Abnormal innate immune response contributes to inflammatory bowel disease (IBD) and experimental mouse colitis. Colitis studies have focused primarily on key regulators of innate immunity, like pathogen recognition receptors and cytoplasmic mediators. Extracellular matrix (ECM) proteins are emerging as modulators of inflammatory responses by virtue of their interactions with pathogen associated molecular patterns (PAMPs), cytokines, growth factors, receptors, and ECM fragments that mimic pathogens or cytokines. The ECM proteins have not been investigated in IBD at great depth from this standpoint. We have shown previously that the ECM protein lumican modulates host sensing of bacterial lipopolysaccharides (LPS) by toll like receptor (TLR) 4, and neutrophil chemotaxis via integrins. Here we investigated the role of lumican in the development of colitis mediated by intra-rectal administration of the hapten 2-4-5, trinitrobenzene sulfonic acid (TNBS) in Lum+/+ and Lum−/− mice. The TNBS-treated Lum+/+ mouse colons showed marked increases in CXCL1, TNF-α and neutrophil infiltration; while these responses were significantly dampened in the Lum−/− mice. The NF-κB transcription factor, known to regulate inflammatory genes, showed a robust increase after TNBS treatment in Lum+/+ but not in Lum−/− colons. Also, nuclear translocation of NF-κB was delayed in LPS-stimulated Lum−/− primary peritoneal macrophages. Thus, the Lum−/− mice have low innate immune and inflammatory responses, but more severe body weight loss and tissue damage, a phenomenon seen in the innate immune impaired Tlr4−/− and MyD88−/− mice. Therefore, lumican promotes intestinal homeostasis by aiding innate immune and inflammatory responses that are beneficial in the early stages of colitis.
Extracellular matrix; lumican; TLR4; CD14; innate immune response; inflammation; murine colitis; neutrophils; tri-nitrobenzene sulfonic acid; dextran sodium sulfate
Abnormalities in the anterior interhemispheric connections provided by the corpus callosum (CC) have long been implicated in major depressive disorder (MDD). The purpose of this study was to investigate interhemispheric connectivity in medication-naive patients with MDD by measuring fractional anisotropy in the CC with diffusion tensor imaging (DTI) techniques.
We obtained DTI scans from medication-naive patients with MDD and from matched healthy controls. Fractional anisotropy values were compared using semiautomatic region of interest methods to localize the regional CC differences between these 2 groups.
We enrolled 27 patients and 27 controls in our study. Fractional anisotropy values were significantly lower in the anterior genu of the CC in the MDD group than in the control group (p = 0.009, corrected); results were not significantly different in any other CC subregions.
As patients with MDD were already experiencing acute episodes, future studies of individuals at risk for MDD are warranted to elucidate the interhemispheric connectivity abnormalities associated with the predisposition to MDD.
The findings demonstrate abnormalities in the structural integrity of the anterior genu of the CC in medication-naive individuals with MDD, which may contribute to impairment of interhemispheric connectivity in patients with this disorder.
MicroRNAs (miRNAs) are important post-transcriptional regulators. Altered expression of miRNAs has recently demonstrated association with human ulcerative colitis (UC). In this study, we attempted to elucidate the roles of miR-126 in the pathogenesis of UC.
Expression of miR-126, miR-21, miR-375 and the potential targets NF-κB inhibitor alpha (IκBα, IKBA or NFKBIA), Polo-like kinase 2 (PLK2) and v-Crk sarcoma virus CT10 oncogene homolog (CRK) were assessed in 52 colonic biopsies from patients with active UC, inactive UC, irritable bowel syndrome (IBS) and from healthy subjects by quantitative RT-PCR and immunofluorescence analyses. Regulation of gene expression by miR-126 was assessed using luciferase reporter construct assays and specific miRNA mimic transfection.
