Atg7−/− mice exhibited disorganized F-actin. Notably, when vital proteins required for autophagy initiation (Atg5 and Atg7) were knocked out in animal Sertoli Cells, both apical and basal endoplasmic specialization was disrupted, leading to a chaotic cytoskeleton structure, deformed spermatozoa heads, and reduced motility [33]. This disruption resulted in autophagy impairment, inefficient degradation of PDZ and LIM domain protein 1, and increased PDLIM1, leading to ineffective cytoplasm clearance during spermatogenesis and the breakdown of cytoskeletal components of spermatozoa [31]. During spermatogenesis, each diploid primary spermatocyte undergoes meiosis, developing into four haploid round spermatids, each occupying a specific nuclear location. Chromatoid bodies, distinctive ribonucleoprotein (RNP) granules, are common cytoplasmic characteristics of haploid round spermatids [31,34,35]. Autophagy agonists and antagonists exacerbate cellular defects in haploid round spermatids, leading to Chromatoid bodies fragmentations [15]. Autophagy is involved in clearing CB materials and maintaining CB homeostasis, acting as a double-edged sword [36,37]. In recent decades, connections between autophagy-related proteins and meiosis have slowly been postulated. Autophagy-related proteins, including LC3, Beclin 1, p62, Atg5, Atg7, Atg16, m-TOR, AMPKα 1/2, and PINK1, along with their upstream regulators, have been observed to interact with meiosis in male spermatozoa [38-41]. Autophagy activation substantially boosts motility, and the expression of LC3 and Atg7 significantly rises from round to elongated spermatids. Importantly, spermatozoa, highly differentiated cells, can be eliminated within Sertoli Cells by autophagy in live animals, ensuring the initiation of the next reproductive cycle [8,42-44].

Spermatogenesis is a highly controlled process that includes mitotic divisions, meiotic processes, and spermiogenesis, ending in the formation of differentiated spermatozoa [5,45]. Autophagy, a cellular quality control system, plays a role in the removal of faulty germ cells and the clearance of cytoplasmic components during sperm formation [36,46]. This ensures the creation of functionally competent spermatozoa that are devoid of cellular detritus and potential genetic defects. Furthermore, the dynamic nature of autophagy enables male reproductive cells to react to numerous stresses, ensuring cellular homeostasis even under difficult situations. Environmental factors such as toxin exposure, nutritional availability, and oxidative stress can all have an impact on male fertility [47-49]. Autophagy is an important adaptive mechanism that helps cells deal with stresses and maintain reproductive function [50,51]. Understanding the particular autophagic responses to various stressors in the male reproductive system sheds light on prospective therapeutic techniques for reducing the negative effects of environmental insults on fertility. The male reproductive system, which includes the testes and epididymis, is a dynamic environment in which autophagy helps to regulate cellular remodeling and energy balance [3,52,53]. Autophagy in the testes helps to remove damaged or extra organelles, allowing for the creation of high-quality sperm. Furthermore, autophagy’s role in the epididymis is receiving study because it may influence sperm maturation and storage. Further research into the molecular processes that drive autophagy in these reproductive organs is required for a complete knowledge of its impact on male reproductive physiology [14,54,55]. While the present literature emphasizes the possible role of autophagy in male reproduction, significant knowledge gaps and areas for further investigation remain. Understanding the complex signaling pathways, molecular actors, and interaction between autophagy and other cellular processes in the male reproductive system remains a difficult but critical job. Furthermore, more research is needed to investigate the translational potential of autophagy modulation for therapeutic approaches in male infertility.

In summary, the potential role of autophagy in the male reproductive system is a fascinating field of study with far-reaching implications for understanding fertility, sperm quality, and environmental reactions. As our understanding grows, clarifying the complexity of autophagy in male reproduction holds the potential for finding novel approaches to improve reproductive health and address male infertility.

Conclusion

Autophagy emerges as a meticulously regulated cellular mechanism crucial for maintaining cellular homeostasis through the degradation and recycling of cellular components. The increasing focus on unraveling the intricacies of autophagy in the male reproductive system has revealed its potential significance in various facets of male reproductive physiology, including spermatogenesis, sperm maturation, and overall testicular function. This review delves into the multifaceted role of autophagy in male fertility, sperm quality, and the response to environmental stressors. The elucidation of molecular mechanisms governing autophagy in male reproductive cells lays the foundation for future research aimed at comprehending the intricate interplay between autophagy and male reproductive health. The insights gained from these studies hold promise for advancing our understanding and potential interventions in the complex relationship between autophagy and male reproductive well-being.

