Zinc inhibits lethal inflammatory shock by preventing microbe-induced interferon signature in intestinal epithelium

The cytokine TNF drives inflammatory diseases, e.g., Crohn's disease. In a mouse model of TNF-induced systemic inflammatory response syndrome (SIRS), severe impact on intestinal epithelial cells (IECs) is observed. Zinc confers complete protection in this model. We found that zinc no longer protects in animals which lack glucocorticoids (GCs), or express mutant versions of their receptor GR in IECs, nor in mice which lack gut microbiota. RNA-seq studies in IECs showed that zinc caused reduction in expression of constitutive (STAT1-induced) interferon-stimulated response (ISRE) genes and interferon regulatory factor (IRF) genes. Since some of these genes are involved in TNF-induced cell death in intestinal crypt Paneth cells, and since zinc has direct effects on the composition of the gut microbiota (such as several Staphylococcus species) and on TNF-induced Paneth cell death, we postulate a new zinc-related anti-inflammatory mechanism. Zinc modulates the gut microbiota, causing less induction of ISRE/IRF genes in crypt cells, less TNF-induced necroptosis in Paneth cells, and less fatal evasion of gut bacteria into the system.

Tapping into the maize root microbiome to identify bacteria that promote growth under chilling conditions

BACKGROUND

When maize (Zea mays L.) is grown in the Northern hemisphere, its development is heavily arrested by chilling temperatures, especially at the juvenile phase. As some endophytes are beneficial for plants under stress conditions, we analyzed the impact of chilling temperatures on the root microbiome and examined whether microbiome-based analysis might help to identify bacterial strains that could promote growth under these temperatures.

RESULTS

We investigated how the maize root microbiome composition changed by means of 16S rRNA gene amplicon sequencing when maize was grown at chilling temperatures in comparison to ambient temperatures by repeatedly cultivating maize in field soil. We identified 12 abundant and enriched bacterial families that colonize maize roots, consisting of bacteria recruited from the soil, whereas seed-derived endophytes were lowly represented. Chilling temperatures modified the root microbiome composition only slightly, but significantly. An enrichment of several chilling-responsive families was detected, of which the Comamonadaceae and the Pseudomonadaceae were the most abundant in the root endosphere of maize grown under chilling conditions, whereas only three were strongly depleted, among which the Streptomycetaceae. Additionally, a collection of bacterial strains isolated from maize roots was established and a selection was screened for growth-promoting effects on juvenile maize grown under chilling temperatures. Two promising strains that promoted maize growth under chilling conditions were identified that belonged to the root endophytic bacterial families, from which the relative abundance remained unchanged by variations in the growth temperature.

CONCLUSIONS

Our analyses indicate that chilling temperatures affect the bacterial community composition within the maize root endosphere. We further identified two bacterial strains that boost maize growth under chilling conditions. Their identity revealed that analyzing the chilling-responsive families did not help for their identification. As both strains belong to root endosphere enriched families, visualizing and comparing the bacterial diversity in these communities might still help to identify new PGPR strains. Additionally, a strain does not necessarely need to belong to a high abundant family in the root endosphere to provoke a growth-promoting effect in chilling conditions. Video abstract.

Association of nationality and education with oral health: a screening programme in Northern Italy

Background

Socioeconomic status (SES) has been proposed as an important determinant of oral health outcomes. The aim of this project is to assess the association between nationality, parents’ educational level and oral health in a sample of children in Udine, Italy.

Methods

Between February and May 2018, in the context of a screening programme carried out to evaluate the oral health status in 6-year-old children, parents filled out a questionnaire investigating behavioural, socioeconomic and demographical factors. For each child the number of decayed, missing and filled deciduous teeth (dmft) and caries prevalence (CP) were assessed.

Results

The screening was conducted on 976 children, 705 (72%) Italian (I) and 271 (28%) foreign residents (F). Not-Italian nationality significantly increased the CP (F: 59.32%; I: 32.74%; RR: 1.81 [95% CI: 1.57-2.10]; Risk Difference: 26.59 [95% CI: 19.98-33.19]) and dmft median value (F: 2±5; I:0±1; p < 0.0001). Stratified by level of education, the differences between I and F were significant when both parents had low educational level (CP: RR = 1.62 [95%; CI: 1.00-2.62]; dmft: F = 5±5; I = 0±3; p < 0.05) and when both parents had high school education (CP: RR = 1.45 [95%; CI: 1.14-1.84]; dmft: F = 2±6; I = 0±2; p < 0.001). Otherwise, when both parents had university degree, nationality did not increase significantly the outcome (CP: RR = 1.17 [95%; CI: 0.91-1.50; p > 0.1]; dmft: F = 0±2; I = 0±0; p > 0.1).

Conclusions

The analyses suggest that being a foreign resident is a risk factor for lower child oral health. Moreover, parents’ educational level seems to be an effect modifier: when parents had a university degree there was no significant difference between Italians and foreign residents, otherwise the lower the level of education, the greater the difference between the categories. These data may help to identify particularly vulnerable groups and to develop preventive strategies.

