Total Tissue RNA Research Articles

Reconstitution of Insulin Action in Muscle, White Adipose Tissue, and Brain of Insulin Receptor Knock-out Mice Fails to Rescue Diabetes

Type 2 diabetes results from an impairment of insulin action. The first demonstrable abnormality of insulin signaling is a decrease of insulin-dependent glucose disposal followed by an increase in hepatic glucose production. In an attempt to dissect the relative importance of these two changes in disease progression, we have employed genetic knock-outs/knock-ins of the insulin receptor. Previously, we demonstrated that insulin receptor knock-out mice (Insr(-/-)) could be rescued from diabetes by reconstitution of insulin signaling in liver, brain, and pancreatic β cells (L1 mice). In this study, we used a similar approach to reconstitute insulin signaling in tissues that display insulin-dependent glucose uptake. Using GLUT4-Cre mice, we restored InsR expression in muscle, fat, and brain of Insr(-/-) mice (GIRKI (Glut4-insulin receptor knock-in line 1) mice). Unlike L1 mice, GIRKI mice failed to thrive and developed diabetes, although their survival was modestly extended when compared with Insr(-/-). The data underscore the role of developmental factors in the presentation of murine diabetes. The broader implication of our findings is that diabetes treatment should not necessarily target the same tissues that are responsible for disease pathogenesis.

Mast Cells Are an Essential Component of Human Radiation Proctitis and Contribute to Experimental Colorectal Damage in Mice

Radiation proctitis is characterized by mucosal inflammation followed by adverse chronic tissue remodeling and is associated with substantial morbidity and mortality. Mast cell hyperplasia has been associated with diseases characterized by pathological tissue remodeling and fibrosis. Rectal tissue from patients treated with radiotherapy shows mast cell hyperplasia and activation, suggesting that these cells play a role in the development of radiation-induced sequelae. To investigate the role of mast cells in radiation damage, experimental radiation proctitis was induced in a mast cell-deficient (W(sh)/W(sh)) mouse model. The colon and rectum of W(sh)/W(sh) and wild-type mice were exposed to 27-Gy single-dose irradiation and studied after 2 and 14 weeks. Irradiated rodent rectum showed mast cell hyperplasia. W(sh)/W(sh) mice developed less acute and chronic rectal radiation damage than their control littermates. Tissue protection was associated with increased tissue neutrophil influx and expression of several inflammatory mediators immediately after radiation exposure. It was further demonstrated that mast cell chymase, tryptase, and histamine could change human muscularis propria smooth muscle cells into a migrating/proliferating and proinflammatory phenotype. These data show that mast cells have deleterious effects on both acute and chronic radiation proctitis, possibly by limiting acute tissue neutrophil influx and by favoring phenotypic orientation of smooth muscle cells, thus making them active participants in the radiation-induced inflammatory process and dystrophy of the rectal wall.

Systems biology of interstitial lung diseases: integration of mRNA and microRNA expression changes

BackgroundThe molecular pathways involved in the interstitial lung diseases (ILDs) are poorly understood. Systems biology approaches, with global expression data sets, were used to identify perturbed gene networks, to gain some understanding of the underlying mechanisms, and to develop specific hypotheses relevant to these chronic lung diseases.MethodsLung tissue samples from patients with different types of ILD were obtained from the Lung Tissue Research Consortium and total cell RNA was isolated. Global mRNA and microRNA were profiled by hybridization and amplification-based methods. Differentially expressed genes were compiled and used to identify critical signaling pathways and potential biomarkers. Modules of genes were identified that formed a regulatory network, and studies were performed on cultured cells in vitro for comparison with the in vivo results.ResultsBy profiling mRNA and microRNA (miRNA) expression levels, we found subsets of differentially expressed genes that distinguished patients with ILDs from controls and that correlated with different disease stages and subtypes of ILDs. Network analysis, based on pathway databases, revealed several disease-associated gene modules, involving genes from the TGF-β, Wnt, focal adhesion, and smooth muscle actin pathways that are implicated in advancing fibrosis, a critical pathological process in ILDs. A more comprehensive approach was also adapted to construct a putative global gene regulatory network based on the perturbation of key regulatory elements, transcription factors and microRNAs. Our data underscores the importance of TGF-β signaling and the persistence of smooth muscle actin-containing fibroblasts in these diseases. We present evidence that, downstream of TGF-β signaling, microRNAs of the miR-23a cluster and the transcription factor Zeb1 could have roles in mediating an epithelial to mesenchymal transition (EMT) and the resultant persistence of mesenchymal cells in these diseases.ConclusionsWe present a comprehensive overview of the molecular networks perturbed in ILDs, discuss several potential key molecular regulatory circuits, and identify microRNA species that may play central roles in facilitating the progression of ILDs. These findings advance our understanding of these diseases at the molecular level, provide new molecular signatures in defining the specific characteristics of the diseases, suggest new hypotheses, and reveal new potential targets for therapeutic intervention.

