Claudin-4-adhesion signaling drives breast cancer metabolism and progression via liver X receptor ß.

BACKGROUND: Cell adhesion is indispensable for appropriate tissue architecture and function in multicellular organisms. Besides maintaining tissue integrity, cell adhesion molecules, including tight-junction proteins claudins (CLDNs), exhibit the signaling abilities to control a variety of physiological and pathological processes. However, it is still fragmentary how cell adhesion signaling accesses the nucleus and regulates gene expression. METHODS: By generating a number of knockout and rescued human breast cell lines and comparing their phenotypes, we determined whether and how CLDN4 affected breast cancer progression in vitro and in vivo. We also identified by RNA sequencing downstream genes whose expression was altered by CLDN4-adhesion signaling. Additionally, we analyzed by RT-qPCR the CLDN4-regulating genes by using a series of knockout and add-back cell lines. Moreover, by immunohistochemistry and semi-quantification, we verified the clinicopathological significance of CLDN4 and the nuclear receptor LXRß (liver X receptor ß) expression in breast cancer tissues from 187 patients. RESULTS: We uncovered that the CLDN4-adhesion signaling accelerated breast cancer metabolism and progression via LXRß. The second extracellular domain and the carboxy-terminal Y197 of CLDN4 were required to activate Src-family kinases (SFKs) and the downstream AKT in breast cancer cells to promote their proliferation. Knockout and rescue experiments revealed that the CLDN4 signaling targets the AKT phosphorylation site S432 in LXRß, leading to enhanced cell proliferation, migration, and tumor growth, as well as cholesterol homeostasis and fatty acid metabolism, in breast cancer cells. In addition, RT-qPCR analysis showed the CLDN4-regulated genes are classified into at least six groups according to distinct LXRß- and LXRßS432-dependence. Furthermore, among triple-negative breast cancer subjects, the "CLDN4-high/LXRß-high" and "CLDN4-low and/or LXRß-low" groups appeared to exhibit poor outcomes and relatively favorable prognoses, respectively. CONCLUSIONS: The identification of this machinery highlights a link between cell adhesion and transcription factor signalings to promote metabolic and progressive processes of malignant tumors and possibly to coordinate diverse physiological and pathological events.

Aberrant expression of claudin-6 contributes to malignant potentials and drug resistance of cervical adenocarcinoma.

Recent studies have revealed that aberrant expression of tight junction (TJ) proteins is a hallmark of various solid tumors and it is recognized as a useful therapeutic target. Claudin-6 (CLDN6), a member of the family of TJ transmembrane proteins, is an ideal therapeutic target because it is not expressed in human adult normal tissues. In this study, we found that CLDN6 is highly expressed in uterine cervical adenocarcinoma (ADC) and that high CLDN6 expression was correlated with lymph node metastasis and lymphovascular infiltration and was an independent prognostic factor. Shotgun proteome analysis revealed that cell-cell adhesion-related proteins and drug metabolism-associated proteins (aldo-keto reductase [AKR] family proteins) were significantly increased in CLDN6-overexpressing cells. Furthermore, overexpression of CLDN6 enhanced cell-cell adhesion properties and attenuated sensitivity to anticancer drugs including doxorubicin, daunorubicin, and cisplatin. Taken together, the results indicate that aberrant expression of CLDN6 enhances malignant potentials and drug resistance of cervical ADC, possibly due to increased cell-cell adhesion properties and drug metabolism. Our findings provide an insight into a new therapeutic strategy, a CLDN6-targeting therapy, against cervical ADC.

Cell adhesion signals regulate the nuclear receptor activity.

