Effects of sodium-glucose co-transporter 2 inhibitors on ultrafiltration in patients with peritoneal dialysis: a protocol for a randomized, double-blind, placebo-controlled, crossover trial (EMPOWERED).

BACKGROUND: Volume overload is common and associated with high mortality in patients on peritoneal dialysis (PD). Traditional strategies including diuretics, water/salt restriction, and icodextrin-based solutions cannot always fully correct this condition, necessitating novel alternative strategies. Recent studies confirmed the expression of sodium-glucose cotransporter 2 (SGLT2) in the human peritoneum. Experimental data suggest that SGLT2 inhibitors decrease glucose absorption from the PD solution, thereby increasing the ultrafiltration volume. This trial aims to assess whether SGLT2 inhibitors increase the ultrafiltration volume in patients on PD. METHODS: The EMPOWERED trial (trial registration: jRCTs051230081) is a multicenter, randomized, double-blind, placebo-controlled, crossover trial. Patients with clinically diagnosed chronic heart failure are eligible regardless of the presence of diabetes if they use at least 3 L/day glucose-based PD solutions. Participants will be randomly assigned (1:1) to receive empagliflozin 10 mg once daily and then placebo or vice versa. Each treatment period will last 8 weeks with a 4-week washout period. This study will recruit at least 36 randomized participants. The primary endpoint is the change in the daily ultrafiltration volume from baseline to week 8 in each intervention period. The key secondary endpoints include changes in the biomarkers of drained PD solutions, renal residual function, and anemia-related parameters. CONCLUSIONS: This trial aims to assess the benefit of SGLT2 inhibitors in fluid management with a novel mechanism of action in patients on PD. It will also provide insights into the effects of SGLT2 inhibitors on solute transport across the peritoneal membrane and residual renal function.

Lypd8 promotes the segregation of flagellated microbiota and colonic epithelia.

Colonic epithelial cells are covered by thick inner and outer mucus layers. The inner mucus layer is free of commensal microbiota, which contributes to the maintenance of gut homeostasis. In the small intestine, molecules critical for prevention of bacterial invasion into epithelia such as Paneth-cell-derived anti-microbial peptides and regenerating islet-derived 3 (RegIII) family proteins have been identified. Although there are mucus layers providing physical barriers against the large number of microbiota present in the large intestine, the mechanisms that separate bacteria and colonic epithelia are not fully elucidated. Here we show that Ly6/PLAUR domain containing 8 (Lypd8) protein prevents flagellated microbiota invading the colonic epithelia in mice. Lypd8, selectively expressed in epithelial cells at the uppermost layer of the large intestinal gland, was secreted into the lumen and bound flagellated bacteria including Proteus mirabilis. In the absence of Lypd8, bacteria were present in the inner mucus layer and many flagellated bacteria invaded epithelia. Lypd8(-/-) mice were highly sensitive to intestinal inflammation induced by dextran sulfate sodium (DSS). Antibiotic elimination of Gram-negative flagellated bacteria restored the bacterial-free state of the inner mucus layer and ameliorated DSS-induced intestinal inflammation in Lypd8(-/-) mice. Lypd8 bound to flagella and suppressed motility of flagellated bacteria. Thus, Lypd8 mediates segregation of intestinal bacteria and epithelial cells in the colon to preserve intestinal homeostasis.

Complement Factor H Mutation W1206R Causes Retinal Thrombosis and Ischemic Retinopathy in Mice.