177 GENE EXPRESSION PROFILES OF IN VITRO- AND IN VIVO-DERIVED BOVINE EMBRYOS

Microarray technology is one of the most powerful tools for gene expression profiling in animal sciences. The objectives of this study were to determine the effect of vitrification on gene expression in in vitro- and in vivo-derived bovine embryos, and to identify differential mRNA expression patterns between embryos produced by in vivo v. in vitro conditions. Three pools of in vivo- and in vitro-derived blastocyst-stage embryos were used for microarray analysis. Total RNA was isolated using the PicoPure RNA Isolation Kit (Arcturus Bioscience, Mountain View, CA). Bovine ovarian tissue total RNA was used as the reference. Total RNA samples were amplified using an Ovation® Pico WTA System (NuGEN Technologies, San Carlos, CA). The bovine 16 846-member microarrays spotted with 70-mer oligonucleotides were purchased from the Bovine Genomics Laboratory, University of Missouri. Amplified cDNA samples were labeled with Alexa Fluor 647 and 546 dyes (Molecular Probes, Eugene, OR), respectively. Combined, labeled samples were dried and resuspended in hybridization buffer containing 50% formamide (vol/vol), 5× SSC, and 0.1% sodium dodecyl sulfate (wt/vol). After denaturation and cooling, cDNA was applied onto a microarray slide. Microarrays were hybridized overnight at 42°C. Following hybridization, the slides were washed with different stringency buffers and water. After drying by centrifugation, the arrays were scanned on a GenePix 4000B scanner (Axon Instruments, Union City, CA). GenePix Pro4.1 software was used for griding and analysis of spot intensities. Good-quality spots were analyzed using the GeneSpring 7.3 software (Agilent Technologies, Inc., CA, Santa Clara, CA). The data were normalized per spot and per array by Lowess normalization. When comparing two treatments, the Welch t-test with Benjamini and Hochberg multiple testing correction was performed to determine the differentially expressed genes between embryo groups. Microarray experiments were performed in 3 biological and 2 technical replicates for all embryo samples. Differentially expressed genes between all embryo groups were identified. The DAVID Functional Annotation Tool was used to analyze the genes that were differentially expressed. The DAVID Functional Annotation Tool determined the co-occurrence probability and provided gene-GO term enrichment analysis to highlight the most relevant GO terms associated with a given gene list. Differentially expressed Kyoto Encyclopedia of Genes and Genomes pathways are as follows: Ribosome, oxidative phosphorylation, spliceosome, and oocyte meiosis were significantly upregulated in the fresh embryos, whereas sphingolipid and purine metabolism was the upregulated in the vitrified in vitro-derived embryos. Gene expression was very similar between fresh and vitrified in vivo-derived, as opposed to in vitro-derived, embryos. This study was funded by the TUBITAK (Project no. KAMAG107G027) and startup funds to Yuksel Agca at the University of Missouri.

Abstract 3049: Overexpression of miR-17 family miRNAs in prostate cancer biopsies: Evidence for a stem-cell-like miRNA profile in high grade/high stage tumors

