Association of genetic variants of the α-kinase 1 gene with type 2 diabetes mellitus in a longitudinal population-based genetic epidemiological study

A Bittersweet Kiss of Gram-Negative Bacteria: The Role of ADP-Heptose in the Pathogenesis of Infection

Due to the global crisis caused by the dramatic rise of drug resistance among Gram-negative bacteria, there is an urgent need for a thorough understanding of the pathogenesis of infections of such an etiology. In light of the limited availability of new antibiotics, therapies aimed at host-pathogen interactions emerge as potential treatment modalities. Thus, understanding the mechanism of pathogen recognition by the host and immune evasion appear to be the key scientific issues. Until recently, lipopolysaccharide (LPS) was recognized as a major pathogen-associated molecular pattern (PAMP) of Gram-negative bacteria. However, recently, ADP-L-glycero-β-D-manno-heptose (ADP-heptose), an intermediate carbohydrate metabolite of the LPS biosynthesis pathway, was discovered to activate the hosts' innate immunity. Therefore, ADP-heptose is regarded as a novel PAMP of Gram-negative bacteria that is recognized by the cytosolic alpha kinase-1 (ALPK1) protein. The conservative nature of this molecule makes it an intriguing player in host-pathogen interactions, especially in the context of changes in LPS structure or even in its loss by certain resistant pathogens. Here, we present the ADP-heptose metabolism, outline the mechanisms of its recognition and the activation of its immunity, and summarize the role of ADP-heptose in the pathogenesis of infection. Finally, we hypothesize about the routes of the entry of this sugar into cytosol and point to emerging questions that require further research.

In vitro kinase assay reveals ADP-heptose-dependent ALPK1 autophosphorylation and altered kinase activity of disease-associated ALPK1 mutants

Alpha-protein kinase 1 (ALPK1) is a pathogen recognition receptor that detects ADP-heptose (ADPH), a lipopolysaccharide biosynthesis intermediate, recently described as a pathogen-associated molecular pattern in Gram-negative bacteria. ADPH binding to ALPK1 activates its kinase domain and triggers TIFA phosphorylation on threonine 9. This leads to the assembly of large TIFA oligomers called TIFAsomes, activation of NF-κB and pro-inflammatory gene expression. Furthermore, mutations in ALPK1 are associated with inflammatory syndromes and cancers. While this kinase is of increasing medical interest, its activity in infectious or non-infectious diseases remains poorly characterized. Here, we use a non-radioactive ALPK1 in vitro kinase assay based on the use of ATPγS and protein thiophosphorylation. We confirm that ALPK1 phosphorylates TIFA T9 and show that T2, T12 and T19 are also weakly phosphorylated by ALPK1. Interestingly, we find that ALPK1 itself is phosphorylated in response to ADPH recognition during Shigella flexneri and Helicobacter pylori infection and that disease-associated ALPK1 mutants exhibit altered kinase activity. In particular, T237M and V1092A mutations associated with ROSAH syndrome and spiradenoma/spiradenocarcinoma respectively, exhibit enhanced ADPH-induced kinase activity and constitutive assembly of TIFAsomes. Altogether, this study provides new insights into the ADPH sensing pathway and disease-associated ALPK1 mutants.

Alpha-kinase1 promotes tubular injury and interstitial inflammation in diabetic nephropathy by canonical pyroptosis pathway

BACKGROUND

Alpha-kinase 1 (ALPK1) is a master regulator in inflammation and has been proved to promote renal fibrosis by promoting the production of IL-1β in diabetic nephropathy (DN) mice. Pyroptosis is involved in high glucose (HG)-induced tubular cells injury, characterized by activation of Gasdermin D (GSDMD) and the release of IL-1β and IL-18, resulting in inflammatory injury in DN. It is reasonable to assume that ALPK1 is involved in pyroptosis-related tubular injury in DN. However, the mechanism remains poorly defined.

