Exploring the in vivo wound healing effects of a recombinant hemolin from the caterpillar Lonomia obliqua

Hemolin proteins are cell adhesion molecules from lepidopterans involved in a wide range of cell interactions concerning their adhesion properties. However, hemolins roles in cell proliferation and wound healing are not fully elucidated. It has been recently reported that rLosac, a recombinant hemolin from the caterpillar Lonomia obliqua, presents antiapoptotic activity and is capable of improving in vitro wound healing. Therefore, this study aimed to explore rLosacs in vivo effects using a skin wound healing model in rats. Methods Circular full-thickness wounds in the rat dorsum skin were treated either with rLosac, or with saline (control), allowing healing by keeping the wounds occluded and moist. During the wound healing, the following tissue regeneration parameters were evaluated: wound closure and collagen content. Furthermore, tissue sections were subjected to histological and immunohistochemical analyses. Results The rLosac treatment has demonstrated its capacity to improve wound healing, as reflected in findings of a larger number of activated fibroblasts, proliferation of epithelial cells, increase of collagen type 1, and decrease of inflammatory infiltrate. Conclusion The findings have indicated the rLosac protein as a very promising molecule for the development of new wound-healing formulations.

Exploring the in vivo wound healing effects of a recombinant hemolin from the caterpillar Lonomia obliqua

Background Hemolin proteins are cell adhesion molecules from lepidopterans involved in a wide range of cell interactions concerning their adhesion properties. However, hemolin's roles in cell proliferation and wound healing are not fully elucidated. It has been recently reported that rLosac, a recombinant hemolin from the caterpillar Lonomia obliqua, presents antiapoptotic activity and is capable of improving in vitro wound healing. Therefore, this study aimed to explore rLosac's in vivo effects using a skin wound healing model in rats. Methods Circular full-thickness wounds in the rat dorsum skin were treated either with rLosac, or with saline (control), allowing healing by keeping the wounds occluded and moist. During the wound healing, the following tissue regeneration parameters were evaluated: wound closure and collagen content. Furthermore, tissue sections were subjected to histological and immunohistochemical analyses. Results The rLosac treatment has demonstrated its capacity to improve wound healing, as reflected in findings of a larger number of activated fibroblasts, proliferation of epithelial cells, increase of collagen type 1, and decrease of inflammatory infiltrate. Conclusion The findings have indicated the rLosac protein as a very promising molecule for the development of new wound-healing formulations.(AU)

Coagulaçäo sangüínea: açäo de substratos e de inibidores peptídicos / Blood Clotting: action of peptide substrates and inhibitors

BuXI, o inibidor do tipo Kunitz isolado das sementes de B. ungulata inativa fator Xa, calicreína plasmática humana, tripsina e o LOPAP, ativador de protrombina isolado das cerdas da lagarta Lonomia obliqua. BvTI, isolado das sementes de B. variegata,l extensamente (70 por cento) homólogo a BuXI, inibe tripsina mas não inibe fator Xa e LOPAP. A diferença mais marcante entre os sítios reativos de BuXI e BvTI encontra-se nos resíduos Met59, Met66 e Thrs7. As constantes de inibição medidas foram confirmadas para tripsina e fator Xa,1 em sistema Biacore. BuXI também inibe o fator Xa no complexo protrombinase. A hidrólise de substratos peptídicos de fluorescência apagada, sintetizados com base nos sítios reativos desses inibidores, foi estudada com fator Xa, LOPAP,1 calicreína plasmática, calicreína pancreática de porco, trombina e tripsina. Abz-VMIAALPRTMFIQ-EDDnp,l peptídeo modelo baseado em BuXI, foi eficientemente hidrolisado fator Xa, mas não Abz-WISALPRSLFIQ-EDDnp baseado em BvTI. A influência do número de resíduos de aminoácidos, para a interação com o tor Xá, foi demonstrada pelo decréscimo de eficiência catalítica da hidrólise de bstratos de cadeia mais curta. Contudo, para trombina, tais mudanças foram de eito menor. Devido à constatação de que BuXI deixa de inibir o fator Xa após ser oxidado, a articipação dos resíduos de metionina para a interação enzima-substrato foi estudada. ais resíduos efetivamente estão envolvidos nas reações catalisadas por fator Xa e OPAP como demonstrado na série de substratos peptídicos baseados nos sítios ativos de BuXI e BvTI, que é desprovido de metionina...(au)