Pleiotropic effect of the proton pump inhibitor esomeprazole leading to suppression of lung inflammation and fibrosis

Background: The beneficial outcome associated with the use of proton pump inhibitors (PPIs) in idiopathic pulmonary fibrosis (IPF) has been reported in retrospective studies. To date, no prospective study has been conducted to confirm these outcomes. In addition, the potential mechanism by which PPIs improve measures of lung function and/or transplant-free survival in IPF has not been elucidated. Methods: Here, we used biochemical, cell biological and preclinical studies to evaluate regulation of markers associated with inflammation and fibrosis. In our in vitro studies, we exposed primary lung fibroblasts, epithelial and endothelial cells to ionizing radiation or bleomycin; stimuli typically used to induce inflammation and fibrosis. In addition, we cultured lung fibroblasts from IPF patients and studied the effect of esomeprazole on collagen release. Our preclinical study tested efficacy of esomeprazole in a rat model of bleomycin-induced lung injury. Furthermore, we performed retrospective analysis of interstitial lung disease (ILD) databases to examine the effect of PPIs on transplant-free survival. Results: The cell culture studies revealed that esomeprazole controls inflammation by suppressing the expression of pro-inflammatory molecules including vascular cell adhesion molecule-1, inducible nitric oxide synthase, tumor necrosis factor-alpha (TNF-alpha) and interleukins (IL-1 beta and IL-6). The antioxidant effect is associated with strong induction of the stress-inducible cytoprotective protein heme oxygenase-1 (HO1) and the antifibrotic effect is associated with potent inhibition of fibroblast proliferation as well as downregulation of profibrotic proteins including receptors for transforming growth factor beta (TGF beta), fibronectin and matrix metalloproteinases (MMPs). Furthermore, esomeprazole showed robust effect in mitigating the inflammatory and fibrotic responses in a murine model of acute lung injury. Finally, retrospective analysis of two ILD databases was performed to assess the effect of PPIs on transplant-free survival in IPF patients. Intriguingly, this data demonstrated that IPF patients on PPIs had prolonged survival over controls (median survival of 3.4 vs 2 years). Conclusions: Overall, these data indicate the possibility that PPIs may have protective function in IPF by directly modulating the disease process and suggest that they may have other clinical utility in the treatment of extra-intestinal diseases characterized by inflammatory and/or fibrotic phases.Stanford School of Medicine [1049528-149- KAVFB]; Tobacco-Related Disease Research Program of the University of California [20FT-0090]; National Institutes of Health National Heart, Lung, and Blood Institute [5K01HL118683, P01HL114470]; Houston Methodist Research Institute [25150001]; Stanford SPARK Translational Research ProgramSCI(E)[email protected]

Potato NAC43 and MYB8 mediated transcriptional regulation of secondary cell wall biosynthesis to contain Phytophthora infestans infection

Resistance to late blight is highly complex and quantitative in nature but has proven difficult to harness due to poor understanding of its molecular and biochemical mechanisms. Secondary cell wall (SCW) biosynthesis is a critical process in late blight resistance, regulated by an array of transcription factors (TF). In the present study, metabolo-transcriptomics approaches were used to functionally characterize that the upregulated StNAC43 and StMYB8 in potato genotypeswere linked to SCW biosynthetic phenylpropanoid metabolites produced in high fold change following Phytophthora infestans infection. The promoter analysis of StNAC43 revealed the presence of ethylene responsive element (ERE), which is the proposed binding site for ethylene responsive factor, ERF3. Sequencing of the ERF3 revealed a frameshift mutation in the susceptible potato genotype. Simultaneous induction of both the ERF3 and StNAC43, following pathogen invasion, enables functioning of the latter to interact with the ERE present in the resistant StNAC43 promoter region. Further, the StNAC43 binds to the secondary NAC binding element in StMYB8 promoter and activates StMYB8 TF. A luciferase transient expression assay elucidated a direct regulatory role of the StMYB8 on SCW biosynthetic genes, by binding to promoters of downstream genes: HCT, PHT, CHS, and flavanone 3-hydroxylase (F3H). Silencing of StNAC43 and StMYB8 affected the late blight resistance by significantly increasing pathogen biomass and decreasing the amounts of hydroxycinnamic acid amides (HCAAs) and flavonoid glycosides. The StNAC43 and StMYB8 TFs are positive activators of SCW biosynthetic genes, which deposit resistance-related metabolites to reinforce SCW and improve resistance against late blight.Kalenahalli N. Yogendra, Kobir Sarkar, Udaykumar Kage, Ajjamada C. Kushalapp

