Adverse Health Effects of the Long-Term Simultaneous Exposure to Arsenic and Particulate Matter in a Murine Model.

PM2.5 and arsenic are two of the most hazardous substances for humans that coexist worldwide. Independently, they might cause multiple organ damage. However, the combined effect of PM2.5 and arsenic has not been studied. Here, we used an animal model of simultaneous exposure to arsenic and PM2.5. Adult Wistar rats were exposed to PM2.5, As, or PM2.5 + As and their corresponding control groups. After 7, 14, and 28 days of exposure, the animals were euthanized and serum, lungs, kidneys, and hearts were collected. Analysis performed showed high levels of lung inflammation in all experimental groups, with an additive effect in the coexposed group. Besides, we observed cartilaginous metaplasia in the hearts of all exposed animals. The levels of creatine kinase, CK-MB, and lactate dehydrogenase increased in experimental groups. Tissue alterations might be related to oxidative stress through increased GPx and NADPH oxidase activity. The findings of this study suggest that exposure to arsenic, PM2.5, or coexposure induces high levels of oxidative stress, which might be associated with lung inflammation and heart damage. These findings highlight the importance of reducing exposure to these pollutants to protect human health.

A monoclonal antibody targeting a large surface of the receptor binding motif shows pan-neutralizing SARS-CoV-2 activity.

Here we report the characterization of 17T2, a SARS-CoV-2 pan-neutralizing human monoclonal antibody isolated from a COVID-19 convalescent individual infected during the first pandemic wave. 17T2 is a class 1 VH1-58/κ3-20 antibody, derived from a receptor binding domain (RBD)-specific IgA+ memory B cell, with a broad neutralizing activity against former and new SARS-CoV-2 variants, including XBB.1.16 and BA.2.86 Omicron subvariants. Consistently, 17T2 demonstrates in vivo prophylactic and therapeutic activity against Omicron BA.1.1 infection in K18-hACE2 mice. Cryo-electron microscopy reconstruction shows that 17T2 binds the BA.1 spike with the RBD in "up" position and blocks the receptor binding motif, as other structurally similar antibodies do, including S2E12. Yet, unlike S2E12, 17T2 retains its neutralizing activity against all variants tested, probably due to a larger RBD contact area. These results highlight the impact of small structural antibody changes on neutralizing performance and identify 17T2 as a potential candidate for future clinical interventions.

The self-association equilibrium of DNAJA2 regulates its interaction with unfolded substrate proteins and with Hsc70.

J-domain proteins tune the specificity of Hsp70s, engaging them in precise functions. Despite their essential role, the structure and function of many J-domain proteins remain largely unknown. We explore human DNAJA2, finding that it reversibly forms highly-ordered, tubular structures that can be dissociated by Hsc70, the constitutively expressed Hsp70 isoform. Cryoelectron microscopy and mutational studies reveal that different domains are involved in self-association. Oligomer dissociation into dimers potentiates its interaction with unfolded client proteins. The J-domains are accessible to Hsc70 within the tubular structure. They allow binding of closely spaced Hsc70 molecules that could be transferred to the unfolded substrate for its cooperative remodelling, explaining the efficient recovery of DNAJA2-bound clients. The disordered C-terminal domain, comprising the last 52 residues, regulates its holding activity and productive interaction with Hsc70. These in vitro findings suggest that the association equilibrium of DNAJA2 could regulate its interaction with client proteins and Hsc70.

Nicotine promotes Mycobacterium tuberculosis H37Rv growth and overexpression of virulence genes.

Tobacco consumption increases the susceptibility to develop infectious diseases such as tuberculosis (TB). Nicotine (Nc) is the main component of cigarette smoke with immunomodulatory properties, however, its effect on Mycobacterium tuberculosis (Mtb) has been scarcely investigated. The present study evaluated the effect of nicotine on the growth of Mtb and on the induction of virulence-related genes. Mycobacteria were exposed to different concentrations of nicotine then Mtb growth was evaluated. Subsequently, the expression of the virulence-related genes lysX, pirG, fad26, fbpa, ompa, hbhA, esxA, esxB, hspx, katG, lpqh, and caeA was evaluated by RT-qPCR. The effect of nicotine on intracellular Mtb was also evaluated. The results showed that nicotine promotes the growth of Mtb both extracellularly and intracellularly and increases the expression of genes related to virulence. In summary, nicotine promotes the growth of Mtb and the expression of virulence-related genes that could be correlated with the increased the risk of smokers developing TB.

