Potential Dietary and Therapeutic Strategies Involving Indole-3-Carbinole in Preclinical Models of Intestinal Inflammation

Diet-microbiota interactions are emerging as important contributors in the pathogenesis of inflammatory bowel diseases (IBD), characterized by chronic inflammation of the GI tract. The aryl hydrocarbon receptor (AhR) transcription factor regulates xenobiotic metabolism and is activated by exogenous ligands, including indole-3-carbinole (I3C), which is found in cruciferous vegetables. However, studies investigating the impact of dietary I3C and AhR in preclinical models resembling human IBD are lacking. Mice (WT or AhR KO in IECs, 6-8 weeks) or SAMP/YitFC and AKR/J control (4 weeks, m/f) were fed an AhR ligand-depleted or I3C (200 ppm)-supplemented diet. There were increased levels of LPS and exacerbated inflammation, resulting in increased mortality in AhRΔIEC mice fed the AhR ligand-depleted diet in response to chronic DSS. The mechanisms underlying the protective effects of I3C supplementation during colonic colitis involved amelioration of intestinal inflammation and restoration of the altered gut microbiota, particularly the families of clostridicae and lachnospriaceae. Furthermore, the AhR-depleted diet led to the emergence of pathobiont Parvibacter caecicola in WT mice. SAMP/YitFc mice with spontaneous ileitis showed significant recovery in epithelial abnormalities when fed dietary I3C. These data demonstrate the critical role of AhR and the mechanisms of dietary I3C in maintaining epithelial homeostasis and ameliorating inflammation.

Quality of COVID-19 information, education and communication materials in India: A content analysis

Objective

This study examined the characteristics and quality of publicly available COVID-19 information education and communication (IEC) materials in India between March and December 2020.

Design

An explanatory sequential mixed-method design was employed to examine the characteristics and quality of 265 purposefully selected IEC materials.

Setting

The IEC materials analysed were those published between March and December 2020 on the Ministry of Health and Family Welfare website, Government of India.

Methods

A checklist was utilised to examine the quality and characteristics of the materials. Thereafter, qualitative analysis provided insights into the contents of the materials with specific focus on the 'COVID-19 continuum of care'.

Results

The majority (73.96%, n = 196) of the selected materials were directed towards the general public and had a focus on prevention (67.55 %, n = 179). Despite COVID-19-associated stigma, only 56 (21.13%) of the materials addressed this issue. However, most (95.47%, n = 253) of the materials adhered to quality standards for contents, readability and aesthetics. This qualitative analysis focused on the contents of selected IEC materials using the concept of 'continuum of care'. The analysis identified three important themes: prevention to early diagnosis and treatment; mitigation of stigma and discrimination surrounding COVID-19; and addressing the infodemic caused by COVID-19.

Conclusion

The quality of materials was mostly satisfactory and appropriate to the emergent requirements. Strengthening audience engagement and attractiveness of the materials might enhance readability and actionability. A bottom-up approach to the development of future IEC materials, involving the community might widen the coverage of vulnerable populations in future crisis events.

Unusual spin-orbit torque switching in perpendicular synthetic antiferromagnets with strong interlayer exchange coupling

Synthetic antiferromagnet (SAF) is an outstanding system for controlling magnetic coupling via tuning the layer thickness and material composition. Here, we control the interlayer exchange coupling (IEC) in a perpendicularly magnetized SAF Pt/Co/Ir/CoFeB/MgO multilayer, which is tuned by varying the nonmagnetic layer Ir thickness and the magnetic layer Co thickness. And we study the spin-orbit torque (SOT) driven magnetization switching of the SAF. In the SAF with a weak IEC, the SOT-driven switching behavior is similar to that of a single ferromagnet system, which is dominated by the external magnetic field. In contrast, in the SAF with an ultra-strong IEC, the saturation magnetic field is large than 50 kOe, and the SOT-driven switching behavior is decided by the effective magnetic field. The effective field is correlated to the external magnetic field, the IEC field, magnetic moments of CoFeB and Co, and magnetic anisotropy. These results may advance the understanding of SOT switching of perpendicular SAFs and promote the applications of SAFs with low stray fields and lower power in spintronic devices.

Calibration matters: II. Measurement of ambient noise in test rooms/areas

Ambient noise measurement is a part of audiometric calibration in which one measures the ambient noise level in a sound room/test area intended for audiometric testing and then decides whether the background noise in the test room meets the maximum permissible ambient noise level (MPANL) requirements specified in national or international standards, e.g., ANSI/ASA S3.1:1999(R2018) or ISO 8253-1:2010 (R2021). If the ambient noise levels are below the MPANLs, clinicians can be sure that the test stimuli they present to patients are not masked by the background noise in the test room/area and their test results are valid and the subsequent clinical decisions are sound. Audiometric testing, however, may not always be carried out in sound rooms/test areas with ambient noise levels below the MPANLs, especially during community outreach or humanitarian services. A thorough understanding on the MPANL requirements for different transducers can help clinicians determine which equipment is appropriate for the test area. This tutorial discusses the rationale and assumptions behind the MPANL specifications, how to measure ambient noise levels of test rooms/areas, and how to apply the national and international standards to determine if the test room is suitable for audiometric testing. Alternative strategies are discussed when the ambient noise levels exceed the specified MPANLs. The rationale and procedures are explained using examples on how to lower the ambient noise levels in test areas, and how to determine the suitable test frequency range and the lowest threshold levels that can be assessed in the test area.

Investigation of Sulfonated Graphene Oxide as the Base Material for Novel Proton Exchange Membranes

This work deals with the development of graphene oxide (GO)-based self-assembling membranes as possible innovative proton conductors to be used in polymer electrolyte membrane fuel cells (PEMFCs). Nowadays, the most adopted electrolyte is Chemours’ Nafion; however, it reveals significant deficiencies such as strong dehydration at high temperature and low humidity, which drastically reduces its proton conductivity. The presence of oxygenated moieties in the GO framework makes it suitable for functionalization, which is required to enhance the promising, but insufficient, proton-carrying features of GO. In this study, sulfonic acid groups (–SO₃H) that should favor proton transport were introduced in the membrane structure via a reaction between GO and concentrated sulfuric acid. Six acid-to-GO molar ratios were adopted in the synthesis procedure, giving rise to final products with different sulfonation degrees. All the prepared samples were characterized by means of TGA, ATR-FTIR and Raman spectroscopy, temperature-dependent XRD, SEM and EDX, which pointed out morphological and microstructural changes resulting from the functionalization stage, confirming its effectiveness. Regarding functional features, electrochemical impedance spectroscopy (EIS) as well as measurements of ion exchange capacity (IEC) were carried out to describe the behavior of the various samples, with pristine GO and commercial Nafion^® 212 used as reference. EIS tests were performed at five different temperatures (20, 40, 60, 80 and 100 °C) under high (95%) and medium (42%) relative humidity conditions. Compared to both GO and Nafion^® 212, the sulfonated specimens demonstrate an increase in the number of ion-carrying groups, as proved by both IEC and EIS tests, which reveal the enhanced proton conductivity of these novel membranes. Specifically, an acid-to-GO molar ratio of 10 produces a six-fold improvement of IEC (4.23 meq g⁻¹) with respect to pure GO (0.76 meq g⁻¹), while a maximum eight-fold improvement (5.72 meq g⁻¹) is achieved in SGO-15.

The Role of the Intestinal Epithelium in the "Weep and Sweep" Response during Gastro-Intestinal Helminth Infections

Simple Summary

The immune system actively combats intruders such as bacteria, viruses, fungi, and protozoan and metazoan parasites using leukocytes. During an infection white blood cells are activated to internalize bacteria or viruses and release a number of molecules to kill pathogens. Unfortunately, those mechanisms are ineffective against larger intruders like helminths, which are too large to be killed by a single immune cell. To eliminate gastro-intestinal helminths an integrated response involving the nervous, endocrine, and immune systems are used to expel the parasites. This is achieved through increased gut hydration and muscle contractions which detach worms from the gut and lead to release outside the body in a “weep and sweep” response. Epithelial cells of the intestine are significant players in this process, being responsible for detecting the presence of helminths in the gut and participating in the regulation of parasite expulsion. This paper describes the role of the gut epithelium in detecting and eliminating helminths from the intestine.