Abstract Complex changes in microRNA (miRNA) expression patterns have been observed in many different types of cancer, including prostate cancer. Although the consequences of deregulation of miRNA expression in human cancer are still largely unknown, the use of miRNAs for cancer classification and prognosis has emerged as an important new area of biomarker research. We compared the tissue expression of miRNAs in prostate biopsies from patients with high grade/high stage tumors with biopsies from patients with no evidence of malignancy. Snap frozen prostate biopsy samples were prospectively collected using tissue printing techniques and total RNA was isolated for miRNA analysis using Agilent miRNA microarrays (Version 1, containing 470 human tissue miRNAs). The prostate cancer cases included in the microarray profiling study had at least 5 of 12 cores positive for cancer and significant areas of Gleason 7 or more. The no-cancer controls showed no prostate cancer, HGPIN or suspicious histology in any of the 12 biopsy cores. In our analysis of miRNA expression patterns, “significant change in expression” was defined as at least 2 fold change and F test (p<0.05). Three different internal reference normalization methods were used in the data analysis; here we classify miRNAs as “overexpressed” or “underexpressed” only when all three methods agree. In high grade/high stage biopsy cancer, 64 of the 470 human tissue miRNAs on the microarray (13.6%) were found to be significantly overexpressed when compared with miRNA expression in biopsies from no-cancer controls. This set of overexpressed miRNAs includes 4 of the 5 miR-200 family miRNAs that have been implicated in the regulation of the epithelial-to-mesenchymal transition (EMT). The cancer-overexpressed miRs also include 6 of the 8 miR-17 family genes; this miRNA family has been implicated in the control of stem-cell differentiation during embryogenesis. Interestingly, the 6 miR-17 family miRs that are overexpressed in high grade/high stage prostate cancer include 2 from each of the 3 polycistronic clusters that encode this highly conserved miR family, an expression pattern similar to the coordinated expression observed in early embryonic development. This robust stem-cell-like miRNA profile offers an interesting new candidate biomarker that may be particularly sensitive to an aggressive prostate cancer phenotype. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3049.

Abstract 4055: Real-time quantitation of primary transcripts of microRNA genes

Abstract Regulation of mature microRNA (miRNA) expression has been shown during the course of biogenesis under different contexts: from transcription, processing of pri-miRNA to pre-miRNA by Drosha, to processing of pre-miRNA to mature miRNA by Dicer. A mature miRNA can be processed from two or more stem-loop precursor loci, which are denoted with numeric suffixes such as −1, −2, etc. As of the 14th Release of the miRBase, there are 154 genes among the 750 miRNA genes that belong to this category. To interrogate regulation of miRNA expression at the transcriptional level for those that can be processed from multiple genomic locations, it requires assays to specifically quantitate the precise locus of interest. We have developed a pipeline to design and select real-time RT-PCR assays to quantitate primary transcripts of miRNA genes. These assays are designed against genomic DNA sequence so the genomic DNA needs to be removed by prior enzyme treatment. We showed that the TaqMan® Pri-miRNA Assays have minimally detectable or no background using either cell lysates or commercial tissue total RNA. Excellent linearity was seen using cDNA synthesized from total RNA, or using 1ng/ul or greater of genomic DNA. The specificity of the assays to distinguish loci that are processed into identical mature miRNA was demonstrated using subcloned plasmids, as well as using breast cancer cell lines that showed concordant expression patterns among such loci with published data in human breast cancer. The TaqMan® Pri-miRNA Assays will be a useful tool to identify the precise loci that contribute to the mature miRNA expression of interest at the transcription level, so as to further investigate the regulatory mechanisms for the differential expression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4055.

Gene expression modulation of rat liver cholesterol metabolism by oleoyl-estrone

Since oleoyl-estrone (OE) decreases circulating cholesterol in the rat, we analyzed the response to OE treatment of hepatic gene expressions related with cholesterol metabolism. Male overweight rats treated with oral OE (10 nmol/g daily) were compared with a pair-fed (PF) group and controls fed ad libitum. Serum parameters and liver lipid and cholesterol contents were measured. Total tissue RNA was used for real-time PCR analysis of the gene expression of enzymes and regulatory factors of liver cholesterol metabolism. Cholesterol-7α-hydroxylase and ABC transporter A1 protein levels were estimated by Western blot. Pair-feeding and OE treatment reduced the expression of 3-hydroxy-3-methyl-glutaryl-CoA synthase. OE increased the expression of the LDL receptor. Cholesterol disposal, through bile acids synthesis, was increased in PF and more markedly in OE rats. Gene expressions of the ABC transporter A1 and apolipoproteins A1 and E were increased in OE rats. The expression of liver X receptor was lower in PF than in OE and controls. The rapid disappearance of circulating cholesterol elicited by OE is consequence of: (1) decreased mevalonate pathway activity, (2) a higher expression of the LDL-receptor, and (3) the activation of the oxidation of cholesterol to form bile acids as a consequence of the higher cholesterol concentrations found in liver, also affected by energy availability.

