The Nicotiana tabacum UGT89A2 enzyme catalyzes the glycosylation of di- and trihydroxylated benzoic acid derivatives.

Glycosyltransferases catalyze the transfer of a glycoside group to a wide range of acceptor compounds to produce glycoconjugates with diverse biological and pharmacological activities. The present work reports the identification and biochemical characterization of Nicotiana tabacum UGT89A2 glycosyltransferase (NtUGT89A2). The enzyme is a monomer in solution that catalyzes the O-ß-glucosylation of di- and tri-hydroxylated and chlorinated derivatives of benzoic acid. NtUGT89A2 has a preference for 2,5-dihydroxybenzoic acid (2,5-DHBA) over 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,4-dihydroxybenzoic acid (2,4-DHBA). Other substrates that can be used by NtUGT89A2 include 3,4,5-trihydroxybenzoic acid and chlorinated derivatives such as 2-chloro-5-hydroxybenzoic acid (2-Cl-5-HBA). The substrates of NtUGT89A2 were identified by thermal stability experiments, where we observed a maximum increase of the thermal denaturation midpoint (Tm) of 10 °C in the presence of 2,5-DHBA and UDP-glucose. On the other hand, the highest specific activity was obtained with 2,5-DHBA (225 ± 1.7 nkat/mg). Further characterization revealed that the enzyme has a micromolar affinity for its substrates. Notably, the enzyme retains full activity after incubation at 70°C for one hour. These results provide a basis for future functional and structural studies of NtUGT89A2.

Radio-miRs: a comprehensive view of radioresistance-related microRNAs.

Radiotherapy is a key treatment option for a wide variety of human tumors, employed either alone or alongside with other therapeutic interventions. Radiotherapy uses high-energy particles to destroy tumor cells, blocking their ability to divide and proliferate. The effectiveness of radiotherapy is due to genetic and epigenetic factors that determine how tumor cells respond to ionizing radiation. These factors contribute to the establishment of resistance to radiotherapy, which increases the risk of poor clinical prognosis of patients. Although the mechanisms by which tumor cells induce radioresistance are unclear, evidence points out several contributing factors including the overexpression of DNA repair systems, increased levels of reactive oxygen species, alterations in the tumor microenvironment, and enrichment of cancer stem cell populations. In this context, dysregulation of microRNAs or miRNAs, critical regulators of gene expression, may influence how tumors respond to radiation. There is increasing evidence that miRNAs may act as sensitizers or enhancers of radioresistance, regulating key processes such as the DNA damage response and the cell death signaling pathway. Furthermore, expression and activity of miRNAs have shown informative value in overcoming radiotherapy and long-term radiotoxicity, revealing their potential as biomarkers. In this review, we will discuss the molecular mechanisms associated with the response to radiotherapy and highlight the central role of miRNAs in regulating the molecular mechanisms responsible for cellular radioresistance. We will also review radio-miRs, radiotherapy-related miRNAs, either as sensitizers or enhancers of radioresistance that hold promise as biomarkers or pharmacological targets to sensitize radioresistant cells.

Assessing Outcome Measurements and Impact of Simulation in Neurocritical Care Training: A Systematic Review.

ABSTRACT: AIM: The use of simulation training in neurocritical care is increasing. Yet, the pooled impact on patient and trainee outcomes remains unclear. This systematic review aims to determine the outcome measurements used after simulation training in neurocritical care and to synthesize the current evidence about the impact of simulation training on these outcomes. METHODS: A 3-step search was conducted in CINAHL, Cochrane, MEDLINE, PsychINFO, and Scopus. The inclusion criteria were composed of studies exploring simulation training in neurocritical care, published in English between 2000 and 2023. Two reviewers independently conducted screening, critical appraisal, and data extraction, using standardized Joanna Briggs Institute tools. Meta-analysis was precluded because of clinical, methodological, and statistical heterogeneity. RESULTS: Nine relevant studies were found: 1 quality improvement project and 8 quasi-experimental studies. The overall quality of the relevant studies was moderate to high (61.1%-77.8%). Three types of outcome measurements for simulation in neurocritical care were identified: knowledge and clinical performance; confidence and comfort; and teamwork, communication, and leadership skills. Simulation training was associated with a significant improvement in knowledge and clinical performance, and confidence and comfort, but not in communication and leadership skills. CONCLUSION: Significant improvement in trainees' outcomes was observed. The current literature includes significant heterogeneity in the methods of evaluating simulation outcomes, although no patient outcomes were observed. Investigating the effect of simulation in neurocritical care training on patient outcomes in future studies is warranted.