Key messages

These findings confirmed the presence of a vulnerable population (foreign residents) in which socioeconomic factors had stronger associations to oral health than Italian citizens. Further research may be useful to identify both protective and risk factors associated with different nationality, in order to evaluate specific interventions in low-SES groups.

Commensal microbiota influence systemic autoimmune responses

Antinuclear antibodies are a hallmark feature of generalized autoimmune diseases, including systemic lupus erythematosus and systemic sclerosis. However, the processes underlying the loss of tolerance against nuclear self-constituents remain largely unresolved. Using mice deficient in lymphotoxin and Hox11, we report that approximately 25% of mice lacking secondary lymphoid organs spontaneously develop specific antinuclear antibodies. Interestingly, we find this phenotype is not caused by a defect in central tolerance. Rather, cell-specific deletion and in vivo lymphotoxin blockade link these systemic autoimmune responses to the formation of gut-associated lymphoid tissue in the neonatal period of life. We further demonstrate antinuclear antibody production is influenced by the presence of commensal gut flora, in particular increased colonization with segmented filamentous bacteria, and IL-17 receptor signaling. Together, these data indicate that neonatal colonization of gut microbiota influences generalized autoimmunity in adult life.

Treatment of patients with arthrosis of the temporomandibular joint by infiltration of sodium hyaluronate: a preliminary study

Patients with degenerative disease of the temporomandibular joint (TMJ) who did not respond to conservative medical therapy (splint therapy, selected grinding or physiotherapy) can be treated by arthrocentesis, which is associated with intra-articular injections of sodium hyaluronate (Hyalgan). In this study, we treated ten dysfunctional patients with degenerative joint disease (DJD) who had been diagnosed clinically and had had the diagnosis confirmed by MRI. All subjects presented impaired mouth opening, joint pain at rest and on movement and impaired masticatory efficiency. We performed one cycle of five infiltrations with joint arthrocentesis and the injection of sodium hyaluronate at weekly intervals. The following parameters were assessed before and after infiltration and at follow-up after 6 months: mouth opening (with a mean of between 36.5 mm and 41.9 mm); sideways movements (to the right 4.9 mm to 8.9 mm and to the left 4.7 mm to 9.2 mm); pain at rest (VAS=1.8 to 0.5) and on movement (VAS=7.8 to 1.1); masticatory efficiency (VAS=5.7 to 8.6); subjective judgement of the functional TMJ limitation level (from 2.8 to 0.8); judgement of efficacy (from 2.4 to 3.2); judgement of tolerability to the therapy (from 2.0 to 3.1). The therapeutic benefits observed can be attributed both to joint arthrocentesis and to the characteristics of sodium hyaluronate itself. All the parameters considered revealed a statistically significant positive variation that persisted over time ( P<0.05). The results obtained by this minimally invasive, fast and easy technique proved to be valid and lasting. This infiltration technique using sodium hyaluronate looks very promising for patients affected by symptomatic DJD who do not respond to conservative medical therapy, reflecting similarly encouraging findings in the orthopaedic treatment of degenerative knee pathology.

[Treatment of temporo-mandibular joint closed-lock using intra-articular injection of mepivacaine with immediate resolution durable in time (six months follow-up)]

BACKGROUND

The purpose of this study was to assess the value of intra-articular fluid injection under pressure, as a technique suggested for temporo-mandibular joint (TMJ) closed-lock treatment, and to determine if there is a persisting lock resolution in time.

METHODS

Twelve patients were studied at our centre, with a diagnosis of TMJ closed-lock, not amenable with conventional therapies. All patients underwent a MRI scan, confirming the presence of anteriorly displaced disk. This technique is based on intra-articular injection of anaesthetic (mepivacaine cloridrate) under pressure, using the so called pumping technique, that allows an inferior distraction of the condyle. The study has a six months follow-up. After closed-lock resolution all patients underwent physiotherapy with guided mouth opening, for one month.

RESULTS

Mandibular function (maximal mouth opening) increased on average of 20.2 mm after treatment, and of 21.1 mm six months later (p=0.00000; with p<0.005). Pain decreased on average from VAS=6.75 to VAS=0.3 (p=0.00001; with p<0.005). The masticatory efficiency improved from VAS=5.25 to VAS=8.75 (p=0.002; p<0.005). Functional TMJ limitation level is significantly increased (p=0.002; p<0.005). Also, patient's efficacy judgement (mean value 3.58= good) and tolerability judgement (mean value 2.92=good) indicate that this therapy is well accepted.

CONCLUSIONS

This technique is easy to perform, well tolerated and does not need specific instruments: it permits the resolution of TMJ closed-lock, decreases the pain and improves masticatory efficiency. All these effects persist in time. Subjects with recent closed-lock have an immediate and complete functional recovery while patients with chronic closed-lock do not.