Intestinal Cell Kinase Is a Novel Participant in Intestinal Cell Signaling Responses to Protein Malnutrition

Nutritional deficiency and stress can severely impair intestinal architecture, integrity and host immune defense, leading to increased susceptibility to infection and cancer. Although the intestine has an inherent capability to adapt to environmental stress, the molecular mechanisms by which the intestine senses and responds to malnutrition are not completely understood. We hereby report that intestinal cell kinase (ICK), a highly conserved serine/threonine protein kinase, is a novel component of the adaptive cell signaling responses to protein malnutrition in murine small intestine. Using an experimental mouse model, we demonstrated that intestinal ICK protein level was markedly and transiently elevated upon protein deprivation, concomitant with activation of prominent pro-proliferation and pro-survival pathways of Wnt/β-catenin, mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK), and protein kinase B (PKB/Akt) as well as increased expression of intestinal stem cell markers. Using the human ileocecal epithelial cell line HCT-8 as an in vitro model, we further demonstrated that serum starvation was able to induce up-regulation of ICK protein in intestinal epithelial cells in a reversible manner, and that serum albumin partially contributed to this effect. Knockdown of ICK expression in HCT-8 cells significantly impaired cell proliferation and down-regulated active β-catenin signal. Furthermore, reduced ICK expression in HCT-8 cells induced apoptosis through a caspase-dependent mechanism. Taken together, our findings suggest that increased ICK expression/activity in response to protein deprivation likely provides a novel protective mechanism to limit apoptosis and support compensatory mucosal growth under nutritional stress.     

Strategies for farmers and policy makers to control nitro-gen losses whilst maintaining crop production

The nitrogen (N) cycle is essentially 'leaky'. The losses of small amounts of nitrate to waters and of ammonia and nitrous oxide to the atmosphere are a part of the global biogeo-chemical N cycle. However, intensive agricultural production, industry and vehicle use have more than doubled the amount of 'reactive' N in the environment, resulting in eutrophication, ecosystem change and health concerns. Research has identified agricultural practices that cause large losses of N and, in some cases, developed solutions. This paper discusses the problems of maintaining productivity while reducing N losses, compares conventional with low input (integrated) and organic farming systems, and discusses wider options. It also looks at the need to integrate studies on N with other environmental impacts, set in the context of the whole farm system, to provide truly sustainable agricultural systems.     

Metagenomics reveals sediment microbial community response to Deepwater Horizon oil spill

The Deepwater Horizon (DWH) oil spill in the spring of 2010 resulted in an input of ∼4.1 million barrels of oil to the Gulf of Mexico; >22% of this oil is unaccounted for, with unknown environmental consequences. Here we investigated the impact of oil deposition on microbial communities in surface sediments collected at 64 sites by targeted sequencing of 16S rRNA genes, shotgun metagenomic sequencing of 14 of these samples and mineralization experiments using ¹⁴C-labeled model substrates. The 16S rRNA gene data indicated that the most heavily oil-impacted sediments were enriched in an uncultured Gammaproteobacterium and a Colwellia species, both of which were highly similar to sequences in the DWH deep-sea hydrocarbon plume. The primary drivers in structuring the microbial community were nitrogen and hydrocarbons. Annotation of unassembled metagenomic data revealed the most abundant hydrocarbon degradation pathway encoded genes involved in degrading aliphatic and simple aromatics via butane monooxygenase. The activity of key hydrocarbon degradation pathways by sediment microbes was confirmed by determining the mineralization of ¹⁴C-labeled model substrates in the following order: propylene glycol, dodecane, toluene and phenanthrene. Further, analysis of metagenomic sequence data revealed an increase in abundance of genes involved in denitrification pathways in samples that exceeded the Environmental Protection Agency (EPA)''s benchmarks for polycyclic aromatic hydrocarbons (PAHs) compared with those that did not. Importantly, these data demonstrate that the indigenous sediment microbiota contributed an important ecosystem service for remediation of oil in the Gulf. However, PAHs were more recalcitrant to degradation, and their persistence could have deleterious impacts on the sediment ecosystem.     

Epidemiological Characteristics of Strongyloidiasis in Inhabitants of Indigenous Communities in Borneo Island,Malaysia

Epidemiological study on strongyloidiasis in humans is currently lacking in Malaysia. Thus, a cross-sectional study was carried out to determine the prevalence of Strongyloides stercoralis infection among the inhabitants of longhouse indigenous communities in Sarawak. A single stool and blood sample were collected from each participant and subjected to microscopy, serological and molecular techniques. Five species of intestinal parasites were identified by stool microscopy. None of the stool samples were positive for S. stercoralis. However, 11% of 236 serum samples were seropositive for strongyloidiasis. Further confirmation using molecular technique on stool samples of the seropositive individuals successfully amplified 5 samples, suggesting current active infections. The prevalence was significantly higher in adult males and tended to increase with age. S. stercoralis should no longer be neglected in any intestinal parasitic survey. Combination of more than 1 diagnostic technique is necessary to increase the likelihood of estimating the ‘true’ prevalence of S. stercoralis.     