Predictors of Endocrine Resistance in a Cohort of Mexican Breast Cancer Patients.

Purpose: This study aimed to determine the prevalence of endocrine resistance in a cohort of Hispanic Mexican breast cancer (BC) patients receiving care at Instituto Nacional de Cancerología (INCan). Additionally, the clinical-pathological factors associated with endocrine resistance were identified, and their impact on patient survival was explored. Methods: A retrospective analysis of 200 BC patients who attended INCan between 2012 and 2016 with estrogen receptor (ER) and progesterone receptor (PR) positive tumors was made. Endocrine resistance was defined according to the International Consensus Guidelines for Advance Breast Cancer 2 definition. Their clinicopathological characteristics were analyzed to determine the association with endocrine resistance presence. We used sensitivity analyses and multivariate-adjusted logistic regressions, Kaplan-Meier curves, and multivariate-adjusted Cox regressions. P-value < 0.05 was considered as statistically significant. Results: Endocrine resistance was observed in 32.5% of patients included in this study. The distinction between hormone resistance and sensitivity was influenced by tumor size and node status. It had a mean diameter of 7.15 cm in endocrine resistance cases compared to 5.71 cm in non-endocrine, with N3 status present in 20% of endocrine resistance cases versus only 2.2% in non-endocrine (p-value < 0.001). The clinical stage exhibited a strong association with endocrine resistance (Risk Ratio [RR] 4.39, 95% confidence interval [95%CI] 1.50, 11.43). Furthermore, endocrine resistance significantly impacted mortality during the follow-up, with a Hazard Ratio [HR] of 23.7 (95%CI 5.20, 108.42) in multivariable-adjusted models. However, a complete pathological response reduced the endocrine resistance risk, as demonstrated by a Risk Ratio (RR) of 0.15 (95% CI 0.03, 0.75). Conclusions: Advanced clinical stage at diagnosis predicted endocrine resistance in Hispanic Mexican BC patients. Complete pathologic response in locally advanced disease patients was also a key predictor of endocrine resistance. These results indicated that endocrine resistance was a critical factor in BC during follow-up.

Antivirulence and antipathogenic activity of Mayan herbal remedies against Pseudomonas aeruginosa.

ETHNOPHARMACOLOGICAL RELEVANCE: The Yucatan Peninsula has a privileged wealth of vascular plants with which various Mayan herbal formulations have been developed. However, studies on their antipathogenic and antivirulence properties are scarce. AIM OF THE STUDY: Identify antivirulence properties in Mayan herbal remedies and determine their antipathogenic capacity in burn wounds infected with Pseudomonas aeruginosa. MATERIALS AND METHODS: An ethnobotanical study was conducted in Mayan communities in central and southern Quintana Roo, Mexico. Furthermore, the antipathogenic capacity of three Mayan herbal remedies was analyzed using an animal model of thermal damage and P. aeruginosa infection. Antivirulence properties were determined by inhibiting phenotypes regulated by quorum sensing (pyocyanin, biofilm, and swarming) and by the secretion of the ExoU toxin. The chemical composition of the most active herbal remedy was analyzed using molecular network analysis. RESULTS: It was found that topical administration of the remedy called "herbal soap" (HS) for eleven days maintained 100% survival of the animals, reduced establishment of the bacteria in the burn and prevented its systemic dispersion. Although no curative effect was recorded on tissue damaged by HS treatment, its herbal composition strongly reduced swarming and ExoU secretion. Through analysis of Molecular Networks, it was possible to carry out a global study of its chemical components, and identify the family of oxindole monoterpenoid alkaloids and carboline and tetrahydropyrididole alkaloids. In addition, flavonols, flavan-3-ols, and quinic acid derivatives were detected. CONCLUSIONS: The antipathogenic and antivirulence capacity of ancient Mayan remedies makes them a potential resource for developing new antibacterial therapies to treat burns infected by P. aeruginosa.