Abstract

Helminths are metazoan parasites infecting around 1.5 billion people all over the world. During coevolution with hosts, worms have developed numerous ways to trick and evade the host immune response, and because of their size, they cannot be internalized and killed by immune cells in the same way as bacteria or viruses. During infection, a substantial Th₂ component to the immune response is evoked which helps restrain Th₁-mediated tissue damage. Although an enhanced Th₂ response is often not enough to kill the parasite and terminate an infection in itself, when tightly coordinated with the nervous, endocrine, and motor systems it can dislodge parasites from tissues and expel them from the gut. A significant role in this “weep and seep” response is attributed to intestinal epithelial cells (IEC). This review highlights the role of various IEC lineages (enterocytes, tuft cells, Paneth cells, microfold cells, goblet cells, and intestine stem cells) during the course of helminth infections and summarizes their roles in regulating gut architecture and permeability, and muscle contractions and interactions with the immune and nervous system.

LKB1 in Intestinal Epithelial Cells Regulates Bile Acid Metabolism by Modulating FGF15/19 Production

BACKGROUND & AIMS

Liver kinase B1 (LKB1) is a master upstream protein kinase involved in nutrient sensing and glucose and lipid metabolism in many tissues; however, its metabolic role in intestinal epithelial cells (IEC) remains unclear. In this study, we investigated the regulatory role of LKB1 on bile acid (BA) homeostasis.

METHODS

We generated mice with IEC-specific deletion of LKB1 (LKB1^ΔIEC) and analyzed the characteristics of IEC development and BA level. In vitro assays with small interfering RNA, liquid chromatography/mass spectrometry, metagenomics, and RNA-sequencing were used to elucidate the regulatory mechanisms underlying perturbed BA homeostasis.

RESULTS

LKB1 deletion resulted in abnormal differentiation of secretory cell lineages. Unexpectedly, BA pool size increased substantially in LKB1^ΔIEC mice. A significant reduction of the farnesoid X receptor (FXR) target genes, including fibroblast growth factor 15/19 (FGF15/19), known to inhibit BA synthesis, was found in the small intestine (SI) ileum of LKB1^ΔIEC mice. We observed that LKB1 depletion reduced FGF15/19 protein level in human IECs in vitro. Additionally, a lower abundance of bile salt hydrolase-producing bacteria and elevated levels of FXR antagonist (ie, T-βMCA) were observed in the SI of LKB1^ΔIEC mice. Moreover, LKB1^ΔIEC mice showed impaired conversion of retinol to retinoic acids in the SI ileum. Subsequently, vitamin A treatment failed to induce FGF15 production. Thus, LKB1^ΔIEC mice fed with a high-fat diet showed improved glucose tolerance and increased energy expenditure.

CONCLUSIONS

LKB1 in IECs manages BA homeostasis by controlling FGF15/19 production.

Circular RNA CircHIPK3 Promotes Homeostasis of the Intestinal Epithelium by Reducing MicroRNA 29b Function

BACKGROUND & AIMS

Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that form covalently closed circles. Although circRNAs influence many biological processes, little is known about their role in intestinal epithelium homeostasis. We surveyed circRNAs required to maintain intestinal epithelial integrity and identified circular homeodomain-interacting protein kinase 3 (circHIPK3) as a major regulator of intestinal epithelial repair after acute injury.

METHODS

Intestinal mucosal tissues were collected from mice exposed to cecal ligation and puncture for 48 hours and patients with inflammatory bowel diseases and sepsis. We isolated primary enterocytes from the small intestine of mice and derived intestinal organoids. The levels of circHIPK3 were silenced in intestinal epithelial cells (IECs) by transfection with small interfering RNAs targeting the circularization junction of circHIPK3 or elevated using a plasmid vector that overexpressed circHIPK3. Intestinal epithelial repair was examined in an in vitro injury model by removing part of the monolayer. The association of circHIPK3 with microRNA 29b (miR-29b) was determined by biotinylated RNA pull-down assays.

RESULTS

Genome-wide profile analyses identified ∼300 circRNAs, including circHIPK3, differentially expressed in the intestinal mucosa of mice after cecal ligation and puncture relative to sham mice. Intestinal mucosa from patients with inflammatory bowel diseases and sepsis had reduced levels of circHIPK3. Increasing the levels of circHIPK3 enhanced intestinal epithelium repair after wounding, whereas circHIPK3 silencing repressed epithelial recovery. CircHIPK3 silencing also inhibited growth of IECs and intestinal organoids, and circHIPK3 overexpression promoted intestinal epithelium renewal in mice. Mechanistic studies revealed that circHIPK3 directly bound to miR-29b and inhibited miR-29 activity, thus increasing expression of Rac1, Cdc42, and cyclin B1 in IECs after wounding.

CONCLUSIONS

In studies of mice, IECs, and human tissues, our results indicate that circHIPK3 improves repair of the intestinal epithelium at least in part by reducing miR-29b availability.

L-lactate promotes intestinal epithelial cell migration to inhibit colitis

Lactate, one of the most common primary metabolites of bacteria and human cells, has been shown to play essential roles in the regulation of inflammatory diseases, including inflammatory bowel diseases. However, whether and how host-derived lactate affects intestinal epithelial homeostasis is still not completely understood. Here, we investigated how L-lactate, mainly produced by host cells, regulates intestinal epithelial cell (IEC) migration to promote intestinal wound healing. Using video microscopy and tracking individual cells, we found that L-lactate enhanced IEC migration in direction persistence and speed. Mechanistically, L-lactate promoted IEC mitochondrial ATP production. The mitochondrial ATP synthase inhibitor, oligomycin, significantly decreased IEC persistence and speed, which inhibited cell migration induced by L-lactate. Furthermore, administering mice with L-lactate suppressed colitis induced by dextran sulfate sodium. In conclusion, our study demonstrates that host-derived L-lactate promotes IEC mitochondrial ATP production to drive cell migration, promoting intestinal wound healing to alleviate intestinal inflammation.

Genomic Analysis of Staphylococcus aureus of the Lineage CC130, Including mecC-Carrying MRSA and MSSA Isolates Recovered of Animal, Human, and Environmental Origins

Most methicillin resistant Staphylococcus aureus (MRSA) isolates harboring mecC gene belong to clonal complex CC130. This lineage has traditionally been regarded as animal-associated as it lacks the human specific immune evasion cluster (IEC), and has been recovered from a broad range of animal hosts. Nevertheless, sporadic mecC-MRSA human infections have been reported, with evidence of zoonotic transmission in some cases. The objective of this study was to investigate the whole-genome sequences of 18 S. aureus CC130 isolates [13 methicillin-resistant (mecC-MRSA) and five methicillin-susceptible (MSSA)] from different sequences types, obtained from a variety of host species and origins (human, livestock, wild birds and mammals, and water), and from different geographic locations, in order to identify characteristic markers and genomic features. Antibiotic resistance genes found among MRSA-CC130 were those associated with the SSCmecXI element. Most MRSA-CC130 strains carried a similar virulence gene profile. Additionally, six MRSA-CC130 possessed scn-sak and one MSSA-ST130 had lukMF'. The MSSA-ST700 strains were most divergent in their resistance and virulence genes. The pan-genome analysis showed that 29 genes were present solely in MRSA-CC130 (associated with SCCmecXI) and 21 among MSSA-CC130 isolates (associated with phages). The SCCmecXI, PBP3, GdpP, and AcrB were identical at the amino acid level in all strains, but some differences were found in PBP1, PBP2, PBP4, and YjbH proteins. An examination of the host markers showed that the 3' region of the bacteriophage φ3 was nearly identical to the reference sequence. Truncated hlb gene was also found in scn-negative strains (two of them carrying sak-type gene). The dtlB gene of wild rabbit isolates included novel mutations. The vwbp gene was found in the three MSSA-ST700 strains from small ruminants and in one MSSA-ST130 from a red deer; these strains also carried a scn-type gene, different from the human and equine variants. Finally, a phylogenetic analysis showed that the three MSSA-ST700 strains and the two MSSA-ST130 strains cluster separately from the remaining MRSA-CC130 strains with the etD2 gene as marker for the main lineage. The presence of the human IEC cluster in some mecC-MRSA-CC130 strains suggests that these isolates may have had a human origin.

