The human bile salt sodium deoxycholate induces metabolic and cell envelope changes in Salmonella Typhi leading to bile resistance

Introduction. Salmonella enterica serovar Typhi (S. Typhi) is the etiological agent of typhoid fever. To establish an infection in the human host, this pathogen must survive the presence of bile salts in the gut and gallbladder. Hypothesis. S. Typhi uses multiple genetic elements to resist the presence of human bile. Aims. To determine the genetic elements that S. Typhi utilizes to tolerate the human bile salt sodium deoxycholate. Methodology. A collection of S. Typhi mutant strains was evaluated for their ability to growth in the presence of sodium deoxycholate and ox-bile. Additionally, transcriptomic and proteomic responses elicited by sodium deoxycholate on S. Typhi cultures were also analysed. Results. Multiple transcriptional factors and some of their dependent genes involved in central metabolism, as well as in cell envelope, are required for deoxycholate resistance. Conclusion. These findings suggest that metabolic adaptation to bile is focused on enhancing energy production to sustain synthesis of cell envelope components exposed to damage by bile salts.

TolA, TolB, and TolR Are Critical Cell Envelope Proteins of Salmonella Enterica Serovar Choleraesuis Affecting Cell Morphology, OMVs Production, and Virulence

The Tol-Pal system of Gram-negative bacteria is necessary for maintaining outer membrane integrity. It is a multiprotein complex of five envelope proteins, TolQ, TolR, TolA, TolB, and Pal. These proteins were first investigated in E. coli, and subsequently been identified in many other bacterial genera. However, the function of the Tol-Pal system in Salmonella Choleraesuis pathogenesis is still unclear. Here, we reported the role of three of these proteins in the phenotype and biology of S. Choleraesuis. We found that mutations in tolA, tolB, and tolR caused severe damage to the cell wall, which was supported by observing the microstructure of spherical forms, long chains, flagella defects, and membrane blebbing. We confirmed that all the mutants significantly decreased S. Choleraesuis survival when exposed to sodium deoxycholate and exhibited a high sensitivity to vancomycin, which may be explained by the disruption of envelope integrity. In addition, tolA, tolB, and tolR mutants displayed attenuated virulence in a mouse infection model. This could be interpreted as a series of defective phenotypes in the mutants, such as severe defects in envelope integrity, growth, and motility. Further investigation showed that all the genes participate in outer membrane vesicles (OMVs) biogenesis. Interestingly, immunization with OMVs from ΔtolB efficiently enhanced murine viability in contrast to OMVs from the wild-type S. Choleraesuis, suggesting its potential use in vaccination strategies. Collectively, this study provides an insight into the biological role of the S. Choleraesuis Tol-Pal system.

Clinical case of fatal panniculitis resulting from administration of lipolytic

The article describes a clinical case of a five-fold administration of a direct lipolytic–phosphatidylcholine / deoxycholic acid for cosmetic purposes, which resulted in widespread septal panniculitis, systemic inflammatory reaction, secondary myositis, thrombotic microangiopathic syndrome, fatty necrosis of the pancreatic head, necrotic nephrosis and multiple organ failure, which led to death of the patient.Materials and methods. Analysis of medical records, histological examination of autopsy material.Conclusions. Injection lipolysis using phosphatidylcholine / deoxycholate causes uncontrolled necrosis of adipose and vascular tissue, fibrosis, which makes the indefinitely long-term consequences of the administration of drugs for the non-surgical treatment of subcutaneous fat deposits. Phosphatidylcholine / sodium deoxycholate is not recommended for use in the presence of general obesity, somatic pathology, or in elderly patients.

Intranasal Zolmitriptan-Loaded Bilosomes with Extended Nasal Mucociliary Transit Time for Direct Nose to Brain Delivery

This study aimed at delivering intranasal zolmitriptan directly to the brain through preparation of bilosomes incorporated into a mucoadhesive in situ gel with extended nasal mucociliary transit time. Zolmitriptan-loaded bilosomes were constructed through a thin film hydration method applying Box–Behnken design. The independent variables were amount of sodium deoxycholate and the amount and molar ratio of cholesterol/Span®40 mixture. Bilosomes were assessed for their entrapment efficiency, particle size and in vitro release. The optimal bilosomes were loaded into mucoadhesive in situ gel consisting of poloxamer 407 and hydroxypropyl methylcellulose. The systemic and brain kinetics of Zolmitriptan were evaluated in rats by comparing intranasal administration of prepared gel to an IV solution. Statistical analysis suggested an optimized bilosomal formulation composition of sodium deoxycholate (5 mg) with an amount and molar ratio of cholesterol/Span®40 mixture of 255 mg and 1:7.7, respectively. The mucoadhesive in situ gel containing bilosomal formulation had a sol-gel temperature of 34.03 °C and an extended mucociliary transit time of 22.36 min. The gelling system possessed enhanced brain bioavailability compared to bilosomal dispersion (1176.98 vs. 835.77%, respectively) following intranasal administration. The gel revealed successful brain targeting with improved drug targeting efficiency and direct transport percentage indices. The intranasal delivery of mucoadhesive in situ gel containing zolmitriptan-loaded bilosomes offered direct nose-to-brain drug targeting with enhanced brain bioavailability.