Association between Gross Motor Competence and Physical Fitness in Chilean Children Aged 4 to 6 Years.

The preschool period is considered critical for the development of motor competence, but as far as we know, no studies have investigated the association between motor competence and physical fitness in Chilean children. The aim of this study was to analyse the association between gross motor competence and physical fitness, controlling for possible confounding factors. A cross-sectional study was conducted with a sample of 144 preschool children (56.25% girls) with an average age of 5.3 years (4 to 6 years) from the Araucanía region, Chile. Motor competence was measured using the Children's Movement Assessment Battery, 2nd Edition (MABC-2). Regarding physical fitness, the components of cardiorespiratory fitness, lower body muscle strength and speed/agility were evaluated using the Battery to Assess FITness in PREschool (PREFIT). Partial correlation models and analysis of variance (ANCOVA) were used to assess differences in physical fitness between motor competence categories, controlling for age and body mass index. The mean fitness scores for cardiorespiratory fitness, lower body muscle strength and speed/agility components were significantly higher in children with higher gross motor competence. In terms of effect size, large values were found for the lower body strength component in model 1 for boys and in model 2 for the total samples of girls and boys. The results of this study suggest that good levels of gross motor competence are associated with better physical fitness levels.

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL) Syndrome: A Case Report and Review of Literature.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant genetic disorder of the small arteries that causes ischemic vascular events, subcortical dementia, behavioral changes, and migraine-like headaches. It is caused by a mutation in the NOTCH3 gene; this disease was first described in 1955 by van Bogaert. We present a 29-year-old woman who presented to the neurology department. She has no history of chronic degenerative diseases. She has been complaining of migraine-like headaches for the past six months. She has cognitive impairment with arithmetic and executive function deficits on neurological examination. Blood biometry and blood chemistry are within normal parameters in her laboratory studies. A viral panel and immunological profile were also performed and were not reactive. A lumbar puncture was performed, and the composition of the cerebrospinal fluid was within normal limits. An MRI was performed, which showed bilateral and symmetric white matter hyperintensities consistent with CADASIL syndrome. There is no specific treatment. Management of these patients is based on symptom control. Neurological sequelae have an important impact on the quality of life and mortality of these patients. For this reason, pharmacological preventive therapies have been sought with controversial evidence.

Kynurenine 3-monooxygenase limits de novo NAD+ synthesis through dietary tryptophan in renal proximal tubule epithelial cell models.

