Endonucleosis mediates internalization of cytoplasm into the nucleus.

Setd8 regulates transcription elongation, mitotic DNA condensation, DNA damage response and replication licensing. Here we show that, in mitogen-stimulated liver-specific Setd8-KO mice, most of the hepatocytes are eliminated by necrosis but a significant number of them survive via entering a stage exhibiting several senescence-related features. Setd8-deficient hepatocytes had enlarged nuclei, chromosomal hyperploidy and nuclear engulfments progressing to the formation of intranuclear vesicles surrounded by nuclear lamina. These vesicles contain glycogen, cytoplasmic proteins and even entire organelles. We term this process "endonucleosis". Intranuclear vesicles are absent in hepatocytes of Setd8/Atg5 knockout mice, suggesting that the process requires the function of the canonical autophagy machinery. Endonucleosis and hyperploidization are temporary, early events in the surviving Setd8-deficient cells. Larger vesicles break down into microvesicles over time and are eventually eliminated. The results reveal sequential events in cells with extensive DNA damage, which function as part of survival mechanisms to prevent necrotic death.

Inflammation-induced TRIM21 represses hepatic steatosis by promoting the ubiquitination of lipogenic regulators.

Nonalcoholic steatohepatitis (NASH) is a leading cause for chronic liver diseases. Current therapeutic options are limited due to an incomplete mechanistic understanding of how steatosis transitions to NASH. Here we show that the TRIM21 E3 ubiquitin ligase is induced by the synergistic actions of proinflammatory TNF-α and fatty acids in livers of humans and mice with NASH. TRIM21 ubiquitinates and degrades ChREBP, SREBP1, ACC1, and FASN, key regulators of de novo lipogenesis, and A1CF, an alternative splicing regulator of the high-activity ketohexokinase-C (KHK-C) isoform and rate-limiting enzyme of fructose metabolism. TRIM21-mediated degradation of these lipogenic activators improved steatosis and hyperglycemia as well as fructose and glucose tolerance. Our study identifies TRIM21 as a negative regulator of liver steatosis in NASH and provides mechanistic insights into an immunometabolic crosstalk that limits fatty acid synthesis and fructose metabolism during metabolic stress. Thus, enhancing this natural counteracting force of steatosis through inhibition of key lipogenic activators via TRIM21-mediated ubiquitination may provide a therapeutic opportunity to treat NASH.

Chronic Pain and Its Association with Depressive Symptoms and Renal Function in Hypertensive Patients.

Chronic pain is a common concern and is considered to be one of the major problems in patients with chronic physical disorders. We studied the effect of pain in patients with hypertension with or without chronic kidney disease (CKD) and the association between pain and symptoms of depression. The study involved 158 hypertensive individuals (59.5% male, mean age 55 years), of whom 47 (29.8%) had CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m2). Pain was assessed with the pain/discomfort domain of the EuroQol-5 D, while depressive symptoms were assessed with the depression module of the Patient health questionnaire (PHQ-9). The prevalence of chronic pain in our sample was 44.3%. Women exhibited chronic pain more often compared to men (57.1% vs. 42.9%, p < 0.001). The presence of CKD was not significantly associated with a higher prevalence of chronic pain among hypertensive patients. Depressive symptoms were significantly associated with the presence of chronic pain. These findings were confirmed in the logistic regression analysis. Chronic pain is common in hypertensive individuals and the association with depression warrants further investigation and may have practical implications in managing these patients.

The RNA-Binding Protein A1CF Regulates Hepatic Fructose and Glycerol Metabolism via Alternative RNA Splicing.

The regulation of hepatic gene expression has been extensively studied at the transcriptional level; however, the control of metabolism through posttranscriptional gene regulation by RNA-binding proteins in physiological and disease states is less understood. Here, we report a major role for the hormone-sensitive RNA-binding protein (RBP) APOBEC1 complementation factor (A1CF) in the generation of hepatocyte-specific and alternatively spliced transcripts. Among these transcripts are isoforms for the dominant and high-affinity fructose-metabolizing ketohexokinase C and glycerol kinase, two key metabolic enzymes that are linked to hepatic gluconeogenesis and found to be markedly reduced upon hepatic ablation of A1cf. Consequently, mice lacking A1CF exhibit improved glucose tolerance and are protected from fructose-induced hyperglycemia, hepatic steatosis, and development of obesity. Our results identify a previously unreported function of A1CF as a regulator of alternative splicing of a subset of genes influencing hepatic glucose production through fructose and glycerol metabolism.

