Molecular characterization of matrix metalloproteinase-1 (MMP-1) in Lucilia sericata larvae for potential therapeutic applications

Background: The salivary glands of Lucilia sericata are the first organs to express specific endopeptidase enzymes. These enzymes play a central role in wound healing, and they have potential to be used therapeutically. Methods: Rapid amplification of cDNA ends and rapid amplification of genomic ends were used to identify the coding sequence of MMP-1 from L. sericata. Different segments of MMP1 gene, namely the middle part, 3' end, and 5' end, were cloned, sequenced, and analyzed using bioinformatics tools to determine the distinct features of MMP-1 protein. Results: Assembling the different segments revealed that the complete mRNA sequence of MMP-1 is 1932 bp long. CDS is 1212 bp long and is responsible for the production of MMP-1 of 404 amino acid residues with a predicted molecular weight of 45.1 kDa. The middle part, 3' end, and 5' end sequences were 933, 503, and 496 bp. In addition, it was revealed that the MMP-1 genomic sequence includes three exons and two introns. Furthermore, the three-dimensional structure of L. sericata MMP-1 protein was evaluated, and its alignment defined that it has high similarity to chain A of human MMP-2 with 100% confidence, 72% coverage, and 38% identity according to the SWISS-MODEL modeling analysis. Conclusions: MMP-1 of L. sericata has a close relationship with its homologs in invertebrates and other insects. The present study significantly contributes to understanding the function, classification, and evolution of the characterized MMP-1 from L. sericata and provides basic required information for the development of an effective medical bioproduct.

Multiple independent introductions of Plasmodium falciparum in South America.

The origin of Plasmodium falciparum in South America is controversial. Some studies suggest a recent introduction during the European colonizations and the transatlantic slave trade. Other evidence--archeological and genetic--suggests a much older origin. We collected and analyzed P. falciparum isolates from different regions of the world, encompassing the distribution range of the parasite, including populations from sub-Saharan Africa, the Middle East, Southeast Asia, and South America. Analyses of microsatellite and SNP polymorphisms show that the populations of P. falciparum in South America are subdivided in two main genetic clusters (northern and southern). Phylogenetic analyses, as well as Approximate Bayesian Computation methods suggest independent introductions of the two clusters from African sources. Our estimates of divergence time between the South American populations and their likely sources favor a likely introduction from Africa during the transatlantic slave trade.

Identification and typing of Cameroonian isolates of P. malariae using monoclonal antibodies against P. brasilianum.

In the present study, monoclonal antibodies raised against Plasmodium brasilianum were used to demonstrate, for the first time, antigenic diversity in natural populations of Plasmodium malariae isolates and as diagnostic tool to detect low parasitaemia P. malariae infection. Seventeen McAbs reacting by indirect immunoflorescence antibody (IFA) assay with no other Plasmodium species than P. brasilianum, were shown to react with P. malariae and were used for typing 29 P. malariae isolates from hyperendemic areas in Yaounde and in three villages of South Cameroon with parasitaemia ranging from 0.01% to 1.8%. All 29 isolates were distinguished by their ability to react with certain antibodies and considered as representing different isolates of P. malariae. One of these McAbs (No. 14) recognized P. malariae isolates to both in Yaounde and from Mengang but not in Edou or in Nkol Mvae, which may recognize a specific epitope that is less common in strains found in these villages and provide evidence of regional variation within the P. malariae parasites. The McAbs Nos. 16 and 17 were used to determine their usefulness as diagnostic tools for 30 suspected blood samples that were collected from patients with fever and it became clear that they could detect sub-microscopical infections of P. malariae. This study supports the concept of using of P. brasilianum as a substitute for P. malariae during immuno-diagnosis of malaria in endemic areas where PCR assay cannot be used for identification of the P. malariae parasites. In addition our results for the first time provide evidence of considerable antigenic diversity of clinical P. malariae isolates in Cameroon.