Differential expression of metallothionein type-2 homologues in leaves and roots of Black pepper (Piper nigrum L)

Black pepper (Piper nigrum L.), member of the family Piperaceae is indigenous to India and is one of the most widely used spices in the world. In this paper we report the results of our attempts to identify a set of genes differentially expressed in the leaves of Piper nigrum, which could facilitate targeted engineering of this valuable crop. A PCR-based Suppression Subtractive Hybridization (SSH) technique was used to generate a leaf-specific subtracted cDNA library of Piper nigrum. A tester population of leaf cDNA was subtracted with a root derived driver cDNA. The efficiency of subtraction was confirmed by PCR analysis using the housekeeping gene actin. On sequence analysis, almost 30 percent of the clones showed homology to metallothionein type-2 gene. The predominance of metallothionein transcripts in the leaf was further confirmed using Real-Time PCR analyses and Northern blot. The possible role of metallothionein type-2 homologues in the leaf is discussed along with the feasibility of using SSH technique for identification of more number of tissue-specific genes from Piper nigrum.

Functional Studies of Acyl-CoA Synthetase 4 in the Rat Liver

Acyl-CoA synthetase 4 (ACS4) is an arachidonate-preferring enzyme abundant in steroidogenic tissues. We examined ACS4 in rat liver, which contains a variety of pathways that use acyl-CoAs, in order to determine subcellular locations. We demonstrate that ACS4 protein was present most abundantly in the mitochondria and to a much lesser extent in the peroxisomes and microsomes. To determined the dietary effects on the level of ACS4 mRNA, northern blotting was carried out using total RNA from the livers of adult male rats fed various diets. Fasting, high fat diet, and fat-free high sucrose diet increased the hepatic level of ACS4 mRNA approximately 2-fold. Furthermore, the levels of ACS4 mRNA were induced by DEHP[Di- (2-ethylhexyl) phthalate]. These data suggest that ACS4 expression in the liver is regulated with a variety of pathways, including beta-oxidation, hormone, and insulin.

Analysis of PDL Fibroblast Change During Mechanical Stimuli in the Rats / 대한치주과학회지

Periodontal disease is characterized by inflammation and subsequent loss and/or damage to tooth-supporting tissues such as bone, cementum, and periodontal ligament.Periodontal ligament and cementum are the key tissues in the initial process of regeneration following periodontal disease.Therefore, studies on cementoblasts, which form cementum are emphasized. It is still unclear which cells cementoblast differentiate from.This study was conducted under the hypothesis that PDL fibroblast can differentiate into either cementoblast or osteoblast depending on the conditions of surrounding tissue.Clinically, with excessive traction force of orthodontic appliances or excessive occlusion hypercementosis is observed, and this has been confirmed histologically.Consequently, activation of cementoblast can be expected in rats when mechanical stimuli are given to PDL fibroblast.Therefore, the purpose of this article is to prove that PDL fibroblast differentiates into cementoblast in rats under mechanical stimuli using histologic and molecular methods. In this study, twenty rats were given hard diet.Ten of them were sacrificed after 1 week, and the others were sacrificed after two weeks.Slides were made from tooth specimen, and they were studied under the microscope. In addition, PDL fibroblast and cementum from the extracted teeth were analyzed with Northern blotting. In histologic examination, as time passed, PDL fibroblast migrated to the dentin side, differentiated into cementoblast, and formed new cementum.In Northern blotting, it was found that mRNA expression of cementoblast-specific proteins such as BSP, OC, OPN, and type I collagen were more prominent in rats sacrificed after 2 weeks of hard-diet than rats sacrificed after 1 week. From these findings we can conclude that PDL fibroblast can differentiate into cementoblast under mechanical stimuli.We think that 'Rat Models' used in this study will be beneficial to future studies regarding cementoblast.