Serum vitamin D in obese and overweight subjects according to estimated glomerular filtration rate.

OBJECTIVE: Obesity and renal disease are both associated with low serum 25(OH)D. The aims of the present study were to (a) assess vitamin D status and compare serum vitamin D levels in overweight/obese versus normal-weight individuals according to eGFR and (b) assess the role of 25(OH)D in the development of secondary hyperparathyroidism (SHPT). DESIGN: Serum 25(OH)D, 1,25(OH)2D, parathyroid hormone (PTH), calcium, and phosphate were measured in 104 subjects with BMI > 25 kg/m2. Participants were categorized according to eGFR (ml/min/1.73m2): G1 ≥ 60 (n = 53), G2 30-59 (n = 35), and G3 15-29 (n = 16). Fifty normal-weight individuals with comparable eGFR served as controls: G1-nw (n = 23), G2-nw (n = 18), and G3-nw (n = 9). RESULTS: 25(OH)D levels were lower in G1 compared to those in G1-nw (21.7 ± 6.5 vs 26.5 ± 7.0 ng/ml, p = 0.005), G2 versus G2-nw (19.0 ± 6.0 vs 25.0 ± 5.2 ng/ml, p = 0.001), and G3 vs G3-nw (15.8 ± 4.7 vs 20.3 ± 4.5 ng/ml, p = 0.030). 1,25(OH)2D and PTH levels were similar in obese/overweight versus normal-weight individuals in each of the eGFR categories. Factors independently associated with low 25(OH)D levels were BMI > 25 kg/m2, lower eGFR, and female gender. Mean 25(OH)D levels were < 30 ng/ml in both overweight and controls, in all eGFR groups. SHPT was universally observed when eGFR was < 30 ml/min/1.73m2. CONCLUSIONS: Lower serum 25(OH)D but similar 1,25(OH)2D and PTH levels were observed in overweight/obese compared to normal-weight individuals. Even though vitamin D insufficiency was common across all eGFR categories, secondary hyperparathyroidism was more prevalent as eGFR declined.

Kmt5a Controls Hepatic Metabolic Pathways by Facilitating RNA Pol II Release from Promoter-Proximal Regions.

H4K20 monomethylation maintains genome integrity by regulating proper mitotic condensation, DNA damage response, and replication licensing. Here, we show that, in non-dividing hepatic cells, H4K20Me1 is specifically enriched in active gene bodies and dynamically regulated by the antagonistic action of Kmt5a methylase and Kdm7b demethylase. In liver-specific Kmt5a-deficient mice, reduced levels of H4K20Me1 correlated with reduced RNA Pol II release from promoter-proximal regions. Genes regulating glucose and fatty acid metabolism were most sensitive to impairment of RNA Pol II release. Downregulation of glycolytic genes resulted in an energy starvation condition partially compensated by AMP-activated protein kinase (AMPK) activation and increased mitochondrial activity. This metabolic reprogramming generated a highly sensitized state that, upon different metabolic stress conditions, quickly aggravated into a senescent phenotype due to ROS overproduction-mediated oxidative DNA damage. The results illustrate how defects in the general process of RNA Pol II transition into a productive elongation phase can trigger specific metabolic changes and genome instability.

Acute bacterial sternoclavicular osteomyelitis in a long-term renal transplant recipient.