Future directions in the context of clinical treatments of various diseases of the male reproductive system with autophagy hold significant promise for advancing therapeutic strategies. Further research efforts should aim to elucidate the specific role of autophagy in the pathogenesis of different male reproductive system disorders, such as infertility, erectile dysfunction, and testicular disorders. Additionally, there is a need to explore the potential of autophagy modulation as a therapeutic target for these conditions.

Declarations

Authors contribution: Conception – MAM, WA; Design – MBA, ASK; Supervision -MKV; Materials –CK, SB, SAP Data Collection and/or Processing – MBA, SA, IR; Analysis and/or Interpretation – MAM, MBA Literature Search – SA, SAP, SA; Writing Manuscript – MBA, AWO; Critical Review – WA.

1. Saha S, Panigrahi DP, Patil S, Bhutia SK. Autophagy in health and disease: A comprehensive review. Biomed Pharmacother. 2018 Aug; 104:485-495. doi: 10.1016/j.biopha.2018.05.007. Epub 2018 May 25. PMID: 29800913.
2. Ravikumar B, Sarkar S, Davies JE, Futter M, Garcia-Arencibia M, Green-Thompson ZW, Jimenez-Sanchez M, Korolchuk VI, Lichtenberg M, Luo S, Massey DC, Menzies FM, Moreau K, Narayanan U, Renna M, Siddiqi FH, Underwood BR, Winslow AR, Rubinsztein DC. Regulation of mammalian autophagy in physiology and pathophysiology. Physiol Rev. 2010 Oct;90(4):1383-435. doi: 10.1152/physrev.00030.2009. PMID: 20959619.
3. Yan Q, Zhang Y, Wang Q, Yuan L. Autophagy: A Double-Edged Sword in Male Reproduction. Int J Mol Sci. 2022 Dec 3;23(23):15273. doi: 10.3390/ijms232315273. PMID: 36499597; PMCID: PMC9741305.
4. Rotimi DE, Singh SK. Interaction between apoptosis and autophagy in testicular function. Andrologia. 2022 Dec;54(11):e14602. doi: 10.1111/and.14602. Epub 2022 Sep 25. PMID: 36161318. 
5. Griswold MD. Spermatogenesis: The Commitment to Meiosis. Physiol Rev. 2016 Jan;96(1):1-17. doi: 10.1152/physrev.00013.2015. PMID: 26537427; PMCID: PMC4698398.
6. Oliveira PF, Alves MG, Oliveira PF, Alves MG. Spermatogenesis. Sertoli Cell Metabolism and Spermatogenesis. 2015:15-24. https://link.springer.com/book/10.1007/978-3-319-19791-3
7. Haseeb A, Tarique I, Bai X, Yang P, Ali Vistro W, Huang Y, Ali Fazllani S, Ahmed Z, Chen Q. Inhibition of autophagy impairs acrosome and mitochondrial crista formation during spermiogenesis in turtle: Ultrastructural evidence. Micron. 2019 Jun; 121:84-89. doi: 10.1016/j.micron.2019.03.006. Epub 2019 Apr 1. PMID: 30953869.
8. Haseeb A, Bai X, Vistro WA, Tarique I, Chen H, Yang P, Gandahi NS, Iqbal A, Huang Y, Chen Q. Characterization of in vivo autophagy during avian spermatogenesis1. Poult Sci. 2019 Oct 1;98(10):5089-5099. doi: 10.3382/ps/pez320. PMID: 31198935.
9. Ali W, Deng K, Sun J, Ma Y, Liu Z, Zou H. A new insight of cadmium-induced cellular evidence of autophagic-associated spermiophagy during spermatogenesis. Environ Sci Pollut Res Int. 2023 Sep;30(45):101064-101074. doi: 10.1007/s11356-023-29548-9. Epub 2023 Aug 30. PMID: 37646926.
10. Ali W, Chen Y, Gandahi JA, Qazi IH, Sun J, Wang T, Liu Z, Zou H. Cross-Talk Between Selenium Nanoparticles and Cancer Treatment Through Autophagy. Biol Trace Elem Res. 2023 Oct 10. doi: 10.1007/s12011-023-03886-8. Epub ahead of print. PMID: 37817045.
