Modulating miR-146a Expression by Hydrogen Sulfide Ameliorates Motor Dysfunction and Axonal Demyelination in Cuprizone-Induced Multiple Sclerosis.

Multiple sclerosis (MS) is a progressive neuro-inflammatory and neuro-autoimmune disease. Although hydrogen sulfide has recently shown potential therapeutic impacts in different neurological diseases, its effects on MS are still obscure. MiR-146a is considered a vital target for different therapeutic approaches in treating MS. The present study is directed to explore the therapeutic effects of NaHS (hydrogen sulfide donor) on cuprizone-induced MS and to explore whether NaHS can mediate its effects via regulating miR-146a expression. A total of 28 male C57Bl/6 mice were divided into 4 groups; control, cuprizone-intoxicated, NaHS control (100 µmol/kg/day, i.p), and NaHS-treated groups. Intriguingly, NaHS treatment managed to improve locomotor coordination and curb neuronal inflammation and demyelination as evidenced by hematoxylin & eosin, and Luxol fast blue staining and the increased myelin basic protein (MBP) content. Additionally, NaHS reduced interleukin-1 receptor-associated kinase-1 (IRAK-1), nuclear transcription factor kappa B (NF-κB), interleukin (IL)-17, and IL-1ß brain levels along with downregulation of miR-146a expression compared with the untreated cuprizone-intoxicated group. Furthermore, NaHS-treated animals revealed much less oxidative stress compared to the untreated animals as evidenced by elevated glutathione and reduced malondialdehyde contents. Altogether, the current work reported that NaHS could improve motor dysfunction and reduce axonal demyelination, oxidative stress, as well as neuro-inflammation in mice with MS. Thus, using H2S-releasing compounds could be a promising approach in MS treatment strategies. The mechanism of these beneficial effects may involve the regulation of miR-146a/NF-κB/IL-1ß axis.

Safety of inhaled ivermectin as a repurposed direct drug for treatment of COVID-19: A preclinical tolerance study.

INTRODUCTION: SARS-CoV-2 replication in cell cultures has been shown to be inhibited by ivermectin. However, ivermectin's low aqueous solubility and bioavailabilityhinders its application in COVID-19 treatment. Also, it has been suggested that best outcomes for this medication can be achieved via direct administration to the lung. OBJECTIVES: This study aimed at evaluating the safety of a novel ivermectin inhalable formulation in rats as a pre-clinical step. METHODS: Hydroxy propyl-ß-cyclodextrin(HP-ß-CD) was used to formulate readily soluble ivermectin lyophilized powder. Adult male rats were used to test lung toxicity for ivermectin-HP-ß-CD formulations in doses of 0.05, 0.1, 0.2, 0.4 and 0.8 mg/kg for 3 successive days. RESULTS: The X-ray diffraction for lyophilized ivermectin-HP-ß-CD revealed its amorphous structure that increased drug aqueous solubility 127-fold and was rapidly dissolved within 5 s in saline.Pulmonary administration of ivermectin-HP-ß-CD in dosesof 0.2, 0.4 and 0.8 mg/kgshowed dose-dependent increase in levels of TNF-α, IL-6, IL-13 and ICAM-1 as well as gene expression of MCP-1, protein expression of PIII-NP and serum levels of SP-D paralleled by reduction in IL-10. Moreover, lungs treated with ivermectin (0.2 mg/kg) revealed mild histopathological alterations, while severe pulmonary damage was seen in rats treated with ivermectin at doses of 0.4 and 0.8 mg/kg. However, ivermectin-HP-ß-CD formulation administered in doses of 0.05 and 0.1 mg/kg revealed safety profiles. CONCLUSION: The safety of inhaledivermectin-HP-ß-CD formulation is dose-dependent. Nevertheless, use of low doses(0.05 and 0.1 mg/kg) could be considered as a possible therapeutic regimen in COVID-19 cases.

Genetic Diversity and Phylodynamics of Avian Coronaviruses in Egyptian Wild Birds.

Avian coronaviruses (ACoVs) are continuously evolving and causing serious economic consequences in the poultry industry and around the globe. Owing to their extensive genetic diversity and high mutation rates, controlling ACoVs has become a challenge. In this context, the potential contribution of wild birds in the disease dynamics, especially in domesticated birds, remains largely unknown. In the present study, five hundred fifty-seven (n = 557) cloacal/fecal swabs were collected from four different wild bird species from eight Egyptian governorates during 2016 and a total of fourteen positive isolates were used for phylodynamics and evolutionary analysis. Genetic relatedness based on spike (S1) gene demonstrated the clustering of majority of these isolates where nine isolates grouped within Egy/variant 2 (IS/885 genotype) and five isolates clustered within Egy/variant 1 (IS/1494/06 genotype). Interestingly, these isolates showed noticeable genetic diversity and were clustered distal to the previously characterized Egy/variant 1 and Egy/variant 2 in Egyptian commercial poultry. The S1 gene based comparison of nucleotide identity percentages revealed that all fourteen isolates reported in this study were genetically related to the variant GI-23 lineage with 92⁻100% identity. Taken together, our results demonstrate that ACoVs are circulating in Egyptian wild birds and highlight their possible contributions in the disease dynamics. The study also proposes that regular monitoring of the ACoVs in wild birds is required to effectively assess the role of wild birds in disease spread, and the emergence of ACoVs strains in the country.