Downregulation of sCD40 and sCTLA4 in Recovered COVID-19 Patients with Comorbidities.

The aim of this study was to analyze molecules associated with regulatory immune response in unvaccinated, recovered COVID-19 patients with and without diabetes mellitus (DM) and hypertension (HTN). We determined anti-SARS-CoV-2 nucleocapsid IgG in plasma by electrochemiluminescence immunoassay. The levels of sCD40, TGF-ß, IL-10, and sCTLA-4 were assessed by ELISA in the serum of the subjects, as well as in healthy donors. We observed that only half of the subjects in the non-comorbid group produced antibodies, whereas all subjects in comorbid groups were IgG-positive for the anti-SARS-CoV-2 nucleocapsid. High levels of sCTL-4 were observed in the non-comorbid group, and the level of IL-10 was observed to increase in seropositive subjects without comorbidities. TGF-ß concentration was similar in all groups studied. Finally, sCD40 decreased in the comorbid group. In conclusion, our results suggest that comorbidities such as DM and HTN alter the production of co-stimulatory inhibitory molecules sCTLA-4 and sCD40 in subjects recovering from mild COVID-19. The alterations observed here were independent of seropositivity, suggesting an effective humoral immune response against COVID-19 separate from the levels of co-stimulatory inhibitory molecules.

TPL2 kinase expression is regulated by the p38γ/p38δ-dependent association of aconitase-1 with TPL2 mRNA.

p38γ and p38δ (p38γ/p38δ) regulate inflammation, in part by controlling tumor progression locus 2 (TPL2) expression in myeloid cells. Here, we demonstrate that TPL2 protein levels are dramatically reduced in p38γ/p38δ-deficient (p38γ/δ-/-) cells and tissues without affecting TPL2 messenger ribonucleic acid (mRNA) expression. We show that p38γ/p38δ posttranscriptionally regulates the TPL2 amount at two different levels. p38γ/p38δ interacts with the TPL2/A20 Binding Inhibitor of NF-κB2 (ABIN2)/Nuclear Factor κB1p105 (NF-κB1p105) complex, increasing TPL2 protein stability. Additionally, p38γ/p38δ regulates TPL2 mRNA translation by modulating the repressor function of TPL2 3' Untranslated region (UTR) mediated by its association with aconitase-1 (ACO1). ACO1 overexpression in wild-type cells increases the translational repression induced by TPL2 3'UTR and severely decreases TPL2 protein levels. p38δ binds to ACO1, and p38δ expression in p38γ/δ-/- cells fully restores TPL2 protein to wild-type levels by reducing the translational repression of TPL2 mRNA. This study reveals a unique mechanism of posttranscriptional regulation of TPL2 expression, which given its central role in innate immune response, likely has great relevance in physiopathology.

Altered CXCR4 dynamics at the cell membrane impairs directed cell migration in WHIM syndrome patients.

Chemokine receptor nanoscale organization at the cell membrane is orchestrated by the actin cytoskeleton and influences cell responses. Using single-particle tracking analysis we show that CXCR4R334X, a truncated mutant chemokine receptor linked to WHIM syndrome (warts, hypogammaglobulinemia, infections, myelokathexis), fails to nanoclusterize after CXCL12 stimulation, and alters the lateral mobility and spatial organization of CXCR4 when coexpressed. These findings correlate with multiple phalloidin-positive protrusions in cells expressing CXCR4R334X, and their inability to correctly sense chemokine gradients. The underlying mechanisms involve inappropriate actin cytoskeleton remodeling due to the inadequate ß-arrestin1 activation by CXCR4R334X, which disrupts the equilibrium between activated and deactivated cofilin. Overall, we provide insights into the molecular mechanisms governing CXCR4 nanoclustering, signaling and cell function, and highlight the essential scaffold role of ß-arrestin1 to support CXCL12-mediated actin reorganization and receptor clustering. These defects associated with CXCR4R334X expression might contribute to the severe immunological symptoms associated with WHIM syndrome.

Structural mechanism for tyrosine hydroxylase inhibition by dopamine and reactivation by Ser40 phosphorylation.

Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of dopamine (DA) and other catecholamines, and its dysfunction leads to DA deficiency and parkinsonisms. Inhibition by catecholamines and reactivation by S40 phosphorylation are key regulatory mechanisms of TH activity and conformational stability. We used Cryo-EM to determine the structures of full-length human TH without and with DA, and the structure of S40 phosphorylated TH, complemented with biophysical and biochemical characterizations and molecular dynamics simulations. TH presents a tetrameric structure with dimerized regulatory domains that are separated 15 Å from the catalytic domains. Upon DA binding, a 20-residue α-helix in the flexible N-terminal tail of the regulatory domain is fixed in the active site, blocking it, while S40-phosphorylation forces its egress. The structures reveal the molecular basis of the inhibitory and stabilizing effects of DA and its counteraction by S40-phosphorylation, key regulatory mechanisms for homeostasis of DA and TH.

SARS-CoV-2 Spike Protein and Its Receptor Binding Domain Promote a Proinflammatory Activation Profile on Human Dendritic Cells.

Dendritic cells (DCs) are the most potent antigen-presenting cells, and their function is essential to configure adaptative immunity and avoid excessive inflammation. DCs are predicted to play a crucial role in the clinical evolution of the infection by the severe acute respiratory syndrome (SARS) coronavirus (CoV)-2. DCs interaction with the SARS-CoV-2 Spike protein, which mediates cell receptor binding and subsequent fusion of the viral particle with host cell, is a key step to induce effective immunity against this virus and in the S protein-based vaccination protocols. Here we evaluated human DCs in response to SARS-CoV-2 S protein, or to a fragment encompassing the receptor binding domain (RBD) challenge. Both proteins increased the expression of maturation markers, including MHC molecules and costimulatory receptors. DCs interaction with the SARS-CoV-2 S protein promotes activation of key signaling molecules involved in inflammation, including MAPK, AKT, STAT1, and NFκB, which correlates with the expression and secretion of distinctive proinflammatory cytokines. Differences in the expression of ACE2 along the differentiation of human monocytes to mature DCs and inter-donor were found. Our results show that SARS-CoV-2 S protein promotes inflammatory response and provides molecular links between individual variations and the degree of response against this virus.

Compendio Nacional de Insumos para la Salud: equidad y acceso universal / National Compendium of Health Commodities: equity and universal access

Resumen: México fue pionero en establecer catálogos para identificar y hacer asequibles insumos médicos para la atención de su población, incluyendo medicamentos, instrumental, equipos y material de curación. Hace medio siglo, en 1971, surgió en el Instituto Mexicano del Seguro Social la iniciativa del llamado Cuadro Básico, que se constituyó como una herramienta fundamental para el funcionamiento de las instituciones públicas de salud, con la cual se establecieron listados de insumos con probada eficacia y seguridad, con claves administrativas asignadas que permitieron su adquisición ordenada. En 2020 se llevó a cabo la transición del Cuadro Básico y Catálogo al Compendio Nacional de Insumos para la Salud, el cual recuperó el espíritu original de sus creadores como un documento vivo y en constante evolución, respaldado por una metodología rigurosa para la revisión de los insumos que se incluyen, basada en la evaluación de su efectividad, seguridad y calidad, y en criterios farmacoeconómicos y consensos interinstitucionales.

Abstract: Mexico pioneered the creation of catalogs for identification and access of the medical commodities necessary for public healthcare, including medicines, medical equipment and wound dressing supplies. Fifty years ago, in 1971, the Instituto Mexicano del Seguro Social started the initiative of the Basic Scheme (Cuadro básico), that became a fundamental tool for provision of healthcare in the public institutions through the establishment of listings of medical supplies with proved safety and efficacy, assigning administrative codes that allowed an orderly acquisition. On 2020, the Basic Scheme and Catalog underwent a transition towards the National Compendium of Health Commodities (Compendio Nacional de Insumos para la Salud), recovering the original spirit of their creators as a live document in constant evolution, supported by a rigorous methodology for the assessment of the medical commodities included, based on evaluations of effectiveness, safety and quality, pharmacoeconomic criteria and interinstitutional consensus.

EQ-5D-5L Health-State Values for the Mexican Population.