11. Ali W, Ma Y, Zhu J, Zou H, Liu Z. Mechanisms of Cadmium-Induced Testicular Injury: A Risk to Male Fertility. Cells. 2022 Nov 14;11(22):3601. doi: 10.3390/cells11223601. PMID: 36429028; PMCID: PMC9688678.
12. Ali W, Deng K, Bian Y, Liu Z, Zou H. Spectacular role of epididymis and bio-active cargo of nano-scale exosome in sperm maturation: A review. Biomed Pharmacother. 2023 Aug; 164:114889. doi: 10.1016/j.biopha.2023.114889. Epub 2023 May 18. PMID: 37209627.
13. Hussain T, Kandeel M, Metwally E, Murtaza G, Kalhoro DH, Yin Y, Tan B, Chughtai MI, Yaseen A, Afzal A, Kalhoro MS. Unraveling the harmful effect of oxidative stress on male fertility: A mechanistic insight. Front Endocrinol (Lausanne). 2023 Feb 13; 14:1070692. doi: 10.3389/fendo.2023.1070692. PMID: 36860366; PMCID: PMC9968806.
14. Raee P, Tan SC, Najafi S, Zandsalimi F, Low TY, Aghamiri S, Fazeli E, Aghapour M, Mofarahe ZS, Heidari MH, Fathabadi FF, Abdi F, Asouri M, Ahmadi AA, Ghanbarian H. Autophagy, a critical element in the aging male reproductive disorders and prostate cancer: a therapeutic point of view. Reprod Biol Endocrinol. 2023 Sep 26;21(1):88. doi: 10.1186/s12958-023-01134-1. PMID: 37749573; PMCID: PMC10521554.
15. Chen H, Huang Y, Bai X, Yang P, Tarique I, Vistro WA, Gandahi NS, Fazlani SA, Chen Q. Apoptotic-like changes in epididymal spermatozoa of soft-shelled turtles, Pelodiscus sinensis, during long-term storage at 4 ºC. Anim Reprod Sci. 2019 Jun; 205:134-143. doi: 10.1016/j.anireprosci.2019.04.014. Epub 2019 May 1. PMID: 31060923.
16. Mohamad Kamal NS, Safuan S, Shamsuddin S, Foroozandeh P. Aging of the cells: Insight into cellular senescence and detection Methods. Eur J Cell Biol. 2020 Aug;99(6):151108. doi: 10.1016/j.ejcb.2020.151108. Epub 2020 Jul 12. PMID: 32800277.
17. Duan Y, Zhao Y, Wang T, Sun J, Ali W, Ma Y, Yuan Y, Gu J, Bian J, Liu Z, Zou H. Taurine Alleviates Cadmium-Induced Hepatotoxicity by Regulating Autophagy Flux. Int J Mol Sci. 2023 Jan 7;24(2):1205. doi: 10.3390/ijms24021205. PMID: 36674718; PMCID: PMC9861963.
18. Tarique I, Shi Y, Gandahi NS, Ding B, Yang P, Chen C, Vistro WA, Chen Q. in vivo cellular evidence of autophagic associated spermiophagy within the principal cells during sperm storage in epididymis of the turtle. Aging (Albany NY). 2020 May 15;12(10):8987-8999. doi: 10.18632/aging.103144. Epub 2020 May 15. PMID: 32414993; PMCID: PMC7288964.
19. Sun J, Chen Y, Wang T, Ali W, Ma Y, Liu Z, Zou H. Role of Mitochondrial Reactive Oxygen Species-Mediated Chaperone-Mediated Autophagy and Lipophagy in Baicalin and N-Acetylcysteine Mitigation of Cadmium-Induced Lipid Accumulation in Liver. Antioxidants (Basel). 2024 Jan 17;13(1):115. doi: 10.3390/antiox13010115. PMID: 38247538; PMCID: PMC10812561.
20. Gao F, Li G, Liu C, Gao H, Wang H, Liu W, Chen M, Shang Y, Wang L, Shi J, Xia W, Jiao J, Gao F, Li J, Chen L, Li W. Autophagy regulates testosterone synthesis by facilitating cholesterol uptake in Leydig cells. J Cell Biol. 2018 Jun 4;217(6):2103-2119. doi: 10.1083/jcb.201710078. Epub 2018 Apr 4. PMID: 29618492; PMCID: PMC5987723. 