Single-nucleotide polymorphisms and rare mutations in factor H (FH; official name, CFH) are associated with age-related macular degeneration and atypical hemolytic uremic syndrome, a form of thrombotic microangiopathy. Mice with the FH W1206R mutation (FHR/R) share features with human atypical hemolytic uremic syndrome. Herein, we report that FHR/R mice exhibited retinal vascular occlusion and ischemia. Retinal fluorescein angiography demonstrated delayed perfusion and vascular leakage in FHR/R mice. Optical coherence tomography imaging of FHR/R mice showed retinal degeneration, edema, and detachment. Histologic analysis of FHR/R mice revealed retinal thinning, vessel occlusion, as well as degeneration of photoreceptors and retinal pigment epithelium. Immunofluorescence showed albumin leakage from blood vessels into the neural retina, and electron microscopy demonstrated vascular endothelial cell irregularity with narrowing of retinal and choroidal vessels. Knockout of C6, a component of the membrane attack complex, prevented the aforementioned retinal phenotype in FHR/R mice, consistent with membrane attack complex-mediated pathogenesis. Pharmacologic blockade of C5 also rescued retinas of FHR/R mice. This FHR/R mouse strain represents a model for retinal vascular occlusive disorders and ischemic retinopathy. The results suggest complement dysregulation can contribute to retinal vascular occlusion and that an anti-C5 antibody might be helpful for C5-mediated thrombotic retinal diseases.

Antibody Inhibition of Properdin Prevents Complement-Mediated Intravascular and Extravascular Hemolysis.

Paroxysmal nocturnal hemoglobinuria (PNH) is a serious blood disorder characterized by dysregulated complement activation on blood cells. Eculizumab, the current standard therapy and a humanized anti-C5 mAb, relieves anemia and thrombosis symptoms of PNH patients by preventing complement-dependent intravascular hemolysis (IVH). However, up to 20% of PNH patients on long-term eculizumab treatment still suffer from significant anemia and are transfusion dependent because of extravascular hemolysis (EVH) of C3-opsonized PNH erythrocytes. In this study, we show that function-blocking anti-properdin (P) mAbs dose-dependently inhibited autologous, complement-mediated hemolysis induced by factor H dysfunction. Furthermore, anti-human P (hP) mAbs potently and dose-dependently inhibited acidified serum-induced hemolysis of PNH erythrocytes (Ham test). In contrast to erythrocytes rescued by anti-C5 mAb, nonlysed PNH erythrocytes rescued by anti-P mAb incurred no activated C3 fragment deposition on their surface. These results suggested that anti-P mAbs may prevent EVH as well as IVH of PNH erythrocytes. To test the in vivo efficacy of anti-hP mAbs in preventing EVH, we generated a P humanized mouse by transgenic expression of hP in P knockout mice (hP-Tg/P-/-). In a murine EVH model, complement-susceptible erythrocytes were completely eliminated within 3 d in control mAb-treated hP-Tg/P-/- mice, whereas such cells were protected and persisted in hP-Tg/P-/- mice treated with an anti-hP mAb. Collectively, these data suggest that anti-P mAbs can inhibit both IVH and EVH mediated by complement and may offer improved efficacy over eculizumab, the current standard therapy for PNH.

Duration of predialysis nephrological care and mortality after dialysis initiation.

BACKGROUND: The duration of predialysis nephrological care that can reduce all-cause and cardiovascular mortality after dialysis initiation has not been clarified. METHODS: A total of 1117 patients who started chronic dialysis treatment from 2006 to 2015 at Osaka General Medical Center were analyzed. Independent risk factors associated with all-cause and cardiovascular mortality after dialysis initiation and early death (death within 12 months after dialysis initiation) were identified using Cox proportional hazards analysis. Moreover, the duration of predialysis nephrology care that could reduce mortality was explored using several different definitions of early referral as well as "6 months" commonly used in previous studies. RESULTS: Of 1117 patients, 834 were referred 6 months before dialysis initiation. During the follow-up period (median, 34 months), 324 patients died after dialysis initiation. Although multivariate Cox analysis did not show a favorable association between early referral of "6 months before dialysis initiation" and all-cause and cardiovascular mortality, 20-month predialysis nephrological care was associated with better first-year overall survival after dialysis initiation (hazard ratio 0.58; 95% confidence interval 0.35-0.98; P = 0.040). CONCLUSION: More than 6 months nephrological care before dialysis initiation was not early enough to reduce all-cause and cardiovascular mortality after dialysis initiation. Our results suggest that nephrology referral 20 months before dialysis initiation would be necessary to reduce first-year overall survival after dialysis initiation.