METHODS

Immunohistochemistry (IHC) staining was performed to detect the expression of pyroptosis- and fibrosis-related proteins in renal sections of DN patients and DN mice. DN models were induced through injection of streptozotocin combined with a high-fat diet. Protein levels of ALPK1, NF-κB, Caspase-1, GSDMD, IL-1β, IL-18 and α-SMA were detected by Western blot. HK-2 cells treated with high-glucose (HG) served as an in vitro model. ALPK1 small interfering RNA (siRNA) was transfected into HK-2 cells to down-regulate ALPK1. The pyroptosis rates were determined by flow cytometry. The concentrations of IL-1β and IL-18 were evaluated by ELISA kits. Immunofluorescence staining was used to observe translocation of NF-κB and GSDMD.

RESULTS

The heat map of differentially expressed genes showed that ALPK1, Caspase-1 and GSDMD were upregulated in the DN group. The expression levels of ALPK1, Caspase-1, GSDMD and CD68 were increased in renal biopsy tissues of DN patients by IHC. ALPK1expression and CD68⁺ macrophages were positively correlated with tubular injury in DN patients. Western blot analysis showed increased expressions of ALPK1, phospho-NF-κB P65, GSDMD-NT, and IL-1β in renal tissues of DN mice and HK-2 cells, accompanied with increased renal fibrosis-related proteins (FN, α-SMA) and macrophages infiltration in interstitial areas. Inhibition of ALPK1 attenuated HG-induced upregulation expressions of NF-κB, pyroptosis-related proteins Caspase-1, GSDMD-NT, IL-1β, IL-18, α-SMA, and pyroptosis level in HK-2 cells. Also, the intensity and nuclear translocation of NF-κB and membranous translocation of GSDMD were ameliorated in HG-treated HK-2 cells after treatment with ALPK1 siRNA.

CONCLUSIONS

Our data suggest that ALPK1/NF-κB pathway initiated canonical caspase-1-GSDMD pyroptosis pathway, resulting in tubular injury and interstitial inflammation of DN.

ALPK1 Accelerates the Pathogenesis of Osteoarthritis by Activating NLRP3 Signaling

Alpha-kinase 1 (ALPK1), a member of the alpha-kinase family, has been shown to be involved in mediating inflammatory responses and is strongly associated with gout; however, its modulatory role in osteoarthritis (OA) remains unclear. Here, we uncovered elevation of ALPK1 in degraded cartilage of destabilized medial meniscus (DMM) and collagenase-induced osteoarthritis (CIOA), two different mouse OA models induced by mechanical stress or synovitis. Intraarticular administration of recombinant human ALPK1 (rhALPK1) in vivo exacerbated OA pathogenesis in both DMM and CIOA mice, whereas ALPK1 knockout reversed this process. In vitro study demonstrated that ALPK1 aggravates metabolic disturbances in chondrocytes by enhancing the production of NOD-like receptor protein 3 (NLRP3), an inflammasome sensors driving interlukin-1β (IL-1β)-mediated inflammatory conditions. Furthermore, the selective inhibition of nuclear factor-κB (NF-κB) or NLRP3 indicates that NLRP3 is a downstream signaling governed by NF-κB in ALPK1-activated chondrocytes. Collectively, these results establish ALPK1 as a novel catabolic regulator of OA pathogenesis, and targeting this signaling may be a promising treatment strategy for OA. © 2022 American Society for Bone and Mineral Research (ASBMR).

Systematic Review of the Role of Alpha-Protein Kinase 1 in Cancer and Cancer-Related Inflammatory Diseases

Simple Summary

Aside from the basic phosphorylation function of alpha-kinase 1 (ALPK1), little is known about its major functions. Researchers have used various forms of biotechnology and human, animal, and cellular models to better understand the relationship of ALPK1 with cancer and cancer-related inflammatory diseases. ALPK1 is involved in the progression of breast, lung, colorectal, oral, and skin cancer as well as lymphoblastic leukemia. ALPK1 has also been implicated in gout, diabetes, and chronic kidney disease, which are thought to be associated with breast, lung, colorectal, urinary tract, pancreatic, and endometrial cancers and lymphoblastic leukemia. ALPK1 upregulates inflammatory cytokines and chemokines during carcinogenesis. The major cytokine involved in carcinogenesis is TNF-α, which activates the NF-κB pathway, and similar inflammatory responses exist in gout, diabetes, and chronic kidney disease. ALPK1 regulates downstream inflammatory mechanisms that lead to cancer development through certain pathways and plays a key role in cancer initiation and metastasis.