Cardiac aorta-derived extracellular matrix scaffold enhances critical mediators of angiogenesis in isoproterenol-induced myocardial infarction mice

An incapability to improve lost cardiac muscle caused by acute ischemic injury remains the most important deficiency of current treatments to prevent heart failure. We investigated whether cardiomyocytes culturing on cardiac aorta-derived extracellular matrix scaffold has advantageous effects on cardiomyocytes survival and angiogenesis biomarkers’ expression. Ten male NMRI mice were randomly divided into two groups: (1) control (healthy mice) and (2) myocardial infarction (MI)-induced model group (Isoproterenol/subcutaneously injection/single dose of 85 mg/kg). Two days after isoproterenol injection, all animals were sacrificed to isolate cardiomyocytes from myocardium tissues. The fresh thoracic aorta was obtained from male NMRI mice and decellularized using 4% sodium deoxycholate and 2000 kU DNase-I treatments. Control and MI-derived cardiomyocytes were seeded on decellularized cardiac aorta (DCA) considered three-dimensional (3D) cultures. To compare, the isolated cardiomyocytes from control and MI groups were also cultured as a two-dimensional (2D) culture system for 14 days. The cell viability was examined by MTT assay. The expression levels of Hif-1α and VEGF genes and VEGFR1 protein were tested by real-time PCR and western blotting, respectively. Moreover, the amount of VEGF protein was evaluated in the conditional media of the 2D and 3D systems. The oxidative stress was assessed via MDA assay. Hif-1α and VEGF genes were downregulated in MI groups compared to controls. However, the resulting data showed that decellularized cardiac aorta matrices positively affect the expression of Hif-1α and VEGF genes. The expression level of VEGFR1 protein was significantly (p ≤ 0.01) upregulated in both MI and healthy cell groups cultured on decellularized cardiac aorta matrices as a 3D system compared to the MI cell group cultured in the 2D systems. Furthermore, MDA concentration significantly decreased in 3D-cultured cells (MI and healthy cell groups) rather than the 2D-cultured MI group (p ≤ 0.015). The findings suggest that cardiac aorta-derived extracellular scaffold by preserving VEGF, improving the cell viability, and stimulating angiogenesis via upregulating Hif-1α, VEGF, and VEGFR1 in cardiomyocytes could be considered as a potential approach along with another therapeutic method to reduce the complications of myocardial infarction and control the progressive pathological conditions related to MI.

A Decellularized Human Limbal Scaffold for Limbal Stem Cell Niche Reconstruction

The transplantation of ex vivo expanded limbal epithelial progenitor cells (LEPCs) on amniotic membrane or fibrin gel is an established therapeutic strategy to regenerate the damaged corneal surface in patients with limbal stem cell deficiency (LSCD), but the long-term success rate is restricted. A scaffold with niche-specific structure and extracellular matrix (ECM) composition might have the advantage to improve long-term clinical outcomes, in particular for patients with severe damage or complete loss of the limbal niche tissue structure. Therefore, we evaluated the decellularized human limbus (DHL) as a biomimetic scaffold for the transplantation of LEPCs. Corneoscleral tissue was decellularized by sodium deoxycholate and deoxyribonuclease I in the presence or absence of dextran. We evaluated the efficiency of decellularization and its effects on the ultrastructure and ECM composition of the human corneal limbus. The recellularization of these scaffolds was studied by plating cultured LEPCs and limbal melanocytes (LMs) or by allowing cells to migrate from the host tissue following a lamellar transplantation ex vivo. Our decellularization protocol rapidly and effectively removed cellular and nuclear material while preserving the native ECM composition. In vitro recellularization by LEPCs and LMs demonstrated the good biocompatibility of the DHL and intrastromal invasion of LEPCs. Ex vivo transplantation of DHL revealed complete epithelialization as well as melanocytic and stromal repopulation from the host tissue. Thus, the generated DHL scaffold could be a promising biological material as a carrier for the transplantation of LEPCs to treat LSCD.

Correlated Transcriptional Responses Provide Insights into the Synergy Mechanisms of the Furazolidone, Vancomycin, and Sodium Deoxycholate Triple Combination in Escherichia coli

Synergistic antibiotic combinations are a promising alternative strategy for developing effective therapies for multidrug-resistant bacterial infections. The synergistic combination of the existing antibiotics nitrofurans and vancomycin with sodium deoxycholate shows promise in inhibiting and killing multidrug-resistant Gram-negative bacteria.

In vivo performance of decellularized tracheal grafts in the reconstruction of long length tracheal defects: Experimental study

Background: The repair of long-segment tracheal lesions remains an important challenge. Nowdays no predictable and dependable substitute has been found. Decellularized tracheal scaffolds have shown to be a promising graft for tracheal transplantation, since it is non-immunogenic. Objective: Evaluate in vivo decellularized tracheal allografts performance to replace long tracheal segment. Methods: Forty-five swines underwent surgery as follows: Fifteen trachea donors and 30 receptors of decellularized trachea allografts. The receptors were randomly divided in five groups ( n = 6). In groups I and II, donor trachea segment was decellularized by 15 cycles with sodium deoxycholate and deoxyribonuclease, in group II, the allograft was reinforced with external surgical steel wire. Groups, III, IV, and V decellularization was reduced to seven cycles, supplemented with cryopreservation in group IV and with glutaraldehyde in group V. A 10 rings segment was excised from the receptor swine and the decellularized trachea graft was implanted to re-establish trachea continuity. Results: Both decellularization cycles caused decreased stiffness. All trachea receptors underwent euthanasia before the third post-implant week due to severe dyspnea and trachea graft stenosis, necrosis, edema, inflammation, hemorrhage, and granulation tissue formation in anastomotic sites. Histologically all showed total loss of epithelium, separation of collagen fibers, and alterations in staining. Conclusions: Both decellularization techniques severely damaged the structure of the trachea and the extracellular matrix of the cartilage, resulting in a no functional graft, in spite of the use of surgical wire, cryopreservation or glutaraldehyde treatment. An important drawback was the formation of fibrotic stenosis in both anastomosis.