Prolonged communication between oocytes and the surrounding somatic cells is one of the unique reproductive physiology in canine. Paracrine Kit ligand (KITL) signaling is a well-known communication between granulosa cells and the oocyte. KITL is a cytokine growth factor secreted by granulosa cells that signals via the c-kit receptor expressed by oocytes. Paracrine factors, including growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), exert their effects by binding with the kinase receptors expressed on the granulosa cells. However, the regulations of GDF9 and BMP15 in the canine KITL expression are currently poorly understood. Therefore, we investigated the effects of GDF9 and BMP15 on the expression of KITL in canine ovarian granulosa cells in vitro. In Annexin V assay recombinant GDF9 and BMP15 did not induce apoptosis in the cultured ovarian granulosa cells. When treated, FSH significantly increased KITL expression, and hCG suppressed its expression. When both FSH and hCG were treated, the expression of KITL was affected by GDF9 and BMP15 in dose and time dependent manner in the luteal granulosa cells. GDF9 (10 ng/mL) significantly decreased KITL expression after12 h. BMP15 (10 ng/mL) significantly also decreased KITL expression after 24 h. Western blot and immunochemistry results indicate that GDF9 activated Smad2/3. After blocking ALK 4/5/7 receptors by SB, GDF9 failed to activate Smad2/3, also BMP15 did not activate Smad1/5/8 after blocking ALK 2/3/6 receptors by DM. So GDF9 exerts its effects via using ALK 4/5/7 receptors to activate SMAD2/3 signaling, and BMP15 binds ALK 2/3/6 receptors to activate SMAD1/5/8 signaling. The expression of KITL was not changed by SB or DM treatment. However, the effect of GDF9 and BMP15, which decreased the expression of KITL, was suppressed by SB or DM treatment. In conclusion, this study provides the first evidence that recombinant GDF9 and BMP15 decrease KITL expression in canine ovarian granulosa cells.

Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in Toll pathway. In this study, we monitored the response of 4 key genes of the insect immune system against Beauveria bassiana JEF-007 in Tenebrio molitor using RT-PCR. To better understand the roles of Toll pathway in mealworm immune system, TmGPR and TmMyD88 was knocked down by RNAi silencing. Target gene expressions were decreased at 6 days post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 days post-dsRNA injection. Silencing of the TmMyD88 and TmGPR resulted in reducing the resistance of the host to fungal infection. However, only dsTmMyD88 showed significant difference with dsEGFP by statistical analysis, which may be due to partial gene knock down of dsGPR. These results indicate that TmMyD88 is required in mealworms for survival against B. bassiana JEF-007.

Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in Toll signaling pathway. In this study, we monitored the response of 4 key genes of the insect immune system against Beauveria bassiana JEF-007 in Tenebrio molitor using RT-PCR. TmGPR, antimicrobial peptide Tenecin 1 and Tenecin 2 were up-regulated after fungal infection. To better understand the roles of Toll signaling pathway in mealworm immune system, TmGRP and TmMyD88 was knocked down by RNAi silencing. Target gene expressions were decreased at 2 days post-dsRNA injection, and dramatically reduced at 6 days post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 days post-dsRNA injection. Silencing of the TmMyD88 and TmGRP resulted in reducing the resistance of the host to fungal infection. However, only dsTmMyD88 showed significant difference with dsEGFP by statistical analysis, which may be due to partial gene knock down of dsGRP. These results indicate that TmMyD88 is required in mealworms for survival against B. bassiana JEF-007.

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of Tuj1 increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous Igf2 may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

Nuclear factor 1 (NFI) was discovered as a protein required for adenovirus DNA replication in vitro, but it is now clear that NFI protein plays an important role in the expression of many cellular genes. NFI-C null mice demonstrated aberrant odontoblast differentiation, abnormal dentin formation, and thus molar lacking roots while other tissues/or gans in the body, including ameloblasts appear to be unaffected and normal. However, little is known about the mechanism of NFI -C function in odontoblast differentiation and dentin formation. In this study, in order to elucidate the molecular mechanisms of odntoblast differentiation, we examined morphological characteristics of the aberrant odontoblast in NFI-C null mice. we also evaluate the expression of dentin sialophosphoprotein (DSPP) and bone sialoprotein (BSP) mRNAs in the MDPC-23 cells by northern analysis after over-expression and inactiγation of NFI -C into mouse MDPC-23 cells Odontoblasts of the NFI-C null mouse were round in shape, lost their polarity, organized as a sheet of cells, and trapped in osteodentin-like mineralized tissue. Abnormal odontoblasts of NFI-C null mouse revealed the absence of an intercellular junctional complex known as the t erminal webs. MDPC-23 cells started to express DSPP mRNA beginning from the postnatal day of 14 and showed a steady increase as differentiating into odontoblasts. Over-expression of NFI -C increased the expression of DSPP mRNA. Inactivation of NFI - C induced BSP mRNA expression. These results suggest that NFI-C plays an important role in odontoblast differentiation in a cell-type specific manner and thus in dentin formation

Previously we have succeeded to isolate stem cells (HEAC) from human eyelid adipose tissue, and functionally differentiate them into insulin-secreting cells. In the present study, we examined whether insulin family members might affect the insulinogenic differentiation of HEAC. Insulin treatment during culture affected little on the insulin and c-peptide secretions from HEAC after culture. However, insulin-like growth factor (IGF) 1 treatment decreased both secretions, whereas IGF2 greatly increased the secretions in a glucose-dependent manner. HEAC treated with IGF2 showed stronger expression of Pdx1, Isl1, Pax6 and PC1/3 genes compared to the control. They also showed distinct staining with insulin and c-peptide antibodies, and dithizone. While insulin or IGF2 treatment increased total cell number by 1.3- or 1.5-fold, respectively, each treatment increased the amount of insulin secretion by 27.1- or 78.1-fold, respectively. IGF2-enhanced insulinogenic differentiation was completely blocked by an antibody against insulin receptor (IR), but not by an antibody against IGF1 receptor (IGF1R). Differentiated HEAC showed expression of both IR and IGF1R genes while they expressed neither IGF2 nor IGF2R genes. Based upon these results, it is suggested that whereas IGF1 might inhibit the insulinogenic differentiation of HEAC, insulin and IGF2 could enhance the differentiation, and that the enhancing effect could be mediated via IR.

Growth/differentiation factor-9 (GDF-9)은 transforming growth factor (TGF-) superfamily의 member로서 난소의 난자에서만 특이적으로 발현되며 정상적인 난포발달에 있어 필수적인 성숙인자로 최근에 알려졌다. 본 연구는 RT-PCR을 통해 생쥐의 원시난포에서의 GDF-9 mRNA의 발현 여부와 함께 난포의 발달단계에 따른 상대적인 발현량을 분석하고자 실시하였다. 본 실험에는 ICR 생쥐를