OBJECTIVE: To generate a value set for the Mexican adult general population to support and facilitate the inclusion of quality-adjusted life years (QALYs) into the health technology assessment process of the Mexican healthcare authorities. METHODS: A representative sample of the Mexican adult population stratified by age, sex and socio-economic status was used. Following version 2.0 of the EuroQol EQ-5D-5L valuation protocol, trained interviewers guided participants in completing composite time trade-off (cTTO) and discrete-choice experiment (DCE) tasks included in the EQ-VT software. Generalized least squares, Tobit and Bayesian models were used for cTTO data. The choice of value set model was based on criteria that included: theoretical considerations, parsimony, logical ordering of coefficients, and statistical significance. RESULTS: Based on quality control criteria and interviewer judgment, 1000 out of 1032 participants provided useable responses. Participants' demographic characteristics were similar to the 2010 Mexican Population Census and followed the socioeconomic structure defined by the Mexican Association of Marketing Research and Public Opinion Agencies (AMAI). The predicted index values in the final cTTO model (a heteroscedastic censored model with Bayesian estimation) ranged from - 0.5960 to 1, with 19.7% of all predicted health state scores less than 0 (i.e., worse than dead). CONCLUSION: This study has generated the first value set representing the stated preferences of the Mexican adult population for use in estimating QALYs. The resulting EQ-5D-5L value set is technically robust and will facilitate health economic analyses as well as quality-of-life studies.

Long-term exposure to particulate matter from air pollution alters airway ß-defensin-3 and -4 and cathelicidin host defense peptides production in a murine model.

Epidemiological studies have associated long-term exposure to environmental air pollution particulate matter (PM) with the development of diverse health problems. They include infectious respiratory diseases related to the deregulation of some innate immune response mechanisms, such as the host defense peptides' expression. Herein, we evaluated in BALB/c mice the effect of long-standing exposure (60 days) to urban-PM from the south of Mexico City, with aerodynamic diameters below 2.5 µm (PM2.5) and 10 µm (PM10) on the lung's gene expression and production of three host defense peptides (HDPs); murine beta-defensin-3, -4 (mBD-3, mBD-4) and cathelin-related antimicrobial peptide (CRAMP). We also evaluated mRNA levels of Il1b and Il10, two cytokines related to the expression of host defense peptides. Exposure to PM2.5 and PM10 differentially induced lung inflammation, being PM2.5, which caused higher inflammation levels, probably associated with a differential deposition on the airways, that facilitate the interaction with alveolar macrophages. Inflammation levels were associated with an early upregulation of the three HDPs assessed and an increment in Il1b mRNA levels. Interestingly, after 28 days of exposure, Il10 mRNA upregulation was observed and was associated with the downregulation of HDPs and Il1b mRNA levels. The upregulation of Il10 mRNA and suppression of HDPs might facilitate microbial colonization and the development of diseases associated with long-term exposure to PM.

Retinoic acid induces antimicrobial peptides and cytokines leading to Mycobacterium tuberculosis elimination in airway epithelial cells.

Tuberculosis (TB) is the leading cause of death by a single infectious agent, Mycobacterium tuberculosis (Mtb). Alveolar macrophages and respiratory epithelial cells are the first cells exposed to Mtb during the primary infection, once these cells are activated, secrete cytokines and antimicrobial peptides that are associated with the Mtb contention and elimination. Vitamins are micronutrients that function as boosters on the innate immune system, however, is unclear whether they have any protective activity during Mtb infection. Thus, we investigated the role of vitamin A (retinoic acid), vitamin C (ascorbic acid), vitamin D (calcitriol), and vitamin E (alfa-tocopherol) as inductors of molecules related to mycobacterial infection in macrophages and epithelial cells. Our results showed that retinoic acid promotes the expression of pro- and anti-inflammatory molecules such as Thymic stromal lymphopoietin (TSLP), ß-defensin-2, IL-1ß, CCL20, ß-defensin-3, Cathelicidin LL-37, TGF-ß, and RNase 7, whereas calcitriol, ascorbic acid, and α-tocopherol lead to an anti-inflammatory response. Treatment of Mtb-infected epithelial cells and macrophage-like cells with the vitamins showed a differential response, where calcitriol reduced Mtb in macrophages, while retinoic acid reduced infection in epithelial cells. Thereby, we propose that a combination of calcitriol and retinoic acid supplementation can drive the immune response, and promotes the Mtb elimination by increasing the expression of antimicrobial peptides and cytokines, while simultaneously modulating inflammation.

Hemagglutinin protein of Peste des Petits Ruminants virus (PPRV) activates the innate immune response via Toll-like receptor 2 signaling.