Cell adhesion is essential for proper tissue architecture and function in multicellular organisms. Cell adhesion molecules not only maintain tissue integrity but also possess signaling properties that contribute to diverse cellular events such as cell growth, survival, differentiation, polarity, and migration; however, the underlying molecular basis remains poorly defined. Here we identify that the cell adhesion signal initiated by the tight-junction protein claudin-6 (CLDN6) regulates nuclear receptor activity. We show that CLDN6 recruits and activates Src-family kinases (SFKs) in second extracellular domain-dependent and Y196/200-dependent manners, and SFKs in turn phosphorylate CLDN6 at Y196/200. We demonstrate that the CLDN6/SFK/PI3K/AKT axis targets the AKT phosphorylation sites in the retinoic acid receptor γ (RARγ) and the estrogen receptor α (ERα) and stimulates their activities. Interestingly, these phosphorylation motifs are conserved in 14 of 48 members of human nuclear receptors. We propose that a similar link between diverse cell adhesion and nuclear receptor signalings coordinates a wide variety of physiological and pathological processes.

The region-selective regulation of endothelial claudin-5 expression and signaling in brain health and disorders.

The neurovascular unit (NVU) consists of neurons, glial cells, microvascular cells, and extracellular matrix, and is involved in a variety of physiological and pathological processes in the central nervous system (CNS). Within the NVU, the microvascular endothelial cells and pericytes principally contribute to maintaining the integrity of the blood-brain barrier (BBB). Various types of cells are connected to each other in the NVU by diverse cell adhesion molecules, of which claudin-5 (CLDN5) is by far the most abundantly expressed tight-junction protein in brain microvascular endothelial cells and absolutely required for the maintenance of the BBB. This review highlights recent progress in understanding the region-specific regulation and dysregulation of CLDN5 expression in CNS health and disorders. We also discuss how CLDN5 expression is regionally disrupted within the NVU. In addition, we focus on the link between cell adhesion and transcription factor signalings and describe the possible involvement of CLDN5-adhesion signaling in brain health and disorders.

Reduced Claudin-12 Expression Predicts Poor Prognosis in Cervical Cancer.

BACKGROUND: Within the claudin (CLDN) family, CLDN12 mRNA expression is altered in various types of cancer, but its clinicopathological relevance has yet to be established due to the absence of specific antibodies (Abs) with broad applications. METHODS: We generated a monoclonal Ab (mAb) against human/mouse CLDN12 and verified its specificity. By performing immunohistochemical staining and semiquantification, we evaluated the relationship between CLDN12 expression and clinicopathological parameters in tissues from 138 cases of cervical cancer. RESULTS: Western blot and immunohistochemical analyses revealed that the established mAb selectively recognized the CLDN12 protein. Twenty six of the 138 cases (18.8%) showed low CLDN12 expression, and the disease-specific survival (DSS) and recurrence-free survival rates were significantly decreased compared with those in the high CLDN12 expression group. We also demonstrated, via univariable and multivariable analyses, that the low CLDN12 expression represents a significant prognostic factor for the DSS of cervical cancer patients (HR 3.412, p = 0.002 and HR 2.615, p = 0.029, respectively). CONCLUSIONS: It can be concluded that a reduced CLDN12 expression predicts a poor outcome for cervical cancer. The novel anti-CLDN12 mAb could be a valuable tool to evaluate the biological relevance of the CLDN12 expression in diverse cancer types and other diseases.

NAD Deficiency, Congenital Malformations, and Niacin Supplementation.

BACKGROUND: Congenital malformations can be manifested as combinations of phenotypes that co-occur more often than expected by chance. In many such cases, it has proved difficult to identify a genetic cause. We sought the genetic cause of cardiac, vertebral, and renal defects, among others, in unrelated patients. METHODS: We used genomic sequencing to identify potentially pathogenic gene variants in families in which a person had multiple congenital malformations. We tested the function of the variant by using assays of in vitro enzyme activity and by quantifying metabolites in patient plasma. We engineered mouse models with similar variants using the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 system. RESULTS: Variants were identified in two genes that encode enzymes of the kynurenine pathway, 3-hydroxyanthranilic acid 3,4-dioxygenase (HAAO) and kynureninase (KYNU). Three patients carried homozygous variants predicting loss-of-function changes in the HAAO or KYNU proteins (HAAO p.D162*, HAAO p.W186*, or KYNU p.V57Efs*21). Another patient carried heterozygous KYNU variants (p.Y156* and p.F349Kfs*4). The mutant enzymes had greatly reduced activity in vitro. Nicotinamide adenine dinucleotide (NAD) is synthesized de novo from tryptophan through the kynurenine pathway. The patients had reduced levels of circulating NAD. Defects similar to those in the patients developed in the embryos of Haao-null or Kynu-null mice owing to NAD deficiency. In null mice, the prevention of NAD deficiency during gestation averted defects. CONCLUSIONS: Disruption of NAD synthesis caused a deficiency of NAD and congenital malformations in humans and mice. Niacin supplementation during gestation prevented the malformations in mice. (Funded by the National Health and Medical Research Council of Australia and others.).