Abstract

Background: Deregulation of conventional protein kinases is associated with the growth and development of cancer cells. Alpha-kinase 1 (ALPK1) belongs to a newly discovered family of serine/threonine protein kinases with no sequence homology to conventional protein kinases, and its function in cancer is poorly understood. Methods: In this systematic review, we searched for and analyzed studies linking ALPK1 to cancer development and progression. Results: Based on the current evidence obtained using human, animal, cellular, and tissue models, ALPK1 is located upstream and triggers cancer cell development and metastasis by regulating the inflammatory response through phosphorylation. Its mRNA and protein levels were found to correlate with advanced tumor size and lymph node metastasis, which occur from the cellular cytoplasm into the nucleus. ALPK1 is also strongly associated with gout, chronic kidney disease, and diabetes, which are considered as inflammatory diseases and associated with cancer. Conclusion: ALPK1 is an oncogene involved in carcinogenesis. Chronic inflammation is the common regulatory mechanism between cancer and these diseases. Future research should focus on identifying inhibitors of serine/threonine and ALPK1 at their phosphorylation sites, which would block various signal transductions and potentially offer kinase-targeted therapeutic agents for patients with cancer and inflammatory diseases.

Preliminary study of genome-wide association identifies novel susceptibility genes for serum mineral elements in the Chinese Han population

Mineral elements (copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg), iron (Fe)) play important biological roles in enzymes, hormones, vitamins, and normal metabolism. The deficiency of mineral elements can lead to abnormal physiological functions. And some elements (such as lead (Pb)) are harmful to the body. We aim to identify genetic loci which can influence the serum levels of mineral elements (Cu, Zn, Ca, Mg, Fe, and Pb). Genotyping was performed using Applied Biosystems Axiom™ PMDA in 587 individuals, and 6,423,076 single-nucleotide polymorphisms (SNPs) were available for the genome-wide association study (GWAS) analysis. The association between genotype and phenotype was analyzed using mixed linear regression (additive genetic model) adjusting by age and gender combined with identical by descent (IBD) matrix. Genetic loci in BCHE-LOC105374194, DTX2P1-UPK3BP1-PMS2P11, VAT1L, LINC00908-LINC00683, LINC01310-NONE, and rs6747410 in VWA3B were identified to be associated with serum Cu element concentration (p < 5 × 10^-6). ADAMTSL1 rs17229526 (p = 4.96 × 10^-6) was significantly associated with serum Zn element levels. Genetic loci in LRP1B, PIGZ-MELTF, LINC01365-LINC02502, and HAPLN3 were related to serum Ca element levels (p < 5 ×1 0^-6). Three SNPs in ALPK1, ASAP1-ADCY8 and IER3IP1-SKOR2 also achieved a significant association with Mg element levels (p < 5 × 10^-6). TACSTD2-MYSM1, LRP1B, and ASAP1-ADCY8 showed suggestive associations with serum Fe element levels (p < 5 × 10^-6). Moreover, the two most significant SNPs associated with Pb were rs304234 in CADPS-LINC00698 (p = 2.47 × 10^-6) and rs12666460 in LOC101928211-GPR37 (p = 1.81 × 10^-6). In summary, we reported 19 suggestive loci associated with serum mineral elements in the Chinese Han population. These findings provided new insights into the potential mechanisms regulating serum mineral elements levels.

