Bud-Poplar-Extract-Embedded Chitosan Films as Multifunctional Wound Healing Dressing

Wounds represent a major global health challenge. Acute and chronic wounds are sensitive to bacterial infection. The wound environment facilitates the development of microbial biofilms, delays healing, and promotes chronic inflammation processes. The aim of the present work is the development of chitosan films embedded with bud poplar extract (BPE) to be used as wound dressing for avoiding biofilm formation and healing delay. Chitosan is a polymer with antimicrobial and hydrating properties used in wound dressing, while BPE has antibacterial, antioxidative, and anti-inflammatory properties. Chitosan-BPE films showed good antimicrobial and antibiofilm properties against Gram-positive bacteria and the yeast Candida albicans. BPE extract induced an immunomodulatory effect on human macrophages, increasing CD36 expression and TGFβ production during M1/M2 polarization, as observed by means of cytofluorimetric analysis and ELISA assay. Significant antioxidant activity was revealed in a cell-free test and in a human neutrophil assay. Moreover, the chitosan-BPE films induced a good regenerative effect in human fibroblasts by in vitro cell migration assay. Our results suggest that chitosan-BPE films could be considered a valid plant-based antimicrobial material for advanced dressings focused on the acceleration of wound repair.

Investigation on the effect of known potent S. aureus NorA efflux pump inhibitors on the staphylococcal biofilm formation

The emergence of multidrug resistant microorganisms has triggered the impending need of developing effective antibacterial strategies.

Diphenyl diselenide derivatives inhibit microbial biofilm formation involved in wound infection

Background

Organoselenium compounds have antimicrobial activity against some bacteria and fungi; furthermore, the antioxidant activity of diselenides has been demonstrated. The aim of the present work was to examine the in vitro minimal inhibitory concentration of a panel of differently substituted diselenides and their effectiveness in inhibiting biofilm formation and dispersing preformed microbial biofilm of Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa and the yeast Candida albicans, all involved in wound infections. Moreover, the cytotoxicity of the compounds was determined in human dermal fibroblast and keratinocytes. In closing, we tested their direct antioxidant activity.

Results

Diselenides showed different antimicrobial activity, depending on the microorganism. All diselenides demonstrated a good antibiofilm activity against S. aureus and S. epidermidis, the compounds camphor diselenide, bis[ethyl-N-(2’-selenobenzoyl) glycinate] and bis[2’-seleno-N-(1-methyl-2-phenylethyl) benzamide] were active against S. pyogenes and C. albicans biofilm while only diselenides 2,2’-diselenidyldibenzoic acid and bis[ethyl-N-(2’-selenobenzoyl) glycinate] were effective against P. aeruginosa. Moreover, the compounds bis[ethyl-N-(2’-selenobenzoyl) glycinate] and bis[2’-seleno-N-(1-methyl-2-phenylethyl) benzamide] showed an antioxidant activity at concentrations lower than the 50 % of cytotoxic concentration.

Conclusions

Because microbial biofilms are implicated in chronic infection of wounds and treatment failure, the combination of antimicrobial activity and potential radical scavenging effects may contribute to the improvement of wound healing. Therefore, this study suggests that bis[ethylN-(2’-selenobenzoyl) glycinate] and bis[2’-seleno-N-(1-methyl-2-phenylethyl) benzamide] are promising compounds to be used in preventing and treating microbial wound infections.

The Deubiquitinase USP17 Regulates the Stability and Nuclear Function of IL-33

IL-33 is a new member of the IL-1 family cytokines, which is expressed by different types of immune cells and non-immune cells. IL-33 is constitutively expressed in the nucleus, where it can act as a transcriptional regulator. So far, no direct target for nuclear IL-33 has been identified, and the regulation of IL-33 nuclear function remains largely unclear. Here, we report that the transcription of type 2 inflammatory cytokine IL-13 is positively regulated by nuclear IL-33. IL-33 can directly bind to the conserved non-coding sequence (CNS) before the translation initiation site in the IL13 gene locus. Moreover, IL-33 nuclear function and stability are regulated by the enzyme ubiquitin-specific protease 17 (USP17) through deubiquitination of IL-33 both at the K48 and at the K63 sites. Our data suggest that IL13 gene transcription can be directly activated by nuclear IL-33, which is negatively regulated by the deubiquitinase USP17.

