Trimerization profile of type IV collagen COL4A5 exon deletion in X-linked Alport syndrome.

BACKGROUND: Alport syndrome (AS) is a genetic kidney disease caused by a mutation in type IV collagen α3, α4, and α5, which are normally secreted as heterotrimer α345(IV). Nonsense mutation in these genes causes severe AS phenotype. We previously revealed that the exon-skipping approach to remove a nonsense mutation in α5(IV) ameliorated the AS pathology. However, the effect of removing an exon on trimerization is unknown. Here, we assessed the impact of exon deletion on trimerization to evaluate their possible therapeutic applicability and to predict the severity of mutations associated with exon-skipping. METHODS: We produced exon deletion constructs (ΔExon), nonsense, and missense mutants by mutagenesis and evaluated their trimer formation and secretion activities using a nanoluciferase-based assay that we previously developed. RESULTS: Exon-skipping had differential effects on the trimer secretion of α345(IV). Some ΔExons could form and secrete α345(IV) trimers and had higher activity compared with nonsense mutants. Other ΔExons had low secretion activity, especially for those with exon deletion near the C-terminal end although the intracellular trimerization was normal. No difference was noted in the secretion of missense mutants and their ΔExon counterpart. CONCLUSION: Exon skipping is advantageous for nonsense mutants in AS with severe phenotypes and early onset of renal failure but applications may be limited to ΔExons capable of normal trimerization and secretion. This study provides information on α5(IV) exon-skipping for possible therapeutic application and the prediction of the trimer behavior associated with exon-skipping in Alport syndrome.

Combinatorial screening for therapeutics in ATTRv amyloidosis identifies naphthoquinone analogues as TTR-selective amyloid disruptors.

Hereditary ATTR amyloidosis is caused by the point mutation in serum protein transthyretin (TTR) that destabilizes its tetrameric structure to dissociate into monomer. The monomers form amyloid fibrils, which are deposited in peripheral nerves and organs, resulting in dysfunction. Therefore, a drug that dissolves amyloid after it has formed, termed amyloid disruptor, is needed as a new therapeutic drug. Here, we first established a high throughput screening system to find TTR interactors from the LOPAC1280 compound library. Among the hit compounds, thioflavin T-based post-treatment assay determined lead compounds for TTR amyloid disruptors, NSC95397 and Gossypol, designated as B and R, respectively. Because these compounds have naphthoquinone-naphthalene structures, we tested 100 naphthoquinone derivatives, and found 10 candidate compounds that disrupted TTR amyloid. Furthermore, to determine whether these 10 compounds are selective for TTR amyloid, we evaluated them against beta-amyloid (Aß1-42). We found two compounds that were selective for TTR and did not disrupt Aß-derived amyloid. Therefore, we succeeded in identifying TTR-selective amyloid disruptors, and demonstrated that naphthoquinone compounds are useful structures as amyloid disruptors. These findings contribute to the on-going efforts to discover new therapeutic tools for TTR amyloidosis.

T3 Intratracheal Therapy Alleviates Pulmonary Pathology in an Elastase-Induced Emphysema-Dominant COPD Mouse Model.

Chronic obstructive pulmonary disease (COPD) is a complex pulmonary condition characterized by bronchitis, emphysema, and mucus stasis. Due to the variability in symptoms among patients, traditional approaches to treating COPD as a singular disease are limited. This led us to focus on phenotype/endotype classifications. In this study, we explore the potential therapeutic role of thyroid hormone (T3) by using mouse models: emphysema-dominant elastase-induced COPD and airway-dominant C57BL/6-ßENaC-Tg to represent different types of the disease. Here, we showed that intratracheal T3 treatment (40, 80 µg/kg, i.t., every other day) resulted in significant improvements regarding emphysema and the enhancement of respiratory function in the elastase-induced COPD model. T3-dependent improvement is likely linked to the up-regulation of Ppargc1a, a master regulator of mitochondrial biogenesis, and Gclm, a factor associated with oxidative stress. Conversely, neither short- nor long-term T3 treatments improved COPD pathology in the C57BL/6-ßENaC-Tg mice. Because the up-regulation of extrathyroidal T3-producing enzyme Dio2, which is also considered a marker of T3 requirement, was specifically observed in elastase-induced COPD lungs, these results demonstrate that exogenous T3 supplementation may have therapeutic potential for acute but not chronic COPD exacerbation. Moreover, this study highlights the relevance of considering not only COPD phenotypes but also COPD endotypes (expression levels of Ppargc1a and/or Dio2) in the research and development of better treatment approaches for COPD.