Differential contribution of C5aR and C5b-9 pathways to renal thrombic microangiopathy and macrovascular thrombosis in mice carrying an atypical hemolytic syndrome-related factor H mutation.

Atypical hemolytic uremic syndrome (aHUS) is a form of thrombotic microangiopathy (TMA) caused by dysregulated complement activation. Clinically, aHUS is effectively treated by an anti-C5 monoclonal antibody (mAb) but whether the disease is mediated by the C5a receptor (C5aR) or C5b-9 pathway, or both, is unknown. Here we address this in a factor H mutant mouse (FHR/R) which developed complement-mediated TMA as well as macrovascular thrombosis caused by an aHUS-related factor H point mutation (mouse W1206R, corresponding to human W1183R). C5 deficiency and anti-C5 mAb treatment blocked all disease manifestations in FHR/R mice. C5aR1 gene deficiency prevented macrovascular thrombosis in various organs but did not improve survival or reduce renal TMA. Conversely, C6 or C9 deficiency significantly improved survival and markedly diminished renal TMA but did not prevent macrovascular thrombosis. Interestingly, as they aged both FHR/R C6-/- and FHR/R C9-/- mice developed glomerular disease reminiscent of C3 glomerulonephritis. Thus, C5aR and C5b-9 pathways drove different aspects of disease in FHR/R mice with the C5aR pathway being responsible for macrovascular thrombosis and chronic inflammatory injury while the C5b-9 pathway caused renal TMA. Our data provide new understanding of the pathogenesis of complement-mediated TMA and macrovascular thrombosis in FHR/R mice and suggest that C5 blockade is more effective for the treatment of aHUS than selectively targeting the C5aR or C5b-9 pathway alone.

Murine systemic thrombophilia and hemolytic uremic syndrome from a factor H point mutation.

Complement plays a key role in host defense, but its dysregulation can cause autologous tissue injury. Complement activation is normally controlled by regulatory proteins, including factor H (FH) in plasma and membrane cofactor protein (MCP) on the cell surface. Mutations in FH and MCP are linked to atypical hemolytic uremic syndrome, a type of thrombotic microangiopathy (TMA) that causes renal failure. We describe here that disruption of FH function on the cell surface can also lead to disseminated complement-dependent macrovascular thrombosis. By gene targeting, we introduced a point mutation (W1206R) into murine FH that impaired its interaction with host cells but did not affect its plasma complement-regulating activity. Homozygous mutant mice carrying this mutation developed renal TMA as well as systemic thrombophilia involving large blood vessels in multiple organs, including liver, lung, spleen, and kidney. Approximately 30% of mutant mice displayed symptoms of stroke and ischemic retinopathy, and 48% died prematurely. Genetic deficiency of complement C3 and factor D prevented both the systemic thrombophilia and renal TMA phenotypes. These results demonstrate a causal relationship between complement dysregulation and systemic angiopathy and suggest that complement activation may contribute to various human thrombotic disorders involving both the micro- and macrovasculature.

Blocking Properdin Prevents Complement-Mediated Hemolytic Uremic Syndrome and Systemic Thrombophilia.

Background Properdin (P) is a positive regulator of the alternative pathway of complement activation. Although P inhibition is expected and has been shown to ameliorate the alternative pathway of complement-mediated tissue injury in several disease models, it unexpectedly exacerbated renal injury in a murine model of C3 glomerulopathy. The role of P in atypical hemolytic uremic syndrome (aHUS) is uncertain.Methods We blocked P function by genetic deletion or mAb-mediated inhibition in mice carrying a factor H (FH) point mutation, W1206R (FHR/R), that causes aHUS and systemic thrombophilia with high mortality.Results P deficiency completely rescued FHR/R mice from premature death and prevented thrombocytopenia, hemolytic anemia, and renal disease. It also eliminated macrovessel thrombi that were prevalent in FHR/R mice. All mice that received a function-blocking anti-P mAb for 8 weeks survived the experimental period and appeared grossly healthy. Platelet counts and hemoglobin levels were significantly improved in FHR/R mice after 4 weeks of anti-P mAb treatment. One half of the FHR/R mice treated with an isotype control mAb but none of the anti-P mAb-treated mice developed stroke-related neurologic disease. Anti-P mAb-treated FHR/R mice showed largely normal renal histology, and residual liver thrombi were detected in only three of 15 treated mice.Conclusions These results contrast with the detrimental effect of P inhibition observed in a murine model of C3 glomerulopathy and suggest that P contributes critically to aHUS pathogenesis. Inhibition of P in aHUS may be of therapeutic benefit.