Propionate Enhances Cell Speed and Persistence to Promote Intestinal Epithelial Turnover and Repair

BACKGROUND AND AIMS

Gut bacteria-derived short-chain fatty acids (SCFAs) play crucial roles in the maintenance of intestinal homeostasis. However, how SCFAs regulate epithelial turnover and tissue repair remain incompletely understood. In this study, we investigated how the SCFA propionate regulates cell migration to promote epithelial renewal and repair.

METHODS

Mouse small intestinal epithelial cells (MSIE) and human Caco-2 cells were used to determine the effects of SCFAs on gene expression, proliferation, migration, and cell spreading in vitro. Video microscopy and single cell tracking were used to assess cell migration kinetically. 5-bromo-2'-deoxyuridine (BrdU) and hydroxyurea were used to assess the effects of SCFAs on migration in vivo. Lastly, an acute colitis model using dextran sulfate sodium (DSS) was used to examine the effects of SCFAs in vivo.

RESULTS

Using video microscopy and single cell tracking, we found that propionate promoted intestinal epithelial cell migration by enhancing cell spreading and polarization, which led to increases in both cell speed and persistence. This novel function of propionate was dependent on inhibition of class I histone deacetylases (HDAC) and GPR43 and required signal transducer and activator of transcription 3 (STAT3). Furthermore, using 5-bromo-2'-deoxyuridine (BrdU) and hydroxyurea in vivo, we found that propionate enhanced cell migration up the crypt-villus axis under homeostatic conditions, while also protecting against ulcer formation in experimental colitis.

CONCLUSION

Our results demonstrate a mechanism by which propionate stimulates cell migration in an HDAC inhibition, GPR43, and STAT3 dependent manner, and suggest that propionate plays an important role in epithelial migration independent of proliferation.

STING controls intestinal homeostasis through promoting antimicrobial peptide expression in epithelial cells

Stimulator of interferon genes (STING) has been shown to play a critical role in orchestrating immune responses to various pathogens through sensing cyclic dinucleotides. However, how STING regulates intestinal homeostasis is still not completely understood. In this study, we found that STING^-/- mice were more susceptible to enteric infection with Citrobacter rodentium compared to wild-type (WT) mice evidenced by more severe intestinal inflammation and impaired bacterial clearance. STING^-/- mice demonstrated lower expression of REG3γ but not β-defensins and Cramp in IECs. Consistently, STING^-/- IECs showed reduced capacity to inhibit bacterial growth. STING agonists, both 10-carboxymethyl-9-acridanone (CMA) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA), promoted REG3γ expression IECs. Furthermore, STING agonists promoted WT but not REG3γ-deficient IEC bacterial killing. Mechanistically, STING agonists activated STAT3 and promoted glycolysis in IECs. Inhibition of STAT3 pathway and glycolysis suppressed STING-induced REG3γ production in IECs, and abrogated STING-mediated IEC killing of C. rodentium. Additionally, treatment with the STING ligand, 2,3-cGAMP, inhibited C. rodentium-induced colitis in vivo. Overall, STING promotes IEC REG3γ expression to inhibit enteric infection and intestinal inflammation, thus, maintaining the intestinal homeostasis.

SIRT2 Contributes to the Regulation of Intestinal Cell Proliferation and Differentiation

BACKGROUND AND AIMS

Intestinal mucosa undergoes a continual process of proliferation, differentiation, and apoptosis. Disruption of this homeostasis is associated with disorders such as inflammatory bowel disease (IBD). We investigated the role of Sirtuin 2 (SIRT2), a NAD-dependent protein deacetylase, in intestinal epithelial cell (IEC) proliferation and differentiation and the mechanism by which SIRT2 contributes to maintenance of intestinal cell homeostasis.

METHODS

IECs were collected from SIRT2-deficient mice and patients with IBD. Expression of SIRT2, differentiation markers (mucin2, intestinal alkaline phosphatase, villin, Na,K-ATPase, and lysozyme) and Wnt target genes (EPHB2, AXIN2, and cyclin D1) was determined by western blot, real-time RT-PCR, or immunohistochemical (IHC) staining. IECs were treated with TNF or transfected with siRNA targeting SIRT2. Proliferation was determined by villus height and crypt depth, and Ki67 and cyclin D1 IHC staining. For studies using organoids, intestinal crypts were isolated.

RESULTS

Increased SIRT2 expression was localized to the more differentiated region of the intestine. In contrast, SIRT2 deficiency impaired proliferation and differentiation and altered stemness in the small intestinal epithelium ex vivo and in vivo. SIRT2-deficient mice showed decreased intestinal enterocyte and goblet cell differentiation but increased the Paneth cell lineage and increased proliferation of IECs. Moreover, we found that SIRT2 inhibits Wnt/β-catenin signaling, which critically regulates IEC proliferation and differentiation. Consistent with a distinct role for SIRT2 in maintenance of gut homeostasis, intestinal mucosa from IBD patients exhibited decreased SIRT2 expression.

CONCLUSION

We demonstrate that SIRT2, which is decreased in intestinal tissues from IBD patients, regulates Wnt-β-catenin signaling and is important for maintenance of IEC proliferation and differentiation.

High prevalence of multidrug resistant S. aureus-CC398 and frequent detection of enterotoxin genes among non-CC398 S. aureus from pig-derived food in Spain

Methicillin-resistant Staphylococcus aureus (MRSA) CC398 is a livestock-associated (LA) lineage, mainly detected in swine. Its dissemination via the food-chain could be a food-safety issue. This work aimed to study the diversity of S. aureus lineages in pork-products, to determine the prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) of lineage CC398, and to study the antimicrobial resistance phenotype/genotype and the virulence traits of recovered isolates. One hundred and one samples of pig-derived food were collected in Northern Spain for S. aureus isolation. Antibiotic resistance profile was analysed, and associated resistance genes were screened by PCR. Detection of CC398 lineage, spa-type, multilocus sequence-type, virulence factors, immune evasion cluster (IEC) genes, and phage ΦSa3 integrase was performed by PCR/sequencing. The prevalence of S. aureus and MRSA among pig-derived food was 33.6% and 21.8%, respectively. Thirty-nine S. aureus isolates were recovered and attributed to 19 spa-types and 12 STs, ST398 being the predominant lineage (n = 25; 64%). MRSA-CC398 isolates (n = 23) were mainly spa-t011 (n = 16) and 82.6% were multidrug-resistant (MDR). All MRSA-CC398 were tetracycline-resistant and IEC-negative and four hosted either eta, tst or sea gene. The two MSSA-CC398 isolates detected were spa-t5452, IEC-positive, and were resistant to penicillin (blaZ) and erythromycin/clindamycin (inducible) (ermT with/without ermC + msrA). Among the 14 non-CC398 isolates, only two were MRSA (ST8, PVL-positive, enterotoxin-positive, IEC-negative). The 12 MSSA isolates included two of lineage CC45 and IEC-positive. CC398 lineage is prevalent among S. aureus of pig-derived food (both MRSA and MSSA), LA-MRSA-CC398/t011 being the clone most represented. The presence of the IEC-positive MSSA-CC398 and MSSA-CC45 isolates in food products highlights the potential implication of handlers in transmission of foodborne pathogens. Moreover, given the high frequency of MDR isolates and virulence genes detected, hygienic practices should be improved to limit the dissemination risk of S. aureus via the food chain.

Prediabetes defined by the International Expert Committee as a risk for development of glomerular hyperfiltration

AIMS

To clarify if prediabetes defined by the International Expert Committee (Prediabetes_IEC) and/or the American Diabetes Society (Prediabetes_ADA) is a risk for incident glomerular hyperfiltration (GH).

METHODS

24,524 health examinees without diabetes, chronic kidney disease (CKD), GH and antihypertensive treatment at baseline, and repeated examinations at least twice during a mean of 5.3 years were retrospectively analysed. Diabetes was defined as fasting plasma glucose (FPG) ≥ 7.0 mmol/L and/or HbA_1c ≥ 47 mmol/mol, CKD by estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or dipstick-positive proteinuria, and GH by upper 95th eGFR in the Japanese adults. Prediabetes_IEC was diagnosed by "HbA_1c 42-46 mmol/mol and/or FPG 6.1-6.9 mmol/L", Prediabetes_ADA by "HbA_1c 39-46 mmol/mol and/or FPG 5.6-6.9 mmol/L", Prediabetes_ADA-IEC for the condition met the ADA but not the IEC prediabetes definition, and the ADA-normal glucose regulation (NGR_ADA) by both HbA_1c and FPG lower than Prediabetes_ADA. Risk of Prediabetes_IEC and Prediabetes_ADA for incident GH was examined by multivariate Cox proportional hazards model with seven covariates and probability of incident GH was calculated on the basis of it.