A Splice Switch in SIGIRR Causes a Defect of IL-37-Dependent Anti-Inflammatory Activity in Cystic Fibrosis Airway Epithelial Cells.

Cystic fibrosis (CF) is a hereditary disease typically characterized by infection-associated chronic lung inflammation. The persistent activation of toll-like receptor (TLR) signals is considered one of the mechanisms for the CF hyperinflammatory phenotype; however, how negative regulatory signals of TLRs associate with CF inflammation is still elusive. Here, we showed that the cell surface expression of a single immunoglobulin interleukin-1 receptor (IL-1R)-related molecule (SIGIRR), a membrane protein essential for suppressing TLRs- and IL-1R-dependent signals, was remarkably decreased in CF airway epithelial cells compared to non-CF cells. Notably, CF airway epithelial cells specifically and highly expressed a unique, alternative splice isoform of the SIGIRR that lacks exon 8 (Δ8-SIGIRR), which results in the production of a C-terminal truncated form of the SIGIRR. Δ8-SIGIRR was expressed intracellularly, and its over-expression abolished the cell surface expression and function of the full-length SIGIRR (WT-SIGIRR), indicating its dominant-negative effect leading to the deficiency of anti-inflammatory activity in CF cells. Consistently, IL-37, a ligand for the SIGIRR, failed to suppress viral dsRNA analogue poly(I:C)-dependent JNK activation and IL-8 production, confirming the reduction in the functional WT-SIGIRR expression in the CF cells. Together, our studies reveal that SIGIRR-dependent anti-inflammatory activity is defective in CF airway epithelial cells due to the unique splicing switch of the SIGIRR gene and provides the first evidence of IL-37-SIGIRR signaling as a target of CF airway inflammation.

Novel Keap1-Nrf2 Protein-Protein Interaction Inhibitor UBE-1099 Ameliorates Progressive Phenotype in Alport Syndrome Mouse Model.

Background: Bardoxolone methyl activates nuclear factor erythroid 2-related factor 2 (Nrf2) via covalent binding and irreversible inhibition of Kelch-like ECH-associated protein 1 (Keap1), the negative regulator of Nrf2. Ongoing clinical trials of bardoxolone methyl show promising effects for patients with CKD. However, the direct inhibition of Keap1-Nrf2 protein-protein interaction (PPI) as an approach to activate Nrf2 is less explored. Methods: We developed a noncovalent Nrf2 activator UBE-1099, which highly selectively inhibits Keap1-Nrf2 PPI, and evaluated its efficacy on the progressive phenotype in an Alport syndrome mouse model (Col4a5-G5X). Results: Similar to bardoxolone methyl, UBE-1099 transiently increased proteinuria and reduced plasma creatinine in Alport mice. Importantly, UBE-1099 improved the glomerulosclerosis, renal inflammation, and fibrosis, and prolonged the life span of Alport mice. UBE-1099 ameliorated the dysfunction of Nrf2 signaling in the renal tissue of Alport mice. Moreover, transcriptome analysis in the glomerulus showed that UBE-1099 induced the expression of genes associated with the cell cycle and cytoskeleton, which may explain its unique mechanism of improvement such as glomerular morphologic change. Conclusions: UBE-1099 significantly ameliorates the progressive phenotype in Alport mice. Our results revealed the efficacy of Keap1-Nrf2 PPI inhibitor for glomerulosclerosis and present a potential therapeutic drug for CKD.

Metformin suppresses epithelial sodium channel hyperactivation and its associated phenotypes in a mouse model of obstructive lung diseases.