Prevention of Fatal C3 Glomerulopathy by Recombinant Complement Receptor of the Ig Superfamily.

Background C3 glomerulopathy (C3G) is a life-threatening kidney disease caused by dysregulation of the alternative pathway of complement (AP) activation. No approved specific therapy is available for C3G, although an anti-C5 mAb has been used off-label in some patients with C3G, with mixed results. Thus, there is an unmet medical need to develop other inhibitors of complement for C3G.Methods We used a murine model of lethal C3G to test the potential efficacy of an Fc fusion protein of complement receptor of the Ig superfamily (CRIg-Fc) in the treatment of C3G. CRIg-Fc binds C3b and inhibits C3 and C5 convertases of the AP. Mice with mutations in the factor H and properdin genes (FHm/mP-/-) develop early-onset C3G, with AP consumption, high proteinuria, and lethal crescentic GN.Results Treatment of FHm/mP-/- mice with CRIg-Fc, but not a control IgG, inhibited AP activation and diminished the consumption of plasma C3, factor B, and C5. CRIg-Fc-treated FHm/mP-/- mice also had significantly improved survival and reduced proteinuria, hematuria, BUN, glomerular C3 fragment, C9 and fibrin deposition, and GN pathology scores.Conclusions Therapeutics developed on the basis of the mechanism of action of soluble CRIg may be effective for the treatment of C3G and should be explored clinically.

C5 inhibition prevents renal failure in a mouse model of lethal C3 glomerulopathy.

C3 glomerulopathy is a potentially life-threatening disease of the kidney caused by dysregulated alternative pathway complement activation. The specific complement mediator(s) responsible for kidney injury in C3 glomerulopathy are yet to be defined and no specific therapy is currently available. We previously developed a mouse model of lethal C3 glomerulopathy with factor H and properdin gene double mutations. Therefore, we used this model to examine the role of C5 and C5a receptor (C5aR) in the pathogenesis of the disease. Disease severity in these factor H/properdin double-mutant mice was found to be correlated with plasma C5 levels, and prophylactic anti-C5 mAb therapy was effective in preventing lethal C3 glomerulopathy. When given to these double-mutant mice that had already developed active disease with severe proteinuria, anti-C5 mAb treatment also prevented death in half of the mice. Deficiency of C5aR significantly reduced disease severity, suggesting that C5aR-mediated inflammation contributed to C3 glomerulopathy. Thus, C5 and C5aR have a critical role in C3 glomerulopathy. Hence, early intervention targeting these pathways may be an effective therapeutic strategy for patients with C3 glomerulopathy.

Ecto-nucleoside triphosphate diphosphohydrolase 7 controls Th17 cell responses through regulation of luminal ATP in the small intestine.

