Short-term storage of human testicular tissue: effect of storage temperature and tissue size

Abstract

During short-term storage, before cryopreservation, testicular tissue quality can be affected by storage medium, duration, temperature and tissue size. We previously established the best storage medium and time for short-term maintenance of tissue. In this study, three different storage temperatures (4°C, room temperature, 37°C) and four tissue sizes (~6 mm; ~ 15 mm; ~ 50 mm or ~80 mm) were assessed over the course of a fixed period of 3 days. Storing human testicular tissue at 37°C caused a significant increase in the number of apoptotic cells per tubule (P = 0.002), compared with fresh control, but this was not the case at 4°C or room temperature. Temperature did not affect viability, tissue morphology or number of spermatogonia in samples. The morphology of the testicular tissue was optimally preserved when stored as large fragments (~50 mm: P = 0.018; ~ 80 mm: P = 0.018). Tissue size did not significantly affect viability, number of spermatogonia or apoptotic cells. Adult human testicular tissue can be preserved at 4°C or room temperature without altering tissue morphology, Sertoli cell morphology, number of spermatogonia or number of apoptotic cells. The tissue does not need to be extensively dissected as tissue morphology is better maintained in larger fragments.

Impact of Temperature and Time Interval Prior to Immature Testicular-Tissue Organotypic Culture on Cellular Niche

“…It has been shown that storage of human ITT at 37°C but not at 4°C or room temperature caused a significant increase in the number of apoptotic cells compared with fresh control [12] which is in agreement with our results where mild-warm-ischemic temperature also resulted in increased cell death. Earlier studies have used either cell morphology analysis [12] or xenografting [44] as markers to assess the functional competence of ITT. However, our study is unique in a way that holding at different time periods was tested to address the functionality and cell niche by organ culture method.…”

“…Studies using several experimental models have shown that holding and manipulation at 4 °C is optimal for ITT [ 10 , 14 , 43 , 44 ] and human ITT can have intact structure up to 3 days at 4 °C [ 13 ]. It has been shown that storage of human ITT at 37 °C but not at 4 °C or room temperature caused a significant increase in the number of apoptotic cells compared with fresh control [ 12 ] which is in agreement with our results where mild-warm-ischemic temperature also resulted in increased cell death. Earlier studies have used either cell morphology analysis [ 12 ] or xenografting [ 44 ] as markers to assess the functional competence of ITT.…”

“…If the retrieved ITT can be cryopreserved with minimal manipulation, the chance to recover optimum number of cells for fertility restoration techniques might increase [10]. Hence, earlier studies have addressed the effects of varying tissue size, storage temperatures, and storage periods in porcine model [10] and in human [11][12][13][14], to recommend the ideal conditions. No loss of cell viability and structural integrity was observed during the length of cooling [10], and proliferative potential was unaltered when cooled tissue was thawed and xenografted [15].…”

Preservation of common carp germ cells under hypothermic conditions: Whole tissue vs isolated cells

“…Even though tissues in cultures have normal physiological diffusion rates and metabolism, hypothermic storage at 4°C slows down the metabolic activity to 10%-12% of the normal activity , and thus, it might hinder the diffusion and circulation of nutrients leading to damages and metabolic impairments in the cells. Additionally, the size of stored fragments might have an effect on cell viability to some extent; however, there are contrasting reports that the tissue size does not influence SSC survival during hypothermic storage (Faes & Goossens, 2017;. On the other hand, in cell suspensions, all cells are equally exposed to the nutrients.…”

“…Hypothermic storage, which is defined as storing biological material at temperatures below its normal physiological temperatures, but higher than the freezing point of the storage solution (Tovar, Navarrete, Rodríguez, Skewes, & Castro, ; Yang & Honaramooz, ), is more favourable for short‐term storage of biological material than cryopreservation. In spite of such advantages of hypothermic storage and the use of this methodology in mammals (Faes & Goossens, ; Jahnukainen, Ehmcke, Hergenrother, & Schlatt, ; Yang & Honaramooz, ; Yang, Steeg, & Honaramooz, ), to the best of our knowledge, there is only one report on successful hypothermic storage of fish germ cells developed for the rainbow trout Oncorhynchus mykiss (Falahatkar, Poursaeid, Kitada, & Yoshizaki, ). The objective of this study was to optimize the short‐term hypothermic conditions (storage at 4°C) for both SSCs and OSCs of common carp Cyprinus carpio as a representative of the cyprinid family.…”