Kidney transplantation is the treatment of choice for a significant number of patients with end-stage renal disease. Although immunosuppression therapy improves graft and patient's survival, it is a major risk factor for infection following kidney transplantation altering clinical manifestations of the infectious diseases and complicating both the diagnosis and management of renal transplant recipients (RTRs). Existing literature is very limited regarding osteomyelitis in RTRs. Sternoclavicular osteomyelitis is rare and has been mainly reported after contiguous spread of infection or direct traumatic seeding of the bacteria. We present an interesting case of acute, bacterial sternoclavicular osteomyelitis in a long-term RTR. Blood cultures were positive for Streptococcus mitis, while the portal entry site was not identified. Magnetic resonance imaging of the sternoclavicluar region and a three-phase bone scan were positive for sternoclavicular osteomyelitis. Eventually, the patient was successfully treated with Daptomycin as monotherapy. In the presence of immunosuppression, the transplant physician should always remain alert for opportunistic pathogens or unusual location of osteomyelitis.

SET9-Mediated Regulation of TGF-ß Signaling Links Protein Methylation to Pulmonary Fibrosis.

TGF-ß signaling regulates a variety of cellular processes, including proliferation, apoptosis, differentiation, immune responses, and fibrogenesis. Here, we describe a lysine methylation-mediated mechanism that controls the pro-fibrogenic activity of TGF-ß. We find that the methyltransferase Set9 potentiates TGF-ß signaling by targeting Smad7, an inhibitory downstream effector. Smad7 methylation promotes interaction with the E3 ligase Arkadia and, thus, ubiquitination-dependent degradation. Depletion or pharmacological inhibition of Set9 results in elevated Smad7 protein levels and inhibits TGF-ß-dependent expression of genes encoding extracellular matrix components. The inhibitory effect of Set9 on TGF-ß-mediated extracellular matrix production is further demonstrated in mouse models of pulmonary fibrosis. Lung fibrosis induced by bleomycin or Ad-TGF-ß treatment was highly compromised in Set9-deficient mice. These results uncover a complex regulatory interplay among multiple Smad7 modifications and highlight the possibility that protein methyltransferases may represent promising therapeutic targets for treating lung fibrosis.

Hepatic cancer stem cells may arise from adult ductal progenitors.

Cancer stem cells (CSCs) are defined as cells within tumors that can self-renew and differentiate into heterogeneous lineages of cancerous cells. The origin of CSCs is not well understood. Recent evidence suggests that CSCs in hepatocellular carcinoma could be generated via oncogenic transformation and partial differentiation of adult hepatic ductal progenitor cells.

Klotho, the Holy Grail of the kidney: from salt sensitivity to chronic kidney disease.

The Klotho gene displays an extremely shortened life span with loss of function missense mutations leading to premature multiple organ failure, thus resembling human premature aging syndromes. The transmembrane form of Klotho protein functions as an obligatory co-receptor for FGF23. Klotho and FGF23 are crucial components for the regulation of vitamin D metabolism and subsequently blood phosphate levels. The secreted Klotho protein has multiple regulatory functions, including effects on electrolyte homeostasis, on growth factor pathways as well as on oxidative stress, which are currently the object of extensive research. Klotho protein deficiency is observed in many experimental and clinical disease models. Genetic polymorphisms such as the G-395A polymorphism in the promoter region of the Klotho gene have been associated with the development of essential hypertension. The kidneys are the primary site of Klotho production, and renal Klotho is decreased in CKD, followed by a reduction in plasma Klotho. Klotho deficiency has been both associated with progression of CKD as well as with its cardinal systemic manifestations, including cardiovascular disease. Thus, Klotho has been suggested both as a risk biomarker for early detection of CKD and additionally as a potential therapeutic tool in the future.

Inflammation, Endothelial Dysfunction and Increased Left Ventricular Mass in Chronic Kidney Disease (CKD) Patients: A Longitudinal Study.