Extracellular ATP is released from live cells in controlled conditions, as well as dying cells in inflammatory conditions, and, thereby, regulates T cell responses, including Th17 cell induction. The level of extracellular ATP is closely regulated by ATP hydrolyzing enzymes, such as ecto-nucleoside triphosphate diphosphohydrolases (ENTPDases). ENTPDase1/CD39, which is expressed in immune cells, was shown to regulate immune responses by downregulating the ATP level. In this study, we analyzed the immunomodulatory function of ENTPDase7, which is preferentially expressed in epithelial cells in the small intestine. The targeted deletion of Entpd7 encoding ENTPDase7 in mice resulted in increased ATP levels in the small intestinal lumen. The number of Th17 cells was selectively increased in the small intestinal lamina propria in Entpd7(-/-) mice. Th17 cells were decreased by oral administration of antibiotics or the ATP antagonist in Entpd7(-/-) mice, indicating that commensal microbiota-dependent ATP release mediates the enhanced Th17 cell development in the small intestinal lamina propria of Entpd7(-/-) mice. In accordance with the increased number of small intestinal Th17 cells, Entpd7(-/-) mice were resistant to oral infection with Citrobacter rodentium. Entpd7(-/-) mice suffered from severe experimental autoimmune encephalomyelitis, which was associated with increased numbers of CD4(+) T cells producing both IL-17 and IFN-γ. Taken together, these findings demonstrate that ENTPDase7 controls the luminal ATP level and, thereby, regulates Th17 cell development in the small intestine.

Intestinal CX3C chemokine receptor 1(high) (CX3CR1(high)) myeloid cells prevent T-cell-dependent colitis.

Adequate activation of CD4(+) T lymphocytes is essential for host defense against invading pathogens; however, exaggerated activity of effector CD4(+) T cells induces tissue damage, leading to inflammatory disorders such as inflammatory bowel diseases. Several unique subsets of intestinal innate immune cells have been identified. However, the direct involvement of innate immune cell subsets in the suppression of T-cell-dependent intestinal inflammation is poorly understood. Here, we report that intestinal CX(3)C chemokine receptor 1(high) (CX(3)CR1(high)) CD11b(+) CD11c(+) cells are responsible for prevention of intestinal inflammation through inhibition of T-cell responses. These cells inhibit CD4(+) T-cell proliferation in a cell contact-dependent manner and prevent T-cell-dependent colitis. The suppressive activity is abrogated in the absence of the IL-10/Stat3 pathway. These cells inhibit T-cell proliferation by two steps. Initially, CX(3)CR1(high) CD11b(+) CD11c(+) cells preferentially interact with T cells through highly expressed intercellular adhesion molecule-1/vascular cell adhesion molecule-1; then, they fail to activate T cells because of defective expression of CD80/CD86. The IL-10/Stat3 pathway mediates the reduction of CD80/CD86 expression. Transfer of wild-type CX(3)CR1(high) CD11b(+) CD11c(+) cells prevents development of colitis in myeloid-specific Stat3-deficient mice. Thus, these cells are regulatory myeloid cells that are responsible for maintaining intestinal homeostasis.

Probiotic Bifidobacterium breve induces IL-10-producing Tr1 cells in the colon.

Specific intestinal microbiota has been shown to induce Foxp3(+) regulatory T cell development. However, it remains unclear how development of another regulatory T cell subset, Tr1 cells, is regulated in the intestine. Here, we analyzed the role of two probiotic strains of intestinal bacteria, Lactobacillus casei and Bifidobacterium breve in T cell development in the intestine. B. breve, but not L. casei, induced development of IL-10-producing Tr1 cells that express cMaf, IL-21, and Ahr in the large intestine. Intestinal CD103(+) dendritic cells (DCs) mediated B. breve-induced development of IL-10-producing T cells. CD103(+) DCs from Il10(-/-), Tlr2(-/-), and Myd88(-/-) mice showed defective B. breve-induced Tr1 cell development. B. breve-treated CD103(+) DCs failed to induce IL-10 production from co-cultured Il27ra(-/-) T cells. B. breve treatment of Tlr2(-/-) mice did not increase IL-10-producing T cells in the colonic lamina propria. Thus, B. breve activates intestinal CD103(+) DCs to produce IL-10 and IL-27 via the TLR2/MyD88 pathway thereby inducing IL-10-producing Tr1 cells in the large intestine. Oral B. breve administration ameliorated colitis in immunocompromised mice given naïve CD4(+) T cells from wild-type mice, but not Il10(-/-) mice. These findings demonstrate that B. breve prevents intestinal inflammation through the induction of intestinal IL-10-producing Tr1 cells.