Serotonin/5-HT1A Signaling in the Neurovascular Unit Regulates Endothelial CLDN5 Expression.

We previously reported that site-selective claudin-5 (CLDN5) breakdown and protein kinase A (PKA) activation are observed in brain microvessels of schizophrenia, but the underlying molecular basis remains unknown. The 5-HT1 receptors decline the intracellular cAMP levels and inactivate the major downstream PKA, and the 5-HT1A receptor is a promising target for schizophrenia. Therefore, we elucidated the involvement of serotonin/5-HT1A signaling in the endothelial CLDN5 expression. We demonstrate, by immunohistochemistry using post-mortem human brain tissue, that the 5-HT1A receptor is expressed in brain microvascular endothelial cells (BMVECs) and mural cells of the normal prefrontal cortex (PFC) gray matter. We also show that PKA is aberrantly activated not only in BMVECs but also in mural cells of the schizophrenic PFC. We subsequently revealed that the endothelial cell-pericyte tube-like structure was formed in a novel two-dimensional co-culture of human primary BMVECs and a human brain-derived pericyte cell line, in both of which the 5-HT1A receptor was expressed. Furthermore, we disclose that the serotonin/5-HT1A signaling enhances endothelial CLDN5 expression in BMVECs under two-dimensional co-culture conditions. Our findings provide novel insights into the physiological and pathological significance of serotonin/5-HT1A signaling in the region-specific regulation of the blood-brain barrier.

Attenuation of pulmonary fibrosis in type I collagen-targeted reporter mice with ALK-5 inhibitors.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease, and consequently, effective antifibrotic drugs are strongly desired. Although we have previously reported a validated Col1a1-Luc Tg rat model for fibrosis, there are only a few mouse models that enable the evaluation of fibrosis in a short time period and with high sensitivity. Therefore, we generated a Col1a1-internal ribosome entry site (IRES)-Luc knock-in (KI) mouse in which the IRES-luciferase gene construct was inserted into the 3'-UTR of the type I collagen alpha 1 gene (Col1a1). There was a high correlation between luciferase activity and hydroxyproline content in the KI mice, which is similar to the result that we have previously reported for the Col1a1-Luc Tg rat model. In a bleomycin (BLM)-induced lung fibrosis model, luciferase activity in the lung showed a significant increase 3 days after BLM treatment, while only a slight increase was observed in the hydroxyproline content. An ALK-5 inhibitor-R-268712-was effective in inhibiting the luciferase activity in both the in vivo BLM-induced lung fibrosis model and in vitro primary mouse lung fibroblasts. This suggests that fibroblasts are the major collagen-producing cells in lung fibrosis. In human lung fibroblasts, TGF-ß stimulation induced α-smooth muscle actin as observed by immunostaining, suggesting that myofibroblast transdifferentiation (MTD) plays an important role in lung fibrosis. Together, these results indicated that ALK-5 inhibitors might affect lung fibrosis mainly via the inhibition of MTD. Thus, the Col1a1-IRES-Luc KI mouse might be useful for the evaluation of antifibrotic effects and their underlying mechanisms.

A novel selective prostaglandin E2 synthesis inhibitor relieves pyrexia and arthritis in Guinea pigs inflammatory models.