INTRODUCTION: Within this longitudinal study we investigated the association of inflammation markers C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNFα) and endothelial dysfunction markers intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) with left ventricular mass indexed for height(2.71) (LVMI) in hypertensive predialysis CKD patients. MATERIAL AND METHODS: From 2004 to 2005, 182 incident consecutive adult patients from the outpatient CKD clinics of two hospitals in Greece with CKD and hypertension or using antihypertensive medication, were included. Of these, 107 patients underwent CRP (mg/l) and LVMI (g/height(2.71)) measurements annually for three years. RESULTS: In the longitudinal analyses, using linear mixed modeling, a higher IL-6 (ß = 1.9 (95%ci:0.38;3.5), inflammation score based on CRP, IL-6 and TNF-α (ß = 5.0 (95%ci:0.72; 9.4) and VCAM-1 (ß = 0.01 (95%ci:0.005;0.02) were associated with higher LVMI. These models were adjusted for age, gender and primary renal disease, and for confounders that on top changed the beta with ≥ 10%, i.e. diuretic use (for IL-6 and inflammation score). CONCLUSION: The results suggest that in predialysis CKD patients, inflammation as well as endothelial dysfunction may play an important role towards the increase in LVMI.

THE IMPACT OF SOCIOECONOMIC FACTORS ON QUALITY OF LIFE OF PATIENTS WITH CHRONIC KIDNEY DISEASE IN GREECE.

BACKGROUND: Quality of Life (QoL) is often poor in people undergoing dialysis and this sometimes contributes to the high rate of morbidity and mortality. The aim of our study is to assess the QoL of patients on haemodialysis in Greece and discuss the socio-demographic factors that affect QoL in this period of financial crisis. DESIGN/PATIENTS: Patients with CKD not on dialysis, plus those undergoing Haemodialysis (HD) and Peritoneal Dialysis (PD) were invited to complete the SF-36 questionnaire electronically, supervised by a trained nurse. Patients were asked about their marital status, education level and monthly household income. Additionally, patients were requested to comment on their subjective financial difficulties. RESULTS: A total of 172 patients were enrolled in the study, 39 of them were undergoing PD, 90 on HD and 43 had CKD. Among those with CKD, on HD and PD, 9.3%, 17.8% and 23.1%, respectively, had 'some/a lot' difficulties in copying with financial problems. The physical component summary score was significant lower in HD, while the summary score of the mental component showed no differences between the groups. In multiple linear regression analysis, age and dialysis had significantly negative correlations with physical functioning scores. Those who were divorced or widowed tended to perform worse in physical scores compared with those who were married. Mental scores were affected only by coping with financial difficulties. CONCLUSIONS: In general terms, people with CKD patients present with a poor QoL. Apart from the burden of the renal disease per se, social and economic factors (divorce, financial difficulties) seem to aggravate their status, especially in this period of financial crisis.

Spontaneous development of hepatocellular carcinoma with cancer stem cell properties in PR-SET7-deficient livers.

PR-SET7-mediated histone 4 lysine 20 methylation has been implicated in mitotic condensation, DNA damage response and replication licensing. Here, we show that PR-SET7 function in the liver is pivotal for maintaining genome integrity. Hepatocyte-specific deletion of PR-SET7 in mouse embryos resulted in G2 phase arrest followed by massive cell death and defect in liver organogenesis. Inactivation at postnatal stages caused cell duplication-dependent hepatocyte necrosis, accompanied by inflammation, fibrosis and compensatory growth induction of neighboring hepatocytes and resident ductal progenitor cells. Prolonged necrotic regenerative cycles coupled with oncogenic STAT3 activation led to the spontaneous development of hepatic tumors composed of cells with cancer stem cell characteristics. These include a capacity to self-renew in culture or in xenografts and the ability to differentiate to phenotypically distinct hepatic cells. Hepatocellular carcinoma in PR-SET7-deficient mice displays a cancer stem cell gene signature specified by the co-expression of ductal progenitor markers and oncofetal genes.

Aliskiren in an alternate-day administration schedule in hypertensive albuminuric patients.

