Figure 6. Mice with hyperglycaemia experience more severe influenza and destruction of the apical junctional complex.
Heterozygous (leprdb/+) and homozygous (leprdb/db) mice were infected with 5.5 × 103 PFU of Auckland/09(H1N1) (n = minimum eight mice per group) or mock infected with PBS (n = minimum three mice per group). (A) Blood glucose concentration prior to infection was assessed. Statistical comparisons were made using a Student’s unpaired t-test. (B) Percentage blood oxygen saturation of mock and IAV-infected mice at 3 days post-infection (d.p.i). Statistical comparisons were made using a one-way ANOVA and Tukey post hoc test. (C) Viral titres (PFU/g) in lung homogenate 3 d.p.i. Statistical comparisons were made using a Student’s unpaired t-test. (D) mRNA detected by qPCR from murine lung homogenate 3 days post-IAV infection. Viral replication represented as viral copy number. Data are pooled from two independent experiments with at least three mice per group. Data are shown as mean ± SEM. Statistical significance was determined using a Student’s t-test. (E) Representative fluorescent immunohistochemistry images (40x magnification) of mock and IAV-infected heterozygous (leprdb/+) and homozygous (leprdb/db) mouse lung tissue sections stained for nucleus and the tight junction protein JAM-1 (blue and green, respectively). (F) Representative fluorescent immunohistochemistry images (40x magnification) of mock and IAV-infected heterozygous (leprdb/+) and homozygous (leprdb/db) mouse lung tissue sections stained for nucleus and the tight junction protein Claudin-4 (blue and green respectively). (G) The percentage of fluorescence intensity of the relevant tight junction molecules (JAM-1 and Claudin-4) in IAV-infected heterozygous (leprdb/+) and homozygous (leprdb/db) mouse lung tissue sections relative to mock-infected counterparts (defined as 100%) at 3 d.p.i. Statistical comparisons were made using a Student’s unpaired t-test *: p<0.05. Data are pooled from three independent experiments (with a minimum of three biological replicates per group) and shown as mean ± SEM. JAM-1: junctional adhesion molecule-1. (H) Levels of cytokines in the lung homogenate of IAV-infected mice at 3 d.p.i. Statistical comparisons were made using a Student’s unpaired t-test. Data are pooled from two independent experiments with at least three mice per group and shown as mean ± SEM. *: p<0.05.