RESULTS

Prediabetes_IEC was a significant risk for incident GH [adjusted HR 1.91, 95% CI 1.32-2.71] but Prediabetes_ADA was not [adjusted HR 1.22, 95% CI 0.93-1.61]. The mean (SD) probability of incident GH was 2.3 (4.5)%, 1.0 (2.3)% and 1.0 (2.4)% for Prediabetes_IEC, Prediabetes_ADA-IEC and NGR_ADA, respectively: the former was significantly larger than the latter two which were not significantly different from each other.

CONCLUSIONS

Prediabetes_IEC was an independent risk for incident GH.

Diversity of staphylococcal species in food producing animals in Spain, with detection of PVL-positive MRSA ST8 (USA300)

This work aimed to determine the prevalence, diversity, antibiotic-resistance phenotype/genotype and virulence factors in staphylococci of farm-animals. Nasal samples of 117 farm-animals (calve: 72; lamb: 37; goat: 8) were collected from one slaughterhouse in La Rioja/Spain and cultured for staphylococci and methicillin-resistant Staphylococcus (MRS) recovery. Identification was performed by MALDI-TOF. Antimicrobial resistance phenotype/genotype was determined by susceptibility testing and specific PCRs. Molecular typing (spa-typing, multilocus-sequence-typing, agr-typing, SCCmec), and detection of 12 virulence genes and human Immune-evasive-cluster (IEC) genes were performed by PCR/sequencing in S. aureus. Two marker genes of arginine catabolic mobile element (ACME) were determined by PCR (USA300-MRSA detection). Staphylococci were identified in 50%, 54% and 21% of goat, lamb and calve samples, respectively. Among the 13 S. aureus isolates recovered, 11 were susceptible to all antimicrobials tested, and two were multidrug-resistant-MRSA [beta-lactams (blaZ, mecA), macrolides [(msr(A)/msr(B)] and fluoroquinolones]. The MSSA harboured either tst or enterotoxin genes, while the MRSA harboured the lukF/lukS-PV genes. Five sequence-types were detected. The two MRSA strains (from lamb and goat) were typed as t5173/ST8/agr-I/SCCmec-IVa/ACME-positive, corresponding to USA300 clone, and were IEC-B-positive. Among the 47 coagulase-negative staphylococci (CoNS), six species were identified, predominating S. simulans (n = 25) and S. sciuri (n = 11). Fifty-three percent of CoNS showed resistance to at least one antimicrobial agent (six multidrug-resistant strains), and the following resistance phenotypes/genotypes were detected: streptomycin [27.6%; ant(6)-Ia, str], tetracycline [23.4%; tet(M), tet(L), tet(K)], clindamycin [19.1%; lnu(A), vgaA], erythromycin [10.6%; erm(C), msr(A)/msr(B)], chloramphenicol (8.5%; fexA), tobramycin (6.4%), penicillin-cefoxitin (4.3%; blaZ, mecA), and SXT (2.1%). The detection of the MRSA-USA300 lineage in food animals is worrisome and should be further monitored.

Interleukin-33 Promotes REG3γ Expression in Intestinal Epithelial Cells and Regulates Gut Microbiota

BACKGROUND & AIMS

Regenerating islet-derived protein (REG3γ), an antimicrobial peptide, typically expressed by intestinal epithelial cells (IEC), plays crucial roles in intestinal homeostasis and controlling gut microbiota. However, the mechanisms that regulate IEC expression of REG3γ are still largely unclear. In this study, we investigated whether and how interleukin (IL) 33, an alarmin produced by IEC in response to injury, regulates REG3γ expression in IEC, thus contributing to intestinal homeostasis.

METHODS

IEC were isolated from wild-type and IL33^-/- mice to determine expression of REG3γ and other antimicrobial peptides by quantitative real-time polymerase chain reaction and Western blot. IEC cell lines were used for mechanistic studies. 16S rRNA pyrosequencing analysis was used for measuring gut microbiota. Citrobacter rodentium was used for enteric infections.

RESULTS

The expression of REG3γ, but not β-defensins, in IECs of IL33^-/- mice was significantly lower than wild-type mice. IL33 treatment induced IEC expression of REG3γ in both mice and human cell lines. Mechanistically, IL33 activated STAT3, mTOR, and ERK1/2 in IEC. Inhibition of these pathways abrogated IL33-induction of REG3γ. IL33^-/- mice demonstrated higher bacteria loads and altered microbiota composition. IL33 did not directly inhibit bacterial growth, but promoted wild-type, not REG3γKO, IECs to kill bacteria in vitro. Consistently, C rodentium infection induced IEC IL33 expression, and IL33^-/- mice demonstrated an impaired bacterial clearance with C rodentium infection.

CONCLUSIONS

Our study demonstrated that IL33, which is produced by IEC in response to injury and inflammatory stimulation, in turn promotes IEC expression of REG3γ, and controls the gut microbiota of the host.

Intestinal epithelial cell-specific IGF1 promotes the expansion of intestinal stem cells during epithelial regeneration and functions on the intestinal immune homeostasis

It is well known that insulin-like growth factor 1 (IGF1) acts as a trophic factor in small intestine under both physiological and pathophysiological conditions. However, it still lacks direct in vivo evidence of the functions of intestinal epithelial cell (IEC)-specific IGF1 under both normal and pathological conditions. Using IEC-specific IGF1-knockout (cKO) mice and Lgr5-eGFP-CreERT mice, we demonstrate that IEC-specific IGF1 can enhance nutrient uptake, reduce protein catabolism and energy consumption, and promote the proliferation and expansion of intestinal epithelial cells, including intestinal epithelial stem cells and intestinal secretory cells. Next, we showed that IEC-specific IGF1 renders IECs resistant to irradiation and promotes epithelial regeneration. Strikingly, transcriptome profiling assay revealed that many differentially expressed genes involved in the differentiation and maturation of lymphoid lineages were significantly suppressed in the cKO mice as compared with the control mice. We demonstrated that deletion of IGF1 in IECs enhances bacterial translocation to the mesenteric lymph nodes and liver. Furthermore, high-throughput sequencing of 16S ribosomal RNA genes of gut microbiota revealed that IEC-specific IGF1 loss profoundly affected the gut microbial composition at various levels of classification. Therefore, our findings shed light on the in vivo roles of IEC-specific IGF1 in intestinal homeostasis, epithelial regeneration, and immunity, broadening our current insights on IGF1 functions.

MicroRNA-mediated dynamic control of mucosal immunity

The gastrointestinal tract is a complex and important physiological and immunological organ embodying the first line of defense by which mucosal immunity regulates the immense number and diversity of naturally encountered antigens and commensal microflora. Effective microRNA (miRNA) control of transcription factors or mediators in mucosal immunity is essential to host defense and homeostasis in both physiologic and pathologic states. MiRNA biology has advanced our understanding of the immune regulatory system network at the level of post-transcriptional gene modification. Increasing knowledge on circulating miRNAs could potentially enhance diagnostic techniques in inflammatory bowel disease (IBD). Furthermore, recent findings on the dynamic role of exosomes vis-à-vis the intercellular transportation of miRNAs may provide insights on the use of miRNA as a target for treating IBD.

CC398 Staphylococcus aureus subpopulations in Belgian patients

Studies based on genome-wide single nucleotide polymorphisms (SNPs) supported the existence of two subpopulations in clonal complex (CC) 398 Staphylococcus aureus: an ancestral human-adapted clade (HC) and an animal-associated clade (AC). In this study, we have investigated the occurrence of genetic markers that allow discrimination of these subpopulations among CC398 isolates collected during 2014 to 2016 from human patients in Belgium. A collection of isolates was investigated by means of spa-typing and 16S-mecA-nuc PCR. CC398 isolates were classified as belonging to the human or the animal clade by using a canonical SNPs PCR and further studied by antimicrobial susceptibility and the presence of toxins, immune evasion cluster (IEC), and resistance genes. A total of 124 (7.8%) human isolates belonged to CC398. They were grouped into HC (n = 58) or AC (n = 66). The genes erm(T), pvl, chp, and scn were predominantly found in HC-CC398, while AC-CC398 isolates carried more frequently than the mecA, erm(C), tet(K), tet(M), and tet(L) genes. Different combinations of gene profiles were observed according to the clade. CC398 isolates from Belgian patients belonged to different subpopulations including typical HC and AC-isolates. Few HC-strains with mecA and AC-isolates harboring IEC were found. CC398 isolates from Belgian patients belonged to different subpopulations including typical HC and AC-isolates, as well as new emerging subpopulations that underline the ability of this lineage to acquire resistance and virulence genes. Further research is needed to evaluate the emergence of these subpopulations in the clinical setting.

