Anti-SPINT2 (aa 181-192) polyclonal antibody

Autosomal-recessive congenital sodium diarrhea (CSD) is characterized by perinatal onset of a persistent watery diarrhea with nonproportionally high fecal sodium excretion. Defective jejunal brush-border Na+/H+ exchange has been reported in three sporadic patients, but the molecular basis of the disease has not been elucidated. We reviewed data from a large cohort of CSD patients (n = 24) and distinguished CSD associated with choanal or anal atresia, hypertelorism, and corneal erosions-i.e., a syndromic form of CSD-occurring in ten families from an isolated form-i.e., classic M-presenting in seven families. Patients from both groups have a high risk of mortality due to immediate electrolyte imbalances and complications from long-term parenteral nutrition in the first years of life, but survivors can eventually adapt to partial or complete enteral nutrition. A genome-wide SNP scan was applied and identified a homozygous c.593-1G -> A splicing mutation in SPINT2, encoding a Kunitz-type serine-protease inhibitor, in one extended kindred with syndromic CSD. The same mutation and four distinct, homozygous or compound heterozygous mutations (p.Y163C, c.1A -> T, c.337+2T -> C, c.553+2T -> A) were identified in all syndromic patients. No SPINT2 mutations were found in classic-CSD patients. SPINT2 mutations were associated with loss of protein synthesis or failure to inhibit the serine protease trypsin in vitro. We delineate syndromic CSD as a distinct disease entity caused by SPINT2 loss-of-function mutations. SPINT2 mutations might lead to an excess of yet unknown serine protease activity in affected tissues.

Toxoplasma gondii provoked rapid and sustained nuclear translocation of signal transducer and activator of transcription (STAT) 6, a central mediator of interleukin (IL)-4, in macrophage-differentiated human acute monocytic leukemia cells without exogenous IL-4 in western blot and immunofluorescence assay. Phosphorylation of STAT6 occurred immediately after the entry of T. gondii and only by live tachyzoites, not by killed or soluble extract. It was impeded by Janus kinase (JAK) 3 inhibitor and small interfering RNA (siRNA) of STAT6. It induced expression of IL-4 responsive genes such as IL-4R, CD40, and CD23. It also mediated expression of two large clusters of C-C chemokine ligands (CCLs) and serine protease inhibitors (SERPINs) in microarray of T. gondii-infected macrophages. CCL1, 2, 8, 13, and 22 and SPINT2, SERPINB3, B4, and B13 were increased by the infection and inhibited by the treatment of JAK3 inhibitor and siRNA-mediated STAT6 silencing, which suggested the expression was governed by STAT6 activation. Secreting those CCLs, T. gondii-infected macrophages may attract more monocytes and Th2 cells of CCR3 and CCR4 to enrich the Th2 environment nearby the infected macrophages, and induced SERPINs may participate in protection from intracellular damages produced by activated lysosomal enzymes and in the inhibition of caspase activity to block the apoptosis. This suggests that T. gondii exploits cytokine cross-regulation through STAT6 activation to obviate various toxoplasmacidal reactions by interferon-gamma.