Nicotinamide adenine dinucleotide (NAD+) is a pivotal coenzyme, essential for cellular reactions, metabolism, and mitochondrial function. Depletion of kidney NAD+ levels and reduced de novo NAD+ synthesis through the tryptophan-kynurenine pathway are linked to acute kidney injury (AKI), whereas augmenting NAD+ shows promise in reducing AKI. We investigated de novo NAD+ biosynthesis using in vitro, ex vivo, and in vivo models to understand its role in AKI. Two-dimensional (2-D) cultures of human primary renal proximal tubule epithelial cells (RPTECs) and HK-2 cells showed limited de novo NAD+ synthesis, likely due to low pathway enzyme gene expression. Using three-dimensional (3-D) spheroid culture model improved the expression of tubular-specific markers and enzymes involved in de novo NAD+ synthesis. However, de novo NAD+ synthesis remained elusive in the 3-D spheroid culture, regardless of injury conditions. Further investigation revealed that 3-D cultured cells could not metabolize tryptophan (Trp) beyond kynurenine (KYN). Intriguingly, supplementation of 3-hydroxyanthranilic acid into RPTEC spheroids was readily incorporated into NAD+. In a human precision-cut kidney slice (PCKS) ex vivo model, de novo NAD+ synthesis was limited due to substantially downregulated kynurenine 3-monooxygenase (KMO), which is responsible for KYN to 3-hydroxykynurenine conversion. KMO overexpression in RPTEC 3-D spheroids successfully reinstated de novo NAD+ synthesis from Trp. In addition, in vivo study demonstrated that de novo NAD+ synthesis is intact in the kidney of the healthy adult mice. Our findings highlight disrupted tryptophan-kynurenine NAD+ synthesis in in vitro cellular models and an ex vivo kidney model, primarily attributed to KMO downregulation.NEW & NOTEWORTHY Nicotinamide adenine dinucleotide (NAD+) is essential in regulating mitochondrial function. Reduced NAD+ synthesis through the de novo pathway is associated with acute kidney injury (AKI). Our study reveals a disruption in de novo NAD+ synthesis in proximal tubular models, but not in vivo, attributed to downregulation of enzyme kynurenine 3-monooxygenase (KMO). These findings highlight a crucial role of KMO in governing de novo NAD+ biosynthesis within the kidney, shedding light on potential AKI interventions.

Design and Characterization of Ocular Inserts Loaded with Dexamethasone for the Treatment of Inflammatory Ophthalmic Disease.

The short precorneal residence time of ophthalmic drops is associated with their low absorption; therefore, the development of ocular inserts capable of prolonging and controlling the ophthalmic release of drugs is an interesting option in the design and development of these drugs. A surface response design was developed, specifically the Central Composite Design (CCD), to produce ophthalmic films loaded with Dexamethasone (DEX) by the solvent evaporation method having experimental levels of different concentrations of previously selected polymers (PVP K-30 and Eudragit RS100.). Once optimization of the formulation was obtained, the in vivo test was continued. The optimal formulation obtained a thickness of 0.265 ± 0.095 mm, pH of 7.11 ± 0.04, tensile strength of 15.50 ± 3.94 gF, humidity (%) of 22.54 ± 1.7, mucoadhesion strength of 16.89 ± 3.46 gF, chemical content (%) of 98.19 ± 1.124, release of (%) 13,510.71, and swelling of 0.0403 ± 0.023 g; furthermore, in the in vivo testing the number and residence time of PMN cells were lower compared to the Ophthalmic Drops. The present study confirms the potential use of polymeric systems using PVPK30 and ERS100 as a new strategy of controlled release of ophthalmic drugs by controlling and prolonging the release of DEX at the affected site by decreasing the systemic effects of the drug.

Enhanced oxidative stress resistance in Ustilago maydis and its implications on the virulence.

The phytopathogenic fungus Ustilago maydis causes corn smut by suppressing host plant defenses, including the oxidative burst response. While many studies have investigated how U. maydis responds to oxidative stress during infection, the consequences of heightened resistance to oxidative stress on virulence remain understudied. This study aimed to identify the effects on virulence in U. maydis strains exhibiting enhanced resistance to hydrogen peroxide (H2O2).To achieve this, we exposed U. maydis SG200 to 20 escalating H2O2 shocks, resulting in an adapted strain resistant to concentrations as high as 60 mM of H2O2, a lethal dose for the initial strain. Genetic analysis of the adapted strain revealed five nucleotide substitutions, two minor copy number variants, and a large amplification event on chromosome nine (1-149 kb) encompassing the sole catalase gene. Overexpressing catalase increased resistance to H2O2; however, this resistance was lower than that observed in the adapted strain. Additionally, virulence was reduced in both strains with enhanced H2O2 resistance.In summary, enhanced H2O2 resistance, achieved through either continuous exposure to the oxidative agent or through catalase overexpression, decreased virulence. This suggests that the response to the oxidative stress burst in U. maydis is optimal and that increasing the resistance to H2O2 does not translate into increased virulence. These findings illuminate the intricate relationship between oxidative stress resistance and virulence in U. maydis, offering insights into its infection mechanisms.

