ABSTRACT
There is a well-established link between abnormal sperm chromatin states and poor motility, however, how these two processes are interdependent is unknown. Here, we identified a possible mechanistic insight by showing that Protamine 2, a nuclear DNA packaging protein in sperm, directly interacts with cytoskeletal protein Septin 12, which is associated with sperm motility. Septin 12 has several isoforms, and we show, that in the Prm2 -/- sperm, the short one (Mw 36 kDa) is mislocalized, while two long isoforms (Mw 40 and 41 kDa) are unexpectedly lost in Prm2 -/- sperm chromatin-bound protein fractions. Septin 12 co-immunoprecipitated with Protamine 2 in the testicular cell lysate of WT mice and with Lamin B1/B2/B3 in co-transfected HEK cells despite we did not observe changes in Lamin B2/B3 protein or SUN4 expression in Prm2 -/- testes. Furthermore, the Prm2 -/- sperm have on average a smaller sperm nucleus and aberrant acrosome biogenesis. In humans, patients with low sperm motility (asthenozoospermia) have imbalanced histone- protamine 1/2 ratio and modified levels of cytoskeletal proteins. We detected retained Septin 12 isoforms (Mw 40 and 41 kDa) in the sperm membrane, chromatin-bound and tubulin/mitochondria protein fractions, which was not true for healthy normozoospermic men. In conclusion, our findings expand the current knowledge regarding the connection between Protamine 2 and Septin 12 expression and localization, resulting in low sperm motility and morphological abnormalities.
ABSTRACT
PURPOSE: To retrospectively compare the incidence of biologic and prosthetic complications in implant-supported fixed dental prostheses (FDP) and removable dental prostheses (RDP) in edentulous patients after up to 10 years. MATERIALS AND METHODS: A total of 13 patients (mean age: 58.8 years, women = 9, men = 4) who had received 14 implant-supported FDPs and a total of 43 patients (mean age: 64.4 years, 22 women, 21 men) who were provided with 50 implant-supported RDPs were included in the study. The RDPs were fixed using locator attachments, ball heads, bars, or double-crowns. Technical, biologic, and prosthetic complications were assessed over a 73.3-month (± 37.7) follow-up period, and the collected data covered the period between 2000 and 2016. Using Kaplan-Meier curve and Breslow tests, the data were statistically analyzed. The level of peri-implant bone margins was determined at least every 2 years. RESULTS: Of the 328 implants placed, 2 had to be removed during the follow-up period. All implant superstructures were still in situ at the end of the observation period. The mean overall complication rate was 0.24 per restoration per year for FDPs and 0.37 per year for RDPs. Reasonable therapeutic interventions allowed for preserving and reestablishing the integrity of all implants and full operability of all superstructures. Prosthetic complications occurred about four to five times more frequently than biologic ones; however, according to Breslow test, the distribution of biologic and prosthetic complications was not significantly different (P > .05) when comparing FDPs and RDPs over 10 years. CONCLUSION: Implant-supported FDPs were not significantly more prone to complications than implant-supported RDPs over time. Prosthetic intervention was required more often than biologic interventions in both approaches.