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death in the world, and has no radical treatment. Inhibition of amiloride-sensitive epithelial sodium ion channel (ENaC) has now been considered as a potential therapeutic target against COPD. One possible modulator of ENaC is AMP-activated protein kinase (AMPK), a key molecule that controls a wide variety of cellular signals; however, little is known about whether metformin, a clinically available AMPK activator, has a protective role against ENaC-associated chronic pulmonary phenotypes, such as emphysema and pulmonary dysfunction. We first used ENaC-overexpressing human bronchial epithelial cells (ß/γENaC-16HBE14o-) and identified that Metformin significantly reduced ENaC activity. Consistently, in vivo treatment of ENaC-overexpressing COPD mouse model (C57BL/6-ßENaC-Tg mice) showed improvement of emphysema and pulmonary dysfunction, without any detrimental effect on non-pulmonary parameters (blood glucose level etc.). Bronchoalveolar lavage fluid (BALF) and lung tissue analyses revealed significant suppression in the infiltration of neutrophils as well as the expression of inflammatory markers (KC), neutrophil gelatinase (MMP9) and macrophage elastase (MMP12) in metformin-treated C57BL/6-ßENaC-Tg mice. Overall, the present study demonstrates that metformin directly inhibits ENaC activity in vitro and provides the first evidence of therapeutical benefit of Metformin for COPD with higher ENaC activity.

Seamless Gene Correction in the Human Cystic Fibrosis Transmembrane Conductance Regulator Locus by Vector Replacement and Vector Insertion Events.

Background: Gene correction via homology directed repair (HDR) in patient-derived induced pluripotent stem (iPS) cells for regenerative medicine are becoming a more realistic approach to develop personalized and mutation-specific therapeutic strategies due to current developments in gene editing and iPSC technology. Cystic fibrosis (CF) is the most common inherited disease in the Caucasian population, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Since CF causes significant multi-organ damage and with over 2,000 reported CFTR mutations, CF patients could be one prominent population benefiting from gene and cell therapies. When considering gene-editing techniques for clinical applications, seamless gene corrections of the responsible mutations, restoring native "wildtype" DNA sequence without remnants of drug selectable markers or unwanted DNA sequence changes, would be the most desirable approach. Result: The studies reported here describe the seamless correction of the W1282X CFTR mutation using CRISPR/Cas9 nickases (Cas9n) in iPS cells derived from a CF patient homozygous for the W1282X Class I CFTR mutation. In addition to the expected HDR vector replacement product, we discovered another class of HDR products resulting from vector insertion events that created partial duplications of the CFTR exon 23 region. These vector insertion events were removed via intrachromosomal homologous recombination (IHR) enhanced by double nicking with CRISPR/Cas9n which resulted in the seamless correction of CFTR exon 23 in CF-iPS cells. Conclusion: We show here the removal of the drug resistance cassette and generation of seamless gene corrected cell lines by two independent processes: by treatment with the PiggyBac (PB) transposase in vector replacements or by IHR between the tandemly duplicated CFTR gene sequences.

Type IV Collagen Variants in CKD: Performance of Computational Predictions for Identifying Pathogenic Variants.

RATIONALE & OBJECTIVE: Pathogenic variants in type IV collagen have been reported to account for a significant proportion of chronic kidney disease. Accordingly, genetic testing is increasingly used to diagnose kidney diseases, but testing also may reveal rare missense variants that are of uncertain clinical significance. To aid in interpretation, computational prediction (called in silico) programs may be used to predict whether a variant is clinically important. We evaluate the performance of in silico programs for COL4A3/A4/A5 variants. STUDY DESIGN SETTING & PARTICIPANTS: Rare missense variants in COL4A3/A4/A5 were identified in disease cohorts, including a local focal segmental glomerulosclerosis (FSGS) cohort and publicly available disease databases, in which they are categorized as pathogenic or benign based on clinical criteria. TESTS COMPARED & OUTCOMES: All rare missense variants identified in the 4 disease cohorts were subjected to in silico predictions using 12 different programs. Comparisons between the predictions were compared with: (1) variant classification (pathogenic or benign) in the cohorts and (2) functional characterization in a randomly selected smaller number (17) of pathogenic or uncertain significance variants obtained from the local FSGS cohort. RESULTS: In silico predictions correctly classified 75% to 97% of pathogenic and 57% to 100% of benign COL4A3/A4/A5 variants in public disease databases. The congruency of in silico predictions was similar for variants categorized as pathogenic and benign, with the exception of benign COL4A5 variants, in which disease effects were overestimated. By contrast, in silico predictions and functional characterization classified all 9 pathogenic COL4A3/A4/A5 variants correctly that were obtained from a local FSGS cohort. However, these programs also overestimated the effects of genomic variants of uncertain significance when compared with functional characterization. Each of the 12 in silico programs used yielded similar results. LIMITATIONS: Overestimation of in silico program sensitivity given that they may have been used in the categorization of variants labeled as pathogenic in disease repositories. CONCLUSIONS: Our results suggest that in silico predictions are sensitive but not specific to assign COL4A3/A4/A5 variant pathogenicity, with misclassification of benign variants and variants of uncertain significance. Thus, we do not recommend in silico programs but instead recommend pursuing more objective levels of evidence suggested by medical genetics guidelines.