Genetic Mapping in Mice Identifies DMBT1 as a Candidate Modifier of Mammary Tumors and Breast Cancer Risk

Low-penetrance breast cancer susceptibility alleles seem to play a significant role in breast cancer risk but are difficult to identify in human cohorts. A genetic screen of 176 N2 backcross progeny of two Trp53(+/-) strains, BALB/c and C57BL/6, which differ in their susceptibility to mammary tumors, identified a modifier of mammary tumor susceptibility in an approximately 25-Mb interval on mouse chromosome 7 (designated SuprMam1). Relative to heterozygotes, homozygosity for BALB/c alleles of SuprMam1 significantly decreased mammary tumor latency from 70.7 to 61.1 weeks and increased risk twofold (P = 0.002). Dmbt1 (deleted in malignant brain tumors 1) was identified as a candidate modifier gene within the SuprMam1 interval because it was differentially expressed in mammary tissues from BALB/c-Trp53(+/-) and C57BL/6-Trp53(+/-) mice. Dmbt1 mRNA and protein was reduced in mammary glands of the susceptible BALB/c mice. Immunohistochemical staining demonstrated that DMBT1 protein expression was also significantly reduced in normal breast tissue from women with breast cancer (staining score, 1.8; n = 46) compared with cancer-free controls (staining score, 3.9; n = 53; P < 0.0001). These experiments demonstrate the use of Trp53(+/-) mice as a sensitized background to screen for low-penetrance modifiers of cancer. The results identify a novel mammary tumor susceptibility locus in mice and support a role for DMBT1 in suppression of mammary tumors in both mice and women.

Protocol: a highly sensitive RT-PCR method for detection and quantification of microRNAs

MicroRNAs (miRNAs) are a class of small non-coding RNAs with a critical role in development and environmental responses. Efficient and reliable detection of miRNAs is an essential step towards understanding their roles in specific cells and tissues. However, gel-based assays currently used to detect miRNAs are very limited in terms of throughput, sensitivity and specificity. Here we provide protocols for detection and quantification of miRNAs by RT-PCR. We describe an end-point and real-time looped RT-PCR procedure and demonstrate detection of miRNAs from as little as 20 pg of plant tissue total RNA and from total RNA isolated from as little as 0.1 μl of phloem sap. In addition, we have developed an alternative real-time PCR assay that can further improve specificity when detecting low abundant miRNAs. Using this assay, we have demonstrated that miRNAs are differentially expressed in the phloem sap and the surrounding vascular tissue. This method enables fast, sensitive and specific miRNA expression profiling and is suitable for facilitation of high-throughput detection and quantification of miRNA expression.

Relationship of antiretroviral treatment to postmortem brain tissue viral load in human immunodeficiency virus–infected patients

Human immunodeficiency virus (HIV)-1 invades the central nervous system (CNS) soon after infection and is partially protected there from host immunity and antiretroviral drugs (ARVs). Sanctuary from highly active antiretroviral therapy (HAART) in the CNS could result in ongoing viral replication, promoting the development of drug resistance and neurological disease. Despite the importance of these risks, no previous study has directly assessed HAART's effects on brain tissue viral load (VL). The authors evaluated 61 HIV-infected individuals for whom both histories of HAART treatment and postmortem brain tissue VL measurements were available. Two groups were defined based on HAART use in the 3 months prior to death: HAART(+) subjects had received HAART, and HAART(-) subjects had not received HAART. HIV RNA was quantified in postmortem brain tissue (log10 copies/10 microg total tissue RNA) and antemortem plasma (log10 copies/ml) by reverse transcriptase-polymerase chain reaction (RT-PCR). Brain tissue VLs were significantly lower among HAART(+) subjects compared to HAART(-) subjects (median 2.6 versus 4.1; P= .0007). These findings suggest that despite the limited CNS penetration of many antiretroviral medications, HAART is at least partially effective in suppressing CNS viral replication. Because some HAART regimens may be better than others in this regard, regimen selection strategies could be used to impede CNS viral activity, limit neuronal dysfunction, and prevent or treat clinical neurocognitive disorders in HIV-infected patients. Furthermore, such strategies might help to prevent the development of ARV resistance.