We found that the expression of miR-126 and miR-21 were significantly increased in active UC group compared to the inactive UC, IBS and healthy control groups (P<0.05). In contrast, the expression of IKBA mRNA and protein was remarkably decreased in the active UC group compared with the other three groups (P<0.05). The expression of miR-126 and IKBA mRNA were inversely correlated in active UC patients (P<0.05). However the expression of miR-375, PLK2 and CRK showed no difference between each group. Furthermore, we demonstrate that endogenous miR-126 and exogenous miR-126 mimic can inhibit IκBα expression. Finally, mutating the miR-126 binding site of the IKBA 3′-UTR reporter construct restored reporter gene expression.
miR-126 may play roles in UC inflammatory activity by down-regulating the expression of IKBA, an important inhibitor of NF-κB signaling pathway.
The Ca2+ paradox represents a good model to study Ca2+ overload injury in ischemic heart diseases. We and others have demonstrated that contracture and calpain are involved in the Ca2+ paradox-induced injury. This study aimed to elucidate their roles in this model. The Ca2+ paradox was elicited by perfusing isolated rat hearts with Ca2+-free KH media for 3 min or 5 min followed by 30 min of Ca2+ repletion. The LVDP was measured to reflect contractile function, and the LVEDP was measured to indicate contracture. TTC staining and the quantification of LDH release were used to define cell death. Calpain activity and troponin I release were measured after Ca2+ repletion. Ca2+ repletion of the once 3-min Ca2+ depleted hearts resulted in almost no viable tissues and the disappearance of contractile function. Compared to the effects of the calpain inhibitor MDL28170, KB-R7943, an inhibitor of the Na+/Ca2+ exchanger, reduced the LVEDP level to a greater extent, which was well correlated with improved contractile function recovery and tissue survival. The depletion of Ca2+ for 5 min had the same effects on injury as the 3-min Ca2+ depletion, except that the LVEDP in the 5-min Ca2+ depletion group was lower than the level in the 3-min Ca2+ depletion group. KB-R7943 failed to reduce the level of LVEDP, with no improvement in the LVDP recovery in the hearts subjected to the 5-min Ca2+ depletion treatment; however, KB-R7943 preserved its protective effects in surviving tissue. Both KB-R7943 and MDL28170 attenuated the Ca2+ repletion-induced increase in calpain activity in 3 min or 5 min Ca2+ depleted hearts. However, only KB-R7943 reduced the release of troponin I from the Ca2+ paradoxic heart. These results provide evidence suggesting that contracture is the main cause for contractile dysfunction, while activation of calpain mediates cell death in the Ca2+ paradox.
Bsister genes have been identified as the closest relatives of class B floral homeotic genes. Previous studies have shown that Bsister genes from eudicots are involved in cell differentiation during ovule and seed development. However, the complete function of Bsister genes in eudicots is masked by redundancy with other genes and little is known about the function of Bsister genes in monocots, and about the evolution of Bsister gene functions. Here we characterize OsMADS29, one of three MADS-box Bsister genes in rice. Our analyses show that OsMADS29 is expressed in female reproductive organs including the ovule, ovule vasculature, and the whole seed except for the outer layer cells of the pericarp. Knock-down of OsMADS29 by double-stranded RNA-mediated interference (RNAi) results in shriveled and/or aborted seeds. Histological analyses of the abnormal seeds at 7 days after pollination (DAP) indicate that the symplastic continuity, including the ovular vascular trace and the nucellar projection, which is the nutrient source for the filial tissue at early development stages, is affected. Moreover, degeneration of all the maternal tissues in the transgenic seeds, including the pericarp, ovular vascular trace, integuments, nucellar epidermis and nucellar projection, is blocked as compared to control plants. Our results suggest that OsMADS29 has important functions in seed development of rice by regulating cell degeneration of maternal tissues. Our findings provide important insights into the ancestral function of Bsister genes.
Gait deficits are important clinical symptoms of Parkinson’s disease (PD). However, existing behavioral tests for the detection of motor impairments in rodents with systemic dopamine depletion only measure akinesia and dyskinesia, and data focusing on gait are scarce. We evaluated gait changes in the methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced C57BL/6 murine model of PD by using a computer-assisted CatWalk system. Correlations of gait parameters with tyrosine hydroxylase (TH) protein levels in the substantia nigra (SN) were also investigated.