PIM1 kinase phosphorylates the human transcription factor FOXP3 at serine 422 to negatively regulate its activity under inflammation

Previous reports have suggested that human CD4(+) CD25(hi)FOXP3(+) T regulatory cells (Tregs) have functional plasticity and may differentiate into effector T cells under inflammation. The molecular mechanisms underlying these findings remain unclear. Here we identified the residue serine 422 of human FOXP3 as a phosphorylation site that regulates its function, which is not present in murine Foxp3. PIM1 kinase, which is highly expressed in human Tregs, was found to be able to interact with and to phosphorylate human FOXP3 at serine 422. T cell receptor (TCR) signaling inhibits PIM1 induction, whereas IL-6 promotes PIM1 expression in in vitro expanded human Tregs. PIM1 negatively regulates FOXP3 chromatin binding activity by specifically phosphorylating FOXP3 at Ser(422). Our data also suggest that phosphorylation of FOXP3 at the Ser(418) site could prevent FOXP3 phosphorylation at Ser(422) mediated by PIM1. Knockdown of PIM1 in in vitro expanded human Tregs promoted FOXP3-induced target gene expression, including CD25, CTLA4, and glucocorticoid-induced tumor necrosis factor receptor (GITR), or weakened FOXP3-suppressed IL-2 gene expression and enhanced the immunosuppressive activity of Tregs. Furthermore, PIM1-specific inhibitor boosted FOXP3 DNA binding activity in in vitro expanded primary Tregs and also enhanced their suppressive activity toward the proliferation of T effector cells. Taken together, our findings suggest that PIM1 could be a new potential therapeutic target in the prevention and treatment of human-specific autoimmune diseases because of its ability to modulate the immunosuppressive activity of human Tregs.

The E3 deubiquitinase USP17 is a positive regulator of retinoic acid-related orphan nuclear receptor γt (RORγt) in Th17 cells

Stable retinoic acid-related orphan nuclear receptor γt (RORγt) expression is pivotal for the development and function of Th17 cells. Here we demonstrate that expression of the transcription factor RORγt can be regulated through deubiquitination, which prevents proteasome-mediated degradation. We establish that USP17 stabilizes RORγt protein expression by reducing RORγt polyubiquitination at its Lys-360 residue. In contrast, knockdown of endogenous USP17 in Th17 cells resulted in decreased RORγt protein levels and down-regulation of Th17-related genes. Furthermore, USP17 expression was up-regulated in CD4(+) T cells from systemic lupus erythematosus patients. Our data reveal a molecular mechanism in which RORγt expression in Th17 cells can be positively regulated by USP17, thereby modulating Th17 cell functions.

Deubiquitination and stabilization of IL-33 by USP21

Interleukin-33 (IL-33) is a dual-function protein that acts both as a secreted cytokine and as a nuclear factor regulating gene transcription. It has been demonstrated that IL-33 exerts its nuclear function in promoting the transcription of NF-κB p65. Here, we show that USP21-mediated deubiquitination of IL-33 affects the transcription of p65. IL-33 can be post-translationally modified by ubiquitination. Ubiquitin-specific protease 21 (USP21) interacts with IL-33 and also localizes in nucleus. The protein stability of IL-33 is maintained by USP21 through deubiquitination. Furthermore, depletion of USP21 reduces IL-33 protein levels and IL-33-mediated NF-κB p65 promoter activity. Our findings reveal the role of ubiquitination modification in regulating the protein stability and the nuclear function of IL-33.

Regulatory T-cell differentiation and their function in immune regulation

Regulatory T-cells (Treg) represent a subset of CD4+ T-cells characterized by high suppressive capacity, which can be generated in the thymus or induced in the periphery. The deleterious phenotype of the Scurfy mouse, which develops an X-linked lymphoproliferative disease resulting from defective T-cell tolerance, clearly demonstrates the importance of Treg cells for the maintenance of immune homeostasis. Although significant progress has been achieved, much information regarding the development, characteristics and function of Treg cells remain lacking. This chapter highlights the most recent discoveries in the field of Treg biology, focusing on the development and role of this cell subset in the maintenance of immune balance.

A critical role for FcgammaRIIB in up-regulation of Fas ligand induced by a microbial polysaccharide

The microbial capsular polysaccharide glucuronoxylomannan (GXM) from the opportunistic fungus Cryptoccocus neoformans is able to alter the innate and adaptive immune response through multi-faceted mechanisms of immunosuppression. The ability of GXM to dampen the immune response involves the induction of T cell apoptosis, which is dependent on GXM-induced up-regulation of Fas ligand (FasL) on antigen-presenting cells. In this study we elucidate the mechanism exploited by GXM to induce up-regulation of FasL. We demonstrate that (i) the activation of FasL is dependent on GXM interaction with FcgammaRIIB (FcγRIIB); (ii) GXM induces activation of c-Jun NH(2) -terminal kinase (JNK) and p38 signal transduction pathways via FcγRIIB; (iii) this leads to downstream activation of c-Jun; (iv) JNK and p38 are simultaneously, but independently, activated; (v) FasL up-regulation occurs via JNK and p38 activation; and (vi) apoptosis occurs via FcγRIIB engagement with consequent JNK and p38 activation. Our results highlight a fast track to FasL up-regulation via FcγRIIB, and assign to this receptor a novel anti-inflammatory role that also accounts for induced peripheral tolerance. These results contribute to our understanding of the mechanism of immunosuppression that accompanies cryptococcosis.

