Preliminary Investigation on the Involvement of Cytoskeleton-Related Proteins, DAAM1 and PREP, in Human Testicular Disorders

Abstract

Herein, for the first time, the potential relationships between the cytoskeleton-associated proteins DAAM1 and PREP with different testicular disorders, such as classic seminoma (CS), Leydig cell tumor (LCT), and Sertoli cell-only syndrome (SOS), were evaluated. Six CS, two LCT, and two SOS tissue samples were obtained during inguinal exploration in patients with a suspect testis tumor based on clinical examination and ultrasonography. DAAM1 and PREP protein levels and immunofluorescent localization were analyzed. An increased DAAM1 protein level in CS and SOS as compared to non-pathological (NP) tissue was observed, while LCT showed no significant differences. Conversely, PREP protein level increased in LCT, while it decreased in CS and SOS compared to NP tissue. These results were strongly supported by the immunofluorescence staining, revealing an altered localization and signal intensity of DAAM1 and PREP in the analyzed samples, highlighting a perturbed cytoarchitecture. Interestingly, in LCT spermatogonia, a specific DAAM1 nuclear localization was found, probably due to an enhanced testosterone production, as confirmed by the increased protein levels of steroidogenic enzymes. Finally, although further studies are needed to verify the involvement of other formins and microtubule-associated proteins, this report raised the opportunity to indicate DAAM1 and PREP as new potential markers, supporting the cytoskeleton dynamics changes occurring during normal and/or pathological cell differentiation.

The simultaneous administration of microplastics and cadmium alters rat testicular activity and changes the expression of PTMA, DAAM1 and PREP

“…With the aim of expanding knowledge about the mechanisms of spermatogenesis and human reproduction, we have previously characterized some proteins, such as PTMA ( Venditti and Minucci, 2017 ; Minucci and Venditti, 2022 ; Venditti et al, 2022 ), and two cytoskeleton-related proteins, DAAM1 ( Minucci and Venditti, 2022 ; Pariante et al, 2016a ; Venditti et al, 2020b ; c ; Venditti et al, 2021a ) and PREP ( Santillo et al, 2019 ; Venditti and Minucci, 2019 ; Venditti et al, 2020b ; Venditti et al, 2021a ; Minucci and Venditti, 2022 ), in the testis, suggesting their involvement in the proliferative and differentiative stages of gametogenesis. In particular, PTMA, one of the most acidic mammalian polypeptides (3.5 isoelectric point), is an anti-apoptotic factor associated with post-meiotic GC progression and SPZ interaction with the oocyte ( Venditti and Minucci, 2017 ).…”

“…In particular, PTMA, one of the most acidic mammalian polypeptides (3.5 isoelectric point), is an anti-apoptotic factor associated with post-meiotic GC progression and SPZ interaction with the oocyte ( Venditti and Minucci, 2017 ). DAAM1 is a formin that promotes the nucleation of unbranched actin filaments ( Pariante et al, 2016a ; Venditti et al, 2018 ; Venditti et al, 2020b ; Venditti et al, 2020c ; Venditti et al, 2021a ; Minucci and Venditti, 2022 ), while PREP is a serine protease associated with microtubules ( Santillo et al, 2019 ; Venditti et al, 2019 ; Venditti and Minucci, 2019 ; Venditti et al, 2020b ; Venditti et al, 2021a ; Minucci and Venditti, 2022 ).…”

First Evidence of the Expression and Localization of Prothymosin α in Human Testis and Its Involvement in Testicular Cancers

“…In addition, the altered hormonal environment may have another consequence on PTMA: indeed, in LCT samples, we also detected a specific localization signal in SPC nucleus that, on the contrary, was not visible in NP. In our previous paper, we found a comparable situation concerning the formin DAAM1 [ 65 ], a protein that was believed to be exclusively cytoplasmic [ 66 , 67 ], but that can be shuttled in the nucleus on the condition of stimulated germ cells proliferation [ 40 , 65 ]. Thus, we can speculate that, also in this case, the enhanced testosterone production and secretion may promote PTMA shuttling to the SPC nucleus to favor their proliferation.…”

“…Testicular tissues biopsies were performed during inguinal exploration in patients with a suspect testis tumor based on clinical examination and ultrasonography. Biopsy was carried out from the suspect testicular lump, and the presence of cancer was confirmed with extemporaneous evaluation by an expert pathologist [ 40 ]. The number of collected samples was 5 NP, 10 CS, and 4 LCT.…”

Fertility of Cryptorchid Testis—An Unsolved Mistery

“…Another issue related to fertility involves defining new markers of normal spermatogenesis dynamics. Recent studies found that proteins, such as the formin, disheveled-associated activator of morphogenesis 1 (DAAM1) regulating actin polymerization, and the prolyl endopeptidase (PREP) protease acting in microtubule-associated processes, are involved in cytoskeletal dynamics which are mandatory for normal testicular development, but also in pathological cell differentiation [ 64 , 65 ].…”