Using an Aluminum Hydroxide–Chitosan Matrix Increased the Vaccine Potential and Immune Response of Mice against Multi-Drug-Resistant Acinetobacter baumannii

Acinetobacter baumannii is a Gram-negative, immobile, aerobic nosocomial opportunistic coccobacillus that causes pneumonia, septicemia, and urinary tract infections in immunosuppressed patients. There are no commercially available alternative antimicrobials, and multi-drug resistance is an urgent concern that requires emergency measures and new therapeutic strategies. This study evaluated a multi-drug-resistant A. baumannii whole-cell vaccine, inactivated and adsorbed on an aluminum hydroxide–chitosan (mAhC) matrix, in an A. baumannii sepsis model in immunosuppressed mice by cyclophosphamide (CY). CY-treated mice were divided into immunized, non-immunized, and adjuvant-inoculated groups. Three vaccine doses were given at 0D, 14D, and 28D, followed by a lethal dose of 4.0 × 108 CFU/mL of A. baumannii. Immunized CY-treated mice underwent a significant humoral response, with the highest IgG levels and a higher survival rate (85%); this differed from the non-immunized CY-treated mice, none of whom survived (p < 0.001), and from the adjuvant group, with 45% survival (p < 0.05). Histological data revealed the evident expansion of white spleen pulp from immunized CY-treated mice, whereas, in non-immunized and adjuvanted CY-treated mice, there was more significant organ tissue damage. Our results confirmed the proof-of-concept of the immune response and vaccine protection in a sepsis model in CY-treated mice, contributing to the advancement of new alternatives for protection against A. baumannii infections.

Oral angiotensin-(1-7) peptide modulates intestinal microbiota improving metabolic profile in obese mice

BACKGROUND

Obesity is a serious health problem which dysregulate Renin-Angiotensin System and intestinal microbiota.

OBJECTIVE

The present study aimed to evaluate the Angiotensin-(1-7) [ANG-(1-7)] oral formulation effects on obese mice intestinal microbiota.

METHODS

Mice were divided into four groups: obese and non-obese treated with ANG-(1-7) and obese and non-obese without ANG-(1-7) during four weeks.

RESULTS

We observed a significant decrease in the fasting plasma glucose, total cholesterol, triglycerides, and Low-density lipoprotein levels and increased High-density lipoprotein in animals treated with ANG-(1-7). The histological analysis showed intestinal villi height reduction in mice treated with ANG-(1-7). Additionally, increased Bacteroidetes and decreased Firmicutes (increased Bacteroidetes/Firmicutes ratio) and Enterobacter cloacae populations were observed in the High-Fat Diet + ANG-(1-7) group. Receptor toll-like 4 (TLR4) intestinal mRNA expression was reduced in the HFD+ ANG-(1-7) group. Finally, the intestinal expression of the neutral amino acid transporter (B0AT1) was increased in animals treated with ANG-(1-7), indicating a possible mechanism associated with tryptophan uptake.

CONCLUSION

The results of the present study suggest for the first time an interaction between oral ANG-(1-7) and intestinal microbiota modulation.

Oral Probiotic Bifidobacterium Longum Supplementation Improves Metabolic Parameters and Alters the Expression of the Renin-Angiotensin System in Obese Mice Liver

BACKGROUND

Obesity and non-alcoholic fatty liver disease (NAFLD) have been increasing at an alarming rate worldwide. Bifidobacterium longum (BL), a common member of the human gut microbiota, has important health benefits through several mechanisms.

OBJECTIVES

We evaluated the BL supplementation effects on body metabolism and renin-angiotensin components hepatic expression in mice fed a high-fat diet.

METHODS

Thirty-two male mice were divided into four groups: standard diet + placebo (ST), standard diet + Bifidobacterium longum (ST + BL), high-fat diet + placebo (HFD) and high-fat diet + Bifidobacterium longum (HFD + BL). Following the obesity induction period, the ST + BL and HFD + BL groups were supplemented with Bifidobacterium longum for 4 weeks. Then, body, biochemical, histological and molecular parameters were evaluated.

RESULTS

HFD + BL mice had a significant decrease in adipose tissue mass and blood glucose levels, as well as a significant reduction in blood glucose during an intraperitoneal glucose tolerance test. The treatment also resulted in reduced levels of total cholesterol and hepatic fat accumulation. Moreover, we observed an increase in angiotensin converting enzyme 2 (ACE2) and Mas receptor (MASR) expression levels in BL-treated obese mice.

CONCLUSIONS

These data demonstrate that BL may have the potential to prevent obesity and NAFLD by modulating the mRNA expression of renin-angiotensin system components.