A method to determine RNA and DNA oxidation simultaneously by HPLC-ECD: greater RNA than DNA oxidation in rat liver after doxorubicin administration

We developed a novel method for the simultaneous extraction and analysis of total tissue RNA and DNA to quantify the RNA and DNA oxidation products 8-oxo-7,8-dihydroguanosine and 8-oxo-7,8-dihydro-2'-deoxyguanosine using HPLC coupled to electrochemical detection (HPLC-ECD). The protein denaturing agents guanidine thiocyanate and phenol/chloroform at neutral pH were found to be very efficient for the isolation of RNA and DNA from rat brain, liver and muscle. The method is very fast, allows extraction at 0 degrees C, gives high yields of pure RNA and DNA with low background oxidation levels, and also determines the RNA/DNA ratio. Experiments with isolated RNA and DNA exposed to the Fenton reagents H2O2/ascorbate/Fe3+ (or Cu2+) resulted in significantly greater RNA oxidation. The RNase inhibitor 2-mercaptoethanol, commonly used for RNA extraction, acted as a pro-oxidant during nucleic acid extraction, an effect attenuated by the inclusion of the metal chelator deferoxamine mesylate. In vivo, administration of doxorubicin (an oxidant generator) to Fisher-344 rats resulted in a significant increase in liver RNA oxidation, but no significantly increased DNA oxidation. This new method could be useful to assess oxidatively damaged RNA and DNA simultaneously, and our data show that RNA is more susceptible to oxidative stress than DNA in vivo and in vitro.

PGE2 release is independent of upregulation of Group V phospholipase A2 during long-term stimulation of P388D1 cells with LPS

P388D1 cells release arachidonic acid (AA) and produce prostaglandin E2 (PGE2) upon long-term stimulation with lipopolysaccharide (LPS). The cytosolic Group IVA (GIVA) phospholipase A2 (PLA2) has been implicated in this pathway. LPS stimulation also results in increased expression and secretion of a secretory PLA2, specifically GV PLA2. To test whether GV PLA2 contributes to PGE2 production and whether GIVA PLA2 activation increases the expression of GV PLA2, we utilized the specific GIVA PLA2 inhibitor pyrrophenone and second generation antisense oligonucleotides (AS-ONs) designed to specifically inhibit expression and activity of GV PLA2. Treatment of P388D1 cells with antisense caused a marked decrease in basal GV PLA2 mRNA and prevented the LPS-induced increase in GV PLA2 mRNA. LPS-stimulated cells release active GV PLA2 into the medium, which is inhibited to background levels by antisense treatment. However, LPS-induced PGE2 release by antisense-treated cells and by control cells are not significantly different. Collectively, the results suggest that the upregulation of GV PLA2 during long-term LPS stimulation is not required for PGE2 production by P388D1 cells. Experiments employing pyrrophenone suggested that GIVA PLA2 is the dominant player involved in AA release, but it appears not to be involved in the regulation of LPS-induced expression of GV PLA2 or cyclooxygenase-2.

Real time PCR quantification of COX-2 mRNA in human ovarian epithelial neoplasm and its correlation with clinical outcome

5055 Objectives: COX-2 has been implicated as tumorogenic in various tumor models. Our previous immunohistochemistry work has shown that normal ovarian epithelium, normal inclusion cysts, serous cystadenofibromas and normal fallopian tube epithelium express COX-2 in a uniform intense pattern while epithelial ovarian carcinoma (EOC) tissues showed variable patterns of COX-2 staining, tending to correlate to the level of tissue differentiation. Our study goals were to quantify COX-2 mRNA expression in a large panel of EOC and to examine for correlation with clinical outcome. Methods: Frozen specimens were obtained from 44 patients with EOC treated between 1995 and 2002. Total tissue RNA was extracted from EOC and 13 benign ovarian tissue samples. COX-2 mRNA was quantitatively analyzed by monitoring the increase in fluorescence by the binding of SYBR green to double-stranded DNA during real-time PCR (Sequence detection system, TaqMan; Applied Biosystems, CA). The copy numbers of cDNA for COX-2 were standardized to glyceraldehyde-3-phosphate dehydrogenase from the same samples. The χ2 test, log-rank test and Kaplan-Meier methods were used for statistical analysis. Results: COX-2 is expressed in benign and malignant ovarian tissues with no significant difference in level of COX-2 mRNA expression. All EOC patients had cytoreductive surgery followed by adjuvant platinum-based chemotherapy. The median follow up was 27 months (CI:1, 109) There were no significant relationships between stage, grade, histology, survival and level of COX-2 mRNA expression. Conclusions: COX-2 is expressed in all benign and malignant ovarian tissues. It is possible that despite a comparable mRNA expression of COX-2 in normal and malignant tissues, that molecular analysis of this enzyme and possible cofactors may still uncover mutations or regulatory factors that implicate COX-2 in the early steps of tumorigenesis, in a manner similar to other tumor models. No significant financial relationships to disclose.