Alpk1 Sensitizes Pancreatic Beta Cells to Cytokine-Induced Apoptosis via Upregulating TNF-α Signaling Pathway

Pancreatic beta cell failure is the hallmark of type 1 diabetes (T1D). Recent studies have suggested that pathogen recognizing receptors (PRRs) are involved in the survival, proliferation and function of pancreatic beta cells. So far, little is known about the role of alpha-protein kinase 1 (ALPK1), a newly identified cytosolic PRR specific for ADP-β-D-manno-heptose (ADP-heptose), in beta cell survival. In current study we aimed to fill the knowledge gap by investigating the role of Alpk1 in the apoptosis of MIN6 cells, a murine pancreatic beta cell line. We found that the expression of Alpk1 was significantly elevated in MIN6 cells exposed to pro-inflammatory cytokines, but not to streptozotocin, low-dose or high-dose glucose. Activation of Alpk1 by ADP heptose alone was insufficient to induce beta cell apoptosis. However, it significantly exacerbated cytokine-induced apoptosis in MIN6 cells. Mechanistic investigations showed that Alpk1 activation was potent to further induce the expression of tumor necrosis factor (TNF)-α and Fas after cytokine stimulation, possibly due to enhanced activation of the TIFA/TAK1/NF-κB signaling axis. Treatment of GLP-1 receptor agonist decreased the expression of TNF-α and Fas and improved the survival of beta cells exposed to pro-inflammatory cytokines and ADP heptose. In summary, our data suggest that Alpk1 sensitizes beta cells to cytokine-induced apoptosis by potentiating TNF-α signaling pathway, which may provide novel insight into beta cell failure and T1D development.

Long noncoding RNA HAR1A regulates oral cancer progression through the alpha-kinase 1, bromodomain 7, and myosin IIA axis

Studies suggested that long noncoding HAR1A RNA may be a tumor suppressor, but its association with oral cancer remains unclear. Here, we show the functional role and mechanisms of HAR1A in oral cancer progression. Microarray analysis was performed to screen the related candidates of long noncoding RNA (lncRNA) in human monocytes. Following lncRNA HAR1A, the regulation of HAR1A, ALPK1, myosin IIA, and BRD7 was tested using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) in oral cancer cells. The inflammatory and epithelial-to-mesenchymal transition marker expressions were analyzed using enzyme-linked immunosorbent assay and western blot. Phenotypic experiments were verified by colony formation assay, transwell migration assay, and Annexin V-apoptotic assay. In the nuclei of cancer cells, HAR1A functions upstream of signaling pathways and knockdown of HAR1A promoted ALPK1 expression and downregulated BRD7 resulting in inflammation and oral cancer progression. In monocytes, the expressions of TNF-α and CCL2 were increased following HAR1A knockdown and reduced following ALPK1 knockdown. HAR1A knockdown upregulated the expression of ALPK1, slug, vimentin, fibronectin, and N-cadherin but reduced the expression of E-cadherin in oral cancer cells. Myosin IIA was primarily located in the cytoplasm and that its decrease in the nuclei of oral cancer cells was likely to demonstrate suppressive ability in late-stage cancer. Our findings suggest that the HAR1A, BRD7, and myosin IIA are tumor suppressors while ALPK1 has oncogene-like property in the nucleus and is involved in inflammation and oral cancer progression. More research for HAR1A activators or ALPK1 inhibitors is required to develop potential therapeutic agents for advanced oral cancer. KEY MESSAGES: lncRNA HAR1A, BRD7, and myosin IIA are tumor suppressors whereas ALPK1 has an oncogenic-like property in the nucleus. lncRNA HAR1A/ALPK1/BRD7/myosin IIA axis plays a critical role in the progression of oral cancer. lncRNA HAR1A localizes upstream of signaling pathways to inhibit ALPK1 expression and then upregulated BRD7. lncRNA HAR1A and ALPK1 are involved in cancer progression via epithelial-to-mesenchymal transition regulations. ALPK1 inhibitors are potential kinase-targeted therapeutic agents for patients with advanced oral cancer.