The gait readouts, including the walking duration, variation of walking speed, step cycle, duty cycle, stance, initial dual stance, terminal dual stance, three- and four-point supports, and the base of support between hind limbs was noted to increase significantly one week after MPTP injection. In contrast, values of the stride length, cadence, swing speed, and diagonal dual support decreased substantially following MPTP treatment (p < 0.05). All of these changes lasted for three weeks after the last MPTP administration. Except for the stance in the fore limbs and the swing speed in the hind limbs, the gait variability in the PD mice showed a closer correlation with the protein levels of TH in the SN than the walking distances in the conventional open field test. Coordination parameters of the regularity index and step pattern were not affected in mice treated with MPTP.
Data of the study suggest that the computer-assisted CatWalk system can provide reliable and objective criteria to stratify gait changes arising from MPTP-induced bilateral lesions in C57/BL6 mice. The extent of gait changes was noted to correlate with the expression of the biomarker for dopaminergic neurons. This novel analytical method may hold promise in the study of disease progression and new drug screening in a murine PD model.
Parkinson’s disease; Gait; MPTP; Tyrosine hydroxylase; Neurochemical correlation
DNA microarrays can detect tuberculosis and its multi-drug resistant form in M. tuberculosis isolates and sputum specimens with high sensitivity and specificity. However, no performance data currently exists for its use in spinal tuberculosis specimens. This study was aimed to assess the performance of the CapitalBio™ DNA microarray in the detection of isoniazid (INH) and rifampicin (RMP) resistance in spinal tuberculosis compared with the BACT/MGIT 960 system.
From March 2009 to December 2011, 153 consecutive patients from Southwest Hospital, Chongqing with clinically and pathologically diagnosed spinal tuberculosis were enrolled into this study. Specimens collected during surgery from the tuberculosis patients were subjected to M. tuberculosis species identification and drug-resistance detection by the CapitalBio™ DNA microarray, and results were compared with those obtained from the absolute concentration drug susceptibility testing.
The CapitalBio™ DNA microarray achieved 93.55% sensitivity for the correct M. tuberculosis species identification of the 93 specimens that tested positive for spinal tuberculosis through culture. In addition, twenty-seven additional patients (45.0%) were detected by the DNA microarray to be positive for M. tuberculosis among sixty spinal tuberculosis patients who were culture negative. Moreover, the DNA microarray had a sensitivity of 88.9% and a specificity of 90.7% for RMP resistance, and the microarray had a sensitivity of 80.0% and a specificity of 91.0% for INH resistance. The mean turn-around time of M. tuberculosis species identification and drug resistance detection using the DNA microarray was 5.8 (range, 4–9) hours.
The CapitalBio™ DNA microarray is a feasible and accurate tool for the species identification of M. tuberculosis and for directly detecting RMP and INH resistance from spinal tuberculosis specimens in fewer than 9 hours.
DNA microarray; Spinal tuberculosis; Drug resistance; Gene mutation
Two atmospheric circulation systems, the mid-latitude Westerlies and the Asian summer monsoon (ASM), play key roles in northern-hemisphere climatic changes. However, the variability of the Westerlies in Asia and their relationship to the ASM remain unclear. Here, we present the longest and highest-resolution drill core from Lake Qinghai on the northeastern Tibetan Plateau (TP), which uniquely records the variability of both the Westerlies and the ASM since 32 ka, reflecting the interplay of these two systems. These records document the anti-phase relationship of the Westerlies and the ASM for both glacial-interglacial and glacial millennial timescales. During the last glaciation, the influence of the Westerlies dominated; prominent dust-rich intervals, correlated with Heinrich events, reflect intensified Westerlies linked to northern high-latitude climate. During the Holocene, the dominant ASM circulation, punctuated by weak events, indicates linkages of the ASM to orbital forcing, North Atlantic abrupt events, and perhaps solar activity changes.
