To gain insights into the role of purinergic receptors in human dental pulp cells (hDPCs) differentiation, we characterized the expression and functional activity of P2Y1 receptors and investigated the effects of ADP on the proliferation and differentiation of this pulp stem-like cell population. Our data showed that ADP did not induce cell proliferation to expose the various ADP concentrations for 72 hours, but the proliferative capacity of hDPCs was inhibited at higher ATP concentrations (100 μM). Using RT-PCR analysis, we found that ADP induced several P2Y receptors including P2Y1 as well as odontoblastic differentiation genes, dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein (DSPP) in a dose-dependent manner. The effects of ADP on the expression of DMP-1 and DSPP mRNA were prevented by the P2Y1 antagonist MRS2179. The extracellular matrix calcium deposits were clearly observed in ADP-treated hDPCs by alizarin red S staining. Quantitative measurement of mineralization induced by ADP was significantly inhibited in MRS2179-treated hDPCs. These results may provide new insights into the molecular regulation of the differentiation of hDPCs.

Poly(ADP-ribosyl)ation is post-translational modification of cellular proteins related to cell survival, cell death, cellular proliferation and epigenetic events. It has recently been shown to be important for pre-implantation development of mouse embryos. However, its function during early embryonic development of pig is not clear. This study investigated the importance of poly(ADP-ribosyl)ation during in vitro development of pig embryos produced by in vitro fertilization(IVF) or parthenogenetic activation (PA). Results showed that, chemical inhibition of PARP by 3-aminobenzamide (3-AB) did not influence the in vitro development of pig embryos up to morula stage (20±3.1 vs. 28.1±1.2%; p>0.05) but significanlty reduced the rate of blastocyst formation (5.2±2.1 vs. 20±3.1%; p<0.05) when compared to non-treated controls. Furthermore, culture of morula stage embryos in the pressence of 3-AB for 24h significantly reduced the rate of blastocyst formation (19.6± 4.6 vs. 41.4±5.3%; p<0.05) and expansion (4.7±3.0 vs. 28.1±6.1; p<0.05). The proportion of large-sized blastocyst (>200 μm) having higher blastocoel volume (15.3×106 μm3) was significantly reduced (p<0.05) in treatment group (32.2±7.8%) compared to non-treated control group (65.7±9.0%). TUNEL assay revealed that poly(ADP-ribosyl)ation-inhibited blastocyst had significantly increased indices of apoptosis than those of non-treated controls (10.88±0.02 vs. 2.71±0.01; p<0.05). These data suggest that Poly(ADP-ribosyl)ation may be important for blastocyst formation in pig embryo.

콩의 생산성을 높이는데 중요한 역할을 하는 효소의 활성변화와 종실 수량과의 관련성을 탐색하기 위해 등숙관련효소인 ADP-glucose pyrophosphorylase(AGP)의 활성변화를 콩 품종별로 등숙기간에 따라 조사한 결과를 요약하면 다음과 같다. 1. 풍산나물콩은 협수 및 잎수가 131개 및 102개로 가장 많았으며, 100립중은 10.4g으로 가장 낮았으나 수량은 275kg/10a으로 가장 높아 물질생산 및 건물축적 효율이 우수한 것으로 나타났는데, 개화시기(R1,R2) 에 AGP의 활성도 가장 높은 경향이었다. 2. 품종별 CO2 동화량은 풍산나물콩이 20.96umolm2s1로 가장 많았으며 검정콩1호는 12.54umolm2s1로 가장 적었다. 3. 단파흑은 개체당 잎면적이 3,968cm2 로 가장 많고 100립중도 30.5g으로 가장 높은 반면 수량은 149kg/10a으로 가장 낮아 건물축적 효율이 가장 낮았으며, 생육단계별 AGP활성도 가장 낮은 수치를 나타냈다. 4. AGP의 small subunit은 60KD의 single band를 나타냈는데 개화기 이후 AGP의 활성변화와 일치하는 경향을 보였다.

To find the mechanism underlying the ADP-induced increase in the outward current in ovulated mouse oocytes, we examined changes in voltage-dependent currents using the whole cell voltage clamp technique and the internal perfusion technique. Eggs were collected from the oviduct of superovulated mice with PMSG and hCG. Membrane potential was held at -60 mV (or -80 mV in the case of recording currents) and step depolarizations or hyperpolarizations were applied for 300 ms. By step depolarizations, outward currents comprising steady-state and time-dependent components were elicited. They were generated in response to the positive potential more than 20 mV with severe outward rectification and were blocked by external TEA, a specific channel blocker, suggesting that they be carried via channels. Internally-perused 5 mM ADP gradually increased outward currents (IK) 1 min after perfusion of ADP and reached slowly to maximum (150~170％) 5 min later over the positive potential range, implying that ADP might not be acted directly to the channels. IK were decreased by 5 mM ATP without affecting the steady-state component of outward current. In contrast to the effect of ADP and ATP on IK, both effect of ATP and ADP on inward currents (ICa) could not be detected due to the continuous decrease in current amplitudes with time-lapse ("run-down" phenomena). To check if there is a G protein-involved regulation in the ionic current of mouse oocytes, 1 mM GTP was applied to the cytoplasmic side, and the outward current and inward currents were recorded. ICa was promptly increased in the presence of GTP whereas IK was not changed. from these results, it is concluded that the ATP-dependent regulation is likely linked in the ADP-induced increase in the outward current, and G protein-involved cellular signalling might affect ion channels carrying and in mouse oocytes.