Gene discovery and genome editing to develop cisgenic crops with improved resistance against pathogen infection

Resistance in plants against pathogen infection is defined as a spectrum of reduced susceptibility, ranging from moderate susceptibility to a hypersensitive response (complete resistance). The genetic improvement of plants is one option to manage diseases. Several quantitative trait loci (QTLs) for disease resistance have been identified, but these contain many genes and the mechanisms by which resistance is imparted are unknown. These operative factors are crucial to assure precise breeding. Several OMICs tools have emerged, along with genomics, to elucidate resistance mechanisms of plants to pathogens. For example, metabolomics of plant–pathogen interactions have led to the discovery of several complex metabolites that are deposited to reinforce secondary cell walls and prevent the spread of the pathogen beyond the initial infection site. Resistance in plants is largely due to antimicrobial biochemicals and/or the structures formed from them; both these lines of defence may be constitutive or induced following pathogen invasion. Pathogen perception leads to induction of resistance-related (RR) proteins and metabolites. Both constitutive and induced RR metabolites are biosynthesized by metabolic pathway genes. The RR proteins and metabolite biosynthetic genes are regulated by hierarchies of resistance (R) genes. A non-functional gene or ‘missing link’ in this hierarchy can inhibit the regulation of genes in specific metabolic pathway and protein production, thus reducing the amounts of RR metabolites and proteins, as well as the associated resistance. In addition, the non-functional biosynthetic R genes also can limit RR proteins and metabolites. Precise replacement of these non-functional genes (r) with functional R genes using genome editing tools, similar to backcross breeding, can significantly improve resistance in commercial crops. The objective of this review paper is to discuss a new concept of resistance, review technologies available for gene discovery, mechanisms of resistance, improvement of the genetic diversity of crop plants based on genome editing tools to produce cisgenic cultivars with durable disease resistance, and the regulatory issues concerning genome editing.Ajjamada C. Kushalappa, Kalenahalli N. Yogendra, Kobir Sarkar, Udaykumar Kage and Shailesh Karr

Mutations in the gene encoding the serine protease inhibitor, Kazal type 1 are associated with chronic pancreatitis

Chronic pancreatitis (CP) is a continuing or relapsing inflammatory disease of the pancreas. In approximately one-third of all cases, no aetiological factor can be found, and these patients are classified as having idiopathic disease. Pathophysiologically, autodigestion and inflammation may be caused by either increased proteolytic activity or decreased protease inhibition. Several studies have demonstrated mutations in the cationic trypsinogen gene (PRSS1) in patients with hereditary or idiopathic CP. It is thought that these mutations result in increased trypsin activity within the pancreatic parenchyma. Most patients with idiopathic or hereditary CP, however, do not have mutations in PRSS1 (ref. 4). Here we analysed 96 unrelated children and adolescents with CP for mutations in the gene encoding the serine protease inhibitor. Kazal type 1 (SPINK1), a pancreatic trypsin inhibitor. We found mutations in 23% of the patients. In 18 patients, 6 of whom were homozygous, we detected a missense mutation of codon 34 (N34S). We also found four other sequence variants. Our results indicate that mutations in SPINK1 are associated with chronic pancreatitis