21. Gao H, Liu C, Li W. Assessing autophagy in the Leydig cells. Autophagy in Differentiation and Tissue Maintenance: Methods and Protocols. 2019:71-85. https://link.springer.com/book/10.1007/978-1-4939-8748-1
22. Tamargo-Gómez I, Mariño G. AMPK: Regulation of Metabolic Dynamics in the Context of Autophagy. Int J Mol Sci. 2018 Nov 29;19(12):3812. doi: 10.3390/ijms19123812. PMID: 30501132; PMCID: PMC6321489.
23. Cai ZY, Yang B, Shi YX, Zhang WL, Liu F, Zhao W, Yang MW. High glucose downregulates the effects of autophagy on osteoclastogenesis via the AMPK/mTOR/ULK1 pathway. Biochem Biophys Res Commun. 2018 Sep 5;503(2):428-435. doi: 10.1016/j.bbrc.2018.04.052. Epub 2018 Jun 29. PMID: 29649480.
24. Pang J, Li F, Feng X, Yang H, Han L, Fan Y, Nie H, Wang Z, Wang F, Zhang Y. Influences of different dietary energy level on sheep testicular development associated with AMPK/ULK1/autophagy pathway. Theriogenology. 2018 Mar 1; 108:362-370. doi: 10.1016/j.theriogenology.2017.12.017. Epub 2017 Dec 14. PMID: 29304491.
25. Zhang J, Zhang X, Liu Y, Su Z, Dawar FU, Dan H, He Y, Gui JF, Mei J. Leucine mediates autophagosome-lysosome fusion and improves sperm motility by activating the PI3K/Akt pathway. Oncotarget. 2017 Dec 4;8(67):111807-111818. doi: 10.18632/oncotarget.22910. PMID: 29340093; PMCID: PMC5762361.
26. Zhang P, Zheng Y, Lv Y, Li F, Su L, Qin Y, Zeng W. Melatonin protects the mouse testis against heat-induced damage. Mol Hum Reprod. 2020 Feb 29;26(2):65-79. doi: 10.1093/molehr/gaaa002. PMID: 31943111.
27. Kaur G, Thompson LA, Dufour JM. Sertoli cells--immunological sentinels of spermatogenesis. Semin Cell Dev Biol. 2014 Jun; 30:36-44. doi: 10.1016/j.semcdb.2014.02.011. Epub 2014 Mar 3. PMID: 24603046; PMCID: PMC4043859.
28. Wong CH, Cheng CY. The blood-testis barrier: its biology, regulation, and physiological role in spermatogenesis. Curr Top Dev Biol. 2005; 71:263-96. doi: 10.1016/S0070-2153(05)71008-5. PMID: 16344108.
29. Yan HH, Mruk DD, Lee WM, Cheng CY. Ectoplasmic specialization: a friend or a foe of spermatogenesis? Bioessays. 2007 Jan;29(1):36-48. doi: 10.1002/bies.20513. PMID: 17187371; PMCID: PMC2804921.
30. Tarique I, Vistro WA, Bai X, Yang P, Hong C, Huang Y, Haseeb A, Liu E, Gandahi NS, Xu M, Liu Y, Chen Q. LIPOPHAGY: a novel form of steroidogenic activity within the LEYDIG cell during the reproductive cycle of turtle. Reprod Biol Endocrinol. 2019 Feb 9;17(1):19. doi: 10.1186/s12958-019-0462-2. PMID: 30738428; PMCID: PMC6368689.
31. Liu C, Wang H, Shang Y, Liu W, Song Z, Zhao H, Wang L, Jia P, Gao F, Xu Z, Yang L, Gao F, Li W. Autophagy is required for ectoplasmic specialization assembly in sertoli cells. Autophagy. 2016 May 3;12(5):814-32. doi: 10.1080/15548627.2016.1159377. Epub 2016 Mar 17. PMID: 26986811; PMCID: PMC4854559.
32. Toyama Y, Maekawa M, Yuasa S. Ectoplasmic specializations in the Sertoli cell: new vistas based on genetic defects and testicular toxicology. Anat Sci Int. 2003 Mar;78(1):1-16. doi: 10.1046/j.0022-7722.2003.00034.x. PMID: 12680465.
33. Zhu Y, Yin Q, Wei D, Yang Z, Du Y, Ma Y. Autophagy in male reproduction. Syst Biol Reprod Med. 2019 Aug;65(4):265-272. doi: 10.1080/19396368.2019.1606361. Epub 2019 Apr 24. PMID: 31014114.