Therapeutic effects of rectal administration of basic fibroblast growth factor on experimental murine colitis

Basic fibroblast growth factor (bFGF) is a promising therapeutic agent for various diseases. It remains unclear, however, whether bFGF is effective for the treatment of inflammatory bowel disease. The aim of this study was to examine the efficacy of bFGF on 2 experimental murine colitis models and to investigate its molecular mechanisms. We evaluated the effects of human recombinant bFGF (hrbFGF) on mice with dextran sulfate sodium (DSS)-induced colitis and mice with trinitrobenzene sulfonic acid (TNBS)-induced colitis as well as normal mice. Body weight, survival rate, and histologic findings of the colonic tissues were examined. Gene expression of tumor necrosis factor (TNF)-alpha, cyclooxygenase (COX)-2, transforming growth factor (TGF)-beta, mucin 2 (MUC2), intestinal trefoil factor (ITF), and vascular endothelial growth factor (VEGF) in the colonic tissues was determined. The proliferation activity of hrbFGF on the colonic epithelium was evaluated by immunohistochemistry. Rectal administration of hrbFGF ameliorated DSS-induced colitis in a dose-dependent manner. Gene expression of TNF-alpha was significantly reduced in the colonic tissues of mice with DSS-induced colitis treated with hrbFGF, whereas MUC2 and ITF messenger RNA expression was up-regulated. Rectal administration of hrbFGF significantly improved the survival rate of mice with TNBS-induced colitis and partially ameliorated colitis. hrbFGF significantly increased the number of Ki-67-positive cells in the colonic epithelium of normal mice, and up-regulated the gene expression of COX-2, TGF-beta, MUC2, ITF, and VEGF in the colonic tissues. Rectal administration of bFGF might be a promising option for the treatment of inflammatory bowel disease.

Gene Expression of Early Hypertrophic Scar Tissue Screened by Means of cDNA Microarrays

Hypertrophic scar is an excessive healing response that often follows thermal injury. The most outstanding morphologic change is the overdeposition of collagen, which is caused by imbalance between synthesis and metabolism of collagen. Previous studies also found that transforming growth factor-beta was the key factor controlling scar formation. However, neither anti-transforming growth factor-beta nor other methods could completely control scar formation and contraction. This fact suggests a multifactorial cause. Fortunately, cDNA microarray throws light on the general alteration at the gene level, and thus could allow us to find some new clues for understanding scar formation and contraction. In this article, we report the results obtained from the scanning of gene expression of hypertrophic scar by means of cDNA microarray. Five cases of early human postburn hypertrophic scars were selected. Total tissue RNA was extracted from each hypertrophic scar sample and the corresponding uninjured region skin tissue; mRNA was further purified by Oligotex and then was reversely transcribed to cDNAs with the incorporation of fluorescent dUTP to prepare the hybridization probes. The mixed probes were hybridized to the cDNA microarray containing 4,096 genes on a type of chemical material-coated glass slide. After high-stringent washing, the hybridized slides were scanned for fluorescent signal detection. Then, the expression and distribution of cytoskeletal genes such as alpha-smooth muscle actin (alpha-SMA) gene; fibroblast tropomyosin TM30(pl) gene; vimentin gene; profilin gene; and BM40 gene of hypertrophic scar at 3, 6, 9, and 12 months age were further quantitatively studied by in situ hybridization or immunohistochemistry. Our data indicated that there were 94 genes overexpressed and 3 genes down-regulated in early postburn hypertrophic scar. These altered genes were related to proto-oncogenes, apoptosis, immune regulatory genes, cytoskeletal elements, metabolism, and so forth. We also found that the detected cytoskeletal gene expression was much more intense at all time points than the control group. Consistent with clinical observation, cytoskeletal genes reached a peak at an early stage and gradually decreased. Our study implied that multiple genes are involved in scar formation and contraction. Interferon is an autosecreted cytokine that might be responsible for self-control of overgrowth of cells in wounds. The early period of hypertrophic scar formation might be a good time for preventing overgrowth and contraction of hypertrophic scar by gene therapy.