Long Noncoding RNA uc.173 Promotes Renewal of the Intestinal Mucosa by Inducing Degradation of MicroRNA 195

BACKGROUND AND AIMS

The mammalian intestinal epithelium self-renews rapidly and homeostasis is preserved via tightly controlled mechanisms. Long noncoding RNAs transcribed from ultraconserved regions (T-UCRs) control different cell functions, but little is known about their role in maintaining the integrity of the intestinal epithelium. We searched for T-UCRs that regulate growth of the intestinal mucosa and investigated the mechanism by which T-UCR uc.173 regulates epithelial renewal.

METHODS

C57BL/6J mice were deprived of food for 48 hours in fasting experiments. Some mice were given intraperitoneal injections of a plasmid encoding LNA-anti-uc.173, to knock down endogenous uc.173. For studies using organoids, primary enterocytes were isolated from the intestine and transfected with the uc.173 transgene to increase uc.173 levels. Intestinal epithelial cells (Caco-2 and IEC-6 lines) were transfected with LNA-anti-uc.173 or uc.173 transgene. We quantified intestinal epithelial renewal based on BrdU incorporation, villus height and crypt depth, and cell number. The association of uc.173 with microRNA 195 (miRNA195) was determined by RNA pull-down assays.

RESULTS

Genome-wide profile analyses identified 21 T-UCRs, including uc.173, that were differentially expressed between intestinal mucosa of fasted vs non-fasted mice. Increasing levels of uc.173 by expression of a transgene increased growth of intestinal epithelial cells and organoids. Decreasing uc.173 levels by LNA-anti-uc.173 in mice reduced renewal of the intestinal epithelium. We found that uc.173 interacted directly with the primary transcript of miRNA195, leading to miRNA195 degradation.

CONCLUSIONS

In analyses of intestinal epithelial cells and mice, we identified uc.173 noncoding RNA that regulates growth of the intestinal mucosa and stimulates intestinal epithelial renewal by reducing levels of miRNA195.

Horses in Denmark Are a Reservoir of Diverse Clones of Methicillin-Resistant and -Susceptible Staphylococcus aureus

Denmark is a country with high prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) clonal complex (CC) 398 in pigs. Even though pig farming is regarded as the main source of human infection or colonization with MRSA CC398, 10-15% of the human cases appear not to be linked to pigs. Following the recent reports of MRSA CC398 in horses in other European countries and the lack of knowledge on S. aureus carriage in this animal species, we carried out a study to investigate whether horses constitute a reservoir of MRSA CC398 in Denmark, and to gain knowledge on the frequency and genetic diversity of S. aureus in horses, including both methicillin-resistant and -susceptible S. aureus (MSSA). Nasal swabs were collected from 401 horses originating from 74 farms, either at their farms or prior to admission to veterinary clinics. Following culture on selective media, species identification by MALDI-TOF MS and MRSA confirmation by standard PCR-based methods, S. aureus and MRSA were detected in 54 (13%) and 17 (4%) horses originating from 30 (40%) and 7 (9%) farms, respectively. Based on spa typing, MSSA differed genetically from MRSA isolates. The spa type prevalent among MSSA isolates was t127 (CC1), which was detected in 12 horses from 11 farms and represents the most common S. aureus clone isolated from human bacteremia cases in Denmark. Among the 17 MRSA carriers, 10 horses from three farms carried CC398 t011 harboring the immune evasion cluster (IEC), four horses from two farms carried IEC-negative CC398 t034, and three horses from two farms carried a mecC-positive MRSA lineage previously associated with wildlife and domestic ruminants (CC130 t528). Based on whole-genome phylogenetic analysis of the 14 MRSA CC398, t011 isolates belonged to the recently identified horse-adapted clone in Europe and were closely related to human t011 isolates from three Danish equine veterinarians, whereas t034 isolates belonged to pig-adapted clones. Our study confirms that horses carry an equine-specific clone of MRSA CC398 that can be transmitted to veterinary personnel, and reveals that these animals are exposed to MRSA and MSSA clones that are likely to originate from livestock and humans, respectively.

Effective communication approaches in tuberculosis control: Health workers' perceptions and experiences

BACKGROUND

Health workers' experiences and understanding of the myths, misconceptions, beliefs about TB, and patients in the community (and effective communication methods) can be useful in designing effective IEC materials and strategies.

OBJECTIVE

To study the perceptions and experiences of health workers regarding TB disease, patients, and effective communication strategies in TB control.

METHODS

A survey was conducted among health workers involved in Directly Observed Treatment Short (DOTS) course. Data regarding general health beliefs, prevalent myths and misconceptions about TB in their respective localities, knowledge level among patients, and utilization of various communication strategies were collected.

RESULTS

There is a significant increase in knowledge about TB during DOTS among patients, as observed by about half of the health workers. TB patients are aware about how TB spreads to others and their responsibilities. Regular interaction with patients is required for treatment adherence. Two thirds of the health workers believe that media-mix strategy can be very effective in creating awareness among the patients as well as the public. Health workers realized that the video player facility on their mobile phones is useful for showing health-related videos.

CONCLUSION

A combination of mass media and interpersonal communication could be effective for TB control. Face-to-face communication with community members, patient-provider discussions, and information through television could be very effective techniques. Exclusive communication materials should be designed for family members of the patients. Smart phones can be used for effective implementation of TB control programs.

Biphasic Ccl20 regulation by Toll-like receptor 9 through the activation of ERK-AP-1 and non-canonical NF-κB signaling pathways

BACKGROUND

Chemokines play key roles in immune homeostasis and inflammatory response. Considering the role of Ccl20 and Toll-like receptor 9 (TLR9) in gut homeostasis and inflammatory bowel disease (IBD), regulation of Ccl20 by bacterial DNA, the TLR9 ligand, merits in-depth studies.

METHODS

We analyzed Ccl20 expression in various epithelial cell (EC) lines by q-PCR and ELISA. In-vivo expression was investigated in isolated murine colonocytes by immunoblotting. Transcriptional regulation of Ccl20 was studied by reporter assays, gene knock-down, electrophoretic mobility shift assay and chromatin immunoprecipitation. Activation of upstream kinases was checked by immunoblotting.

RESULTS

We showed low levels of Ccl20 expression in mouse colonic ECs, but marked induction by in vivo treatment with bacterial DNA. This corroborated with persistent Ccl20 induction in different EC lines. We found involvement of MAP-kinases during the early hours after stimulation, and a novel AP-1site (-252bp) regulated the expression in colonic ECs. More importantly, mutually exclusive transcriptional regulation by AP-1 (cjun/cfos) and non-canonical NF-κB (RelB/p52) downstream of MEK-ERK and NIK-IKK-α-NF-κB2 (p100) phosphorylation, respectively was responsible for persistent Ccl20 expression in the colonic cells, while canonical NF-κB isoforms played no role.

CONCLUSIONS

Persistent Ccl20 induction by TLR9 in colonic ECs involves early and delayed activation of two independent signaling pathways. This is the first report of non-canonical NF-κB activation and Ccl20 expression in the colonic ECs by TLR9.

GENERAL SIGNIFICANCE

Our study will help to better understand immune regulation by Ccl20 in the intestine and may be exploited for future development of novel therapeutics against IBD.

Numerically simulated exposure of children and adults to pulsed gradient fields in MRI

PURPOSE

To determine exposure to gradient switching fields of adults and children in a magnetic resonance imaging (MRI) scanner by evaluating internal electric fields within realistic models of adult male, adult female, and child inside transverse and longitudinal gradient coils, and to compare these results with compliance guidelines.