Activation of heat shock response improves biomarkers of NAFLD in patients with metabolic diseases.

Nonalcoholic fatty liver disease (NAFLD) is often accompanied by metabolic disorders such as metabolic syndrome and type 2 diabetes (T2DM). Heat shock response (HSR) is one of the most important homeostatic abilities but is deteriorated by chronic metabolic insults. Heat shock (HS) with an appropriate mild electrical stimulation (MES) activates HSR and improves metabolic abnormalities including insulin resistance, hyperglycemia and inflammation in metabolic disorders. To analyze the effects of HS + MES treatment on NAFLD biomarkers, three cohorts including healthy men (two times/week, n = 10), patients with metabolic syndrome (four times/week, n = 40), and patients with T2DM (n = 100; four times/week (n = 40) and two, four, seven times/week (n = 20 each)) treated with HS + MES were retrospectively analyzed. The healthy subjects showed no significant alterations in NAFLD biomarkers after the treatment. In patients with metabolic syndrome, many of the NAFLD steatosis markers, including fatty liver index, NAFLD-liver fat score, liver/spleen ratio and hepatic steatosis index and NAFLD fibrosis marker, aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, were improved upon the treatment. In patients with T2DM, all investigated NAFLD steatosis markers were improved and NAFLD fibrosis markers such as the AST/ALT ratio, fibrosis-4 index and NAFLD-fibrosis score were improved upon the treatment. Thus, HS + MES, a physical intervention, may become a novel treatment strategy for NAFLD as well as metabolic disorders.

Metformin ameliorates the severity of experimental Alport syndrome.

Metformin is widely used for the treatment of type 2 diabetes, and increasing numbers of studies have shown that metformin also ameliorates tumor progression, inflammatory disease, and fibrosis. However, the ability of metformin to improve non-diabetic glomerular disease and chronic kidney disease (CKD) has not been explored. To investigate the effect of metformin on non-diabetic glomerular disease, we used a mouse model of Alport syndrome (Col4a5 G5X) which were treated with metformin or losartan, used as a control treatment. We also investigated the effect of metformin on adriamycin-induced glomerulosclerosis model. Pathological and biochemical analysis showed that metformin or losartan suppressed proteinuria, renal inflammation, fibrosis, and glomerular injury and extended the lifespan in Alport syndrome mice. Transcriptome analysis showed that metformin and losartan influenced molecular pathways-related to metabolism and inflammation. Metformin altered multiple genes including metabolic genes not affected by losartan. Metformin also suppressed proteinuria and glomerular injury in the adriamycin-induced glomerulosclerosis mouse model. Our results showed that metformin ameliorates the glomerular sclerosis and CKD phenotype in non-diabetic chronic glomerular diseases. Metformin may have therapeutic potential for not only diabetic nephropathy but also non-diabetic glomerular disease including Alport syndrome.

The role of discoidin domain receptor 2 in the renal dysfunction of alport syndrome mouse model.

Alport syndrome (AS) is a hereditary glomerular nephritis caused by mutation in one of the type IV collagen genes α3/α4/α5 that encode the heterotrimer COL4A3/4/5. Failure to form a heterotrimer due to mutation leads to the dysfunction of the glomerular basement membrane, and end-stage renal disease. Previous reports have suggested the involvement of the receptor tyrosine kinase discoidin domain receptor (DDR) 1 in the progression of AS pathology. However, due to the similarity between DDR1 and DDR2, the role of DDR2 in AS pathology is unclear. Here, we investigated the involvement of DDR2 in AS using the X-linked AS mouse model. Mice were treated subcutaneously with saline or antisense oligonucleotide (ASO; 5 mg/kg or 15 mg/kg per week) for 8 weeks. Renal function parameters and renal histology were analyzed, and the gene expressions of inflammatory cytokines were determined in renal tissues. The expression level of DDR2 was highly elevated in kidney tissues of AS mice. Knockdown of Ddr2 using Ddr2-specific ASO decreased the Ddr2 expression. However, the DDR2 ASO treatment did not improve the proteinuria or decrease the BUN level. DDR2 ASO also did not significantly ameliorate the renal injury, inflammation and fibrosis in AS mice. These results showed that Ddr2 knockdown by ASO had no notable effect on the progression of AS indicating that DDR2 may not be critically involved in AS pathology. This finding may provide useful information and further understanding of the role of DDRs in AS.

