Secretions released from mesenchymal stem cells improve spermatogenesis restoration of cytotoxic treatment with busulfan in azoospermia mice.

This study aimed at the efficacy of sequential treatment of bone marrow-derived mesenchymal stem cell secretion for busulfan-treated azoospermia in mice. The conditioned media (CM) was obtained from bone marrow mesenchymal stem cells (MSCs) or 293 cells. Chemically induced azoospermia mice received 200 µl MSC-CM or 293-CM twice a week intravenously for three consecutive weeks. The histological assessment of spermatogenic recovery quantifying the expression of meiosis-associated genes, and Sertoli cell barrier functional factors were assessed. The characteristics of TM4 cells (Sertoli cell line) after pre-incubation of MSC-CM in vitro were also obtained. The MSC-CM group had the most spermatogenic colonies among the three groups (p < .05), but no spermatids were seen. Expressions of the meiosis-associated genes Dazl, Vasa, Miwi, Stra8, CyclinA1, Pgk2 and Scp3 in MSC-CM testis were remarkably higher compared with 293-CM and busulfan groups respectively (p < .05). The levels of Sertoli cell barrier functional factors, for example ICAM-1 and N-cadherin, were significantly increased during MSC-CM treatment (p < .05). Moreover, pre-incubation of MSC-CM particularly accelerated the CD54 (ICAM-1) and CD44 expressions of TM4 cells and promoted cell inherent adhesion. MSC-CM treatment can significantly improve the short-term restoration of spermatogonial structures of chemically induced azoospermia related to facilitating Sertoli cell adhesion integrity.

Mesenchymal stem cell-secreted factors delayed spermatogenesis injuries induced by busulfan involving intercellular adhesion molecule regulation.

The present study was designed to investigate the therapeutic effect of bone marrow MSC-derived factors on gonadotropic toxicity induced by busulfan in vivo. The conditioned media (CM) was obtained from MSCs in serum-free incubation for 48 hr and concentrated ~25-fold by ultrafiltration. The CM of HEK 293 cells was treated as control (293-CM). MSC-CM was injected into busulfan mice via caudal veins after 1 day of busulfan treatment for 2 weeks (200 µl per dose/twice weekly）. Compared to the 293-CM group, testicular injury was delayed in MSC-CM group, including reduced vacuolations of cells in the basal compartment of the seminiferous epithelium and detachment of cells from basement membrane. Apoptotic spermatogenic cells were significantly decreased in MSC-CM group (p ï¼œ 0.05). Interesting N-cadherin，ICAM-1 and P-cadherin expressions significantly increased in MSC-CM group, while occludin, ZO-1 and connexin 43 expressions showed no difference among MSC-CM, 293-CM and busulfan groups. Present results suggest MSC-secreted factors protect spermatogenesis impairment after busulfan treatment by reducing the apoptosis of spermatogenic cells and enhancing intercellular adhesion molecule expressions.

[Investigation of Atmospheric Formaldehyde and Glyoxal Based on Differential Optical Absorption Spectroscopy].

This paper proposes a method to monitor atmospheric HCHO and CHOCHO with high temporal resolution based on differential optical absorption spectroscopy (DOAS) in Shanghai urban area. Based on the characteristic absorbing structure of HCHO and CHOCHO, different fitting intervals were chosen for spectral analysis in order to avoid the absorption of interfering gases and reduce the residuals of spectral analysis. The resulting optical thickness of the target gas is used to obtain HCHO and CHOCHO concentrations, which were averaged at (4.0±1.6) and (3.4±1.2) µg·m-3 in October 2013, respectively. The averaged concentrations of HCHO in workdays were higher than those in holidays due to the impacts of its anthropogenic emission sources, while no obvious differences of averaged CHOCHO concentrations between workdays and holidays were observed. Diurnal patterns of HCHO and CHOCHO were alike. In the early morning, both the HCHO and CHOCHO concentrations peaked at 06:00­07:00, and then decreased rapidly to the minimum around 09:00. Afterwards, the concentrations increased continuously until sunset and kept in a relatively stable level in the evening. To explore the possible emission source and formation mechanism of atmospheric HCHO, four typical periods, i.e. steady-state stage at night, morning rush hours, photochemical reaction stage and evening rush hours, were classified for source apportionment.NO2 is regarded as the indicator for primary source of ambient HCHO.As the intermediate products of photochemical reactions, HCHO has a similar formation mechanism in common with CHOCHO. Therefore, it is reasonable to use CHOCHO as an indicator for secondary source of ambient HCHO. The linear regression analysis showed a good agreement between modeled and observed HCHO concentrations, the correlation coefficients R2 ranged from 0.60 to 0.81. Secondary sources of HCHO were estimated to contribute to one third of ambient HCHO concentrations in Shanghai urban area.