Increased HIV-1 Mucosal Replication Is Associated With Generalized Mucosal Cytokine Activation

The purpose of this study was to characterize intestinal mucosal cytokine profiles in subjects with HIV-1 infection and their relation to mucosal viral load (MVL). Intestinal mucosal cytokine mRNA (interleukin [IL]-2, interferon [IFN]-gamma, IL-12, IL-10, IL-1beta, tumor necrosis factor [TNF]-alpha, IL-6, and regulated upon activation, normal T-cell expressed and secreted [RANTES]) and HIV-1 RNA were quantified using real-time polymerase chain reaction (PCR). On the basis of MVL quantification, the HIV-1-infected subjects were divided into 3 groups: undetectable MVL (<50 copies/microg of tissue total RNA), low MVL (>50 but <5000 copies/microg of tissue total RNA), and high MVL (>5000 copies/microg of tissue total RNA). Compared with the control group, significant reductions in RANTES, IL-2, and IFNgamma expression were seen in the undetectable MVL group (P < 0.005). IL-6 was significantly increased in all the HIV groups (P < 0.005), and RANTES, IL-10, and IFNgamma were increased in the high MVL group (P < 0.005). Subjects with high MVL have generalized immune activation with increases in T helper (Th)1, Th2, and proinflammatory cytokines, whereas subjects with undetectable MVL have reduced expression of multiple cytokines. The pathologic basis for these observations is unclear but may relate to the success or failure of antiretroviral therapy in controlling mucosal viral replication.

Influence of zinc deficiency on the mRNA expression of zinc transporters in adult rats

The accumulation of zinc in the cell is a sum of influx and efflux processes via transporter proteins, like the four Zn transporters (ZnT1–4), the divalent cation transporter 1 (DCT1) and of storage processes mainly bound to metallothionein (MT). To study the effect of Zn deficiency on mRNA expression levels, adult rats were used as an animal model. Food intake was restricted to 8 g/day containing 2 g Zn/g fortified with pure phytate in Zn deficiency rats and 58 g Zn/g in controls (n = 7). At day 1, 2, 4, 7, 11, 16, 22, and 29 of Zn deficiency, 3 animals were sacrificed, respectively (n = 24). Zn deficiency was evident from reduced plasma Zn, plasma alkaline phosphatase activity and severe mobilization of Zn from tissue stores (mainly skeleton), while food intake and body weight remained unaffected. Tissues representing Zn absorption (jejunum, colon), Zn storage and utilization (muscle, liver), and Zn excretion (kidney) were retrieved. Total RNA contents increased in colon ( p = 0.003) and trend to decrease in liver (p = 0.086). Zn deficiency was without effect on tissue total RNA concentrations in muscle tissue and kidney. Real-time reverse transcription (RT) polymerase chain reaction (PCR) assays were developed and a relative quantification on the basis of GAPDH was applied. Assays allowed a relative and accurate quantification of mRNA molecules with a sufficiently high sensitivity and repeatability. All known Zn transporter subtypes were found in the tissues. ZnT3 was newly elucidated and sequenced in rat tissues. Expression patterns and reactions to Zn deficiency were specific for the tissue analysed. Expression results imply that some transporters are expressed constitutively, whereas others are highly regulated in tissues responsible for Zn homeostasis. The most distinct changes of expression levels were shown in colon which can therefore be postulated as a highly Zn sensitive tissue. MT was down-regulated in all tissues, massively in liver ( p < 0.001) and in colon ( p = 0.002) and in tendency also in the jejunum and kidney. In parallel with intracellular Zn status it is a potent candidate gene for Zn deficiency. ZnT1 and ZnT2 showed a significant up-regulation of mRNA expression in colon ( p = 0.032 and p = 0.026) and for ZnT2 a trend of down regulation in jejunum ( p = 0.098). This study provides the first comparative view of regulation of gene expression and fully quantitative expression analysis of all known Zn transporters in a non growing adult rat model on a constant platform and therefore allows a direct comparison.