Intrapopulation analysis of longitudinal lifespan in Caenorhabditis elegans identifies W09D10.4 as a novel AMPK-associated healthspan shortening factor.

Caenorhabditis elegans is a model organism widely used for longevity studies. Current advances have been made in the methods that allow automated monitoring of C. elegans behavior. However, ordinary manual assays as well as automated methods have yet to achieve qualitative whole-life analysis of C. elegans longevity based on intrapopulation variation. Here, we utilized live-cell analysis system to determine the parameters of nematode lifespans. Image-based superposition method enabled to determine not only frailty in worms, but also to measure individual and longitudinal lifespan, healthspan, and frailspan. Notably, k-means clustering via principal component analysis revealed four clusters with distinct longevity patterns in wild-type C. elegans. Physiological relevance of clustering was confirmed by assays with pharmacological and/or genetic manipulation of AMP-activated protein kinase (AMPK), a crucial regulator of healthspan. Finally, we focused on W09D10.4 among the possible regulators extracted by integrative expression analysis with existing data sets. Importantly, W09D10.4 knockdown increased the high-healthspan populations only in the presence of AMPK, suggesting that W09D10.4 is a novel AMPK-associated healthspan shortening factor in C. elegans. Overall, the study establishes a novel platform of longitudinal lifespan in C. elegans, which is user-friendly, and may be a useful pharmacological tool to identify healthspan modulatory factors.

Mild electrical stimulation with heat shock attenuates renal pathology in adriamycin-induced nephrotic syndrome mouse model.

Nephrotic syndrome (NS) is a renal disorder that is characterized by massive proteinuria, hypoalbuminemia and edema. One of the main causes of NS is focal segmental glomerulosclerosis (FSGS), which has extremely poor prognosis. Although steroids and immunosuppressants are the first line of treatment, some FSGS cases are refractory, prompting the need to find new therapeutic strategies. We have previously demonstrated that an optimized combination treatment of mild electrical stimulation (MES) and heat shock (HS) has several biological benefits including the amelioration of the pathologies of the genetic renal disorder Alport syndrome. Here, we investigated the effect of MES + HS on adriamycin (ADR)-induced NS mouse model. MES + HS suppressed proteinuria and glomerulosclerosis induced by ADR. The expressions of pro-inflammatory cytokines and pro-fibrotic genes were also significantly downregulated by MES + HS. MES + HS decreased the expression level of cleaved caspase-3 and the number of TUNEL-positive cells, indicating that MES + HS exerted anti-apoptotic effect. Moreover, MES + HS activated the Akt signaling and induced the phosphorylation and inhibition of the apoptotic molecule BAD. In in vitro experiment, the Akt inhibitor abolished the MES + HS-induced Akt-BAD signaling and anti-apoptotic effect in ADR-treated cells. Collectively, our study suggested that MES + HS modulates ADR-induced pathologies and has renoprotective effect against ADR-induced NS via regulation of Akt-BAD axis.

A novel condition of mild electrical stimulation exerts immunosuppression via hydrogen peroxide production that controls multiple signaling pathway.

Different modes of exogenous electrical stimulation at physiological strength has been applied to various diseases. Previously, we extensively demonstrated the usability of mild electrical stimulation (MES) with low frequency pulse current at 55 pulses per second (MES55) for several disease conditions. Here we found that MES with high frequency pulse-current (5500 pulse per second; MES5500) suppressed the overproduction of pro-inflammatory cytokines induced by phorbol myristate acetate/ionomycin in Jurkat T cells and primary splenocytes. MES5500 also suppressed the overproduction of inflammatory cytokines, improved liver damage and reduced mouse spleen enlargement in concanavalin-A-treated BALB/c mice. The molecular mechanism underlying these effects included the ability of MES5500 to induce modest amount of hydrogen peroxide and control multiple signaling pathways important for immune regulation, such as NF-κB, NFAT and NRF2. In the treatment of various inflammatory and immune-related diseases, suppression of excessive inflammatory cytokines is key, but because immunosuppressive drugs used in the clinical setting have serious side effects, development of safer methods of inhibiting cytokines is required. Our finding provides evidence that physical medicine in the form of MES5500 may be considered as a novel therapeutic tool or as adjunctive therapy for inflammatory and immune-related diseases.