The toll-like receptor (TLR) family comprises both cell-surface and intracellular receptors that recognize different types of pathogen-associated molecular patterns (PAMPs) leading to the production of pro-inflammatory cytokines and subsequent development of adaptive immunity. TLR2 is a cell-surface receptor initially thought to act as a bacterial sentinel but also shown to recognize a number of viral glycoproteins. In this study, we sought to characterize the role of TLR2 in the activation of the immune response by peste des petits ruminants virus (PPRV), a morbillivirus of the Paramixoviridae family that causes an acute, highly contagious disease in goats and sheep. Using human embryonic kidney (HEK) 293 cells stably expressing human (h)TLR2 but lacking any other TLR, we found that PPRV induces IL-8 production in a dose-dependent manner. That activation is only observed in cells expressing hTLR2 and is greatly reduced when the receptor is blocked by pretreatment with specific antibody. We identified hemagglutinin (H) as the viral protein responsible of TLR2 activation by performing the same assays with purified recombinant mammalian-expressed H protein. Exogenous addition of recombinant H protein to cell culture induces high levels of interleukin (IL)-8 only in TLR2-expressing cells. Moreover, H engagement on TLR2 in the monocytic cell line THP-1 activates extracellular-signal-regulated kinase (ERK) signaling. Stimulation of primary ovine dendritic cells with either inactivated PPRV or purified recombinant H protein results in transcription of pro-inflammatory cytokines and the secretion of the Th1-polarizing cytokine IL-12. The role of these host immune mechanisms in the control of PPR is discussed.

Lactococcus lactis NZ9000 Prevents Asthmatic Airway Inflammation and Remodelling in Rats through the Improvement of Intestinal Barrier Function and Systemic TGF-ß Production.

INTRODUCTION: The use of probiotics has been broadly popularized due to positive effects in the attenuation of aberrant immune responses such as asthma. Allergic asthma is a chronic respiratory disease characterized by airway inflammation and remodelling. OBJECTIVE: This study was aimed to evaluate the effect of oral administration of Lactococcus lactis NZ9000 on asthmatic airway inflammation and lung tissue remodelling in rats and its relation to the maintenance of an adequate intestinal barrier. METHODS: Wistar rats were ovalbumin (OVA) sensitized and challenged and orally treated with L. lactis. Lung inflammatory infiltrates and cytokines were measured, and remodelling was evaluated. Serum OVA-specific immunoglobulin (Ig) E levels were assessed. We also evaluated changes on intestinal environment and on systemic immune response. RESULTS: L. lactis diminished the infiltration of proinflammatory leucocytes, mainly eosinophils, in the bronchoalveolar compartment, decreased lung IL-4 and IL-5 expression, and reduced the level of serum allergen-specific IgE. Furthermore, L. lactis prevented eosinophil influx, collagen deposition, and goblet cell hyperplasia in lung tissue. In the intestine, L. lactis-treated asthmatic rats increased Peyer's patch and goblet cell quantity and mRNA expression of IgA, MUC-2, and claudin. Additionally, intestinal morphological alterations were normalized by L. lactis administration. Splenocyte proliferative response to OVA was abolished, and serum levels of transforming growth factor (TGF)-ß were increased by L. lactis treatment. CONCLUSIONS: These findings suggest that L. lactis is a potential candidate for asthma prevention, and the effect is mediated by the improvement of intestinal barrier function and systemic TGF-ß production.

Thioredoxin-80 protects against amyloid-beta pathology through autophagic-lysosomal pathway regulation.

Aggregation and accumulation of amyloid beta (Aß) are believed to play a key role in the pathogenesis of Alzheimer's disease (AD). We previously reported that Thioredoxin-80 (Trx80), a truncated form of Thioredoxin-1, prevents the toxic effects of Aß and inhibits its aggregation in vitro. Trx80 levels were found to be dramatically reduced both in the human brain and cerebrospinal fluid of AD patients. In this study, we investigated the effect of Trx80 expression using in vivo and in vitro models of Aß pathology. We developed Drosophila melanogaster models overexpressing either human Trx80, human Aß42, or both Aß42/Trx80 in the central nervous system. We found that Trx80 expression prevents Aß42 accumulation in the brain and rescues the reduction in life span and locomotor impairments seen in Aß42 expressing flies. Also, we show that Trx80 induces autophagosome formation and reverses the inhibition of Atg4b-Atg8a/b autophagosome formation pathway caused by Aß42. These effects were also confirmed in human neuroblastoma cells. These results give insight into Trx80 function in vivo, suggesting its role in the autophagosome biogenesis and thus in Aß42 degradation. Our findings put Trx80 on the spotlight as an endogenous agent against Aß42-induced toxicity in the brain suggesting that strategies to enhance Trx80 levels in neurons could potentially be beneficial against AD pathology in humans.

