Spermatogonial Stem Cell Culture in Oncofertility.

Infertility caused by chemotherapy or radiation treatments negatively impacts patient-survivor quality of life. The only fertility preservation option available to prepubertal boys who are not making sperm is cryopreservation of testicular tissues that contain spermatogonial stem cells (SSCs) with potential to produce sperm and/or restore fertility. SSC transplantation to regenerate spermatogenesis in infertile adult survivors of childhood cancers is a mature technology. However, the number of SSCs obtained in a biopsy of a prepubertal testis may be small. Therefore, methods to expand SSC numbers in culture before transplantation are needed. Here we review progress with human SSC culture.

Green Synthesis of Chromium Nanoparticles and Their Effects on the Growth of the Prawn Macrobrachium rosenbergii Post-larvae.

This study deals with synthesis of chromium nanoparticles (CrNPs) from potassium dichromate using the aqueous extract of Allium sativum. They were characterized through UV-VIS light, FE-SEM, EDX, XRD, and FT-IR, which revealed uniform, mono-dispersive, and highly stable CrNPs of 31-64-nm size. The Artemia nauplii was enriched with 4.94 mg/L of CrNPs (24-h LC50) at different durations (½, 1, 2, and 4 h) and then fed to Macrobrachium rosenbegii post-larvae (PL) for 30 days as live feed. The results showed that ½- and 1-h enriched Artemia nauplii led to significant improvements in nutritional indices including growth and survival, and concentrations of tissue biochemical constituents, such as total protein, amino acid, carbohydrate, and lipid of M. rosenbergii PL (P < 0.05), which suggests that this concentration of CrNPs was non-toxic to M. rosenbergii PL. This was confirmed by the insignificant alterations recorded in activities of SOD and CAT (P > 0.05) in M. rosenbergii PL fed with ½- and 1-h enriched Artemia nauplii as live feed. After that, SOD and CAT activities started to increase. Therefore, this optimized concentration of CrNPs (4.94 mg/L) is recommended for enrichment of Artemia nauplii for ½-1-h duration as a sustainable material in the nursery of M. rosenbergii.

Human Testis Extracellular Matrix Enhances Human Spermatogonial Stem Cell Survival In Vitro.

IMPACT STATEMENT: This study developed and characterized human testis extracellular matrix (htECM) and porcine testis ECM (ptECM) for testing in human spermatogonial stem cell (hSSC) culture. Results confirmed the hypothesis that ECM from the homologous species (human) and homologous tissue (testis) is optimal for maintaining hSSCs. We describe a simplified feeder-free, serum-free condition for future iterative testing to achieve the long-term goal of stable hSSC cultures. To facilitate analysis and understand the fate of hSSCs in culture, we describe a multiparameter, high-throughput, quantitative flow cytometry approach to rapidly count undifferentiated spermatogonia, differentiated spermatogonia, apoptotic spermatogonia, and proliferative spermatogonia in hSSC cultures.

Abnormal lipid processing but normal long-term repopulation potential of myc-/- hepatocytes.

Establishing c-Myc's (Myc) role in liver regeneration has proven difficult particularly since the traditional model of partial hepatectomy may provoke an insufficiently demanding proliferative stress. We used a model of hereditary tyrosinemia whereby the affected parenchyma can be gradually replaced by transplanted hepatocytes, which replicate 50-100-fold, over several months. Prior to transplantation, livers from myc-/- (KO) mice were smaller in young animals and larger in older animals relative to myc+/+ (WT) counterparts. KO mice also consumed more oxygen, produced more CO2 and generated more heat. Although WT and KO hepatocytes showed few mitochondrial structural differences, the latter demonstrated defective electron transport chain function. RNAseq revealed differences in transcripts encoding ribosomal subunits, cytochrome p450 members and enzymes for triglyceride and sterol biosynthesis. KO hepatocytes also accumulated neutral lipids. WT and KO hepatocytes repopulated recipient tyrosinemic livers equally well although the latter were associated with a pro-inflammatory hepatic environment that correlated with worsening lipid accumulation, its extracellular deposition and parenchymal oxidative damage. Our results show Myc to be dispensable for sustained in vivo hepatocyte proliferation but necessary for maintaining normal lipid homeostasis. myc-/- livers resemble those encountered in non-alcoholic fatty liver disease and, under sustained proliferative stress, gradually acquire the features of non-alcoholic steatohepatitis.