Reverse Transcriptase qPCR Research Articles

Involvement of estrogen receptor-related receptors in human ovarian endometriosis

To determine whether decreased estrogen receptor alpha (ER-α) expression in endometriotic lesions could be balanced by an increased expression of estrogen receptor-related receptors (ERRs). To evaluate whether ERR-α expression is influenced by hormonal change in fertile and menopausal women. Prospective controlled study. University Hospital, Department of Gynecology. Twenty-five women: 20 women of reproductive age with (n = 10) and without (control; n = 10) endometriosis and 5 menopausal women. Real-time polymerase chain reaction (qPCR). Immunohistochemistry. The ER and ERR expression levels were studied by reverse transcriptase-qPCR, ELISA, and immunohistochemistry using endometriotic and normal endometrial tissues. The ERR-α protein distribution was performed by immunohistochemistry in fertile and menopausal women. Increased levels of ER-β were associated with ER-α, ERR-α, and ERR-γ reductions in ectopic tissue but not in eutopic and normal endometria. Similar levels of ERR-β were found in women with and without endometriosis. The ERR-α expression was similar in proliferative and secretory endometrial samples, whereas a down-regulation of this receptor was found in atrophic tissue. Our data confirm the up-regulation of ER-β as the principal receptor involved in the progression of human endometriosis. In addition, we found that ERR-α seems to be unresponsive to hormonal changes during the menstrual cycle.

Effect of fibre- and starch-rich finishing diets on methanogenic Archaea diversity and activity in the rumen of feedlot bulls

Methanogenesis plays an important role in maintaining low hydrogen partial pressure in the rumen and consequently in feed digestion. Diet composition and lipid supplementation are known to influence the extent of methane (CH4) production in ruminants. However, the impact of diet composition on rumen methanogens is poorly understood. This study examined CH4 production and methanogen community abundance, diversity and metabolic activity in the rumen of fattening bulls fed a fibrous diet (F; n=10) or a starch rich diet supplemented with extruded linseed (SL; n=10). Net CH4 emissions from bulls fed SL were lower than emissions from bulls fed F. Methanogenic Archaea were studied using culture independent methods targeting the functional mcrA gene. Methanogen abundance was similar in the two groups of bulls, but protozoa numbers were 65% lower in the F group. The SL diet decreased methanogen diversity and metabolic activity, which were evaluated by PCR-DGGE and reverse transcriptase qPCR, respectively. In contrast, no changes occurred in bacterial numbers and diversity between diets. Data indicate that reduction in net CH4 production with the SL diet was associated with changes in rumen microbiota, particularly methanogen activity. Characterization of the activity and structure of the whole rumen microbiota should provide a better prediction of methanogenesis.This paper is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

Curcumin modulates the immune response associated with LPS-induced periodontal disease in rats

Curcumin is a plant-derived dietary spice ascribed various biological activities. Curcumin therapeutic applications have been studied in a variety of conditions, but not on periodontal disease. Periodontal disease is a chronic inflammatory condition initiated by an immune response to micro-organisms of the dental biofilm. Experimental periodontal disease was induced in rats by injecting LPS in the gingival tissues on the palatal aspect of upper first molars (30 µg LPS, 3 times/week for 2 weeks). Curcumin was administered to rats daily via oral gavage at 30 and 100 mg/kg body weight. Reverse transcriptase-qPCR and ELISA were used to determine the expression of IL-6, TNF-α and prostaglandin E(2) synthase on the gingival tissues. The inflammatory status was evaluated by stereometric and descriptive analysis on hematoxylin/eosin-stained sections, whereas modulation of p38 MAPK and NK-κB signaling was assessed by Western blot. Curcumin effectively inhibited cytokine gene expression at mRNA and protein levels, but NF-κB was inhibited only with the lower dose of curcumin, whereas p38 MAPK activation was not affected. Curcumin produced a significant reduction on the inflammatory infiltrate and increased collagen content and fibroblastic cell numbers. Curcumin potently inhibits innate immune responses associated with periodontal disease, suggesting a therapeutic potential in this chronic inflammatory condition.

Biodynamics of HCV infection in haemodialysis patients in Pahang

Hepatitis C is a global disease, WHO has described it as a “viral time bomb”. In Malaysia, the sero-prevalence is 1.6%. HCV infection is frequent in patients undergoing maintenance haemodialysis, with prevalence between 8 and 10%. Hepatitis C has an adverse effect on both patient and graft survival in those who get renal transplants. There are relatively scarce reports on the natural fluctuation in viral load and alpha interferon (α-IFN) level in patients on chronic hemodialysis. Methods A longitudinal short-term three months study where 27 chronic hemodialysis patients infected with known HCV genotypes were recruited from seven hemodialysis centers in Pahang. Serum samples were collected monthly, both pre- and post-hemodialysis sessions, over a period of three months. Viral RNA was extracted from serum using QIAamp Viral RNA Extraction kit (Qiagen). The HCV viral load was measured using one step reverse transcriptase qPCR (Applied Biosystems) targeting the 5`HCV non-coding region. The serum α-IFN level was measured using commercial ELISA kit (Amersham, UK). Six biochemical liver function tests (AST, ALP, TP, albumin, ALT and TB) were also done for all pre-hemodialysis samples. Results All patients showed persistant low level viral load (Fig.1) that varied significantly over the study period (P = 0.001). HCV genotype 1 viral load was significantly higher than that of genotype 3 (Fig.2). The difference between pre- and post-haemodialysis viral load was statistically insignificant. No significant correlation between viral load and liver function status was noted. No correlation was observed between pre-haemodialysis serum α-IFN level and pre-haemodialysis viral load. The difference between pre and post-haemodialysis plasma α-IFN levels was statistically insignificant.