MATERIALS AND METHODS

Patients inside x-, y-, and z-gradient coils were simulated using anatomically realistic models of adult male, adult female, and child. The induced electric fields were computed for 1 kHz sinusoidal current with a magnitude of 1 A in the gradient coils. Rheobase electric fields were then calculated and compared to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) 2004 and International Electrotechnical Commission (IEC) 2010 guidelines. The effect of the human body, coil type, and skin conductivity on the induced electric field was also investigated.

RESULTS

The internal electric fields are within the first level controlled operating mode of the guidelines and range from 2.7V m^-1 to 4.5V m^-1 , except for the adult male inside the y-gradient coil (induced field reaches 5.4V m^-1 ).The induced electric field is sensitive to the coil type (electric field in the skin of adult male: 4V m^-1 , 4.6V m^-1 , and 3.8V m^-1 for x-, y-, and z-gradient coils, respectively), the human body model (electric field in the skin inside y-gradient coil: 4.6V m^-1 , 4.2V m^-1 , and 3V m^-1 for adult male, adult female, and child, respectively), and the skin conductivity (electric field 2.35-4.29% higher for 0.1S m^-1 skin conductivity compared to 0.2S m^-1 ).

CONCLUSION

The y-gradient coil induced the largest fields in the patients. The highest levels of internal electric fields occurred for the adult male model. J. Magn. Reson. Imaging 2016;44:1360-1367.

Mechanisms of Microbe-Host Interaction in Crohn's Disease: Dysbiosis vs. Pathobiont Selection

Crohn’s disease (CD) is a systemic chronic inflammatory condition mainly characterized by discontinuous transmural pathology of the gastrointestinal tract and frequent extraintestinal manifestations with intermittent episodes of remission and relapse. Genome-wide association studies identified a number of risk loci that, catalyzed by environmental triggers, result in the loss of tolerance toward commensal bacteria based on dysregulated innate effector functions and antimicrobial defense, leading to exacerbated adaptive immune responses responsible for chronic immune-mediated tissue damage. In this review, we discuss the inter-related role of changes in the intestinal microbiota, epithelial barrier integrity, and immune cell functions on the pathogenesis of CD, describing the current approaches available to investigate the molecular mechanisms underlying the disease. Substantial effort has been dedicated to define disease-associated changes in the intestinal microbiota (dysbiosis) and to link pathobionts to the etiology of inflammatory bowel diseases. A cogent definition of dysbiosis is lacking, as well as an agreement of whether pathobionts or complex shifts in the microbiota trigger inflammation in the host. Among the rarely available animal models, SAMP/Yit and TNF^deltaARE mice are the best known displaying a transmural CD-like phenotype. New hypothesis-driven mouse models, e.g., epithelial-specific Caspase8^−/−, ATG16L1^−/−, and XBP1^−/− mice, validate pathway-focused function of specific CD-associated risk genes highlighting the role of Paneth cells in antimicrobial defense. To study the causal role of bacteria in initiating inflammation in the host, the use of germ-free mouse models is indispensable. Unraveling the interactions of genes, immune cells and microbes constitute a criterion for the development of safe, reliable, and effective treatment options for CD.

Socio-cultural features and help-seeking preferences for leprosy and turbeculosis: a cultural epidemiological study in a tribal district of Maharashtra, India

Background

India is a major contributor to the global burden of leprosy and tuberculosis (TB), which adversely affects the poorest tribal communities. Despite prioritisation by disease control programmes, programme performance for leprosy and TB in tribal communities continues to be a challenge. In addition to access to services and infrastructural limitations, socio-cultural concepts of illness causation and related help seeking (HS) rooted in distinct features of tribal culture need to be addressed to improve programme outcomes.

Methods

A cultural epidemiological survey of leprosy and TB patients was carried out using a locally adapted, semi-structured explanatory model interviews. A total of 100 leprosy and 50 TB patients registered for treatment at government health facilities were selected randomly from tribal dominant blocks of the Thane district, Maharashtra state. The perceived causes (PCs) of leprosy and TB in patients were compared based on prominence categories. The relationship between PCs as predictors, and disease conditions and HS preferences as outcome variables were assessed using multivariate logistic regression.

Results

In the multivariate logistic regression model with disease conditions as outcome variables, TB patients were significantly more likely to report PCs in the categories of ingestion; health, illness and injury; and traditional, cultural and supernatural. Tuberculosis patients more frequently first sought help from private facilities as compared to leprosy patients who preferred government health facilities. In a combined analysis of leprosy and TB patients employing multivariate logistic regression, it was found that patients who reported PCs in the environmental and contact-related categories were more likely to visit traditional rather than non-traditional practitioners. In another multivariate combined model, it was found that patients who reported PCs in the traditional, cultural and supernatural category were significantly more likely to visit private rather than public health facilities.

Conclusion

Cultural concepts about illness causation and associated HS behaviours should be considered as priorities for action, which in turn would provide the necessary impetus to ensure that tribal patients seek help in a timely and appropriate manner, and could facilitate improvement in programme performance in general.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-015-0064-y) contains supplementary material, which is available to authorized users.

[Hypertension in scleroderma: A vital emergency]

PURPOSE

In systemic sclerosis, hypertension is feared because it is often heralding severe renal impairment. The objective of our study was to identify the frequency of arterial hypertension and clarify its etiologies in this condition.

PATIENTS/METHODS

Our study was prospective. From January 2008 to May 2012, we have included all patients over the age of 16 years which featured a systemic scleroderma meeting the criteria for classification of Leroy and Medsger modified. Blood pressure was systematic and hypertension was defined as a greater than 140/90 mmHg PAS/PAD.

RESULTS

We have collected 60 patients. It was 50 women and 10 men with an average age of 41.1 ans ± 13.03. Arterial hypertension was noted in sixteen patients (26.7%) with an average age of 48.8 years ± 13.21. It was nine diffuse cutaneous systemic scleroderma of six limited cutaneous scleroderma and one case of scleroderma sine scleroderma. Etiologic research hypertension had concluded to a renal cause in 12 patients. It was five scleroderma renal crisis (SRC), three vascular nephropathies, four chronic kidney failure (CKD) including three terminals and a moderate CKD. An 'essential' so-called HTA was observed in four patients. Hypertension was a major sign that reported five cases of SRC. These patients had received treatment anti hypertensive and renal extra cleansing.

DISCUSSION

Hypertension is common in systemic scleroderma. Our data approximates of literature when its frequency and severity.

CONCLUSION

Hypertension is a major warning sign that under no circumstances should overlook it or novo or secondary aggravation. Its support must be very early under penalty to put at stake the life-threatening in particular during the CRS.

High prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carrying the mecC gene in a semi-extensive red deer (Cervus elaphus hispanicus) farm in Southern Spain

The objective was to determine the prevalence of Staphylococcus aureus nasal carriage in red deer of a semi-extensive farm and in humans in contact with the estate animals, and to characterize obtained isolates. Nasal swabs of 65 deer and 15 humans were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base. Isolates were identified by microbiological and molecular methods. Antimicrobial susceptibility profile was determined for 16 antibiotics by disk-diffusion and the presence of eight antibiotic resistance genes, seven virulence genes and genes of immune-evasion-cluster (IEC) was analyzed by PCR. S. aureus was typed by PFGE-SmaI, spa, agr, SCCmec and MLST. Isolates were detected in 16 deer (24.6%). Eleven S. aureus isolates were methicillin-resistant (MRSA), and five were methicillin-susceptible (MSSA). All MRSA harbored mecC gene and were agr-III/SCCmecXI/ST1945 (four spa-t843 and seven spa-t1535). All mecC-MRSA carried blaZ-SCCmecXI and etd2, were IEC-type-E, and belonged to the same PFGE pattern. The five MSSA were typed as spa-t2420/agr-I/ST133. Regarding humans, S. aureus was recovered from six samples (40%). The isolates were MSSA and were typed as spa-t002/agr-II, spa-t012/agr-III or spa-t822/agr-III and showed different IEC types (A, B, D and F). blaZ and erm(A) genes were detected, as well as cna and tst genes. As conclusion, red deer analyzed in this study are frequent carriers of mecC-MRSA CC130 (16.9%), they are characterized by few resistance and virulence determinants, and by the presence of IEC type-E. Deer could be a source of mecC-MRSA which could potentially be transmitted to other animals, or even to humans.

