Harderian gland-derived stem cells as a cytotherapy in a guinea pig model of carboplatin-induced hearing loss.

BACKGROUND: Stem cells therapy of hearing loss is a challenging field due to lacking self-regenerative capacity of cochlea. Harderian gland of guinea pigs was thought to harbour a unique type of progenitors which could restore the damaged cochlear tissues. THE AIM: of this study was to isolate Harderian gland derived stem cells (HG-SCs) and investigate their efficacy in restoring the damaged cochlear tissue in carboplatin-induced hearing loss. METHODOLOGY: Sixty female and 10 male pigmented guinea pigs were used; the male animals were HG-SCs donors, while the females were assigned into 3 groups; control, hearing loss (HL) and HG-SC-treated groups. Auditory reflexes were assessed throughout the study. The animals were euthanized 35 days after HG-SCs transplantation, the cochleae were extracted and processed for assessment by light microscope and scanning electron microscope. Morphometric assessment of stria vascularis thickness, hair cells and spiral ganglia neuronal number and optical density of TLR4 expression were done. RESULTS: The isolated HG-SCs had the same morphological and phenotypical character as mesenchymal stem cells. HL group revealed destruction of organ of Corti, stria vascularis and spiral ganglion with decreased morphometric parameters. Restoration of both cochlear structure and function was observed in HG-SC-treated group along with a significant increase in IHCs, OHCs numbers, stria vascularis thickness and spiral ganglionic cell count to be close to the values of control group. CONCLUSION: The isolated HG-SCs were proved to restore structure and function of cochlea in guinea pig model of hearing loss.

Effects of insulin and metformin on fetal kidney development of streptozotocin-induced gestational diabetic albino rats / 대한해부학회지

Gestational diabetes mellitus is one of common medical complications of pregnancy. Hyperglycemia in utero impairs renal development and produces renal anomalies. Metformin has antioxidant properties and better glycemic control. Aim: assessment insulin and metformin effects on renal development of streptozotocin-induced gestational diabetic albino rats. Sixty virgin female albino rats were used. Once pregnancy confirmed, animals were randomly assigned into control, metformin, diabetic, diabetic plus insulin, diabetic plus metformin and diabetic plus insulin and metformin treated groups. Rats were sacrificed on the 20th day of gestation; fetuses were extracted and weighted. Fetal kidneys were extracted prepared for light, morphometric and electron microscopic examination. Diabetic followed by diabetic plus metformin treated groups revealed retardation of glomerular development in the cortical and Juxtaglomerular zones with a significant increase in the early immature glomerular stages and immature to mature glomerular ratio compared to other groups. Diabetic group also showed morphometric changes, shrunken and empty glomeruli, vacuolar degeneration and hemorrhage. Diabetic plus metformin group showed minimal improvement while diabetic plus insulin and diabetic plus insulin and metformin groups showed developmental, histopathological and morphometric improvement with best results in the combination group. Gestational diabetes mellitus (GDM) possess deleterious effects on fetal kidney development. Insulin improves the glycemic state and decreases GDM effects on fetal kidneys. Metformin produces mild protection while the combination of insulin and metformin produces the best glycemic control and protect fetal kidneys.