Prostaglandin E2 (PGE2), one of the terminal products in the cyclooxygenase pathway, plays an important role in various inflammatory responses. To determine whether selective inhibition of PGE2 may relieve these inflammatory symptoms, we synthesized a selective PGE2 synthesis inhibitor, compound A [1-(6-fluoro-5,7-dimethyl-1,3-benzothiazol-2-yl)-N-[(1S,2R)-2-(hydroxymethyl)cyclohexyl]piperidine-4-carboxamide], then investigated the effects on pyrexia, arthritis and inflammatory pain in guinea pigs. In LPS-stimulated guinea pig macrophages, compound A selectively inhibited inducible PGE2 biosynthesis in a dose-dependent manner whereas enhanced the formation of thromboxane B2 (TXB2). Compound A suppressed yeast-evoked PGE2 production selectively and enhanced the production of TXB2 and 6-keto PGF1αin vivo. In addition, compound A relieved yeast-induced pyrexia and also suppressed paw swelling in an adjuvant-induced arthritis model. The effect on gastrointestinal (GI) ulcer formation was also evaluated and compound A showed a lower GI adverse effect than indomethacin. However, compound A failed to relieve yeast-induced thermal hyperalgesia. These results suggest that selective inhibition of PGE2 synthesis may have anti-pyretic and anti-inflammatory properties without GI side effect, but lack the analgesic efficacy.

Simultaneous Inhibition of PGE2 and PGI2 Signals Is Necessary to Suppress Hyperalgesia in Rat Inflammatory Pain Models.

Prostaglandin E2 (PGE2) is well known as a mediator of inflammatory symptoms such as fever, arthritis, and inflammatory pain. In the present study, we evaluated the analgesic effect of our selective PGE2 synthesis inhibitor, compound I, 2-methyl-2-[cis-4-([1-(6-methyl-3-phenylquinolin-2-yl)piperidin-4-yl]carbonyl amino)cyclohexyl] propanoic acid, in rat yeast-induced acute and adjuvant-induced chronic inflammatory pain models. Although this compound suppressed the synthesis of PGE2 selectively, no analgesic effect was shown in both inflammatory pain models. Prostacyclin (PGI2) also plays crucial roles in inflammatory pain, so we evaluated the involvement of PGI2 signaling in rat inflammatory pain models using prostacyclin receptor (IP) antagonist, RO3244019. RO3244019 showed no analgesic effect in inflammatory pain models, but concomitant administration of compound I and RO3244019 showed analgesic effects comparable to celecoxib, a specific cyclooxygenase- (COX-) 2 inhibitor. Furthermore, coadministration of PGE2 receptor 4 (EP4) antagonist, CJ-023423, and RO3244019 also showed an analgesic effect. These findings suggest that both PGE2 signaling, especially through the EP4 receptor, and PGI2 signaling play critical roles in inflammatory pain and concurrent inhibition of both signals is important for suppression of inflammatory hyperalgesia.

Aberrant expression of claudin-4 and -7 in hepatocytes in the cirrhotic human liver.

The liver comprises hepatocytes and non-parenchymal cells such as bile duct epithelial cells. Claudin-4 and -7 are not expressed in hepatocytes under physiological conditions. It was reported that claudin-7 increased in human pulmonary fibroses. We therefore investigated claudin-4 and -7 expressions in human cirrhotic livers, in which hepatocyte proliferation is severely delayed. We examined liver tissues from 50 patients with liver tumors. The expression of claudin-4 and -7 in hepatocytes significantly increased with the grade of fibrosis, not with inflammatory activity, in the liver tissues of chronic hepatitis. The number of claudin-4- and -7-positive cells observed was greater than that of alpha-fetoprotein-positive hepatic progenitor cells. In primary cultures of mouse hepatocytes, the expression of claudin-4 and -7 was not induced by treatment with proinflammatory cytokines. In immunohistochemical analysis of liver tissues of 3,5-diethoxycarbonyl-1,4-dihydrocollidine-treated mice and primary cultures of mouse hepatocytes, the expression of claudin-4 and -7 increased with proliferation of progenitor cells. However, the claudin-4- and -7-positive cells were not always progenitor cells. Thus, claudin-4 and -7 were observed in hepatocytes of severely damaged mouse and human livers. These findings suggest that claudin-4- and -7-positive hepatocytes may exist during the process of differentiation from progenitor cells into mature hepatocytes.

Tight junction protein claudin-4 is modulated via ΔNp63 in human keratinocytes.

