Intestinal apoptotic changes linked to metabolic status in fasted and refed rats

Intestinal apoptosis and expression of apoptosis inducers - the cytokines TNFalpha, TGFbeta1 - and the intestinal transcription factor Cdx2, were studied according to two different metabolic and hormonal phases which characterize long-term fasting: the long period of protein sparing during which energy expenditure is derived from lipid oxidation (phase II), and the later phase characterized by a rise in body protein utilization and plasma corticosterone (phase III). Apoptosis was further studied in 2, 6, and 24 h refed rats. Morphological apoptotic events were observed by environmental and conventional scanning electron microscopy and a TUNEL test was used to characterize the final stages of apoptotic death. The gene and protein expressions of TNFalpha, TGFbeta1, and Cdx2 were measured. Apoptotic events and TNFalpha, TGFbeta1, and Cdx2 gene and protein expressions did not vary significantly during phase II as compared to the normally fed animals. However, a phase III fasting induced a delay in intestinal epithelial apoptosis, along with a 92, 58, and 25% decrease in TNFalpha, TGFbeta1, and Cdx2 mRNAs, respectively. The amounts of TNFalpha, TGFbeta1, and Cdx2 proteins decreased by 70, 36, and 25%, respectively. Apoptosis was restored rapidly after a 2 h refeeding following the phase III, accompanied by a significant increase in TNFalpha, TGFbeta1, and Cdx2 mRNA and the protein levels, compared to the phase III fasting values. The concomitant decreases in cytokines and Cdx2 and in apoptotic cells during phase III suggest the preservation of enterocytes during this critical fasting period in order to optimize nutrient absorption as soon as food is available and thus, to rapidly restore body mass

Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study

Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Specific expression of lactase in the jejunum and colon during postnatal development and hormone treatments in the rat.

The expression of lactase was compared in the jejunum and colon of the rat at the levels of enzyme activity and protein and RNA content. We found that the enzyme proteins and the corresponding mRNAs share common features and are encoded by a single gene in both intestinal segments. In the jejunum, large amounts of lactase mRNA and proteins were detected during postnatal development as well as in adult rats, despite the 10-fold decline in lactase specific activity which occurs at weaning. In contrast, in the colon the expression of lactase was restricted to early postnatal development. In the colon, the enzymic activity of lactase and the amounts of protein and mRNA followed parallel development profiles with a peak at day 4 after birth. Injections of thryoxine or epidermal growth factor into neonates led to small modifications in the expression of lactase in the jejunum. On the other hand, these treatments caused a large decline in lactase activity in the colon that paralleled a decrease in the amount of lactase protein and mRNA. These data indicate that the expression of lactase is mainly regulated at the post-transcriptional level in the jejunum, whereas it is controlled at the pretranslational level in the colon

Cytokine gene expression during postnatal small intestinal development: regulation by glucocorticoids

BACKGROUND—In the intestinal mucosa, numerous cytokines produced by the epithelium, fibroblasts, and immune cells were shown to affect epithelial differentiation and proliferation through epithelial-mesenchymal and epithelial-immune cell interactions. To date, the importance of cytokines in postnatal development of the rat small intestine has not been established.
AIM—To investigate the developmental changes in expression of mucosal cytokines in the postnatal maturation of the rat small intestinal epithelium and their regulation by glucocorticoids (GC).
METHODS—Mucosal maturation was assessed by the onset of sucrase-isomaltase (SI) mRNA, analysed by in situ hybridisation. The amount of transforming growth factor β1 (TGF-β1), β2 (TGF-β2), tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β), and TGF-α was analysed by reverse transcription-polymerase chain reaction (RT-PCR) in mucosal extracts from weaning (14-21 days old) and adult rats, or one day after an injection of hydrocortisone (HC) in 11 day old rats. Similarly, expression of cytokines and the regulatory effect of GC were studied on cultured subepithelial myofibroblasts cloned from postnatal jejunum and ileum cultured in the absence or presence of dexamethasone (DX).
RESULTS—TGF-β1, TGF-β2, and IL-1β decreased during the third week of life while levels of TNF-α increased and TGF-α remained constant. In parallel, SI transcripts increased and showed a progressive accumulation in the apical part of the enterocytes first localised at the base of the villi from 18 days onwards. Interestingly, precocious induction of SI mRNA by HC paralleled the decrease in expression of TGF-β isoforms and of IL-1β. All cytokines were expressed in the myofibroblast cell lines. In addition, the results showed that TNF-α was differentially expressed in basal culture conditions and after DX stimulation in jejunal and ileal myofibroblasts. DX decreased IL-1β but not the TGF-β isoforms, similar to that in vivo.
CONCLUSIONS—This study shows that mucosal cytokines are developmentally regulated and that GC are potentially involved in this regulation in parallel with maturation of the gut mucosa at weaning.


Keywords: small intestine; weaning; maturation; fibroblasts; cytokine