Crohn's disease-associated adherent invasive Escherichia coli modulate levels of microRNAs in intestinal epithelial cells to reduce autophagy

BACKGROUND & AIMS

Levels of microRNAs are altered in intestinal tissues of patients with Crohn's disease (CD). The adherent-invasive Escherichia coli (AIEC), which colonize the ileal mucosa of patients with CD, adhere to and invade intestinal epithelial cells. We investigated the mechanism by which AIEC infection alters the expression of microRNAs and the host immune response.

METHODS

Levels of microRNAs in human intestinal epithelial T84 cells and in mouse enterocytes were measured using quantitative reverse-transcription polymerase chain reaction. Luciferase assays were used to measure binding of microRNAs to the 3'-untranslated region of messenger RNA targets. Binding of nuclear factor-κB to promoters of genes encoding microRNAs was assessed by chromatin immunoprecipitation assays. Autophagy was measured by immunoblot analyses and immunofluorescent labeling of LC3. Anti-microRNAs were transferred to mice using ileal loops. Biopsy specimens from the terminal ileum of patients with ulcerative colitis (n = 20), CD (n = 20), or individuals without inflammatory bowel disease undergoing surveillance colonoscopies (controls, n = 13) were collected during endoscopic examination.

RESULTS

AIEC infection up-regulated levels of microRNA (MIR) 30C and MIR130A in T84 cells and in mouse enterocytes by activating nuclear factor-κB. Up-regulation of these microRNAs reduced the levels of ATG5 and ATG16L1 and inhibited autophagy, leading to increased numbers of intracellular AIEC and an increased inflammatory response. In ileal biopsy samples of patients with CD, there was an inverse correlation between levels of MIR30C and MIR130A and those of ATG5 and ATG16L1, supporting in vitro findings. Inhibition of MIR30C and MIR130A in cultured intestinal epithelial cells and in mouse enterocytes blocked AIEC-induced inhibition of ATG5 and ATG16L1 expression and restored functional autophagy. This resulted in more effective clearance of intracellular AIEC and reduced AIEC-induced inflammation.

CONCLUSIONS

Infection with AIEC up-regulates microRNAs to reduce expression of proteins required for autophagy and autophagy response in intestinal epithelial cells. Ileal samples from patients with CD have increased levels of these same microRNAs and reduced levels of ATG5 and ATG16L1.

Cellular FLICE-like inhibitory protein secures intestinal epithelial cell survival and immune homeostasis by regulating caspase-8

BACKGROUND & AIMS

The intestinal epithelium generates a barrier that protects mammals from potentially harmful intestinal contents, such as pathogenic bacteria. Dysregulation of epithelial cell death has been implicated in barrier dysfunction and in the pathogenesis of intestinal inflammation. We investigated mechanisms of cell-death regulation in the intestinal epithelium of mice.

METHODS

Conditional knockout mice (either inducible or permanent) with deletion of cellular FLICE-inhibitory protein (cFlip) or caspase-8 in the intestinal epithelium were analyzed by histology and high-resolution endoscopy. We assessed the effects of cFlip or caspase-8 deficiency on intestinal homeostasis.

RESULTS

Expression of cFlip in the intestinal epithelium was required for constitutive activation of caspase-8 under steady-state conditions. Intestinal expression of cFlip was required for development; disruption of the gene encoding cFlip from the intestinal epithelium (cFlip(fl/fl) VillinCre(+) mice) resulted in embryonic lethality. When cFlip was deleted from the intestinal epithelium of adult mice (cFlip(iΔIEC) mice), the animals died within a few days from severe tissue destruction, epithelial cell death, and intestinal inflammation. Death of cFlip-depleted intestinal epithelial cells was regulated extrinsically and required the presence of death receptor ligands, such as tumor necrosis factor-α and CD95 ligand, but was independent of receptor-interacting protein 3. cFlip deficiency was associated with strong up-regulation of caspase-8 and caspase-3 activity and excessive apoptosis in intestinal crypts.

CONCLUSIONS

cFlip is required for intestinal tissue homeostasis in mice. It controls the level of activation of caspase-8 to promote survival of intestinal epithelial cells.

Do-it-yourself histidine-tagged bovine enterokinase: a handy member of the protein engineer's toolbox

Enterokinase, a two-chain duodenal serine protease, activates trypsinogen by removing its N-terminal propeptide. Due to a clean cut after the non-primed site recognition sequence, the enterokinase light chain is frequently employed in biotechnology to separate N-terminal affinity tags from target proteins with authentic N-termini. In order to obtain large quantities of this protease, we adapted an in vitro folding protocol for a pentahistidine-tagged triple mutant of the bovine enterokinase light chain. The purified, highly active enzyme successfully processed recombinant target proteins, while the pentahistidine-tag facilitated post-cleavage removal. Hence, we conclude that producing enterokinase in one's own laboratory is an efficient alternative to the commercial enzyme.

Hanging drop: an in vitro air toxic exposure model using human lung cells in 2D and 3D structures

Using benzene as a candidate air toxicant and A549 cells as an in vitro cell model, we have developed and validated a hanging drop (HD) air exposure system that mimics an air liquid interface exposure to the lung for periods of 1h to over 20 days. Dose response curves were highly reproducible for 2D cultures but more variable for 3D cultures. By comparing the HD exposure method with other classically used air exposure systems, we found that the HD exposure method is more sensitive, more reliable and cheaper to run than medium diffusion methods and the CULTEX(®) system. The concentration causing 50% of reduction of cell viability (EC50) for benzene, toluene, p-xylene, m-xylene and o-xylene to A549 cells for 1h exposure in the HD system were similar to previous in vitro static air exposure. Not only cell viability could be assessed but also sub lethal biological endpoints such as DNA damage and interleukin expressions. An advantage of the HD exposure system is that bioavailability and cell concentrations can be derived from published physicochemical properties using a four compartment mass balance model. The modelled cellular effect concentrations EC50cell for 1h exposure were very similar for benzene, toluene and three xylenes and ranged from 5 to 15 mmol/kgdry weight, which corresponds to the intracellular concentration of narcotic chemicals in many aquatic species, confirming the high sensitivity of this exposure method.

Exopolysaccharides of Synechocystis aquatilis are sulfated arabinofucans containing N-acetyl-fucosamine

Cyanobacteria are known to be a rather diverse group of organisms regarding e.g. morphology, metabolism and composition of excreted exopolysaccharides (EPS). Considering the high number of known cyanobacterial species the EPS from only a small percentage are investigated in detail. This work examined EPS from the unicellular strains of Synechocystis aquatilis and S. pevalekii with various methods. The results emphasize the heterogeneity of cyanobacterial EPS. S. pevalekii secrets complex hetero-polysaccharides and acidic proteins as proteoglycan-complexes whereas the protein-free but highly sulfated EPS from S. aquatilis only consist of 4 dominant monosaccharides. Especially remarkable is the composition of these EPS: an arabinofucan with higher amounts of N-acetyl-fucosamine (FucNAc) and only minor quantities of glucose. Both EPS and the newly found component FucNAc in EPS from S. aquatilis extend the possible components of cyanobacterial EPS and the knowledge of heterogeneity of cyanobacterial metabolites.

Chitin-binding domains of Escherichia coli ChiA mediate interactions with intestinal epithelial cells in mice with colitis

BACKGROUND & AIMS

Inducible chitinase 3-like-1 is expressed by intestinal epithelial cells (IECs) and adheres to bacteria under conditions of inflammation. We performed a structure-function analysis of the chitin-binding domains encoded by the chiA gene, which mediates the pathogenic effects of adherent invasive Escherichia coli (AIEC).

METHODS

We created AIEC (strain LF82) with deletion of chiA (LF82-ΔchiA) or that expressed chiA with specific mutations. We investigated the effects of infecting different IEC lines with these bacteria compared with nonpathogenic E coli; chitinase activities were measured using the colloidal chitin-azure method. Colitis was induced in C57/Bl6 mice by administration of dextran sodium sulfate, and mice were given 10(8) bacteria for 15 consecutive days by gavage. Stool/tissue samples were collected and analyzed.