Background. Lupus nephritis (LN) remains a major cause of morbidity and end-stage renal disease. Dysfunction of B lymphocytes is thought to be important in the pathogenesis of SLE/LN. Intrarenal B cells have been found in several forms of inflammatory kidney diseases although their role in LN renal is not well defined. Methods. Intrarenal B cells were analyzed in 192 renal biopsies from patients diagnosed with lupus nephritis. Immunohistochemical staining of serial sections was performed for each LN patient using CD20, CD3, and CD21 antibodies. Results. Intrarenal B cells were more likely to be associated with class IV LN and were mainly distributed in the renal interstitium, with very few in the glomerulus. The systemic lupus erythematosus disease activity index (SLEDAI), blood urea nitrogen, and serum creatinine levels were all significantly greater in the LN-B cell groups (all P < 0.05). LN renal activity and chronicity indices correlated with B-cells infiltrates (all P < 0.0001). Renal biopsies were classified into four distinct categories according to the organizational grade of inflammatory cell infiltrates. Germinal center- (GC-) like structures were not identified in any LN biopsies. Conclusion. It is hypothesized that intrarenal B cells enhance immunological responses and exaggerate the local immune response to persisting autoimmune damage in the tubulointerstitium.
CD4+ memory T cells include the Th17 cell population, which has been shown to be implicated in autoimmune and inflammatory diseases. These memory T cells express higher IL-23R and produce more IL-17 compared with their naive counterparts. However, the molecular mechanisms that regulate IL-23R expression in human T cells are not completely understood. MicroRNAs play important roles in a wide range of biological events through posttranscriptional suppression of target mRNAs. In this article, we provide evidence that a specific microRNA, Let-7f, inhibits IL-23R expression in human CD4+ memory T cells. Endogenous expression of Let-7f in memory T cells is significantly lower when compared with naive T cells, and Let-7f blocks IL-23R expression through its complementary target sequence within 3′ untranslated region of target gene. Furthermore, exogenous transfection of a Let-7f mimic into memory T cells results in downregulation of IL-23R and its downstream cytokine, IL-17. Our findings reveal a novel mechanism in regulating the IL-23/IL-23R pathway and subsequent downstream IL-17 production, which may provide novel therapeutics for human inflammatory and autoimmune diseases.
In the title compound, [Ir(C11H6F2N)2(C7H6NO)(H2O)]·CH3OH, the IrIII ion adopts an octahedral geometry, and is coordinated by two 3,5-difluoro-2-(pyridin-2-yl)phenyl ligands, one molecule of water and one benzamidate anion. The two 2-(4,6-difluorophenyl)pyridyl ligands are arranged in a cis-C,C′ and trans-N,N′ fashion. Additionally, there is a bystanding methanol molecule outside the coordination sphere of the IrIII ion. In the crystal, molecules of the title compound are linked by O—H⋯O and O—H⋯N hydrogen bonds. One F atom of each ligand is equally disordered over two sites. The C atom of the solvent molecule is likewise disordered over two sites in a 0.589 (11):0.411 (11) ratio.
Crohn's disease (CD) and ulcerative colitis (UC) result from pathophysiologically distinct dysregulated immune responses, as evidenced by the preponderance of differing immune cell mediators and circulating cytokine expression profiles. MicroRNAs (miRNAs) are small, noncoding RNAs that act as negative regulators of gene expression and have an increasingly recognized role in immune regulation. We hypothesized that differences in circulating immune cells in CD and UC patients are reflected by altered miRNA expression and that miRNA expression patterns can distinguish CD and UC from normal healthy individuals.
Peripheral blood was obtained from patients with active CD, inactive CD, active UC, inactive UC and normal healthy adults. Total RNA was isolated and miRNA expression assessed using miRNA microarray and validated by mature miRNA quantitative RT-PCR.
Five miRNAs were significantly increased and two miRNAs (149* and miRplus-F1065) were significantly decreased in the blood of active CD patients as compared to healthy controls. Twelve miRNAs were significantly increased and miRNA-505* was significantly decreased in the blood of active UC patients as compared to healthy controls. Ten miRNAs were significantly increased and one miRNA was significantly decreased in the blood of active UC patients as compared to active CD patients.
Peripheral blood miRNAs can be used to distinguish active CD and UC from healthy controls. The data support the evidence that CD and UC are associated with different circulating immune cells types and that the differential expression of peripheral blood miRNAs may form the basis of future diagnostic tests for IBD.
microRNA; Crohn's disease; ulcerative colitis; peripheral blood
Galectin-3 is an animal lectin that has been implicated in wound healing and is decreased in inflammatory bowel disease (IBD). Matrix metalloproteinase-7 (MMP7) also known as matrilysin-1, a protease shown to cleave extracellular matrix proteins, is highly expressed in IBD tissues, especially at the leading edge of gastrointestinal ulcers. The ability of MMP7 to cleave galectin-3 and influence wound healing has not been reported previously.