Effects of interferon alpha on human osteoprogenitor cell growth and differentiation in vitro.

The specific effects of interferon alpha (IFNalpha), on the differentiation pathways of human osteogenic cells are not known. The aim of this study was to investigate possible effects of IFNalpha on osteogenic development by investigating cell differentiation, colony formation (colony forming unit-fibroblastic, CFU-F), cell proliferation, and gene expression, in particular bone morphogenetic protein (BMP) expression, of human bone marrow osteoprogenitor cells. Human bone marrow fibroblasts were cultured with or without the addition of IFNalpha (5-1,000 IU/ml) in the presence and absence of dexamethasone (10 nM) and ascorbate (100 microM), which are agents known to affect osteogenic differentiation. IFNalpha produced a significant dose-dependent inhibition of cell proliferation and alkaline phosphatase specific activity at concentrations as low as 50 IU/ml. IFNalpha (50-1,000 IU/ml) inhibited the stimulation of alkaline phosphatase specific activity induced by ascorbate and dexamethasone. Examination of CFU-F showed dose- and time-dependent inhibitions of colony formation and reductions in both colony size and alkaline phosphatase-positive CFU-F colonies particularly at earlier times. Reactivity with an antibody specific for osteoprogenitors (HOP-26), was reduced in IFNalpha-treated cultures. Northern blot analysis showed a significant dose-dependent up-regulation of BMP-2 mRNA, estrogen receptor alpha mRNA and osteocalcin mRNA expression in ascorbate/dexamethasone cultures. In contrast, IFNalpha significantly inhibited BMP-2 mRNA expression in the absence of ascorbate and dexamethasone. In conclusion, IFNalpha inhibits human osteoprogenitor cell proliferation, CFU- F formation, HOP-26 expression, and alkaline phosphatase specific activity and modulates BMP-2 gene expression. These results suggest a role for IFNalpha in local bone turnover through the specific and direct modulation of osteoprogenitor proliferation and differentiation.     

Targeting CoV-2 spike RBD and ACE-2 interaction with flavonoids of Anatolian propolis by in silico and in vitro studies in terms of possible COVID-19 therapeutics

Propolis is a multi-functional bee product rich in polyphenols. In this study, the inhibitory effect of Anatolian propolis against SARS-coronavirus-2 (SARS-CoV-2) was investigated in vitro and in silico. Raw and commercial propolis samples were used, and both samples were found to be rich in caffeic acid, p-coumaric acid, ferulic acid, t-cinnamic acid, hesperetin, chrysin, pinocembrin, and caffeic acid phenethyl ester (CAPE) at HPLC-UV analysis. Ethanolic propolis extracts (EPE) were used in the ELISA screening test against the spike S1 protein (SARS-CoV-2): ACE-2 interaction for in vitro study. The binding energy values of these polyphenols to the SARS-CoV-2 spike and ACE-2 protein were calculated separately with a molecular docking study using the AutoDock 4.2.6 program. In addition, the pharmacokinetics and drug-likeness properties of these eight polyphenols were calculated according to the SwissADME tool. The binding energy value of pinocembrin was highest in both receptors, followed by chrysin, CAPE, and hesperetin. Based on the in silico modeling and ADME (absorption, distribution, metabolism, and excretion) behaviors of the eight polyphenols, the compounds exhibited the potential ability to act effectively as novel drugs. The findings of both studies showed that propolis has a high inhibitory potential against the Covid-19 virus. However, further studies are now needed.     

Arg16/Gly beta2-adrenergic receptor polymorphism alters the cardiac output response to isometric exercise.

Normotensive adults homozygous for glycine (Gly) of the Arg16/Gly beta2-adrenergic-receptor polymorphism have 1) greater forearm beta2-receptor mediated vasodilation and 2) a higher heart rate (HR) response to isometric handgrip than arginine (Arg) homozygotes. To test the hypothesis that the higher HR response in Gly16 subjects serves to maintain the pressor response [increased cardiac output (CO)] in the setting of augmented peripheral vasodilation to endogenous catecholamines, we measured continuous HR (ECG), arterial pressure (Finapres), and CO (transthoracic echocardiography) during isometric, 40% submaximal handgrip to fatigue in healthy subjects homozygous for Gly (n = 30; mean age +/- SE: 30 +/- 1.2, 13 women) and Arg (n = 17, age 30 +/- 1.6, 11 women). Resting data were similar between groups. Handgrip produced similar increases in arterial pressure and venous norepinephrine and epinephrine concentrations; however, HR increased more in the Gly group (60.1 +/- 4.3% increase from baseline vs. 45.5 +/- 3.9%, P = 0.03), and this caused CO to be higher (Gly: 7.6 +/- 0.3 l/m vs. Arg: 6.5 +/- 0.3 l/m, P = 0.03), whereas the decrease in systemic vascular resistance in the Gly group did not reach significance (P = 0.09). We conclude that Gly16 homozygotes generate a higher CO to maintain the pressor response to handgrip. The influence of polymorphic variants in the beta2-adrenergic receptor gene on the cardiovascular response to sympathoexcitation may have important implications in the development of hypertension and heart failure.