Higher Blood Uric Acid in Female Humans and Mice as a Protective Factor against Pathophysiological Decline of Lung Function.

The oxidant/antioxidant imbalance plays a pivotal role in the lung. Uric acid (UA), an endogenous antioxidant, is highly present in lung tissue, however, its impact on lung function under pathophysiological conditions remains unknown. In this work, pharmacological and genetic inhibition of UA metabolism in experimental mouse models of acute and chronic obstructive pulmonary disease (COPD) revealed that increased plasma UA levels improved emphysematous phenotype and lung dysfunction in accordance with reduced oxidative stress specifically in female but not in male mice, despite no impact of plasma UA induction on the pulmonary phenotypes in nondiseased mice. In vitro experiments determined that UA significantly suppressed hydrogen peroxide (H2O2)-induced oxidative stress in female donor-derived primary human bronchial epithelial (NHBE) cells in the absence of estrogen, implying that the benefit of UA is limited to the female airway in postmenopausal conditions. Consistently, our clinical observational analyses confirmed that higher blood UA levels, as well as the SLC2A9/GLUT9 rs11722228 T/T genotype, were associated with higher lung function in elderly human females. Together, our findings provide the first unique evidence that higher blood UA is a protective factor against the pathological decline of lung function in female mice, and possibly against aging-associated physiological decline in human females.

Trimerization and Genotype-Phenotype Correlation of COL4A5 Mutants in Alport Syndrome.

INTRODUCTION: Alport syndrome is a hereditary glomerulonephritis that results from the disruption of collagen α345(IV) heterotrimerization caused by mutation in COL4A3, COL4A4 or COL4A5 genes. Many clinical studies have elucidated the correlation between genotype and phenotype, but there is still much ambiguity and insufficiency. Here, we focused on the α345(IV) heterotrimerization of α5(IV) missense mutant as a novel factor to further understand the pathophysiology of Alport syndrome. METHODS: We selected 9 α5(IV) missense mutants with typical glycine substitutions that clinically differed in disease progression. To quantify the trimerization of each mutant, split nanoluciferase-fused α3/α5 mutants and α4 were transfected into the cells, and intracellular and secreted heterotrimer were detected by luminescence using an assay that we developed previously. RESULTS: Trimer formation and secretion patterns tended to be similar to the wild type in most of the mutations that did not show proteinuria at a young age. On the other hand, trimer secretion was significantly reduced in all the mutations that showed proteinuria and early onset of renal failure. One of these mutants has low ability of intracellular trimer formation, and the others had the defect of low-level secretion. In addition, the mutant that is assumed to be nonpathogenic has similar trimer formation and secretion pattern as wild-type α5(IV). CONCLUSION: The result of cell-based α345(IV) heterotrimer formation assay was largely correlated with clinical genotype-phenotype. These trimerization assessments provide additional phenotypic considerations and may help to distinguish between pathogenic and nonpathogenic mutations.

The DsbA-L gene is associated with respiratory function of the elderly via its adiponectin multimeric or antioxidant properties.

Oxidative stress and inflammation play a key role in the age-related decline in the respiratory function. Adipokine in relation to the metabolic and inflammatory systems is attracting growing interest in the field of respiratory dysfunction. The present clinical and experimental studies investigated the role of the disulfide bond-forming oxidoreductase A-like protein (DsbA-L) gene, which has antioxidant and adiponectin multimeric (i.e. activation) properties, on the respiratory function of the elderly. We performed a retrospective longitudinal genotype-phenotype relationship analysis of 318 Japanese relatively elderly participants (mean age ± standard deviation: 67.0 ± 5.8 years) during a health screening program and an in vitro DsbA-L knock-down evaluation using 16HBE14o-cells, a commonly evaluated human airway epithelial cell line. The DsbA-L rs1917760 polymorphism was associated with a reduction in the ratio of forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) and %FEV1 and with the elevation of the prevalence of FEV1/FVC < 70%. We also confirmed that the polymorphism was associated with a decreased respiratory function in relation to a decrease in the ratio of high-molecular-weight adiponectin/total adiponectin (as a marker of adiponectin multimerization) and an increase in the oxidized human serum albumin (as an oxidative stress marker). Furthermore, we clarified that DsbA-L knock-down induced oxidative stress and up-regulated the mucus production in human airway epithelial cells. These findings suggest that the DsbA-L gene may play a role in protecting the respiratory function of the elderly, possibly via increased systemic adiponectin functions secreted from adipocytes or through systemic and/or local pulmonary antioxidant properties.