Compendio Nacional de Insumos para la Salud: equidad y acceso universal.

México fue pionero en establecer catálogos para identificar y hacer asequibles insumos médicos para la atención de su población, incluyendo medicamentos, instrumental, equipos y material de curación. Hace medio siglo, en 1971, surgió en el Instituto Mexicano del Seguro Social la iniciativa del llamado Cuadro Básico, que se constituyó como una herramienta fun-damental para el funcionamiento de las instituciones públicas de salud, con la cual se establecieron listados de insumos con probada eficacia y seguridad, con claves administrativas asignadas que permitieron su adquisición ordenada. En 2020 se llevó a cabo la transición del Cuadro Básico y Catálogo al Compendio Nacional de Insumos para la Salud, el cual recuperó el espíritu original de sus creadores como un do-cumento vivo y en constante evolución, respaldado por una metodología rigurosa para la revisión de los insumos que se incluyen, basada en la evaluación de su efectividad, seguridad y calidad, y en criterios farmacoeconómicos y consensos interinstitucionales.

Robotic-Assisted and Laparoscopic Sigmoid Resection.

BACKGROUND AND OBJECTIVES: Published comparisons of minimally invasive approaches to colon surgery are limited. The objective of the current study is to compare the effectiveness of robotic-assisted and laparoscopic sigmoid resection. METHODS: A multicenter retrospective comparative analysis of perioperative outcomes from consecutive robotic-assisted and laparoscopic sigmoid resections performed between 2010 and 2015 by six general and colorectal surgeons, who are experienced in both robotic-assisted and laparoscopic surgical techniques and who had >50 annual case volumes for each approach. Baseline characteristics and surgical risk factors between the two groups were balanced using a propensity score methodology with inverse probability of treatment weighting. Mean standardized differences were reported, and in all instances, a p-value < 0.05 was considered statistically significant. RESULTS: Three hundred thirty-six cases (robotic-assisted, n = 211; laparoscopic, n = 125) met eligibility criteria and were included in the study. Following weighting, patient demographics and baseline characteristics were comparable between the robotic-assisted (n = 344) and laparoscopic (n = 349) groups. The laparoscopic group was associated with shorter operating room and surgical times. The robotic-assisted group had lower estimated blood loss and shorter time to first flatus compared to the laparoscopic group. Rates of complications post discharge to 30 d tended to be lower for the RA group: 5.1% vs 8.6% [p = 0.0657]. The RA group also had lower rates of readmissions and reoperations: 4% vs 8% [p = 0.029] and 0.5% vs 5.1% [p = 0.0003], respectively. CONCLUSIONS: Robotic-assisted sigmoid colon resection is clinically effective and provides a minimally invasive alternative to the laparoscopic approach with improved intraoperative and postoperative outcomes for colorectal patients.

Host Defense Peptide RNase 7 Is Down-regulated in the Skin of Diabetic Patients with or without Chronic Ulcers, and its Expression is Altered with Metformin.

BACKGROUND: Diabetic foot ulcers (DFUs) are one of the main complications in patients with type 2 diabetes mellitus (DM2), previous studies have reported that DM2 patients have lower production of host defense peptides (HDP). AIM OF THE STUDY: To investigate the expression of RNase 7, cathelicidin, HBD-2, and psoriasin in biopsies obtained from DM2 patients with or without DFU. METHODS: Biopsies from DFU patients grade 3 according to Wagner's classification, from diabetic patients without ulcer and from healthy donors were obtained. qPCR, immunohistochemistry and cell line cultures were performed. To assess whether L-isoleucine, calcitriol, phenyl butyrate, metformin, glyburide or insulin induced RNase 7, keratinocytes were stimulated, and RNase 7 expression was evaluated. RESULTS: Our data showed that RNase 7 levels were decreased in both diabetic groups when were compared with skin from healthy donors. Since most of the DM2 patients are treated with drugs to reduce glycemia, we investigated whether glyburide, metformin or insulin were able to induce any change regarding RNase 7 production. Results showed that metformin reduces the expression of RNase 7 in in vitro treated keratinocytes, suggesting that the chronic use of metformin should be evaluated in DFU patients, whereas calcitriol, phenyl butyrate and L-isoleucine did not increase the RNase 7 production. CONCLUSIONS: Due RNase 7 has antimicrobial activity, its downregulation can make prone to DM2 patients to develop infections and impaired wound healing.