A microbial polysaccharide reduces the severity of rheumatoid arthritis by influencing Th17 differentiation and proinflammatory cytokines production

Rheumatoid arthritis (RA) is a chronic and debilitating autoimmune disease characterized by chronic joint inflammation with subsequent cartilage and bone destruction. RA is emerging as a model of IL-17-driven autoimmune inflammatory disease. IL-17 is a marker for Th17 cells, with its master regulator being the retinoic acid receptor-related orphan receptor (RORgammat) regulated by STAT3 signaling. Glucuronoxylomannan (GXM), a polysaccharide representing the main component of the capsular material of the opportunistic yeast Cryptococcus neoformans, exhibits potent immunosuppressive properties both in vitro and in vivo. The present study investigates the effects of GXM treatment on the progression of collagen-induced arthritis. GXM suppressed clinical signs of collagen-induced arthritis and blocked joint erosion progression. This effect was mediated by down-regulation of key cytokines involved in the pathogenesis of RA such as TNF-alpha and IL-1beta, and up-regulation of the inhibitory cytokine IL-10. Moreover, a reduction of IL-6 and TGF-beta, which inhibit Th17 differentiation with consequent decreased IL-17 production at the local and systemic level, was observed. The effect of GXM on Th17 differentiation mirrored the reduction in STAT3 activation and inhibition of RORgammat synthesis. Consequently, this work highlights the beneficial properties of an efficacious compound that could eventually be destined to the clinic.

[Comparison of four measurements of sickness absence in workers in the Veneto Region: interpretation and applicability. Data from Italian National Social Security Institute, 1997-2002]

BACKGROUND

In 2005, 52% of workers in the Veneto Region reported one or more sick leave spells in the previous 12 months, compared with 16% reported in the European Survey on Working Condition in 2000 (ESWC), although health conditions were better in the Veneto Region than in the ESWC.

OBJECTIVES

Since the above findings were based on answers to a questionnaire, we used an objective source of information in order to further investigate the problem.

METHODS

The source of data consisted of the sick leave records of workers in the Veneto Region, 1997-2002, which were obtained from the Italian National Social Security Institute (INPS). Four measurements were used: (1) frequency = number of sick-leave spells during the study period/number of insured persons at risk for sickness absence during the study period; (2) cumulative incidence = number of persons with at least one new sick-leave spell during the study period/number of insured persons at risk for sickness absence during the study period; (3) sick-leave rate = number of sick-leave days during the study period/number of insured persons at risk for sickness absence during the study period; (4) duration of absence = number of sick-leave days in new sick leave spells during the study period/number of new sick-leave spells during the study period. Cumulative incidence could only be analyzed by statistical methods (binomial regression).

RESULTS

The first three measurements gave overlapping results. The values were highest in industry, lowest in agriculture, and intermediate in crafts and services; they were highest in middle-aged subjects and lowest in younger and older individuals; the time trend increased up to 1999 and then decreased slowly. Cumulative incidence was 52.0%, 38.0%, 36.4% and 22.9%, in industry, services, crafts, and agriculture, respectively, and 42.8% in the total population. The results of binomial regression confirmed the above pattern, as well as an excess in women, in white collar workers, and in various occupational categories which, however, were probably not due to occupational exposures since in each occupational category the risk was always higher in industry than in crafts. By contrast, the sick-leave rate was higher in crafts and agriculture and lower in services and industry; it increased exponentially with age and did not show real differences between males and females.

CONCLUSIONS

The choice of measurements influences the results; duration of absence could be used to detect areas of suspected work-related diseases, while cumulative incidence might be more helpful to detect areas of suspected absenteeism/presenteeism.

[Safety and health in workers employed in industry. Data from Industrial Accidents Compensation Board (INAIL) and National Social Security Institute (INPS), Veneto Region, 1994-2002]

BACKGROUND

A decreasing time trend for occupational injuries and sickness absence would be the effect of the new legislation (D.Lgs. 626/94 and successive laws) on prevention in occupational settings. Conversely, the reduction of INPS disability would reflect a health improvement due to non-occupational causes.

OBJECTIVES

The aim of the study was to investigate the efficacy of the new legislation among employees in industry (where the law was mainly applied), via the time trend of three standardized rates in the Veneto Region.