In the epidermis, tight junction (TJ) structure is specifically located in the stratum granulosum, where the expression of ΔNp63, a p53 family transcription factor, is attenuated. Since the relationship between ΔNp63 and barrier function has not been fully uncovered, we assessed expression profiles of TJ proteins in skin tissues and cultured keratinocytes. The results showed that expression of ΔNp63 and that of claudin-4 were inversely correlated in healthy human epidermis. In vitro studies using HaCaT keratinocytes revealed functional relevance of ΔNp63 and claudin-4. Curiously, Toll-like receptor (TLR)-3 ligand, which is known to be liberated from damaged cells, suppressed ΔNp63 expression and concomitantly upregulated claudin-4 expression in primary keratinocytes. More interestingly, a broad expression pattern of claudin-4 was found in the epidermis of atopic dermatitis (AD), a barrier defect disorder, which contains ΔNp63-lacking keratinocytes as we reported previously. Therefore, upregulation of claudin-4 expression regulated by ΔNp63 might be associated with complementary or repair responses of damaged keratinocytes with AD.

Alternaria induces STAT6-dependent acute airway eosinophilia and epithelial FIZZ1 expression that promotes airway fibrosis and epithelial thickness.

The fungal allergen, Alternaria, is specifically associated with severe asthma, including life-threatening exacerbations. To better understand the acute innate airway response to Alternaria, naive wild-type (WT) mice were challenged once intranasally with Alternaria. Naive WT mice developed significant bronchoalveolar lavage eosinophilia following Alternaria challenge when analyzed 24 h later. In contrast to Alternaria, neither Aspergillus nor Candida induced bronchoalveolar lavage eosinophilia. Gene microarray analysis of airway epithelial cell brushings demonstrated that Alternaria-challenged naive WT mice had a >20-fold increase in the level of expression of found in inflammatory zone 1 (FIZZ1/Retnla), a resistin-like molecule. Lung immunostaining confirmed strong airway epithelial FIZZ1 expression as early as 3 h after a single Alternaria challenge that persisted for ≥5 d and was significantly reduced in STAT6-deficient, but not protease-activated receptor 2-deficient mice. Bone marrow chimera studies revealed that STAT6 expressed in lung cells was required for epithelial FIZZ1 expression, whereas STAT6 present in bone marrow-derived cells contributed to airway eosinophilia. Studies investigating which cells in the nonchallenged lung bind FIZZ1 demonstrated that CD45(+)CD11c(+) cells (macrophages and dendritic cells), as well as collagen-1-producing CD45(-) cells (fibroblasts), can bind to FIZZ1. Importantly, direct administration of recombinant FIZZ1 to naive WT mice led to airway eosinophilia, peribronchial fibrosis, and increased thickness of the airway epithelium. Thus, Alternaria induces STAT6-dependent acute airway eosinophilia and epithelial FIZZ1 expression that promotes airway fibrosis and epithelial thickness. This may provide some insight into the uniquely pathogenic aspects of Alternaria-associated asthma.

Comparison of clinical findings and subjective symptoms in a case of multiple evanescent white dot syndrome (MEWDS): A case report from a patient's perspective.

A 38-year-old pathologist developed multiple evanescent white dot syndrome (MEWDS). He documented his visual impairment in detail utilizing a light microscope for pathological diagnosis. Notably, the subjective defects illustrated by the patient were in good spatiotemporal agreement with diagnostic outcomes. The present report enhances the understanding of visual impairment associated with MEWDS through a comparative analysis of subjective experiences and objective clinical findings.

Exploratory study on the relationship between urinary sodium/potassium ratio, salt intake, and the antihypertensive effect of esaxerenone: the ENaK Study.