OBJECTIVE: It has been suggested that aliskiren has a long half-life and maintains a blood pressure (BP)-lowering effect following a missed dose. We tested the hypothesis that every other day (eod) administration of aliskiren has the same effects as the once daily (od) dosing in albuminuric hypertensive patients. METHODS: Fifteen hypertensive patients, after a 4-week wash-out period on clonidine, received 300 mg aliskiren od as the sole treatment. In patients who remained out of target, other nonrenin-angiotensin system blockers were added. Patients who completed a 24-week (w24) treatment period were switched to eod administration of aliskiren for an additional period of 24 weeks (w48). RESULTS: Thirteen patients completed the full study protocol. The mean office BP was reduced at the end of w24 (-9/3 mmHg), a reduction that continued to be observed at w48 (-11/1 mmHg). At the end of the study, the 48 h ambulatory BP monitoring was divided into two 24 h periods. The mean 24 h systolic BP, and the mean daytime systolic and diastolic BP were significantly lower (P<0.05) in the first 24 h (when aliskiren was taken) compared with the second period. Central hemodynamics showed no significant differences at any time during monitoring. Administration of aliskiren resulted in a median reduction of urine albumin/creatinine ratio of 103 mg/g (od) and 102 mg/g (eod). Differences in plasma renin activity, plasma renin concentration, and aldosterone-level measurements were not significant. CONCLUSION: The BP-lowering effect of eod aliskiren administration, although adequate, is less efficient compared with od administration, despite the fact that in terms of reducing albuminuria, it appears to be effective.

Multicenter epidemiological study to assess the population of CKD patients in Greece: results from the PRESTAR study.

BACKGROUND: Chronic Kidney Disease (CKD) is a relatively common condition not only associated with increased morbidity and mortality but also fuelling End Stage Renal Disease (ESRD). Among developed nations, Greece has one of the highest ESRD incidence rates, yet there is limited understanding of the epidemiology of earlier stages of CKD. METHODS: Cross-sectional survey of pre-dialysis CKD outpatients in nephrology clinics in the National Health Care system between October 2009 and October 2010. Demographics, cause of CKD, blood pressure, level of renal function, duration of CKD and nephrology care, and specialty of referral physician were collected and analyzed. Different methods for estimating renal function (Cockroft-Gault [CG], CKD-Epi and MDRD) and staging CKD were assessed for agreement. RESULTS: A total of 1,501 patients in 9 centers were enrolled. Diabetic nephropathy was the most common nephrologist assigned cause of CKD (29.7%). In total, 36.5% of patients had self-referred to the nephrologist; patients with diabetes or serum creatinine above 220 µmol/l (eGFR<40 ml/min/1.73 m2) were more likely to have been referred by a physician. Agreement between MDRD and CKD-Epi, but not between CG, the other estimating equations, was excellent. There was substantial heterogeneity with respect to renal diagnoses, referral patterns and blood pressure among participating centers. CONCLUSIONS: In this first epidemiologic assessment of CKD in Greece, we documented delayed referral and high rates of self-referral among patients with CKD. eGFR reporting, currently offered by a limited number of laboratories, may facilitate detection of CKD at an earlier, more treatable stage.

Environmental and stressful factors affecting the occurrence of kidney stones and the kidney colic.

The first renal disease described from Hippocrates is nephrolithiasis with renal colic, which is the pain of stone passage and is also a common renal problem with easily recognizable characteristics. There has been much written about dietary factors, which have unequivocally been proved to play an important role in the formation of kidney stones. In this regard, it is of interest that the contribution of factors such as stressful events, life style, or occupation in the formation of kidney stones has not been well studied. This review examines the clinical evidence of the stressful events and other environmental factors affecting the occurrence of kidney stones.

A case of encapsulating peritoneal sclerosis presented shortly after renal transplantation.

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis (PD), characterized by extensive intraperitoneal fibrosis and encasement of bowel loops. It typically associates with long-term PD and progressive loss of ultrafiltration. The management of EPS has evolved substantially from the original report of this entity and now includes immunosuppressive agents, antifibrotic agents, nutritional support, and surgical intervention. Although the exact cause of this condition remains obscure and despite the possible positive effect of immunosuppression on EPS, it has been described in the post-transplant setting upon the discontinuation of PD. We report such a case of a former PD patient who presented with EPS a month after renal transplantation. This article will highlight the current views regarding the management of post-transplant EPS and introduce the problem of long-term PD patients on the deceased-donor transplant waiting list.