ALPK1 regulates streptozotocin-induced nephropathy through CCL2 and CCL5 expressions

ALPK1 is associated with chronic kidney disease, gout and type 2 diabetes mellitus. Raised renal ALPK1 level in patients with diabetes was reported. Accelerated fibrotic nephropathies were observed in hyperglycaemic mice with up-regulated ALPK1. The aim of this study was to identify the mediators contributing to ALPK1 effect involving in nephropathies induction. The haematoxylin and eosin staining, Masson's trichrome and immunohistochemical analysis of ALPK1, NFkB, CCL2 and CCL5 were performed in the mice kidney. Cytokine antibody array analysis was performed in streptozotocin-treated wild-type mice (WT-STZ) and streptozotocin-treated ALPK1 transgenic mice (TG-STZ). The ALPK1 levels were measured in mice kidney and in cultured cells. We found that the higher levels of renal CCL2/MCP-1, CCL5/Rantes and G-CSF expression in TG-STZ compared with the WT-STZ. Glucose increased ALPK1 expressions in monocytic THP1 and human kidney-2 cells. The protein expression of ALPK1, NFkB and lectin was up-regulated in glucose-treated HK-2 cells. Knockdown of ALPK1 reduced CCL2 and CCL5 mRNA levels, whereas overexpressed ALPK1 increased CCL2 and CCL5 in cultured kidney cells. Taken together, these results show that high glucose increases ALPK1 and chemokine levels in the kidney. Elevated ALPK1 expression enhances renal CCL2 and CCL5 expressions in vivo and in vitro. ALPK1 is a mediator for CCL2 and CCL5 chemokine up-regulation involving in diabetic nephropathies induction.

Evolutionary history of disease-susceptibility loci identified in longitudinal exome-wide association studies

Background

Our longitudinal exome‐wide association studies previously detected various genetic determinants of complex disorders using ~26,000 single‐nucleotide polymorphisms (SNPs) that passed quality control and longitudinal medical examination data (mean follow‐up period, 5 years) in 4884–6022 Japanese subjects. We found that allele frequencies of several identified SNPs were remarkably different among four ethnic groups. Elucidating the evolutionary history of disease‐susceptibility loci may help us uncover the pathogenesis of the related complex disorders.

Methods

In the present study, we conducted evolutionary analyses such as extended haplotype homozygosity, focusing on genomic regions containing disease‐susceptibility loci and based on genotyping data of our previous studies and datasets from the 1000 Genomes Project.

Results

Our evolutionary analyses suggest that derived alleles of rs78338345 of GGA3, rs7656604 at 4q13.3, rs34902660 of SLC17A3, and six SNPs closely located at 12q24.1 associated with type 2 diabetes mellitus, obesity, dyslipidemia, and three complex disorders (hypertension, hyperuricemia, and dyslipidemia), respectively, rapidly expanded after the human dispersion from Africa (Out‐of‐Africa). Allele frequencies of GGA3 and six SNPs at 12q24.1 appeared to have remarkably changed in East Asians, whereas the derived alleles of rs34902660 of SLC17A3 and rs7656604 at 4q13.3 might have spread across Japanese and non‐Africans, respectively, although we cannot completely exclude the possibility that allele frequencies of disease‐associated loci may be affected by demographic events.

Conclusion

Our findings indicate that derived allele frequencies of nine disease‐associated SNPs (rs78338345 of GGA3, rs7656604 at 4q13.3, rs34902660 of SLC17A3, and six SNPs at 12q24.1) identified in the longitudinal exome‐wide association studies largely increased in non‐Africans after Out‐of‐Africa.