To determine whether MMP7 cleaves galectin-3 and modulates wound healing in intestinal epithelial cells.
The cleaved fragments of galectin-3 were identified by N-terminal sequencing and mass spectrometry. Western blotting was used to detect the cleaved galectin-3 products in a colonic epithelial cell line (T84 cells). Cell migration was studied by in vitro scratch method.
We demonstrate for the first time that MMP7 cleaves galectin-3 in vitro, resulting in three cleaved fragments (20.2 kDa, 18.9 kDa and 15.5 kDa). Exogenous treatment of T84 cells with recombinant MMP7 resulted in the appearance of secreted galectin-3 cleavage fragments in the supernatant. MMP7 inhibited cell migration and resulted in wound retraction and the addition of MMP7 to galectin-3 abrogated the wound healing and cell migration induced by galectin-3.
We have demonstrated that galectin-3 is a substrate for MMP7. Cleavage of galectin-3 may be one mechanism by which MMP7 inhibits wound healing. This study has significance in understanding delayed wound healing in chronic intestinal diseases like intestinal ulcers and IBD where MMP7 protein expression is elevated with a decreased galectin-3 protein expression.
MMP7; galectin-3; inflammatory bowel disease; wound healing; cell migration
It has been demonstrated that triptolide inhibits the growth of several types of cancer cells in vitro and prevents tumor growth in vivo by inducing apoptosis and autophagy. Here we showed that Tripchlorolide (T4) significantly suppressed the proliferation of A549 cells in a dose- and time-dependent manner. This suppressive effect was diminished when cells were pretreated with 3-Methylamphetamine (3-MA). After the cells were treated with T4, the LC3 II protein expression was significantly increased, and autophagosomes were observed by TEM. However, almost no apoptosis was observed in A549 treated with T4. These results suggest that T4 induces A549 cell death predominantly through the activation of the autophagy pathway instead of the apoptosis pathway.
tripchlorolide; autophagy; A549; lung cancer; apoptosis; LC3
Introduction. Posttraumatic stress disorder (PTSD) is accompanied by poor general psychological status (GPS). In the present study, we investigated the effects of a Chinese herbal formula on GPS in earthquake survivors with PTSD. Methods. A randomized, double-blind, placebo-controlled trial compared a Chinese herbal formula, Xiao-Tan-Jie-Yu-Fang (XTJYF), to placebo in 2008 Sichuan earthquake survivors with PTSD. Patients were randomized into XTJYF (n = 123) and placebo (n = 122) groups. Baseline-to-end-point score changes in the three global indices of the Symptom Checklist-90-Revised (SCL-90-R) and rates of response in the SCL global severity index (GSI) were the primary endpoints. A subanalysis of the nine SCL factors and the sleep quality score were secondary endpoints. Results and Discussion. Compared to placebo, the XTJYF group was significantly improved in all three SCL global indices (P = 0.001~0.028). More patients in the XTJYF group reported “much improved” than the placebo group (P = 0.001). The XTJYF group performed significantly better than control in five out of nine SCL factors (somatization, obsessive-compulsive behavior, depression, anxiety, and hostility (P = 0.001~0.036)), and in sleep quality score (P < 0.001). XTJYF produced no serious adverse events. These findings suggest that XTJYF may be an effective and safe treatment option for improving GPS in patients with PTSD.
The molecular profile of low-grade mucoepidermoid carcinomas remains to be clarified. In the present study, matrix metalloproteinase (MMP) expression was compared in low-grade mucoepidermoid carcinoma (MEC) and typical lung cancer. The expression of MMP-2, MMP-7 and MMP-9 was detected by immunohistochemistry in a cohort of 110 patients (34 with low-grade MEC and 76 with matched typical lung cancers). A positive MMP-2 expression was found to be 35.29 vs. 65.79% in low-grade MEC and typical NSCLCs (p=0.003); a positive MMP-7 expression was 41.18 vs. 55.26% (p=0.172); and a positive MMP-9 expression was 35.29 vs. 57.89% (p=0.028). In conclusion, the expression of MMP-2 and MMP-9 in low-grade MEC is lower than that in typical lung carcinomas.
non-small cell lung cancer; matrix metalloproteinases; mucoepidermoid carcinoma
The most recent strategy for schistosomiasis control in the People's Republic of China aims to reduce the likelihood of environmental contamination of schistosome eggs. Despite considerable progress, it is believed that achievements would be further consolidated with additional intermediate host snail control measures. We provide an empirical framework for discerning the relative contribution of intrinsic effects (density feedback) from other extrinsic drivers of snail population dynamics.