Excessive salt intake is one of the causes of hypertension, and reducing salt intake is important for managing the risk of hypertension and subsequent cardiovascular events. Esaxerenone, a mineralocorticoid receptor blocker, has the potential to exert an antihypertensive effect in hypertensive patients with excessive salt intake, but evidence is still lacking, especially in clinical settings. We aimed to determine if baseline sodium/potassium ratio and baseline estimated 24-h urinary sodium excretion can predict the antihypertensive effect of esaxerenone in patients with essential hypertension inadequately controlled with an angiotensin receptor blocker (ARB) or a calcium channel blocker (CCB). This was an exploratory, open-label, interventional study with a 4-week observation period and a 12-week treatment period. Esaxerenone was orally administered once daily in accordance with the Japanese package insert. In total, 126 patients met the eligibility criteria and were enrolled (ARB subcohort, 67; CCB subcohort, 59); all were included in the full analysis set (FAS) and safety analysis. In the FAS, morning home systolic blood pressure (SBP)/diastolic blood pressure (DBP) significantly decreased from baseline to end of treatment (primary efficacy endpoint) (-11.9 ± 10.9/ - 6.4 ± 6.8 mmHg, both p < 0.001); a similar trend was observed in both subcohorts. Significant reductions were also shown in bedtime home and office SBP/DBP (all p < 0.001). Each BP change was consistent regardless of the urinary sodium/potassium ratio or estimated 24-h urinary sodium excretion at baseline. The urinary albumin-creatinine ratio (UACR) and N-terminal pro-brain natriuretic peptide (NT-proBNP) significantly decreased from baseline to Week 12 in the total population and both subcohorts. No new safety concerns were raised. Esaxerenone significantly decreased morning home, bedtime home, and office BP; UACR; and NT-proBNP in this patient population, regardless of concomitant ARB or CCB use. The antihypertensive effect of esaxerenone was independent of the urinary sodium/potassium ratio and estimated 24-h urinary sodium excretion at baseline.

Efficacy and Safety of Esaxerenone in Hypertensive Patients with Left Ventricular Hypertrophy (ESES-LVH) Study: A Multicenter, Open-Label, Prospective, Interventional Study.

INTRODUCTION: In contrast to the antihypertensive effect of esaxerenone, there is little evidence of its cardioprotective effect. We investigated the efficacy and safety of esaxerenone in patients with uncontrolled hypertension and left ventricular hypertrophy taking a renin-angiotensin system inhibitor (RASi) or calcium-channel blocker (CCB). METHODS: This was a multicenter, open-label, exploratory study with a 24-week treatment period. Esaxerenone was orally administered at an initial dose of 2.5 mg/day (maximum dose: 5 mg/day). The primary endpoints were the change in morning home systolic blood pressure (BP)/diastolic BP and change and percentage change in left ventricular mass index (LVMI) from baseline to end of treatment (EOT). Key secondary endpoints included change from baseline in bedtime home and office BP, achievement rate of target BP, and safety. RESULTS: In total, 60 patients were enrolled. Morning home systolic/diastolic BP was significantly decreased from baseline to EOT in the total population (- 11.5/ - 4.7 mmHg, p < 0.001) and in both the RASi and CCB subcohorts (all p < 0.01). Significant reductions in bedtime home and office BP were shown in the total population and both subcohorts. LVMI was also significantly decreased from baseline to EOT in the total population (- 9.9 g/m2, - 8.5%, both p < 0.001) and both subcohorts (all p < 0.05). The incidences of treatment-emergent adverse events (TEAEs) and drug-related TEAEs were 35.0% and 3.3%, respectively; most were mild or moderate. No new safety concerns were identified. CONCLUSION: Esaxerenone showed favorable antihypertensive and cardioprotective effects and safety in hypertensive patients with cardiac hypertrophy. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCTs071190043).

Multifocal and microscopic chromophobe renal cell carcinomatous lesions associated with 'capsulomas' without FCLN gene abnormality.

Chromophobe renal cell carcinoma (RCC) accounts for approximately 5% of renal epithelial neoplasms. Multiple and/or bilateral chromophobe RCCs in an individual are generally rare but frequently occur in patients with Birt-Hogg-Dubé syndrome (BHDS) and in patients with tuberous sclerosis complex (TSC). The responsible genes in both BHDS and TSC act as tumor suppressors. Therefore, it seems that some genetic backgrounds are required for the generation and progression of multiple chromophobe RCCs. Here, we report a case of multiple and bilateral chromophobe RCCs along with several small-sized capsular angiomyolipomas known as 'capsulomas' in a 39-year-old woman who had neither a particular medical history nor specific gene mutation. There has been no report of sporadic multiple chromophobe RCCs and 'capsulomas' developing in a patient without genetic features, having potential for novel genetic variation.