Role of SLC5A8 as a Tumor Suppressor in Cervical Cancer.

BACKGROUND: The SLC5A8 gene is silenced in various types of cancer, including cervical cancer; we recently demonstrated that the SLC5A8 gene is also silenced in cervical cancer by hypermethylation of the CpG island in the gene promoter. This study aims to analyze whether SLC5A8 could be a tumor suppressor in cervical cancer. METHODS: After ectopic expressing SLC5A8 in the HeLa cell line, we evaluated its effects on cell behavior both in vitro and in vivo by Confocal immunofluorescence, cell proliferation, migration assays, and xenograft transplants. RESULTS: Overexpression of SLC5A8 in the HeLa cell line decreased its proliferation by arresting cancer cells in the G1 phase and inhibiting cellular migration. Furthermore, we observed that pyruvate increased the SLC5A8 effect, inducing S-phase arrest and inhibiting the entry into mitosis. SLC5A8 decreased tumor growth in xenograft transplants, significantly reducing the volume and tumor weight at 35 days of analysis. CONCLUSIONS: In summary, our results indicate that SLC5A8 has a role as a tumor suppressor in cervical cancer.

The Effects of a Physical Activity Intervention on Adiposity, Physical Fitness and Motor Competence: A School-Based, Non-Randomized Controlled Trial.

Evidence suggests that early physical activity interventions are a means of preventing childhood obesity and are more effective when delivered in a school setting and based on the ecological model. Therefore, the present study aims to determine the effect of a multicomponent intervention based on the ecological model on adiposity, physical fitness and motor competence in children aged 4 to 5 years. METHODS: This study is a non-randomized controlled trial involving 173 children from Chile. The intervention was based on an ecological model and consisted of a physical activity program with three simultaneous parts, affecting intra- and interpersonal dimensions. The adiposity index, body mass index and waist circumference were measured. For physical fitness, muscle strength in the lower part, speed/agility and cardiorespiratory fitness were measured. Motor competence was assessed using catching, aiming and dynamic and static balance tests. RESULTS: After the intervention, there was no reduction in adiposity indices; in the intervention group, body mass index increased significantly with a high effect size. The intervention group showed significant differences in physical fitness in the components of muscle strength in the lower part (p = 0.000) and speed/agility (p = 0.002). For motor competence, the intervention group showed significant improvements in most components. CONCLUSIONS: The multicomponent intervention did not reduce adiposity indices; however, it caused significant improvements in the physical fitness and motor competence components, so it seems prudent to continue implementing it, given the benefits that adequate levels of motor competence and physical fitness bring to children's health, both in the short and long term.

Synergistic Effect of Retinoic Acid and Lactoferrin in the Maintenance of Gut Homeostasis.

Lactoferrin (LF) is a glycoprotein that binds to iron ions (Fe2+) and other metallic ions, such as Mg2+, Zn2+, and Cu2+, and has antibacterial and immunomodulatory properties. The antibacterial properties of LF are due to its ability to sequester iron. The immunomodulatory capability of LF promotes homeostasis in the enteric environment, acting directly on the beneficial microbiota. LF can modulate antigen-presenting cell (APC) biology, including migration and cell activation. Nonetheless, some gut microbiota strains produce toxic metabolites, and APCs are responsible for initiating the process that inhibits the inflammatory response against them. Thus, eliminating harmful strains lowers the risk of inducing chronic inflammation, and consequently, metabolic disease, which can progress to type 2 diabetes mellitus (T2DM). LF and retinoic acid (RA) exhibit immunomodulatory properties such as decreasing cytokine production, thus modifying the inflammatory response. Their activities have been observed both in vitro and in vivo. The combined, simultaneous effect of these molecules has not been studied; however, the synergistic effect of LF and RA may be employed for enhancing the secretion of humoral factors, such as IgA. We speculate that the combination of LF and RA could be a potential prophylactic alternative for the treatment of metabolic dysregulations such as T2DM. The present review focuses on the importance of a healthy diet for a balanced gut and describes how probiotics and prebiotics with immunomodulatory activity as well as inductors of differentiation and cell proliferation could be acquired directly from the diet or indirectly through the oral administration of formulations aimed to maintain gut health or restore a eubiotic state in an intestinal environment that has been dysregulated by external factors such as stress and a high-fat diet.