RESULTS

LF82-ΔchiA had significantly less adhesion to IEC lines than LF82. Complementation of LF82-ΔchiA with the LF82 chiA gene, but not chiA from nonpathogenic (K12) E coli, increased adhesion. We identified 5 specific polymorphisms in the chitin-binding domain of LF82 chiA (at amino acids 362, 370, 378, 388, and 548) that differ from chiA of K12 and were required for LF82 to interact directly with IECs. This interaction was mediated by an N-glycosylated asparagine in chitinase 3-like-1 (amino acid 68) on IECs. Mice infected with LF82, or LF82-ΔchiA complemented with LF82 chiA, developed more severe colitis after administration of dextran sodium sulfate than mice infected with LF82-ΔchiA or LF82 that expressed mutant forms of chiA.

CONCLUSIONS

AIEC adheres to an N-glycosylated chitinase 3-like-1 on IECs via the chitin-binding domain of chiA. This mechanism promotes the pathogenic effects of AIEC in mice with colitis.

Cardiac resynchronization therapy allows the optimization of medical treatment in heart failure patients

AIM

Cardiac resynchronization therapy (CRT) is recommended for selected patients with advanced heart failure (HF) despite optimal medical treatment. However, the doses of pharmaceuticals in this population are often limited by adverse effects. We compared the drug regimens of 21 patients before and 6 months after they underwent the implantation CRT systems.

METHODS

We studied 17 men and four women (mean age=63.4 ± 11 years) presenting in New York Heart Association HF classes III-IV, and with a left ventricular ejection fraction (LVEF) ≤ 35% and cardiac dyssynchrony, who underwent implantation of CRT systems.

RESULTS

At baseline, 52% of patients were treated with β-adrenergic blockers (β-B), though in optimal doses in only 19%. The introduction of (β-B) was complicated by cardiogenic shock in three patients. At baseline, all patients were treated with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), of whom 76% received optimal doses. After 6 months of CRT, β-B were administered to 76% of patients, in optimaklon ACE or ARB but 75% of them were receiving maximal doses. After 6 months of CRT, β blockers have been introduced in 72% of patients and maximal doses have been achieved in 60% of them. Maximal doses of ACE or ARB were reached in 95% of the study population. We noticed that systolic blood pressure was higher after implantation. There was also a significant improvement in functional status and left ventricular ejection fraction compared to baseline.

CONCLUSION

CRT is an efficacious adjunctive device therapy to standard medical therapy for patients with heart failure and cardiac dyssynchrony. Its benefits are in addition to those afforded by standard pharmacological therapy. Achieving maximal doses of medical treatment and the possibility of introducing β blockers after CRT prove that CRT and pharmacological treatment are complementary strategies and should not be considered as competitive.

Isolation and characterization of intestinal stem cells based on surface marker combinations and colony-formation assay

BACKGROUND & AIMS

Identification of intestinal stem cells (ISCs) has relied heavily on the use of transgenic reporters in mice, but this approach is limited by mosaic expression patterns and difficult to directly apply to human tissues. We sought to identify reliable surface markers of ISCs and establish a robust functional assay to characterize ISCs from mouse and human tissues.

METHODS

We used immunohistochemistry, real-time reverse-transcription polymerase chain reaction, and fluorescence-activated cell sorting (FACS) to analyze intestinal epithelial cells isolated from mouse and human intestinal tissues. We compared different combinations of surface markers among ISCs isolated based on expression of Lgr5-green fluorescent protein. We developed a culture protocol to facilitate the identification of functional ISCs from mice and then tested the assay with human intestinal crypts and putative ISCs.

RESULTS

CD44(+)CD24(lo)CD166(+) cells, isolated by FACS from mouse small intestine and colon, expressed high levels of stem cell-associated genes. Transit-amplifying cells and progenitor cells were then excluded based on expression of GRP78 or c-Kit. CD44(+)CD24(lo)CD166(+) GRP78(lo/-) putative stem cells from mouse small intestine included Lgr5-GFP(hi) and Lgr5-GFP(med/lo) cells. Incubation of these cells with the GSK inhibitor CHIR99021 and the E-cadherin stabilizer Thiazovivin resulted in colony formation by 25% to 30% of single-sorted ISCs.

CONCLUSIONS

We developed a culture protocol to identify putative ISCs from mouse and human tissues based on cell surface markers. CD44(+)CD24(lo)CD166(+), GRP78(lo/-), and c-Kit(-) facilitated identification of putative stem cells from the mouse small intestine and colon, respectively. CD44(+)CD24(-/lo)CD166(+) also identified putative human ISCs. These findings will facilitate functional studies of mouse and human ISCs.

Extraction, chemical characterization and biological activity determination of broccoli health promoting compounds

Broccoli (Brassica oleracea L. var. Italica) contains substantial amount of health-promoting compounds such as vitamins, glucosinolates, phenolic compounds, and dietary essential minerals; thus, it benefits health beyond providing just basic nutrition, and consumption of broccoli has been increasing over the years. This review gives an overview on the extraction and separation techniques, as well as the biological activity of some of the above mentioned compounds which have been published in the period January 2008 to January 2013. The work has been distributed according to the different families of health promoting compounds discussing the extraction procedures and the analytical techniques employed for their characterization. Finally, information about the different biological activities of these compounds has been also provided.

ER stress-induced cell death mechanisms

The endoplasmic-reticulum (ER) stress response constitutes a cellular process that is triggered by a variety of conditions that disturb folding of proteins in the ER. Eukaryotic cells have developed an evolutionarily conserved adaptive mechanism, the unfolded protein response (UPR), which aims to clear unfolded proteins and restore ER homeostasis. In cases where ER stress cannot be reversed, cellular functions deteriorate, often leading to cell death. Accumulating evidence implicates ER stress-induced cellular dysfunction and cell death as major contributors to many diseases, making modulators of ER stress pathways potentially attractive targets for therapeutics discovery. Here, we summarize recent advances in understanding the diversity of molecular mechanisms that govern ER stress signaling in health and disease. This article is part of a Special Section entitled: Cell Death Pathways.

Involvement of JAK/STAT signaling in the pathogenesis of inflammatory bowel disease

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway constitute the fulcrum in many vital cellular processes, including cell growth, differentiation, proliferation, and regulatory immune functions. Various cytokines, growth factors, and protein tyrosine kinases communicate through the JAK/STAT pathway and regulate the transcription of numerous genes. In addition to their critical roles in a plethora of key cellular activities, the JAK/STAT signaling pathways also have been implicated in the pathogenesis of several diseases, including inflammatory bowel disease (IBD), especially since a JAK inhibitor recently has been shown to be effective in the treatment of ulcerative colitis. The aim of this review is to highlight the recent findings on the regulatory mechanism of JAK/STAT signaling pathways and to reveal the evolving comprehension of their interface which might be of interest for clinicians involved in IBD therapy. Further, it is described how these signaling pathways have been exploited for the development of promising novel JAK inhibitors with anti-inflammatory effects verified in clinical trials.

Template protocol for clinical trials investigating vaccines--focus on safety elements

This document is intended as a guide to the protocol development for trials of prophylactic vaccines. The template may serve phases I-IV clinical trials protocol development to include safety relevant information as required by the regulatory authorities and as deemed useful by the investigators. This document may also be helpful for future site strengthening efforts.

Information, Education, and Communication Services in MCH Care Provided at an Urban Health Center

Background:

Regular IEC programs during antenatal and intranatal period, through individual or group approach, brings desirable changes in health practices of people, resulting in a healthy mother and a healthy baby.

Materials and Methods:

This study was conducted to assess the level of IEC services regarding pregnancy and child care, received by the women at an MCH clinic of an urban health center, where the study subjects comprised 400 antenatal (AN) and postnatal (PN) women and mothers of children under five years.

Results:

Warning signs of danger was explained to only 10% of the AN and PN women. Advice regarding family planning appeared to be the most frequently covered, though that too was explained to less than half of the subjects. About one third of the women were advised on breast feeding. Only 8% of the mothers had been told about all issues regarding pregnancy and child care. Breast feeding and weaning was properly explained to 85.7 and 81.1% of the total mothers of U5 children. Advice regarding subsequent nutrition was given to 60.9% of mothers. About only a quarter of the total mothers were advised on home management of diarrhea and acute respiratory infections. Very few mothers were counseled about the growth pattern of the children and none were shown the growth chart. Only 12.9% of the mothers were informed about all issues.

Conclusion:

IEC regarding maternal and child care other than feeding practices is a neglected service in the health facility where the study was conducted.