Influence of class M1 glutathione S-transferase (GST Mu) polymorphism on GST M1 gene expression level and tumor size in oral squamous cell carcinoma

Glutathione S-transferases (GST) are antioxidant enzymes and oxidative stress markers in oral carcinogenesis. They present a system of polymorphic proteins. Some variants are associated with increased sensitivity to toxic compounds, as it is known for the GSTM1-null variant allele. However, the influence of the GSTM1 allele variant genotype on GSTM1-mRNA quantity in oral squamous cell carcinoma (OSCC) and normal mucosa as well as the impact on prognosis remains unclear. The genotype for GSTM1 (mutation vs. wild type) was determined by polymerase chain reaction (PCR) using genomic DNA extracted from peripheral blood from 28 OSCC patients. From the same patients, 28 pairs of OSCC cells and normal oral mucosal cells were obtained by brush biopsy. mRNA was extracted from these paired samples and the expression levels of GSTM1 were examined by real-time reverse transcriptase qPCR (RT-qPCR). The mRNA expression of the OSCC samples was normalized against an external standard, as well as to the corresponding normal mucosa. The coincidence of GSTM1 genotype and GSTM1-mRNA-expression level was examined. In 15 patients (54%), the null genotype GSTM1 was present. In the GSTM1-null allele group, the GSTM1 gene expression level was determined at 1.63 (mean: 3.08; SD 3.4) folds vs. 3.6 (mean: 10.5; SD 14.2) folds in the group with the positive genotype (p=0.06), if calibrated vs. individual normal mucosa. More T3 and T4 OSCCs (+38%), higher UICC stadia (+38%) and more lymphatic metastasis (+28%) were seen in the group with the negative allele. Furthermore, positive GSTM1 genotype and enhanced GSTM1 gene expression was accompanied with increased tumor size, lymphatic metastasis status and UICC stadium. A coincidence of null type GSTM1 and lowered GSTM1 gene expression was observed. The larger tumors and more frequent lymph node metastases in this group could be explained by the insufficient cell protection by GST.

Prostate-specific antigen mRNA and protein levels in laser microdissected cells of human prostate measured by real-time reverse transcriptase–quantitative polymerase chain reaction and immuno–quantitative polymerase chain reaction

Laser-assisted microdissection has mainly been used in cancer studies to excise pure cell populations from heterogeneous tissues. Cancer and normal cells selected by laser-assisted microdissection have frequently been used for mRNA expression studies usually by reverse transcriptase-quantitative polymerase chain reaction (qPCR). Recently, real time immuno-qPCR was developed as a new tool for highly sensitive measurements of proteins. Using reverse transcriptase-qPCR and immuno-qPCR, we measured the amounts of prostate-specific antigen mRNA and its corresponding protein in homogeneous and comparable cell populations, collected from normal and cancer prostates by laser-assisted microdissection. With these techniques, prostate-specific antigen mRNA and protein were quantified over a wide range of concentrations with a sensitivity sufficient to analyze single prostate cells (LNCaP). We did not find significant differences in prostate-specific antigen protein and mRNA between normal and cancer cells. The expression of prostate-specific antigen protein and mRNA was highly correlated in both normal and pathological cells. In microdissected peritubular stromal areas of prostate cancers, the concentration of prostate-specific antigen protein was about 100 times higher than in normal prostate, indicating an increased transit of secreted prostate-specific antigen. In the same samples, prostate-specific antigen mRNA was not detectable. Our data demonstrate, for the first time, the feasibility of simultaneous application of reverse transcriptase-qPCR and immuno-qPCR in studies of homogeneous cell populations, collected by laser-assisted microdissection. The approach is expected to become a very powerful tool for expression studies in human cancers at both mRNA and protein levels.

Oxygen Effect on Dehalococcoides Viability and Biomarker Quantification

Oxygen-sensitive Dehalococcoides bacteria play crucial roles in detoxification of chlorinated contaminants (e.g., chlorinated ethenes), and bioremediation monitoring relies on quantification of Dehalococcoides DNA and RNA biomarkers. To explore the effects of oxygen on Dehalococcoides activity, viability, and biomarker quantification, batch experiments with a tetrachloroethene-to-ethene dechlorinating consortium (Bio-Dechlor INOCULUM [BDI]) harboring multiple Dehalococcoides strains were performed to quantify the effects of < or = 4 mg/L dissolved oxygen. Oxygen inhibited reductive dechlorination, and only incomplete dechlorination to vinyl chloride (VC) occurred following oxygen consumption and extended incubation periods (89 days). Following 30 days of oxygen exposure and subsequent oxygen removal (i.e., reversibility experiments), all trichloroethene- (TCE-) fed cultures dechlorinated TCE to VC, but VC dechlorination to ethene occurred in only one out of fourteen replicates. These results suggest that Dehalococcoides strains respond differently to oxygen exposure, and strains catalyzing the VC-to-ethene dechlorination step are more susceptible to oxygen inhibition. Quantitative real-time PCR (qPCR) analysis detected a 1-1.5 order-of-magnitude decrease in the number of Dehalococcoides biomarker genes (i.e., 16S rRNA gene and the reductive dehalogenase [RDase] genes tceA, vcrA, bvcA) in the oxygen-amended cultures, but qPCR analysis failed to distinguish viable, dechlorinating from irreversibly inhibited (nonviable) Dehalococcoides cells. Reverse transcriptase qPCR (RT-qPCR) detected Dehalococcoides gene transcripts in the oxygen-amended, non-dechlorinating cultures, and biomarker transcription did not always correlate with dechlorination (in)activity. Enhanced molecular tools that complement existing protocols and provide quantitative information on the viability and activity of the Dehalococcoides population are desirable.