34. Goh WS, Falciatori I, Tam OH, Burgess R, Meikar O, Kotaja N, Hammell M, Hannon GJ. piRNA-directed cleavage of meiotic transcripts regulates spermatogenesis. Genes Dev. 2015 May 15;29(10):1032-44. doi: 10.1101/gad.260455.115. PMID: 25995188; PMCID: PMC4441051.
35. Meikar O, Da Ros M, Korhonen H, Kotaja N. Chromatoid body and small RNAs in male germ cells. Reproduction. 2011 Aug;142(2):195-209. doi: 10.1530/REP-11-0057. Epub 2011 Jun 7. PMID: 21652638.
36. Wang M, Zeng L, Su P, Ma L, Zhang M, Zhang YZ. Autophagy: a multifaceted player in the fate of sperm. Hum Reprod Update. 2022 Feb 28;28(2):200-231. doi: 10.1093/humupd/dmab043. PMID: 34967891; PMCID: PMC8889000.
37. Da Ros M, Lehtiniemi T, Olotu O, Fischer D, Zhang FP, Vihinen H, Jokitalo E, Sironen A, Toppari J, Kotaja N. FYCO1 and autophagy control the integrity of the haploid male germ cell-specific RNP granules. Autophagy. 2017 Feb;13(2):302-321. doi: 10.1080/15548627.2016.1261319. Epub 2016 Dec 8. PMID: 27929729; PMCID: PMC5324852.
38. Xiong M, Zhu Z, Tian S, Zhu R, Bai S, Fu K, Davis JG, Sun Z, Baur JA, Zheng K, Ye L. Conditional ablation of Raptor in the male germline causes infertility due to meiotic arrest and impaired inactivation of sex chromosomes. FASEB J. 2017 Sep;31(9):3934-3949. doi: 10.1096/fj.201700251R. Epub 2017 May 10. PMID: 28490482.
39. Aparicio IM, Espino J, Bejarano I, Gallardo-Soler A, Campo ML, Salido GM, Pariente JA, Peña FJ, Tapia JA. Autophagy-related proteins are functionally active in human spermatozoa and may be involved in the regulation of cell survival and motility. Sci Rep. 2016 Sep 16; 6:33647. doi: 10.1038/srep33647. PMID: 27633131; PMCID: PMC5025659.
40. Vistro WA, Zhang Y, Bai X, Yang P, Huang Y, Qu W, Baloch AS, Wu R, Tarique I, Chen Q. In Vivo Autophagy Up-Regulation of Small Intestine Enterocytes in Chinese Soft-Shelled Turtles during Hibernation. Biomolecules. 2019 Nov 1;9(11):682. doi: 10.3390/biom9110682. PMID: 31683886; PMCID: PMC6920937.
41. Ali W, Bian Y, Ali H, Sun J, Zhu J, Ma Y, Liu Z, Zou H. Cadmium-induced impairment of spermatozoa development by reducing exosomal-MVBs secretion: a novel pathway. Aging (Albany NY). 2023 Apr 25;15(10):4096-4107. doi: 10.18632/aging.204675. Epub 2023 Apr 25. PMID: 37220720; PMCID: PMC10258001.
42. Yang P, Ahmed N, Wang L, Chen H, Waqas Y, Liu T, Haseeb A, Bangulzai N, Huang Y, Chen Q. In vivo autophagy and biogenesis of autophagosomes within male haploid cells during spermiogenesis. Oncotarget. 2017 May 26;8(34):56791-56801. doi: 10.18632/oncotarget.18221. PMID: 28915631; PMCID: PMC5593602.
43. Ahmed N, Yang P, Huang Y, Chen H, Liu T, Wang L, Nabi F, Liu Y, Chen Q. Entosis Acts as a Novel Way within Sertoli Cells to Eliminate Spermatozoa in Seminiferous Tubule. Front Physiol. 2017 May 30; 8:361. doi: 10.3389/fphys.2017.00361. PMID: 28611685; PMCID: PMC5447735.
44. Ahmed N, Yang P, Chen H, Ujjan IA, Haseeb A, Wang L, Soomro F, Faraz S, Sahito B, Ali W, Chen Q. Characterization of inter-Sertoli cell tight and gap junctions in the testis of turtle: Protect the developing germ cells from an immune response. Microb Pathog. 2018 Oct; 123:60-67. doi: 10.1016/j.micpath.2018.06.037. Epub 2018 Jun 26. PMID: 29959039.
