A fingerprint of plasma proteome alteration after local tissue damage induced by Bothrops leucurus snake venom in mice

Bothrops spp. is responsible for about 70% of snakebites in Brazil, causing a diverse and complex pathophysiological condition. Bothrops leucurus is the main species of medical relevance found in the Atlantic coast in the Brazilian Northeast region. The pathophysiological effects involved B. leucurus snakebite as well as the organism's reaction in response to this envenoming, it has not been explored yet. Thus, edema was induced in mice paw using 1.2, 2.5, and 5.0 μg of B. leucurus venom, the percentage of edema was measured 30 min after injection and the blood plasma was collected and analyzed by shotgun proteomic strategy. We identified 80 common plasma proteins with differential abundance among the experimental groups and we can understand the early aspects of this snake envenomation, regardless of the suggestive severity of an ophidian accident. The results showed B. leucurus venom triggers a thromboinflammation scenario where family's proteins of the Serpins, Apolipoproteins, Complement factors and Component subunits, Cathepsins, Kinases, Oxidoreductases, Proteases inhibitors, Proteases, Collagens, Growth factors are related to inflammation, complement and coagulation systems, modulators platelets and neutrophils, lipid and retinoid metabolism, oxidative stress and tissue repair. Our findings set precedents for future studies in the area of early diagnosis and/or treatment of snakebites. SIGNIFICANCE: The physiopathological effects that the snake venoms can cause have been investigated through classical and reductionist tools, which allowed, so far, the identification of action mechanisms of individual components associated with specific tissue damage. The currently incomplete limitations of this knowledge must be expanded through new approaches, such as proteomics, which may represent a big leap in understanding the venom-modulated pathological process. The exploration of the complete protein set that suffer modifications by the simultaneous action of multiple toxins, provides a map of the establishment of physiopathological phenotypes, which favors the identification of multiple toxin targets, that may or may not act in synergy, as well as favoring the discovery of biomarkers and therapeutic targets for manifestations that are not neutralized by the antivenom.

Effect of swimming training on nerve morphological recovery after compressive injury

OBJECTIVE

This study aims to investigate morphological alterations caused by partial sciatic nerve ligation (PNL) and the efficacy of a moderate-intensity swimming training as therapeutic strategy for nerve regeneration.

METHODS

A number of 30 male adult mice were equally divided in control, 14 days after PNL (PNL 14 days), 42 days after PNL (PNL 42 days), 70 days after PNL (PNL 70 days) and 5-week exercise training after 7 days post-lesion (PNL trained 35 days) groups. PNL trained 35 days group began with a 10-min session for 3 days and this time was gradually increased by 10 min every three sessions until the animals had swum for 50 min per session. Morphoquantitative analysis was carried out to assess nerve regeneration in each group.

RESULTS

PNL 14 days group exhibited less degenerating signs than PNL 42 days group, where most post-lesion alterations were visualized. Nerve area and minimum diameter were significantly lower (p < 0.05) than control group. PNL 70 days group showed a greater degree of regenerating fibers and similar morphometric parameters to control group. PNL trained 35 days demonstrated signs of regeneration, reaching control group values in the morphometric analysis.

DISCUSSION

PNL promotes great histopathological changes, which became more visible at 42 post-injury days. A natural nerve-regeneration tendency was observed throughout time, as observed in PNL 70 days group; nevertheless, moderate swimming training was found to be a therapeutic resource for nerve regeneration, accelerating such process from a morphoquantitative perspective.

ABBREVIATIONS

ANOVA: One-way analysis of variance; BDNF: Brain-derived neurotrophic factor; FGF-2: Fibroblast growth factor 2; GDNF: Glial cell line derived neurotrophic factor; IGF: Insulin-link growth factor; IL-1β: Interleukin-1β; NGF: Neural growth factor; PBS: Phosphate-buffered saline; PNL: Partial sciatic nerve ligation.