Six novel susceptibility loci for coronary artery disease and cerebral infarction identified by longitudinal exome-wide association studies in a Japanese population

Coronary artery disease (CAD) and cerebral infarction (CI) remain major causes of morbidity and mortality in humans. Recent genome-wide association studies have identified various genetic variants associated with these diseases. However, these studies were commonly conducted in a cross-sectional manner. Therefore, the present research performed longitudinal exome-wide association studies for CAD and CI using data on ~244,000 genotyped variants and the clinical data of 6,026 Japanese individuals who had attended annual health checkups for several years (mean followed-up period, 5±3 years). Following quality controls, the significance [false discovery rate (FDR) of <0.05] of association of the diseases with 24,651 single nucleotide polymorphisms (SNPs) in 5,989 individuals for three inheritance models was tested using the generalized estimating equation model. SNPs that reached statistical significance were further screened against a threshold of approxdf (a scale of small effective sample size) of >30. The longitudinal exome-wide association studies revealed that three SNPs [rs4606855 of ADGRE3 (P=2.5×10^-6; FDR=0.031; approxdf=71), rs3746414 of ZFP64 (P=5.9×10^-6; FDR=0.048; approxdf=93) and rs7132908 of FAIM2 (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=65)] were significantly associated with the prevalence of CAD. A different set of three SNPs [rs6580741 of FAM186A (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=48), rs1324015 of LINC00400 (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=49) and rs884205 of TNFRSF11A (P<2.0×10^-16; FDR<4.9×10^-12; approxdf=32)] was significantly associated with CI. The comparison of disease incidence with these SNPs demonstrated that all the minor alleles were associated with decreased susceptibility to CAD or CI. In conclusion, six novel SNPs were identified as susceptibility loci for CAD (rs4606855 of ADGRE3, rs3746414 of ZFP64, and rs7132908 of FAIM2) or CI (rs6580741 of FAM186A, rs1324015 of LINC00400, and rs884205 of TNFRSF11A).

Risk of incident benign prostatic hyperplasia in patients with gout: a retrospective cohort study

BACKGROUND

This retrospective cohort study evaluated the association between gout and the risk of benign prostatic hyperplasia among men by using data from Taiwan's National Health Insurance Research Database.

METHODS

Population-based representative insurance (outpatient and inpatient) claims data of 29,269 patients with gout and 29,269 matched patients without gout (1:1 ratio) for the period of 1997-2010 in Taiwan were identified. The association between gout and benign prostatic hyperplasia was evaluated using the Cox proportional hazards model. The associations of age by gout and gout phenotypes with benign prostatic hyperplasia risk were estimated.

RESULTS

Patients with gout had a higher incidence rate of benign prostatic hyperplasia than those in the matched gout-free group (19.62 vs. 10.11 events per 1000 person-years). Compared with the gout-free group, the adjusted hazard ratios (HRs) (95% confidence intervals (CIs)) for benign prostatic hyperplasia were 1.30 (1.24-1.36). The gout-to-benign prostatic hyperplasia association was modified by age (P_interaction < 0.0001) in gout patients the age groups of 20-40 years (adjusted HR 2.74, P < 0.0001) and 41-60 years (adjusted HR 1.39, P < 0.0001) but not in the age group of >60 years (adjusted HR 1.07, P = 0.063). Compared with gouty tophi, a higher risk of benign prostatic hyperplasia was noted in gouty nephropathy (adjusted HR 1.30, 95% CI 1.12-1.50).

CONCLUSIONS

Our results suggest that male gout is positively related to benign prostatic hyperplasia, particularly in young gout patients and those with gouty nephropathy.

Association of smoking with prevalence of common diseases and metabolic abnormalities in community-dwelling Japanese individuals