45. Suede SH, Malik A, Sapra A. Histology, spermatogenesis. 2020. https://www.ncbi.nlm.nih.gov/books/NBK553142/
46. Lv C, Wang X, Guo Y, Yuan S. Role of Selective Autophagy in Spermatogenesis and Male Fertility. Cells. 2020 Nov 23;9(11):2523. doi: 10.3390/cells9112523. PMID: 33238415; PMCID: PMC7700316.
47. Sengupta P, Banerjee R. Environmental toxins: alarming impacts of pesticides on male fertility. Hum Exp Toxicol. 2014 Oct;33(10):1017-39. doi: 10.1177/0960327113515504. Epub 2013 Dec 17. PMID: 24347299.
48. Meli R, Monnolo A, Annunziata C, Pirozzi C, Ferrante MC. Oxidative Stress and BPA Toxicity: An Antioxidant Approach for Male and Female Reproductive Dysfunction. Antioxidants (Basel). 2020 May 10;9(5):405. doi: 10.3390/antiox9050405. PMID: 32397641; PMCID: PMC7278868.
49. Tremellen K. Oxidative stress and male infertility--a clinical perspective. Hum Reprod Update. 2008 May-Jun;14(3):243-58. doi: 10.1093/humupd/dmn004. Epub 2008 Feb 14. PMID: 18281241.
50. Duan Y, Zhang Y, Wang T, Sun J, Ali W, Ma Y, Yuan Y, Gu J, Bian J, Liu Z, Zou H. Interactive mechanism between connexin43 and Cd-induced autophagic flux blockage and gap junctional intercellular communication dysfunction in rat hepatocytes. Heliyon. 2023 Oct 14;9(10):e21052. doi: 10.1016/j.heliyon.2023.e21052. PMID: 37876489; PMCID: PMC10590978.
51. Sun J, Bian Y, Ma Y, Ali W, Wang T, Yuan Y, Gu J, Bian J, Liu Z, Zou H. Melatonin alleviates cadmium-induced nonalcoholic fatty liver disease in ducks by alleviating autophagic flow arrest via PPAR-α and reducing oxidative stress. Poult Sci. 2023 Aug;102(8):102835. doi: 10.1016/j.psj.2023.102835. Epub 2023 Jun 3. PMID: 37343350; PMCID: PMC10404762.
52. Kirat D, Alahwany AM, Arisha AH, Abdelkhalek A, Miyasho T. Role of Macroautophagy in Mammalian Male Reproductive Physiology. Cells. 2023 May 5;12(9):1322. doi: 10.3390/cells12091322. PMID: 37174722; PMCID: PMC10177121.
53. Cescon M, Chianese R, Tavares RS. Environmental Impact on Male (In)Fertility via Epigenetic Route. J Clin Med. 2020 Aug 5;9(8):2520. doi: 10.3390/jcm9082520. PMID: 32764255; PMCID: PMC7463911.
54. Moreira BP, Oliveira PF, Alves MG. Molecular mechanisms controlled by mTOR in male reproductive system. International journal of molecular sciences. 2019 20:1633. doi: 10.3390/ijms20071633.
55. Wang M, Wang XF, Li YM, Chen N, Fan Y, Huang WK, Hu SF, Rao M, Zhang YZ, Su P. Cross-talk between autophagy and apoptosis regulates testicular injury/recovery induced by cadmium via PI3K with mTOR-independent pathway. Cell Death Dis. 2020 Jan 22;11(1):46. doi: 10.1038/s41419-020-2246-1. PMID: 31969557; PMCID: PMC6976559.
56. Rahman MA, Saikat ASM, Rahman MS, Islam M, Parvez MAK, Kim B. Recent Update and Drug Target in Molecular and Pharmacological Insights into Autophagy Modulation in Cancer Treatment and Future Progress. Cells. 2023 Jan 31;12(3):458. doi: 10.3390/cells12030458. PMID: 36766800; PMCID: PMC9914570.
57. Arain S, Rehman Q, Azeem M, Jahanzaib M, Waheed A, Riaz A, Lanjar Z, Ayoob A, Shazinosh, Bilawal M. Biotechnological therapies for animal reproduction in the livestock sector. Pure and Applied Biology.2023; 12:2; 1269-1285. http://dx.doi.org/10.19045/bspab.2023.120130