Lanosterol Synthase Genetic Variants, Endogenous Ouabain, and Both Acute and Chronic Kidney Injury

Rationale & Objective Studies of humans and animals have suggested that endogenous ouabain (EO) and related genes are mediators of acute (AKI) and chronic kidney injury. We sought to examine the relationship among EO levels, genetic variants in lanosterol synthase (LSS; an enzyme that catalyzes synthesis of cholesterol, a precursor of EO), and both AKI and chronic kidney injury. Study Design 2 prospective observational cohort studies and a cross-sectional study of kidney tissue. Setting & Participants (1) A prospective cohort study of patients undergoing cardiovascular surgery, (2) measurement of EO concentration in kidney tissue removed because of an adjacent tumor, and (3) a prospective cohort study of patients with newly diagnosed essential hypertension. Exposure Missense variant in LSS (A instead of C allele at rs2254524), which leads to a valine to leucine substitution at amino acid 642. Outcomes Development of postoperative AKI in the cardiovascular surgery cohort, EO concentration in kidney tissue, and estimated glomerular filtration rate (eGFR) reductions in the essential hypertension cohort. Analytical Approach Logistic regression for analysis of postoperative AKI, analysis of variance for EO concentration in kidney tissue, and generalized linear models for changes in eGFR over time. Results AKI incidence following cardiovascular surgery was greater among those with the LSS rs2254524 AA genotype (30.7%) than in those with the CC genotype (17.4%; P=0.001). LSS rs2254524 AA kidneys had higher EO concentrations than CC kidneys (2.14±0.29 vs 1.25±0.08ng/g; P Limitations These associations do not necessarily represent causal relationships; LSS rs2254524 variants may have effects on other steroid hormones. Conclusions These findings support the potential value of LSS rs2254524 genotype–based risk stratification to identify patients at high risk for AKI before cardiovascular surgery, as well as predict accelerated eGFR in the setting of hypertension. These findings also suggest that LSS may in part drive EO-mediated kidney damage. EO may represent a new potential therapeutic target for the prevention of AKI and slowing of kidney damage in the setting of hypertension

Cellular Senescence: Aging, Cancer, and Injury

Cellular senescence is a permanent state of cell cycle arrest that occurs in proliferating cells subjected to different stresses. Senescence is, therefore, a cellular defense mechanism that prevents the cells to acquire an unnecessary damage. The senescent state is accompanied by a failure to re-enter the cell cycle in response to mitogenic stimuli, an enhanced secretory phenotype and resistance to cell death. Senescence takes place in several tissues during different physiological and pathological processes such as tissue remodeling, injury, cancer, and aging. Although senescence is one of the causative processes of aging and it is responsible of aging-related disorders, senescent cells can also play a positive role. In embryogenesis and tissue remodeling, senescent cells are required for the proper development of the embryo and tissue repair. In cancer, senescence works as a potent barrier to prevent tumorigenesis. Therefore, the identification and characterization of key features of senescence, the induction of senescence in cancer cells, or the elimination of senescent cells by pharmacological interventions in aging tissues is gaining consideration in several fields of research. Here, we describe the known key features of senescence, the cell-autonomous, and noncell-autonomous regulators of senescence, and we attempt to discuss the functional role of this fundamental process in different contexts in light of the development of novel therapeutic targets

<i>Lactobacillus paracasei</i> CBA L74 Metabolic Products and Fermented Milk for Infant Formula Have Anti-Inflammatory Activity on Dendritic Cells <i>In Vitro</i> and Protective Effects against Colitis and an Enteric Pathogen <i>In Vivo</i>

<div><p>The rapid expansion of commercially available fermented food products raises important safety issues particularly when infant food is concerned. In many cases, the activity of the microorganisms used for fermentation as well as what will be the immunological outcome of fermented food intake is not known. In this manuscript we used complex <i>in vitro</i>, <i>ex-vivo</i> and <i>in vivo</i> systems to study the immunomodulatory properties of probiotic-fermented products (culture supernatant and fermented milk without live bacteria to be used in infant formula).</p><p>We found <i>in vitro</i> and <i>ex-vivo</i> that fermented products of <i>Lactobacillus paracasei</i> CBA L74 act via the inhibition of proinflammatory cytokine release leaving anti-inflammatory cytokines either unaffected or even increased in response to <i>Salmonella</i> typhimurium. These activities are not dependent on the inactivated bacteria but to metabolic products released during the fermentation process. We also show that our <i>in vitro</i> systems are predictive of an <i>in vivo</i> efficacy by the fermented products. Indeed CBA L74 fermented products (both culture medium and fermented milk) could protect against colitis and against an enteric pathogen infection (<i>Salmonella</i> typhimurium). Hence we found that fermented products can act via the inhibition of immune cell inflammation and can protect the host from pathobionts and enteric pathogens. These results open new perspectives in infant nutrition and suggest that <i>L. paracasei</i> CBA L74 fermented formula can provide immune benefits to formula-fed infants, without carrying live bacteria that may be potentially dangerous to an immature infant immune system.</p></div