Smoking is a significant risk factor for cardiovascular diseases (CVDs). Given that certain common pathologies, including hypertension, dyslipidemia and type 2 diabetes mellitus, are major risk factors for CVDs, the association of smoking with CVDs may be attributable, at least in part, to its effects on common diseases. The aim of the present study was to determine the association of smoking with the prevalence of common diseases and metabolic abnormalities in community-dwelling Japanese individuals. The study included 5,959 subjects (1,302 current smokers, 1,418 past smokers and 3,239 nonsmokers) recruited to the Inabe Health and Longevity Study, a longitudinal genetic epidemiological study of atherosclerotic, cardiovascular and metabolic diseases. Various metabolic parameters and prevalence of common diseases were compared between smokers and nonsmokers using multivariable regression or logistic regression analysis with adjustments for age. Analysis indicated significantly higher serum concentrations of triglycerides and lower concentrations of high-density lipoprotein (HDL)-cholesterol in current smokers compared with nonsmokers in men and women. Serum concentrations of creatinine and systolic blood pressure were significantly lower and estimated glomerular filtration rate was higher in male current smokers. In addition, body weight was higher in female current smokers. In multivariable logistic regression analysis, smoking was significantly associated with the prevalence of dyslipidemia [P=6.3×10^-10; odds ratio (OR), 1.81], hypertriglyceridemia (P=2.3×10^-20; OR, 2.39), hypo-HDL-cholesterolemia (P=2.0×10^-9; OR, 2.14), metabolic syndrome (P=0.0003; OR, 1.61) and chronic kidney disease (P=4.4×10^-15; OR, 0.54) in men, but not in women. The results indicated that smoking is significantly associated with various metabolic abnormalities and prevalence of common diseases in Japanese individuals, with certain sex differences, which may lead to accelerated development of CVDs.

Troxerutin protects against diabetic cardiomyopathy through NF‑κB/AKT/IRS1 in a rat model of type 2 diabetes

Troxerutin is a bioflavonoid, which can be used to treat venous disorders, thrombosis and cerebrovascular diseases. Recent studies have demonstrated that it may also be used to prevent edemas. However, it is not known whether troxerutin protects against the cardiomyopathic complications of diabetes. In the present study, a rat model of type 2 diabetes was used to investigate the potential for troxerutin to protect against diabetic cardiomyopathy, through changes to nuclear factor‑κB (NF‑κB) expression. Troxerutin administration significantly reduced heart rate, blood pressure, blood glucose and plasma triglyceride levels across all measured time points. Furthermore, troxerutin significantly reduced reactive oxygen species levels, NF‑κB protein expression, and suppressed the phosphorylated forms of AKT, insulin receptor substrate 1 (IRS1) and c‑Jun N‑terminal kinase (JNK). These results suggested that troxerutin protects against cardiomyopathy via alterations in NF‑κB, AKT and IRS1 signaling, in a rat model of type 2 diabetes.

Association of renal function with clinical parameters and conditions in a longitudinal population-based epidemiological study

The aim of the present study was to examine the association of renal function with clinical parameters and conditions in the general population. Study subjects comprised 6,027 community-dwelling individuals who were recruited to the Inabe Health and Longevity Study: A longitudinal genetic epidemiological study of atherosclerotic, cardiovascular and metabolic diseases. The cutoff value, which was used to divide the subjects into those with normal and those with low estimated glomerular filtration rate (eGFR), was 60 ml/min/1.73 m2. Bonferroni's correction was applied to establish the statistical significance of the association. Longitudinal analysis using the generalized linear mixed-effect model, following adjustments for age and gender, revealed that the eGFR was significantly associated (P<0.0017) with serum levels of triglycerides, low-density lipoprotein cholesterol, uric acid, blood glycosylated hemoglobin content, fasting plasma glucose and body mass index. These parameters decreased curvilinearly with increases in eGFR. Furthermore, eGFR correlated positively with serum levels of high-density lipoprotein (HDL) cholesterol. Longitudinal analysis using the generalized estimating equation following adjustment for age and gender indicated a significant association (P<0.0024) between eGFR and prevalence of hypertension, type 2 diabetes mellitus, hypo-HDL cholesterolemia, hyperuricemia and obesity. Thus, low eGFR results in detrimental effects on various clinical parameters and conditions, resulting in increased risk of hypertension, dyslipidemia, type 2 diabetes mellitus, hyperuricemia and obesity.