Effect of Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2) deletion on intestinal colonization and systemic dissemination in chickens.

Salmonella's virulence genes are located in two regions known as Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2). SPI-1 allows the bacteria to invade the intestine, while SPI-2 is important for intracellular survival and replication, although it is also necessary for intestinal disease. The aim of this study was to evaluate the effect of the deletion of SPI-1 or SPI-2 genes on the intestinal and systemic salmonellosis using the avian model. Groups of chickens were orally infected with 1010 Colony-Forming Units (CFU) of S. Typhimurium SL1344 WT strain, as well as mutants ∆SPI-1 or ∆SPI-2. At different times post-infection, 5 chickens from each group were euthanized and examined postmortem. Cecum and liver were taken from each chicken for determination of CFU's, histopathological analysis and immunochemistry. Bacterial colonies were recovered from the liver and cecum samples infected with WT strain, while in the cultures from the organs infected with the mutant strains no colonies were recovered or were drastically affected in the ability to survive. In histopathological analysis, the WT strain produced lesions in liver and ceca, and it was detected by immunohistochemistry throughout the course of the infection. On the other hand, organs of chickens infected with ∆SPI-1 or ∆SPI-2 showed attenuated lesions and the immunohistochemistry revealed less bacteria compared to the WT strain. Taken together, our results show the importance of SPI-1 and SPI-2 genes for the complete intestinal and systemic disease in an in vivo avian model.

Synthesis, antibiofilm activity and molecular docking of N-acylhomoserine lactones containing cinammic moieties.

We prepared a series of cinnamoyl-containing furanones by an affordable and short synthesis. The nineteen compounds hold a variety of substituents including electron-donating, electron-withdrawing, bulky and meta-substituted phenyls, as well as heterocyclic rings. Compounds showed antibiofilm activity in S. aureus, K. pneumoniae and, more pronounced, against P. aeruginosa. The disruption of quorum sensing (QS) was tested using the violacein test and molecular docking predicted the antagonism of LasR as a plausible mechanism of action. The trimethoxylated and diene derivatives showed the best antibiofilm and anti-QS properties, thus becoming candidates for further modifications.

Harnessing the Reactivity of Duclauxin toward Obtaining hPTP1B1-400 Inhibitors.

Duclauxin (1) from Talaromyces sp. IQ-313 was reported as a putative allosteric modulator of human recombinant protein tyrosine phosphatase 1B (400 amino acids) (hPTP1B1-400), a validated target for the treatment of type II diabetes. Based on these findings, a one-strain-many-compound (OSMAC) experiment on the IQ-313 strain generated derivatives 5a, 6, and 7. Moreover, a one-/two-step semisynthetic approach guided by docking toward hPTP1B1-400 produced 38 analogs, a series (A) incorporating a lactam functionalization at C-1 (8a-15a, 36a, and 37a) and a series (B) containing a lactam at C-1 and an extra unsaturation between C-7 and C-8 (5b, 11b-37b). In vitro evaluation and structure-activity relationship (SAR) analysis revealed that analogs from the B series are up to 10-fold more active than 1 and derivatives from the A series. Furthermore, duclauxin (1) and 36b were assessed for their potential acute toxicity, estimating their LD50 to be higher than 300 mg/kg. Moreover, 36b significantly reduced glycemia in an insulin tolerance test in mice, suggesting that its mechanism of action is through the PTP1B inhibition.

Association of SLC12A1 and GLUR4 Ion Transporters with Neoadjuvant Chemoresistance in Luminal Locally Advanced Breast Cancer.