Differential membrane expression of Toll-like receptors and intracellular cytokine induction in peripheral blood monocytes of patients with chronic kidney disease and diabetic nephropathy.

BACKGROUND: Toll-like receptors (TLRs) are key players in the innate immune system whose activation leads to an inflammatory response. Inflammation plays an important role in the pathogenesis of chronic kidney disease (CKD) and diabetes mellitus. The aim of our study was to assess the proinflammatory state of nondialysis CKD patients by evaluating the membrane expression of TLR2 and TLR4 and the intracellular IL-1ß and IL-6 production in response to the ligand Pam3Cys-Ser-(Lys)4 (Pam3CSK4). METHODS: 85 nondialysis CKD patients [mean estimated glomerular filtration rate: 34 (17-90) ml/min/1.73 m(2)] were divided in 2 groups: 55 nondiabetic CKD patients (CKD group) and 30 patients with diabetic nephropathy (DN group). The two groups were compared with 36 healthy subjects (control group). TLR2 and TLR4 membrane expression in monocytes and Pam3CSK4-induced intracellular production of IL-1ß and IL-6 were assessed by flow cytometry. RESULTS: Both patient groups showed increased TLR2 membrane expression compared with the control group, both at baseline (p < 0.05 for both) and after Pam3CSK4 stimulation (p < 0.05 for both). The DN group exhibited significantly higher TLR4 expression at baseline compared to the CKD and control groups (p < 0.04 and p < 0.02, respectively). Intracellular IL-1ß and IL-6 levels at baseline were significantly lower in CKD patients compared to the DN and control groups. After Pam3CSK4 stimulation, intracellular IL-1ß and IL-6 increased in all groups, but were lower in the CKD group versus the control group or DN group, which exhibited higher levels than the controls. CONCLUSIONS: Nondialysis CKD patients showed significant alterations in TLR2 and TLR4 membrane expression, and impaired Pam3CSK4-induced cytokine production in monocytes, a phenomenon that is markedly influenced by the presence of diabetes.

Longitudinal association of body mass index and waist circumference with left ventricular mass in hypertensive predialysis chronic kidney disease patients.

BACKGROUND: This study aimed to investigate the association of both body mass index (BMI) and waist circumference (WC) with left ventricular mass (LVM) in hypertensive predialysis chronic kidney disease (CKD) patients. METHODS: From 2004 to 2005, 206 consecutive incident adult patients from the outpatient CKD clinics of two hospitals in Greece were included. Inclusion criteria were the presence of CKD and hypertension. BMI (kg/m(2)), WC (cm) and LVM (g) were assessed annually for 3 years. RESULTS: The mean age was 68.1 years, mean BMI 29.1 kg/m(2) and mean WC was 103.7 cm. The median LVM was 245.7 g (n = 179). In the cross-sectional data, linear regression models showed that WC {ß = 1.2 [95% confidence interval (CI) 0.15; 2.3]}, and not BMI [ß = 2.1 (95% CI: -0.70; 4.8)], was significantly associated with LVM. After adjustment for age, sex, primary renal disease, smoking and history of cardiovascular disease, both BMI [ß = 4.7 (95% CI: 2.0; 7.4] and WC [ß = 1.2 (95% CI: 0.14; 2.3)] were significantly associated with LVM. These associations were pronounced in CKD stage 1-3, but not in CKD stage 4-5. In the longitudinal analysis, linear mixed models adjusting for confounders showed that both an increase in BMI [ß = 2.9 (95% CI: 0.74; 5.1)] and an increase in WC [ß = 1.1 (95% CI: 0.28; 1.8)] were significantly associated with an increase in LVM. CONCLUSIONS: In hypertensive predialysis CKD patients, both BMI and WC were associated with LVM in CKD stage 1-3, but not in CKD stage 4-5. In the longitudinal analysis, both an increase in BMI and WC were associated with an increase in LVM. Future studies should focus on mechanisms responsible for the associations between anthropometric variables and LVM.