Development of a High-Yield Isolation Protocol Optimized for the Retrieval of Active Muscle Satellite Cells from Mouse Skeletal Muscle Tissue

Background and Objectives@#Difficulties often encountered in separating and purifying active muscle satellite cells (MSCs) from skeletal muscle tissues have limited the supply of cells for muscle therapy and artificial meat production. Here, we report an effective isolation protocol to economically and conveniently retrieve active MSCs from skeletal muscle tissues in mice. @*Methods@#and Results: We optimized an enzyme-based tissue digestion protocol for isolating skeletal muscle-derived primary cell population having a large number of active MSCs and described a method of differential plating (DP) for improving purity of active MSCs from skeletal muscle-derived primary cell population. Then, the age of the mouse appropriate to the isolation of a large number of active MSCs was elucidated. The best isolation yield of active MSCs from mouse skeletal muscle tissues was induced by the application of DP method to the primary cell population harvested from skeletal muscle tissues of 2-week-old mice digested in 0.2% (w/v) collagenase type II for 30 min at 37℃ and then in 0.1% (w/v) pronase for 5 min at 37℃. @*Conclusions@#The protocol we developed not only facilitates the isolation of MSCs but also maximizes the retrieval of active MSCs. Our expectation is that this protocol will contribute to the development of original technologies essential for muscle therapy and artificial meat industrialization in the future.

Screening of Integrin Heterodimers Expressed Functionally on the Undifferentiated Spermatogonial Stem Cells in the Outbred ICR Mice

Background and Objectives@#Outbred mice are widely used in toxicology, pharmacology, and fundamental biomedical research. However, there have been no reports of in vitro culture systems for spermatogonial stem cells (SSCs) derived from these mice. @*Methods@#As a step towards constructing a non-cellular niche supporting the in vitro maintenance of outbred mouse SSC self-renewal, we systematically investigated the types of integrin heterodimers that are expressed transcriptionally, translationally, and functionally in SSCs derived from Imprinting Control Region (ICR) mice. @*Results@#Among the genes encoding 25 integrin subunits, integrin α1, α5, α6, α9, αV, and αE, and integrin β1 and β5 had significantly higher transcriptional levels than the other subunits. Furthermore, at the translational level, integrin α5, α6, α9, αV, and αE, and β1 were localized on the surface of SSCs, but integrin α1 and β5 not. Moreover, significantly stronger translational expression than integrin α9 and αE was observed in integrin α5, α6, αV, and β1. SSCs showed significantly increased adhesion to fibronectin, laminin, tenascin C and vitronectin, and functional blocking of integrin α5β1, α6β1, α9β1 or αVβ1 significantly inhibited adhesion to these molecules. @*Conclusions@#We confirmed that integrin α5β1, α6β1, α9β1 and αVβ1 actively function on the surface of undifferentiated SSCs derived from outbred ICR mice.

Age-related change of Iba-1 immunoreactivity in the adult and aged gerbil spinal cord / 대한해부학회지

In the present study, we examined change of ionized calcium-binding adapter molecule 1 (Iba-1) in the adult and aged gerbil spinal cords. Significant change of morphological feature and neuronal cell loss were not observed in both adult and aged spinal cords of gerbil after NeuN immunohistochemistry and Fluoro-Jade B histofluoresce staining. Iba-1–immunoreactive microglia broadly distributed in the spinal cord. Most of Iba-1–immunoreactive microglia showed ramified forms in the adult gerbil cervical and lumbar spinal cords. However, morphological changes of Iba-1–immunoreactive microglia were observed in the cervical and lumbar regions of the aged gerbil spinal cord. These microglia were showed a hypertrophied body with shortened swollen processes which was characteristic of activated microglia. In addition, Iba-1 protein level significantly higher in aged cervical and lumbar spinal cords than those in the adult gerbil. The present study showed an increase of activated forms of Iba-1–immunoreactive microglia and its protein level without marked changes in morphological features and neuronal loss in the aged spinal cord compared to those in the adult gerbil spinal cord. This result suggests that the increase of Iba-1 expression in the aged spinal cord may be closely associated with age-related changes in aged gerbil spinal cord.

Rapamycin treatment during in vitro maturation of oocytes improves embryonic development after parthenogenesis and somatic cell nuclear transfer in pigs

This study was conducted to investigate the effects of rapamycin treatment during in vitro maturation (IVM) on oocyte maturation and embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in pigs. Morphologically good (MGCOCs) and poor oocytes (MPCOCs) were untreated or treated with 1 nM rapamycin during 0-22 h, 22-42 h, or 0-42 h of IVM. Rapamycin had no significant effects on nuclear maturation and blastocyst formation after PA of MGCOCs. Blastocyst formation after PA was significantly increased by rapamycin treatment during 22-42 h and 0-42 h (46.6% and 46.5%, respectively) relative to the control (33.3%) and 0-22 h groups (38.6%) in MPCOCs. In SCNT, blastocyst formation tended to increase in MPCOCs treated with rapamycin during 0-42 h of IVM relative to untreated oocytes (20.3% vs. 14.3%, 0.05 < p < 0.1), while no improvement was observed in MGCOCs. Gene expression analysis revealed that transcript abundance of Beclin 1 and microtubule-associated protein 1 light chain 3 mRNAs was significantly increased in MPCOCs by rapamycin relative to the control. Our results demonstrated that autophagy induction by rapamycin during IVM improved developmental competence of oocytes derived from MPCOCs.

A case of successful IVF in the patient with atypically low serum estradiol level / 대한산부인과학회잡지

It has been known that estradial(E2) level is concerned with the quality, number and growing of follicles. Determination of the serum levels of E2 has been used to predict the oocyte maturity. We experienced the rare case who has significantly low serum E2 level(551.26 pg/ml) in spite of multiple ovarian responses by sonographic finding, but from her we obtained 23 oocytes on MCD#16 after COH with ultrashort protocol(HP-FSH 150 IU, daily). The numbers of retrieved oocyte were 23 and fertilization rate was 56.6%, so the result of IVF-ET was successful twin pregnancy. Serum estradiol level and sonographic finding are essential to measure the number and growing of follicles, but E2 levels may be too unreliable to be used as sole parameter for the number and maturity of oocytes.