We set up experiments in two study locations to collect reproduction data of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum. We applied a set of four population dynamic models that have been widely used to study phenomenological time-series data to examine the properties of demographic density feedback patterns from abundance data. We also contrasted the obtained results with the component feedback of density on survival rate to determine whether adult survival was the principal driver of the demographic feedback observed.
Demographic density feedback models (Ricker- and Gompertz-logistic) accounted for > 99% of Akaike's information criterion model weight, with the Gompertz ranking highest in all O. hupensis population groups. We found some evidence for stronger compensatory feedback in the O. hupensis population from Sichuan compared to a Jiangsu population. Survival rates revealed strong component feedback, but the log-linear relationships (i.e. Gompertz) had less support in the demographic feedback analysis.
Our findings indicate that integrated schistosomiasis control measures must continue to reduce parasite abundance further because intermediate host snail populations tend to grow exponentially at low densities, especially O. hupensis populations in mountainous regions. We conclude that density feedback in adult survival is the principal component contribution to the demographic phenomenon observed in the population fitness (r)-abundance relationship.
RNA silencing is a potent mechanism of antiviral defense response in plants and other organisms. For counterdefense, viruses have evolved a variety of suppressors of RNA silencing (VSRs) that can inhibit distinct steps of a silencing pathway. We previously identified Pns10 encoded by Rice dwarf phytoreovirus (RDV) as a VSR, the first of its kind from double-stranded RNA (dsRNA) viruses. In this study we investigated the mechanisms of Pns10 function in suppressing systemic RNA silencing in the widely used Nicotiana benthamiana model plant. We report that Pns10 suppresses local and systemic RNA silencing triggered by sense mRNA, enhances viral replication and/or viral RNA stability in inoculated leaves, accelerates the systemic spread of viral infection, and enables viral invasion of shoot apices. Mechanistically, Pns10 interferes with the perception of silencing signals in recipient tissues, binds double-stranded small interfering RNA (siRNAs) with two-nucleotide 3′ overhangs, and causes the downregulated expression of RDR6. These results significantly deepen our mechanistic understanding of the VSR functions encoded by a dsRNA virus and contribute additional evidence that binding siRNAs and interfering with RDR6 expression are broad mechanisms of VSR functions encoded by diverse groups of viruses.
CCTG tetranucleotide repeat expansion is associated with a hereditary neurological disease called myotonic dystrophy type 2 (DM2). The underlying reasons that lead to genetic instability and thus repeat expansion during DNA replication remains elusive. Here, we have shown CCTG repeats have a high propensity to form metastable hairpin and dumbbell structures using high-resolution nuclear magnetic resonance (NMR) spectroscopy. When the repeat length is equal to three, a hairpin with a two-residue CT loop is formed. In addition to the hairpin, a dumbbell structure with two CT-loops is formed when the repeat length is equal to four. Nuclear Overhauser effect (NOE) and chemical shift data reveal both the hairpin and dumbbell structures contain a flexible stem comprising a C-bulge and a T·T mismatch. With the aid of single-site mutation samples, NMR results show these peculiar structures undergo dynamic conformational exchange. In addition to the intrinsic flexibility in the stem region of these structures, the exchange process also serves as an origin of genetic instability that leads to repeat expansion during DNA replication. The structural features provide important drug target information for developing therapeutics to inhibit the expansion process and thus the onset of DM2.