Melinjo seed extract increases adiponectin multimerization in physiological and pathological conditions.

Melinjo seed extract (MSE) contains large amounts of polyphenols, including dimers of trans-resveratrol (e.g. gnetin C, L, gnemonoside A, B and D), and has been shown to potentially improve obesity. However, there is no clinical evidence regarding the anti-obesity effects of MSE, and its mechanisms are also unclear. We investigated the hypothesis that MSE supplementation increases the adiponectin (APN) multimerization via the up-regulation of disulfide bond A oxidoreductase-like protein (DsbA-L) under either or both physiological and obese conditions. To investigate the effect of MSE on the physiological condition, 42 healthy young volunteers were enrolled in a randomized, double-blind placebo-controlled clinical trial for 14 days. The participants were randomly assigned to the MSE 150 mg/day, MSE 300 mg/day or placebo groups. Furthermore, in order to investigate the effect of MSE on APN levels under obese conditions, we administered MSE powder (500 or 1000 mg/kg/day) to control-diet- or high-fat-diet (HFD)-fed C57BL/6 mice for 4 weeks. All participants completed the clinical trial. The administration of MSE 300 mg/day was associated with an increase in the ratio of HMW/total APN in relation to the genes regulating APN multimerization, including DsbA-L. Furthermore, this effect of MSE was more pronounced in carriers of the DsbA-L rs191776 G/T or T/T genotype than in others. In addition, the administration of MSE to HFD mice suppressed their metabolic abnormalities (i.e. weight gain, increased blood glucose level and fat mass accumulation) and increased the levels of total and HMW APN in serum and the mRNA levels of ADIPOQ and DsbA-L in adipose tissue. The present study suggests that MSE may exert beneficial effects via APN multimerization in relation to the induction of DsbA-L under both physiological and obese conditions.

Azithromycin Inhibits Constitutive Airway Epithelial Sodium Channel Activation in Vitro and Modulates Downstream Pathogenesis in Vivo.

Epithelial sodium channel (ENaC) is an amiloride-sensitive sodium ion channel that is expressed in epithelial tissues. ENaC overexpression and/or hyperactivation in airway epithelial cells cause sodium over-absorption and dysregulated ciliary movement for mucus clearance; however, the agents that suppress constitutive airway ENaC activation are yet to be clinically available. Here, we focused on macrolides, which are widely used antibiotics that have many potential immunomodulatory effects. We examined whether macrolides could modulate constitutive ENaC activity and downstream events that typify cystic fibrosis (CF) and chronic obstructive pulmonary diseases (COPD) in in vitro and in vivo models of ENaC overexpression. Treatment of ENaC-overexpressing human bronchial epithelial cells (ß/γENaC-16HBE14o- cells) with three macrolides (erythromycin, clarithromycin, azithromycin) confirmed dose-dependent suppression of ENaC function. For in vivo studies, mice harboring airway specific ßENaC overexpression (C57BL/6J-ßENaC-transgenic mice) were treated orally with azithromycin, a well-established antimicrobial agent that has been widely prescribed. Azithromycin treatment modulated pulmonary mechanics, emphysematous phenotype and pulmonary dysfunction. Notably, a lower dose (3 mg kg-1) of azithromycin significantly increased forced expiratory volume in 0.1 s (FEV0.1), an inverse indicator of bronchoconstriction. Although not statistically significant, improvement of pulmonary obstructive parameters such as emphysema and lung dysfunction (FEV0.1%) was observed. Our results demonstrate that macrolides directly attenuate constitutive ENaC function in vitro and may be promising for the treatment of obstructive lung diseases with defective mucociliary clearance, possibly by targeting ENaC hyperactivation.