Ovine male genital duct epithelial cells differentiate in vitro and express functional CFTR and ENaC

To investigate the biology of the male genital duct epithelium, we have established cell cultures from the ovine vas deferens and epididymis epithelium. These cells develop tight junctions, high transepithelial electrical resistance, and a lumen-negative transepithelial potential difference as a sign of active transepithelial ion transport. In epididymis cultures the equivalent short-circuit current (I(sc)) averaged 20.8 ± 0.7 μA/cm2 (n = 150) and was partially inhibited by apical application of amiloride with an inhibitor concentration of 0.64 μM. In vas deferens cultures, I(sc) averaged 14.4 ± 1.1 μA/cm2 (n = 18) and was also inhibited by apical application of amiloride with a half-maximal inhibitor concentration (K(i)) of 0.68 μM. The remaining amiloride-insensitive I(sc) component in epididymis and vas deferens cells was partially inhibited by apical application of the Cl- channel blocker diphenylamine-2-carboxylic acid (1 mM). It was largely dependent on extracellular Cl- and, to a lesser extent, on extracellular HCO-3. It was further stimulated by basolateral application of forskolin (10-5 M), which increased I(sc) by 3.1 ± 0.3 μA/cm2 (n = 65) in epididymis and 0.9 ± 0.1 μA/cm2 (n = 11) in vas deferens. These findings suggest that cultured ovine vas deferens and epididymis cells absorb Na+ via amiloride-sensitive epithelial Na+ channels (ENaC) and secrete Cl- and HCO-3 via apical cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels. This interpretation is supported by RT-PCR data showing that vas deferens and epididymis cells express CFTR and ENaC mRNA

Physiological and anatomical aspects of the reproduction of mice with reduced Syndecan-1 expression

Abstract Background Syndecan-1 is a heparan sulfate proteoglycan acting as a co-receptor for cytokines and growth factors mediating developmental, immunological and angiogenic processes. In human, the uteroplacental localization of Syndecan-1 and its reduced expression in pregnancy-associated pathologies, such as the intrauterine growth restriction, suggests an influence of Syndecan-1 in embryo-maternal interactions. The aim of the present study was to identify the effect of a reduced expression of Syndecan-1 on the reproductive phenotype of mice and their progenies. Methods Reproductive characteristics have been investigated using animals with reduced Syndecan-1 and their wildtype controls after normal mating and after vice versa embryo transfers. Female mice were used to measure the estrus cycle length and the weight gain during pregnancy, as well as for histological examination of ovaries. Male mice were examined for the concentration, motility, viability and morphology of spermatozoa. Organs like heart, lung, liver, kidney, spleen, brain and ovaries or testes and epididymis of 6-month-old animals were isolated and weighed. Statistical analyses were performed using two-tailed students t-test with P < .05 and P < .02, chi square test (P < .05) and Fisher’s Exact Test (P < .05). A linear and a non-linear mixed-effects model were generated to analyze the weight gain of pregnant females and of the progenies. Results Focusing on the pregnancy outcome, the Syndecan-1 reduced females gave birth to larger litters. However, regarding the survival of the offspring, a higher percentage of pups with less Syndecan-1 died during the first postnatal days. Even though the ovaries and the testes of Syndecan-1 reduced mice showed no histological differences and the ovaries showed a similar number of primary and secondary follicles and corpora lutea, the spermatozoa of Syndecan-1 reduced males showed more tail and midpiece deficiencies. Concerning the postnatal and juvenile development the pups with reduced Syndecan-1 expression remained lighter and smaller regardless whether carried by mothers with reduced Syndecan-1 or wildtype foster mothers. With respect to anatomical differences kidneys of both genders as well as testes and epididymis of male mice with reduced syndecan-1 expression weighed less compared to controls. Conclusions These data reveal that the effects of Syndecan-1 reduction are rather genotype- than parental-dependent

Metabolic and behavioral parameters of mice with reduced expression of Syndecan-1.

Energy balance is essential for all species. Ligand-receptor interactions mediate processes that regulate body activities like reproduction and metabolism based on the energy status. Such receptors are the heparan sulfate proteoglycans and specifically the family of syndecans. Therefore we investigated the differences of metabolic parameters of heterozygous Syndecan 1 mice (Sdc1+/-) with reduced expression of Sdc1 and the corresponding wild type mice. Sdc1+/- mice have a reduced body weight although they show increased leptin and decreased corticosterone levels. Furthermore, their food and water intake is increased. This is accompanied with less adipose tissue, smaller adipocytes and thus an increased density of adipocytes. For the detailed analysis of the metabolism the automated PhenoMaster system has been used, which allowed continuous and undisturbed recording of food and water intake, energy expenditure and movement. The reason for the lower body weight was the higher energy expenditure of these animals compared to controls. Additionally, female Sdc1+/- mice showed an increased locomotor activity. Referring to organs, the intestine in Sdc1+/- mice was heavier and longer, but no differences at the cellular level could be observed. These findings were independent of normal mating or vice versa embryo transfers of Sdc1+/- and wild type embryos in recipient females of the other genotype. Herein we showed that the reduced expression of Sdc1 led to an altered metabolism on fetal as well as on maternal side, which may play a role in the growth restriction observed in human pregnancy pathologies and in mice lacking Sdc1