Chemoresistance to standard neoadjuvant treatment commonly occurs in locally advanced breast cancer, particularly in the luminal subtype, which is hormone receptor-positive and represents the most common subtype of breast cancer associated with the worst outcomes. Identifying the genes associated with chemoresistance is crucial for understanding the underlying mechanisms and discovering effective treatments. In this study, we aimed to identify genes linked to neoadjuvant chemotherapy resistance in 62 retrospectively included patients with luminal breast cancer. Whole RNA sequencing of 12 patient biopsies revealed 269 differentially expressed genes in chemoresistant patients. We further validated eight highly correlated genes associated with resistance. Among these, solute carrier family 12 member 1 (SLC12A1) and glutamate ionotropic AMPA type subunit 4 (GRIA4), both implicated in ion transport, showed the strongest association with chemoresistance. Notably, SLC12A1 expression was downregulated, while protein levels of glutamate receptor 4 (GLUR4), encoded by GRIA4, were elevated in patients with a worse prognosis. Our results suggest a potential link between SLC12A1 gene expression and GLUR4 protein levels with chemoresistance in luminal breast cancer. In particular, GLUR4 protein could serve as a potential target for drug intervention to overcome chemoresistance.

Aquiluscidin, a Cathelicidin from Crotalus aquilus, and the Vcn-23 Derivative Peptide, Have Anti-Microbial Activity against Gram-Negative and Gram-Positive Bacteria.

Anti-microbial peptides play a vital role in the defense mechanisms of various organisms performing functions that range from the elimination of microorganisms, through diverse mechanisms, to the modulation of the immune response, providing protection to the host. Among these peptides, cathelicidins, a well-studied family of anti-microbial peptides, are found in various animal species, including reptiles. Due to the rise in anti-microbial resistance, these compounds have been suggested as potential candidates for developing new drugs. In this study, we identified and characterized a cathelicidin-like peptide called Aquiluscidin (Aq-CATH) from transcripts obtained from the skin and oral mucosa of the Querétaro's dark rattlesnake, Crotalus aquilus. The cDNA was cloned, sequenced, and yielded a 566-base-pair sequence. Using bioinformatics, we predicted that the peptide precursor contains a signal peptide, a 101-amino-acid conserved cathelin domain, an anionic region, and a 34-amino-acid mature peptide in the C-terminal region. Aq-CATH and a derived 23-amino-acid peptide (Vcn-23) were synthesized, and their anti-microbial activity was evaluated against various species of bacteria in in vitro assays. The minimal inhibitory concentrations against bacteria ranged from 2 to 8 µg/mL for both peptides. Furthermore, at concentrations of up to 50 µM, they exhibited no significant hemolytic activity (<2.3% and <1.2% for Aquiluscidin and Vcn-23, respectively) against rat erythrocytes and displayed no significant cytotoxic activity at low concentrations (>65% cell viability at 25 µM). Finally, this study represents the first identification of an antimicrobial peptide in Crotalus aquilus, which belongs to the cathelicidin family and exhibits the characteristic features of these peptides. Both Aq-CATH and its derived molecule, Vcn-23, displayed remarkable inhibitory activity against all tested bacteria, highlighting their potential as promising candidates for further antimicrobial research.

Molecular mechanisms of resveratrol as chemo and radiosensitizer in cancer.

One of the primary diseases that cause death worldwide is cancer. Cancer cells can be intrinsically resistant or acquire resistance to therapies and drugs used for cancer treatment through multiple mechanisms of action that favor cell survival and proliferation, becoming one of the leading causes of treatment failure against cancer. A promising strategy to overcome chemoresistance and radioresistance is the co-administration of anticancer agents and natural compounds with anticancer properties, such as the polyphenolic compound resveratrol (RSV). RSV has been reported to be able to sensitize cancer cells to chemotherapeutic agents and radiotherapy, promoting cancer cell death. This review describes the reported molecular mechanisms by which RSV sensitizes tumor cells to radiotherapy and chemotherapy treatment.