Coagulation induced by C3aR-dependent NETosis drives protumorigenic neutrophils during small intestinal tumorigenesis

Excessive activation of blood coagulation and neutrophil accumulation have been described in several human cancers. However, whether hypercoagulation and neutrophilia are linked and involved in cancer development is currently unknown. Here we show that spontaneous intestinal tumorigenesis correlates with the accumulation of low-density neutrophils with a pro-tumorigenic N2 phenotype and unprompted neutrophil extracellular traps (NET) formation. We find that increased circulating lipopolysaccharide induces upregulation of complement C3a receptor on neutrophils and activation of the complement cascade. This leads to NETosis, induction of coagulation and N2 polarization, which prompts tumorigenesis, showing a novel link between coagulation, neutrophilia and complement activation. Finally, in a cohort of patients with small but not large intestinal cancer, we find a correlation between neutrophilia and hypercoagulation. This study provides a mechanistic explanation for the tumour-promoting effects of hypercoagulation, which could be used as a new biomarker or as a therapeutic target

<i>Lactobacillus paracaseii</i> CBA L74 supernatant has anti-inflammatory properties on MoDCs.

<p>MoDCs were infected with either <i>Salmonella</i> SL1344 (MOI 10∶1) or <i>Lactobacillus</i> CBA L74 (MOI 10∶1) for 1 hour in medium without antibiotics or in the presence of 2% LB, MRS, FB62 supernatant (Sn FB62) or CBA L74 supernatant in MRS (Sn CBA L74). After washing and 24 h incubations in medium with antibiotics cytokine abundance was evaluated. A. Concentrations of IL-12p70 and IL-10 as determined by ELISA and CBA assays respectively. B. The % of response relative to FB62 infected MoDCs is shown after grouping six experiments together. C. Anti-inflammatory index calculated as ratio of IL-10/IL12p70 concentrations. * p<0,05; *** p<0,001.</p

Oral administration of fermented milk preparation protects against colitis.

<p>Mice (n = 5) were orally administered on a daily basis for 14 consecutive days (days −2 to 11) with vehicle (water), non-fermented milk (NFM) or fermented milk (FM). Acute colitis was induced by dissolving 3% DSS in drinking water for 9 days (days 0–9). A, Single mouse body weight curves, Kaplan-Meier survival and colon length for vehicle, NFM and FM. B. Body weight curves (mean ± SEM) for two pooled experiments. * p<0,05; ** p<0,01.</p

Fermented milk preparation has anti-inflammatory properties on MoDCs.

<p>MoDCs were infected with <i>Salmonella</i> FB62 (MOI 10:1) for 1 hour in medium without antibiotics or in different infant formulas: non-fermented milk (NFM) and fermented milk (FM) obtained through fermentation of Lactobacillus CBA L74 alone (CBA L74), fermentation in the presence <i>S. thermophilus</i> TH3 (S. th) or double fermentation with CBA L74 and <i>S. thermophilus</i> TH3 (CBA L74+S. th). After washing and 24 h incubations in medium with antibiotics cytokine abundance was evaluated. Panels show % of response of IL-12p70 and IL-10 relative to MoDCs infected with SL1334 in medium without antibiotics. *** p<0,001.</p

CBA L74 fermented milk reduces inflammatory mediators expression.

<p>At the end of the experiment described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0087615#pone-0087615-g005" target="_blank">Figure 5</a> RNA was extracted from colons and expression levels of Tbet, Gata3, Inf-γ, Il-17a, Il-6, Il-22, Il-33, Il-1β, Kc, Ccl2, Cox2, iNos, Ahr, Indo, Zo-1, Reg3β, Reg3γ were assessed by RT-qPCR. Expression levels are normalized to the housekeeping mRNA Ralp32. Dots represent individual mice measurements, lines represent the average value.</p

BALB/c and C57BL/6 Mice Differ in Polyreactive IgA Abundance, which Impacts the Generation of Antigen-Specific IgA and Microbiota Diversity

SummaryThe interrelationship between IgAs and microbiota diversity is still unclear. Here we show that BALB/c mice had higher abundance and diversity of IgAs than C57BL/6 mice and that this correlated with increased microbiota diversity. We show that polyreactive IgAs mediated the entrance of non-invasive bacteria to Peyer’s patches, independently of CX3CR1+ phagocytes. This allowed the induction of bacteria-specific IgA and the establishment of a positive feedback loop of IgA production. Cohousing of mice or fecal transplantation had little or no influence on IgA production and had only partial impact on microbiota composition. Germ-free BALB/c, but not C57BL/6, mice already had polyreactive IgAs that influenced microbiota diversity and selection after colonization. Together, these data suggest that genetic predisposition to produce polyreactive IgAs has a strong impact on the generation of antigen-specific IgAs and the selection and maintenance of microbiota diversity