The role of the angiotensin II type I receptor blocker telmisartan in the treatment of non-alcoholic fatty liver disease: a brief review

Non-alcoholic fatty liver disease (NAFLD) is currently considered an important component of metabolic syndrome (MetS). The spectrum of NAFLD includes conditions that range from simple hepatic steatosis to non-alcoholic steatohepatitis. NAFLD is correlated with liver-related death and is predicted to be the most frequent indication for liver transplantation by 2030. Insulin resistance is directly correlated to the central mechanisms of hepatic steatosis in NAFLD patients, which is strongly correlated to the imbalance of the renin–angiotensin system, that is involved in lipid and glucose metabolism. Among the emerging treatment approaches for NAFLD is the anti-hypertensive agent telmisartan, which has positive effects on liver, lipid, and glucose metabolism, especially through its action on the renin–angiotensin system, by blocking the ACE/AngII/AT1 axis and increasing ACE2/Ang(1–7)/Mas axis activation. However, treatment with this drug is only recommended for patients with an established indication for anti-hypertensive therapy. Thus, there is an increased need for large randomized controlled trials with the aim of elucidating the effects of telmisartan on liver disease, especially NAFLD. From this perspective, the present review aims to provide a brief examination of the pathogenesis of NAFLD/NASH and the role of telmisartan on preventing liver disorders and thus to improve the discussion on potential therapies.

Effects of Dietary Macronutrient Composition on FNDC5 and Irisin in Mice Skeletal Muscle

BACKGROUND

Fibronectin type III domain containing 5 (FNDC5) and its protein product Irisin are therapeutic targets for obesity-associated disorders. Irisin plays an important role in energy regulation, inducing browning of white adipocytes, and improving obesity. We aimed to investigate the association between muscle Irisin expression and dietary quality.

METHODS

Twenty-eight female mice were divided into four groups and fed the following experimental diets for 60 days: standard diet (SD), high-carbohydrate diet (HCD), high-fat diet (HFD), and high-protein diet (HPD). We evaluated body weight, food intake, serum total cholesterol, triacylglycerol, and glucose. We also performed glucose tolerance and insulin sensitivity tests. Expression of FNDC5 was evaluated by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) of soleus muscle. Western blot was used to assess Irisin protein expression.

RESULTS

The major finding of the present study was that HFD and HCD were associated with a downregulation of FNDC5. In addition to these results, we noted a significant reduction in skeletal muscle Irisin level. HPD prevented reductions of both FNDC5 and Irisin levels, as well as increased brown adipose tissue, compared to the control group.

CONCLUSIONS

In conclusion, we observed that the HPD type of diet can change both FNDC5 expression and Irisin levels. Thus, the HPD might be the most appropriate diet to achieve high amounts of Irisin, a target molecule for the treatment of obesity and its co-morbidities.

Reversible posterior leucoencephalopathy syndrome associated with bone marrow transplantation

Reversible posterior leucoencephalopathy syndrome (RPLS) has previously been described in patients who have renal insufficiency, eclampsia, hypertensive encephalopathy and patients receiving immunosuppressive therapy. The mechanism by which immunosuppressive agents can cause this syndrome is not clear, but it is probably related with cytotoxic effects of these agents on the vascular endothelium. We report eight patients who received cyclosporine A (CSA) after allogeneic bone marrow transplantation or as treatment for severe aplastic anemia (SSA) who developed posterior leucoencephalopathy. The most common signs and symptoms were seizures and headache. Neurological dysfunction occurred preceded by or concomitant with high blood pressure and some degree of acute renal failure in six patients. Computerized tomography studies showed low-density white matter lesions involving the posterior areas of cerebral hemispheres. Symptoms and neuroimaging abnormalities were reversible and improvement occurred in all patients when given lower doses of CSA or when the drug was withdrawn. RPLS may be considered an expression of CSA neurotoxicity.

[Use of botulinum toxin in the treatment of laryngeal dystonia (spasmodic dysphonia): preliminary study of twelve patients]

Laryngeal dystonia (spasmodic dysphonia) is a movement disorder characterized by involuntary contractions of laryngeal muscles involved with vocalization. The introduction of botulinum toxin in the treatment of laryngeal dystonia had a major clinical impact due to the striking improvement of symptoms. We report the preliminary results of therapeutical use of botulinum toxin in the treatment of twelve patients with laryngeal dystonia. After an extensive clinical evaluation, the patients underwent a videostroboscopic exam for diagnostic confirmation. Botulinum toxin was injected in the cricothyreoid membrane, directed towards the thyreoaritenoid muscle, with the aid of eletromyography needles. Most of patients who underwent botulinum toxin injection had a significant improvement of their symptoms (83%), with effects lasting for four months in average and without important side effects.