METHODS

The numerator for the rate of occupational accidents (cases occurring in industry workers in the Veneto Region, broken down for sex, age and calendar years) was supplied by INAIL. The denominator for the above rate, as well as numerators and denominators for disability and sickness absence were supplied by INPS. Data were available from 1994 to 2002 for accidents and disability, and from 1997 to 2002 for sickness absence. In every year from 1994 to 2002, the rates were standardized for age and sex with the direct method, using an internal "standard" population. The time trend of year-specific standardized rates was analyzed by Joinpoint regression software.

RESULTS

Among industrial workers in the Veneto Region, occupational accidents increased by 0.4% yearly, while disability decreased by 2.56% from 1994 to 2002. Sick absence increased up to 1999, then decreased.

CONCLUSIONS

This epidemiological pattern is difficult to explain. The increase in accidents could be due to the increase of non-European Union workers and/or to the fact that accidents on the way to or from work were recognized as occupational accidents by INAIL starting from 2000. Both these phenomena could have contributed to increase the rate that was otherwise diminishing. On the other hand, this same situation could be due to insufficient efficacy of the legislation (D.Lgs. 626/94 and successive laws) for preventing occupational accidents and diseases.

[Association between causes of lNPS compensated disability and occupational category (Veneto Region, 1994-2002): a surveillance method for occupational diseases?]

BACKGROUND

According to Italian law, workers are insured against disability through the National Social Security Institute (INPS), whose records contain information on diseases causing disability and occupational histories.

OBJECTIVES

Using the INPS data, our objective was to identify any excess risk of disabling diseases in relation to the occupational categories.

METHODS

Insurance covers all private sector employees, a small proportion of public sector employees, agricultural labourers, domestic workers, self-employed workers (craftsmen, commercial dealers,farmers), and few other occupational categories. For each insured worker, a database was created containing registry data, occupational history and, for compensated workers, the disease code, for each year from 1994 to 2002. A cohort study design was adopted, in which references were self-employed workers (with mixed exposure) to whom different categories of employees in agriculture, industry, crafts, and services were compared. Data were analyzed by means of Poisson regression, estimating the Incidence Rate Ratio (IRR) and confidence interval (CI) at 99.99%, instead of 95%, in order to set the threshold of error for the entire study at 0.05.

RESULTS

In the construction industry there were significantly high risks of disability in both industry and crafts for tumours (industry: IRR = 2.07; IC = 1. 67-2.57; crafts: 2.57; 1.89-3.18), circulatory disorders (industry: IRR = 2.24; IC = 1.65-3.04; crafts.: 3.06; 2.16-4.32), and bone and joint diseases (industry. IRR = 5.0; IC = 3.15-7.94; crafts: 6.58; 5.04-8.59).

CONCLUSIONS

The advantage of this approach is to recruit a large number of subjects at limited cost. The procedure here proposed is a mainly exploratory approach aimed at establishing new study hypotheses: disability, in fact, is acknowledged by INPS when its cause is not occupational according to the current literature.

Laparoscopic cryomyolysis: An alternative to myomectomy in women with symptomatic fibroids

BACKGROUND

The purpose of this study was to determine whether cryomyolysis may present an alternative valid surgical procedure to hysterectomy or myomectomy for selected women with symptomatic fibroids who wish to preserve their uterus but do not desire future pregnancies.

METHODS

Sixty-three women with symptomatic fibroids who refused either myomectomy or hysterectomy, requesting a conservative surgery for myomata, underwent laparoscopic cryomyolysis using a 3- to 5-mm or 8-mm cryoprobe (CRYOcare system).

RESULTS

Our study showed a mean (+/-standard deviation) decrease of myoma volume of 60.3% (+/-20.7) and complete symptom relief in 83.6% (p < 0.001) of patients after a 12-month follow-up from cryomyolysis. No significant intra- or postoperative complications were noted.

CONCLUSION

Cryomyolysis is an effective laparoscopic procedure for obtaining myoma shrinkage and symptom relief in women with symptomatic fibroids who desire to preserve their uterus.

Slow dynamics and aging in a constrained diffusion model

We carry out a complete analysis of the schematic diffusive model recently introduced for the description of supercooled liquids and glassy systems above the glass temperature. The model is described by a trivial equilibrium measure and the presence of kinetics constraints is mimicked through a rapidly decreasing mobility at high particle density. The governing equation describing a sudden quench process is investigated analytically in a mean field approach and by means of numerical simulations. For deep quenches a long lasting off-equilibrium dynamics is observed in dense systems before equilibration is achieved, where time translational invariance lacks and the system ages. The kinetics is slow in this time domain since the average particle diffusivity D decreases in time, as opposed to the standard diffusion case of a constant D, that is recovered only in equilibrium. The autocorrelation function decays slower than an exponential, falling in mean field as an enhanced power law. The linear response function is computed and the modalities of the break-down of the fluctuation dissipation theorem are analytically investigated, showing that an effective temperature can be defined which slowly approaches the bath temperature from above.