The cornea continues to mature after birth to develop a fully functional, refractive and protective barrier tissue. Here we investigated the complex biological events underlying this process by profiling global genome-wide gene expression patterns of the immature postnatal day 10 and seven week-old adult mouse cornea. The lens and tendon were included in the study to increase the specificity of genes identified as up regulated in the corneal samples. Notable similarities in gene expression between the cornea and the tendon were in the mesenchymal extracellular matrix collagen (types I, III, V, VI) and proteoglycan (lumican, decorin and biglycan) genes. Expression similarities in the cornea and lens were limited to certain epithelial genes and the crystallins. Approximately 76 genes were over expressed in the cornea samples that showed basal expression levels in the lens and tendon. Thirty-two of these were novel with no known functions in the cornea. These include genes with a potential role in protection against oxidative stress (Dhcr24, Cdo1, Akr1b7, Prdx6), inflammation (Ltb4dh, Wdr1), ion-transport (Pdzk1ip1, Slc12a2, Slc25a17) and transcription (Zfp36l3, Pdzk1ip1). Direct comparison of the cornea of two ages showed selective up regulation of 50 and 12 genes in the P10 and adult cornea, respectively. Of the up regulated P10 genes several encode extracellular matrix collagens and proteoglycans that are stable components of the adult cornea and their high transcriptional activity at P10 indicate a period of active corneal growth and matrix deposition in the young cornea. Much less is known about the genes selectively over expressed in the adult cornea; some relate to immune response and innervation (Npy), and possibly to electron transport (Cyp24a1, Cyp2f2) and others of yet unknown functions in the cornea (Rgs10, Psmb8, Xlr4)). This study detected expression of genes with known functions in the cornea, providing additional validation of the microarray experiments. Importantly, it identified several novel genes whose functions have not been investigated in the cornea.
Gene expression pattern; cornea maturation; postnatal cornea; adult cornea; corneal stroma; lens; tendon; extracellular matrix
Inadequate clearance of apoptotic cells by macrophages is one of the reasons for the breakdown of self-tolerance. Class A scavenger receptors, macrophage receptor with collagenous structure (MARCO) and scavenger receptor A (SR-A), which are expressed on macrophages, play important roles in the uptake of apoptotic cells. A previous study reported the presence of the anti-MARCO antibody in lupus-prone mice and systemic lupus erythematosus (SLE) patients. The purpose of this study was to investigate the prevalence of anti-class A scavenger receptor antibodies in patients with various autoimmune diseases, in particular SLE, and the functional implication of those autoantibodies in the phagocytic clearance of apoptotic cells by macrophages.
Purified recombinant scavenger receptor cysteine-rich (SRCR) polypeptide (ligand-binding domain of MARCO) and recombinant SR-A were used as antigens. By using enzyme-linked immunosorbent assay, the anti-SRCR and anti-SR-A antibodies were detected in the sera of untreated patients with SLE (n = 65), rheumatoid arthritis (n = 65), primary Sjögren syndrome (n = 25), and healthy blood donors (n = 85). The effect of IgG purified from SLE patients or healthy controls on the phagocytosis of apoptotic cells by macrophages was measured by the flow cytometry assay.
Anti-SRCR antibodies were present in patients with SLE (18.5%) and rheumatoid arthritis (3.1%), but not in those with primary Sjögren syndrome. Anti-SR-A antibodies were present in patients with SLE (33.8%), rheumatoid arthritis (13.8%), and primary Sjögren syndrome (12.0%). IgG from SLE patients positive for anti-SRCR or anti-SR-A antibodies showed a higher inhibition rate on binding of apoptotic cells to macrophages than IgG from healthy controls (both P < 0.05). IgG from SLE patients positive for both anti-SRCR and anti-SR-A antibodies showed a significantly higher inhibition rate on ingestion of apoptotic by macrophages than IgG from healthy controls (P < 0.05).
Our results indicated that autoantibodies to class A scavenger receptors might contribute to the breakdown of self-tolerance by impairing the clearance of apoptotic debris and play a role in the pathogenesis of autoimmune disease, especially in SLE.