The gene expression profiling of human visceral adipose tissue and its secretory functions

In order to fully understand the physiological functions of adipose tissue, especially its secretory functions, and to provide a basis for the identification of novel obesity related genes, the gene expression profiling of human visceral adipose tissue was established by using cDNA array. 33 P -labelled cDNA, derived from visceral adipose tissue total RNA, was hybridized to a cDNA array containing over 16,000 expressed sequence-tagged clones which represent human singleton genes. The expressed sequence tag (EST) was considered to be expressed in visceral adipose tissue when the ratio of signal to noise was greater than or equal to 2. The results were analyzed with bioinformatics. Totally, 8230 genes were found to be expressed in visceral adipose tissue with 5200 known genes and 3030 known ESTs. Most of 84 secretory proteins, 120 receptors, and 74 transcription factors expressed in adipose tissue were newly identified. Many appetite-regulating related peptides or receptors and some reproduction-related genes were first found to be expressed in adipose tissue. Eight autocrine/paracrine systems were described for the first time in the visceral adipose tissue. These results clearly demonstrate that the visceral adipose tissue has important secretory functions and there is a complex local autocrine/paracrine regulatory network. The present work suggests that the visceral adipose tissue is an important component of the neuroendocrine-immune network and plays an important role in regulating appetite not only via endocrine but also via autocrine/paracrine systems. The visceral adipose tissue might also play a role in regulating reproduction and sexual function.

A highly efficient ligand-regulated Cre recombinase mouse line shows that LoxP recombination is position dependent.

Conditional gene inactivation using the Cre/loxP system is widely used, but the difficulty in properly regulating Cre expression remains one of the bottlenecks. One approach to regulate Cre activity utilizes a mutant estrogen hormone-binding domain (ERT) to keep Cre inactive unless the non-steroidal estrogen analog 4-hydroxytamoxifen (OHT) is present. Here we describe a mouse strain expressing Cre-ERT from the ubiquitously expressed ROSA26 (R26) locus. We demonstrate efficient temporal and spatial regulation of Cre recombination in vivo and in primary cells derived from these mice. We show the existence of marked differences in recombination frequencies between different substrates within the same cell. This has important consequences when concurrent switching of multiple alleles within the same cell is needed, and highlights one of the difficulties that may be encountered when using reporter mice as indicator strains.

Hypoxia activates jun-N-terminal kinase, extracellular signal-regulated protein kinase, and p38 kinase in pulmonary arteries.

Chronic alveolar hypoxia is the major cause of pulmonary hypertension. The cellular mechanisms involved in hypoxia- induced pulmonary arterial remodeling are still poorly understood. Mitogen-activated protein kinase (MAPK) is a key enzyme in the signaling pathway leading to cellular growth and proliferation. The purpose of this investigation was to determine the roles that MAPKs, specifically Jun-N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), and p38 kinase, play in the hypoxia-induced pulmonary arterial remodeling. Rats were exposed to normobaric hypoxia (10% O(2)) for 1, 3, 7, or 14 d. Hypoxia caused significant remodeling in the pulmonary artery characterized by thickening of pulmonary arterial wall and increases in tissue mass and total RNA. JNK, ERK, and p38 kinase tyrosine phosphorylations and their activities were significantly increased by hypoxia. JNK activation peaked at Day 1 and ERK/p38 kinase activation peaked after 7 d of hypoxia. The results from immunohistochemistry show that hypoxia increased phospho-MAPK staining in both large and small intrapulmonary arteries. Hypoxia also upregulated vascular endothelial growth factor messenger RNA (mRNA) and platelet-derived growth factor receptor mRNA levels in pulmonary artery with a time course correlated to the activation of ERK and p38 kinase. The gene expressions of c-jun, c-fos, and egr-1, known as downstream effectors of MAPK, were also investigated. Hypoxia upregulated egr-1 mRNA but downregulated c-jun and c-fos mRNAs. These data suggest that hypoxia-induced activation of JNK is an early response to hypoxic stress and that activation of ERK and p38 kinase appears to be associated with hypoxia-induced pulmonary arterial remodeling.