Enhanced alpha-kinase 1 accelerates multiple early nephropathies in streptozotocin-induced hyperglycemic mice

Alpha-kinase 1 (ALPK1) is associated with chronic kidney disease (CKD), type 2 diabetes mellitus and gout. Elevated ALPK1 levels have been observed in the kidneys of patients with diabetes and the white blood cells of patients with gout. As renal injury is a common outcome of CKD, diabetes and gout, the aim of this study was to investigate the effect of ALPK1 in the development of renal injury in a hyperglycemic condition. Hyperglycemia was induced in wild-type and ALPK1 transgenic mice by an intraperitoneal injection of streptozotocin (STZ). Functional and histological examinations were performed after 3weeks. STZ-treated ALPK1 transgenic mice exclusively showed arteriolar sclerosis and fibrous thickening of the Bowman's capsule in the kidney. This was accompanied by body weight loss, severe hyperglycemia, and low serum insulin levels. Renal renin and serum renin protein levels were higher in STZ-treated ALPK1 transgenic mice, whereas cGKII protein level was decreased by ALPK1 in human embryonic kidney 293 (HEK293) cells. ALPK1 up-regulated TGF-beta1 levels and transcription of fibrosis-related genes, including MMP-9, FIBRONECTIN, and TIMP1. MSU crystals increased ALPK1 transcription in cultured kidney cells. Finally, ALPK1 enhanced production of MSU crystals-induced IL-1beta in mice. Stimulation of soluble sodium urate induced IL-1beta and Alpk1 mRNA production in mice kidney. Taken together, these data show that an increase in ALPK1 results in accelerated fibrotic nephropathies, primarily through the enhancement of renin, TGF-beta1, and IL-1beta. Renal or blood ALPK1 levels are involved in the induction of fibrotic renal injury in an experimental model of hyperglycemia.

Age-related changes in clinical parameters and their associations with common complex diseases

The aim of the present study was to clarify the age-related changes in 13 clinical parameters and their associations with common complex diseases. Study subjects comprised 6,027 community-dwelling individuals who were recruited to a population-based longitudinal genetic epidemiological study. Bonferroni's correction was applied to compensate for multiple comparisons of association and P<0.0011 was considered statistically significant. Body mass index and waist circumference increased with age up to ~50 years and decreased thereafter in men, whereas the two parameters increased linearly with age in women. The prevalence of obesity was highest (41.1%) in men aged 40-49 years, after which it decreased with age. The prevalence of obesity in women increased with age to ≤32.2% in those aged ≥70 years. Systolic and mean blood pressure (BP), as well as pulse pressure, increased linearly with age in all subjects, whereas diastolic BP increased with age up to ~60 years and subsequently decreased. The prevalence of hypertension increased with age to ≤69.9 or 68.5% at age ≥70 years in men and women, respectively. The fasting plasma glucose level, blood hemoglobin A1c content and the prevalence of type 2 diabetes mellitus increased gradually with age in men and women. The serum triglyceride concentration increased with age up to ~50 years and decreased thereafter in men, whereas it increased linearly with age in women. The prevalence of hypertriglyceridemia increased to a peak of 56.8% at age 50-59 years and subsequently decreased in men, whereas in women it increased with age to ≤34.9% at ≥70 years. The serum high-density lipoprotein (HDL)-cholesterol concentration increased with age up to ~50 years and decreased thereafter in women. The prevalence of hypo-HDL-cholesterolemia increased gradually with age in women. The serum concentration of low-density lipoprotein (LDL)-cholesterol increased with age up to ~50 years and subsequently declined in men, whereas it increased linearly with age in women. The prevalence of hyper-LDL-cholesterolemia increased with age to ≤53.4% at 50-59 years in men and ≤63.9% at 60-69 years in women and it decreased thereafter in the two genders. The serum creatinine concentration and the estimated glomerular filtration rate increased or decreased linearly with age, respectively. The prevalence of chronic kidney disease (CKD) increased with age to ≤45.1 or 39.6% at ≥70 years in men and women, respectively. Therefore, these results indicate that 13 clinical parameters, as well as the prevalence of obesity, hypertension, type 2 diabetes mellitus, dyslipidemia and CKD, were significantly associated with age. They may therefore prove informative for the prevention of these diseases and contribute to the achievement of a healthy long life and successful aging.