The genomic sequences of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) worldwide are publicly available and are derived from studies due to the increase in the number of cases. The importance of study of mutations is related to the possible virulence and diagnosis of SARS‐CoV‐2. To identify circulating mutations present in SARS‐CoV‐2 genomic sequences in Mexico, Belize, and Guatemala to find out if the same strain spread to the south, and analyze the specificity of the primers used for diagnosis in these samples. Twenty three complete SARS‐CoV‐2 genomic sequences, available in the GISAID database from May 8 to September 11, 2020 were analyzed and aligned versus the genomic sequence reported in Wuhan, China (NC_045512.2), using Clustal Omega. Open reading frames were translated using the ExPASy Translate Tool and UCSF Chimera (v.1.12) for amino acid substitutions analysis. Finally, the sequences were aligned versus primers used in the diagnosis of COVID‐19. One hundred and eighty seven distinct variants were identified, of which 102 are missense, 66 synonymous and 19 noncoding. P4715L and P5828L substitutions in replicase polyprotein were found, as well as D614G in spike protein and L84S in ORF8 in Mexico, Belize, and Guatemala. The primers design by CDC of United States showed a positive E value. The genomic sequences of SARS‐CoV‐2 in Mexico, Belize, and Guatemala present similar mutations related to a virulent strain of greater infectivity, which could mean a greater capacity for inclusion in the host genome and be related to an increased spread of the virus in these countries, furthermore, its diagnosis would be affected.

Activated protein C (APC) is generated from the cleavage of protein C by thrombin coupled to thrombomodulin and, subsequently, is released as protein C activation peptide (papC). The aim of this study was to evaluate the effect of papC on human dermal microvascular endothelial cells (HMEC-1), activated with 5 ng/ /mL TNF-a. Flow cytometry showed that papC inhibited the expression of VCAM-1 and ICAM-1, after activation with TNF-a. Similarly, RT-PCR analysis revealed that 2 and 4 pM papC inhibited the expression of VCAM-1 and IL-8 mRNA in TNF-a-treated HMEC-1. In addition, the expression of endothelial nitric oxide synthase (eNOS) increased in HMEC-1 treated with papC, compared to those without treatment. Furthermore, Jurkat cell adhesion to HMEC-1 induced by TNF-a was significantly inhibited after the addition of papC, compared to HMEC-1 without papC (p = 0.03). Finally, a control peptide analog to papC showed no effect on the expression of ICAM and VCAM on the surface of HMEC-1. In conclusion, our results suggest that papC exerts antiinflammatory effects on endothelial cells.

Activated protein C (APC) is generated from the cleavage of protein C by thrombin coupled to thrombomodulin and, subsequently, is released as protein C activation peptide (papC). The aim of this study was to evaluate the effect of papC on human dermal microvascular endothelial cells (HMEC-1), activated with 5 ng//mL TNF-α. Flow cytometry showed that papC inhibited the expression of VCAM-1 and ICAM-1, after activation with TNF-a. Similarly, RT-PCR analysis revealed that 2 and 4 pM papC inhibited the expression of VCAM-1 and IL-8 mRNA in TNF-α-treated HMEC-1. In addition, the expression of endothelial nitric oxide synthase(eNOS) increased in HMEC-1 treated with papC, compared to those without treatment. Furthermore, Jurkat cell adhesion to HMEC-1 induced by TNF-a was significantly inhibited after the addition of papC, compared to HMEC-1 without papC (p = 0.03). Finally, a control peptide analog to papC showed no effect on the expression of ICAM and VCAM on the surface of HMEC-1. In conclusion, our results suggest that papC exerts anti-inflammatory effects on endothelial cells.

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