Colonic microbiota ferment non-absorbed dietary fiber to produce prodigious amounts of short chain fatty acids (SCFAs) that benefit the host through a myriad of metabolic, trophic, and chemopreventative effects. The chemopreventative effects of the SCFA butyrate are, in part, mediated through induction of p21 gene expression. In this study, we assessed the role of microRNA(miRNA) in butyrate's induction of p21 expression. The expression profiles of miRNAs in HCT-116 cells and in human sporadic colon cancers were assessed by microarray and quantitative PCR. Regulation of p21 gene expression by miR-106b was assessed by 3′ UTR luciferase reporter assays and transfection of specific miRNA mimics. Butyrate changed the expression of 44 miRNAs in HCT-116 cells, many of which were aberrantly expressed in colon cancer tissues. Members of the miR-106b family were decreased in the former and increased in the latter. Butyrate-induced p21 protein expression was dampened by treatment with a miR-106b mimic. Mutated p21 3′UTR-reporter constructs expressed in HCT-116 cells confirmed direct miR-106b targeting. Butyrate decreased HCT-116 proliferation, an effect reversed with the addition of the miR-106b mimic. We conclude that microbe-derived SCFAs regulate host gene expression involved in intestinal homeostasis as well as carcinogenesis through modulation of miRNAs.
Endothelial barrier dysfunction contributes to morbidity in sepsis. We tested the hypothesis that raising the intracellular ascorbate concentration protects the endothelial barrier from septic insult by inhibiting protein phosphatase type 2A. Monolayer cultures of microvascular endothelial cells were incubated with ascorbate, dehydroascorbic acid (DHAA), NADPH oxidase inhibitors apocynin and diphenyliodonium, or PP2A inhibitor okadaic acid, and then were exposed to septic insult (lipopolysaccharide and interferon-γ). Under standard culture conditions that depleted intracellular ascorbate, septic insult stimulated oxidant production and PP2A activity, dephosphorylated phosphoserine and phosphothreonine residues in the tight junction-associated protein occludin, decreased the abundance of occludin at cell borders, and increased monolayer permeability to albumin. NADPH oxidase inhibitors prevented PP2A activation and monolayer leak, showing that these changes required reactive oxygen species. Okadaic acid, at a concentration that inhibited PP2A activity and monolayer leak, prevented occludin dephosphorylation and redistribution, implicating PP2A in the responses of occludin to septic insult. Incubation with ascorbate or DHAA raised intracellular ascorbate concentrations and mitigated the effects of septic insult. In conclusion, ascorbate acts within microvascular endothelial cells to inhibit septic stimulation of oxidant production by NADPH oxidase and thereby prevents PP2A activation, PP2A-dependent dephosphorylation and redistribution of occludin, and disruption of the endothelial barrier.
Ascorbate; Endothelial cells; Interferon-γ; Lipopolysaccharide; NADPH oxidase; Occludin; Permeability; Protein phosphatase type 2A; Sepsis
Crohn’s disease (CD) and ulcerative colitis (UC) are associated with expression differences in genes involved in immune function, wound healing, and tissue remodeling. Micro-RNAs (miRNAs) are small, noncoding RNAs that act as potent negative regulators of gene expression and are differentially expressed in chronic inflammatory diseases, including UC. We examined the expression of miRNAs in tissues from different intestinal regions and in patients with active ileal and colonic CD.
Colonoscopic pinch biopsies were obtained from the terminal ileum, cecum, transverse colon, sigmoid colon, and rectum of normal, healthy adults and from the ileum and sigmoid colon of patients with active ileal and colonic CD. miRNA expression was assessed using miRNA microarray and validated by mature miRNA quantitative reverse-transcription polymerase chain reaction (RT-PCR).
Ten intestine region-specific miRNAs were identified. Three miRNAs were increased and one miRNA was decreased in the terminal ileum as compared to the colon. Six other miRNAs expressed varying levels of expression among the colon regions. Five miRNAs were found to be differentially expressed in tissues of patients with active colonic CD, with three increased and two decreased as compared to normal, healthy controls. Similarly, four miRNAs were found to be significantly increased in tissues of patients with active ileal CD.
The expression differences between ileal CD, colonic CD, and previously identified UC-associated miRNAs support the likelihood that miRNAs influence differing inflammation-related gene expression in each inflammatory bowel disease (IBD) subtype and may form the basis for future diagnostic tests and therapeutic targets for IBD.
microRNA; Crohn’s disease; inflammatory bowel diseases; gene expression; microarray