Factors Associated with the Antihypertensive Effect of Esaxerenone and Serum Potassium Elevation: A Pooled Analysis of Seven Phase III Studies.

INTRODUCTION: This study investigated factors associated with the antihypertensive effects of esaxerenone and the incidence of serum potassium elevation in patients with hypertension. METHODS: Using pooled data from seven phase III studies, the study analyzed factors associated with changes in office systolic (SBP) and diastolic (DBP) blood pressure from baseline to 12 weeks, and factors associated with incidence of serum potassium levels ≥ 5.5 mEq/L in esaxerenone-treated patients. RESULTS: Overall, 1466 and 1472 patients were included in the full analysis and safety analysis sets, respectively. Male sex (4.02/2.40 mmHg), weight ≥ 78.4 kg (4.62/2.09 mmHg), hypertension duration ≥ 10 years (2.66/1.71 mmHg), prior antihypertensive treatment (2.38/1.40 mmHg), plasma aldosterone concentration ≥ 120 pg/mL (1.66/1.17 mmHg), urinary albumin-to-creatinine ratio (UACR) ≥ 300 mg/gCr (8.94/4.85 mmHg) or 30-299 mg/gCr (5.17/4.15 mmHg), and smoking (2.62/1.27 mmHg) were associated with mean changes in SBP and DBP. Fasting blood glucose ≥ 126 mg/dL (- 2.73 mmHg) was associated with the mean change in SBP only, and older age (65-74 years, - 2.12 mmHg; and ≥ 75 years, - 3.06 mmHg) with mean change in DBP only. Factors significantly associated with incidence of serum potassium levels ≥ 5.5 mEq/L were higher baseline serum potassium (≥ 4.5 mEq/L, odds ratio [OR] 6.702); lower estimated glomerular filtration rate (≥ 90 mL/min/1.73 m2, OR 0.148; 60-89 mL/min/1.73 m2, OR 0.331 vs 30-59 mL/min/1.73 m2, respectively); higher UACR (30-299 mg/gCr, OR 7.317); higher DBP (≥ 100 mmHg, OR 3.248); and grade I hypertension (OR 2.168). CONCLUSION: Esaxerenone is effective in patients with a broad range of backgrounds, though some factors may predict increased benefit. Regarding elevated serum potassium, careful therapeutic management is recommended for patients with higher baseline serum potassium and reduced renal function. CLINICAL TRIAL REGISTRATION: UMIN000047026.

The Src-Family Kinases SRC and BLK Contribute to the CLDN6-Adhesion Signaling.

Cell adhesion molecules, including integrins, cadherins, and claudins (CLDNs), are known to activate Src-family kinases (SFKs) that organize a variety of physiological and pathological processes; however, the underlying molecular basis remains unclear. Here, we identify the SFK members that are coupled with the CLDN6-adhesion signaling. Among SFK subtypes, BLK, FGR, HCK, and SRC were highly expressed in F9 cells and concentrated with CLDN6 along cell borders during epithelial differentiation. Immunoprecipitation assay showed that BLK and SRC, but not FGR or HCK, form a complex with CLDN6 via the C-terminal cytoplasmic domain. We also demonstrated, by pull-down assay, that recombinant BLK and SRC proteins directly bind to the C-terminal cytoplasmic domain of CLDN6 (CLDN6C). Unexpectedly, both recombinant SFK proteins recognized the CLDN6C peptide in a phosphotyrosine-independent manner. Furthermore, by comparing phenotypes of F9:Cldn6:Blk-/- and F9:Cldn6:Src-/- cells with those of wild-type F9 and F9:Cldn6 cells, we revealed that BLK and SRC are essential for CLDN6-triggered cellular events, namely epithelial differentiation and the expression of retinoid acid receptor target genes. These results indicate that selective SFK members appear to participate in the CLDN-adhesion signaling.