Risk Factors for Overly Rapid Correction in Patients with Profound Hyponatremia: A Retrospective Cohort Study.

Objective Overly rapid correction of profound hyponatremia can lead to osmotic demyelination syndrome; however, the incidence of and risk factors for overly rapid correction in patients with profound hyponatremia have not been thoroughly examined. Therefore, this study examined the incidence of and risk factors for overly rapid correction in patients with profound hyponatremia. Methods This single-center, retrospective cohort study conducted at an 865-bed teaching hospital analyzed data from 144 new inpatients with profound hyponatremia (initial serum sodium [Na+] level of <125 mEq/L) treated in our department between January 2014 and December 2022. Overly rapid correction was defined as serum Na+ correction of >10 mEq/L at 24 h. We examined the incidence of and risk factors for overly rapid correction.Results Thirty (20.8%) patients met the overly rapid correction criteria; however, none developed osmotic demyelination syndrome. A low initial serum Na+ level, female sex, primary polydipsia, and low frequency of follow-up in 24 h were significant independent risk factors for overly rapid correction in the multivariable analysis (p=0.020, p=0.011, p=0.014, and p=0.025, respectively). Conclusion Our study shows that a low initial serum Na+ level, female sex, primary polydipsia, and low frequency of follow-up within 24 h are associated with an increased risk for overly rapid correction of profound hyponatremia. Therefore, we suggest that physicians perform careful management when managing patients with profound hyponatremia with the risk factors for overly rapid correction identified in this study.

Referral pattern to nephrologist and prognosis in diabetic kidney disease patients: Single center retrospective cohort study.

BACKGROUND: Management of diabetic kidney disease (DKD) to prevent end-stage kidney disease (ESKD) has become a major challenge for health care professionals. This study aims to investigate the characteristics of patients with DKD when they are first referred to a nephrologist and the subsequent prognoses. METHODS: A total of 307 patients who were referred to our department from October 2010 to September 2014 at Osaka General Medical Center were analyzed. Independent risk factors associated with renal replacement therapy (RRT) and cardiovascular composite events (CVE) following their nephrology referral were later identified using Cox proportional hazards analysis. RESULTS: Of 307 patients, 26 (8.5%), 67 (21.8%), 134 (43.6%), and 80 (26.1%) patients were categorized as having chronic kidney disease (CKD) stages 3a, 3b, 4, and 5, respectively. The median estimated glomerular filtration rate (eGFR) and urinary protein levels were 22.3 mL/min/1.73 m2 and 2.83 g/gCr, respectively, at the time of the nephrology referral. During the follow-up period (median, 30 months), 121 patients required RRT, and more than half of the patients with CKD stages 5 and 4 reached ESKD within 60 months following their nephrology referral; 30% and <10% of the patients with CKD stages 3b and 3a, respectively, required RRT within 60 months following their nephrology referral. CONCLUSION: Patients with DKD were referred to nephrologist at CKD stage 4. Although almost half of the patients with CKD stage 5 at the time of nephrology referral required RRT within one-and-a-half years after the referral, kidney function of patients who were referred to nephrologist at CKD stage 3 and 4 were well preserved.

Successful Pregnancy Outcome in a Patient with Juvenile Idiopathic Arthritis in Adulthood, Amyloid A Amyloidosis, and Chronic Kidney Disease Using Tocilizumab with Strict Blood Pressure Control.

Pregnancies with chronic kidney disease (CKD) and high disease activity in rheumatic diseases are high-risk events with adverse outcomes for both the mother and fetus. We herein report a 35-year-old woman with juvenile idiopathic arthritis (JIA), amyloid A (AA) amyloidosis related to JIA, and CKD stage G4A2 who wished to have children. She achieved a successful pregnancy, even in the presence of these multiple risk factors, using tocilizumab to control the disease activity of JIA and AA amyloidosis, along with antihypertensive drugs to control her blood pressure before and during pregnancy.

Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome with recurrent acute cholecystitis: a case report.

Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) can induce life-threatening complications, including acute kidney injury, encephalopathy, and gastrointestinal complications. On the other hand, there have been few reports of cholecystitis associated with STEC-HUS. In this study, we report the case of an 83-year-old Japanese man who developed recurrent acute cholecystitis associated with STEC-HUS. Prior to establishing a definite diagnosis of STEC-HUS, plasma exchange and hemodialysis were initiated, which resulted in a rapid increase in the platelet count and decrease in lactate dehydrogenase levels. The patient presented an enlarged gallbladder detected by computed tomography during the course of treatment. Due to recurrent flare-ups, the patient had to undergo several rounds of endoscopic retrograde biliary drainage and, ultimately, cholecystectomy to prevent relapse of acute cholecystitis. Since cholecystitis was thought to have been caused by complex mechanisms in this case, we discussed those from multiple perspectives. This case report highlights the need for particular care to be given to the management of pre-existing diseases as well as STEC-HUS, especially in older patients.

Use of xanthine oxidase inhibitor febuxostat inhibits renal interstitial inflammation and fibrosis in unilateral ureteral obstructive nephropathy.

BACKGROUND: Renal interstitial fibrosis is the common pathway in progressive renal diseases, where oxidative stress promotes inflammation and macrophage infiltration. Febuxostat is a novel nonpurine xanthine oxidase (XO)-specific inhibitor for treating hyperuricemia. While some reports suggest a relationship between hyperuricemia and chronic kidney disease (CKD), the renoprotective mechanism of an XO inhibitor in CKD remains unknown. Recent reports have focused on XO as a source of oxidative stress. METHODS: Here, we investigate the potential of febuxostat to reduce fibrogenic and inflammatory responses in an established interstitial fibrosis model-unilateral ureteric obstruction (UUO). Male Sprague-Dawley rats were divided into three groups: sham-operated group, vehicle-treated UUO group, and febuxostat-treated UUO group. RESULTS: Treatment with febuxostat diminished XO activity in obstructed kidneys, and suppressed nitrotyrosine, a marker of oxidative stress. Consequently, febuxostat inhibited early proinflammatory cytokine expression, followed by a reduction of interstitial macrophage infiltration. In addition, febuxostat suppressed transforming growth factor-ß messenger RNA expression, thereby ameliorating smooth muscle alpha actin and type I collagen expression. CONCLUSION: Our results provide evidence for the renoprotective action of febuxostat against the formation of interstitial fibrosis. A decrease in macrophage infiltration and interstitial fibrosis, along with a decrease of the oxidative stress marker, strongly suggests the existence of a causal relationship between them. Febuxostat may have therapeutic value in slowing or preventing interstitial fibrosis in patients with CKD.

Commensal microbiota induce LPS hyporesponsiveness in colonic macrophages via the production of IL-10.

Several subsets of innate immune cells, all with unique properties, reside within the intestinal lamina propria. However, compared with intestinal dendritic cells (DCs), intestinal macrophages are less well characterized. In this study, we examined the properties of macrophages in the colonic lamina propria (LMφ). Colonic DCs (LDC) showed LPS-induced production of IL-12p40. In contrast, LMφ showed constitutive IL-10 production and unresponsiveness to LPS in terms of inflammatory cytokine production. Comparison of the gene expression profiles between LMφ and LDC revealed that LMφ preferentially expressed IL-10-related genes. LMφ obtained from mice lacking IL-10 or Stat3 showed hyperproduction of tumour necrosis factor (TNF)-α and IL-6 in response to LPS. IL-10 production in the large intestine was mainly induced by LMφ and regulatory T cells and was dependent on the presence of commensal microbiota. Accordingly, LMφ from germ-free mice showed less production of IL-10 and increased levels of LPS-induced TNF-α and IL-6 production. Taken together, these results demonstrate that the activity of LMφ to produce pro-inflammatory cytokines is negatively regulated through commensal microbiota-dependent IL-10 production in the large intestine.

Exaggerated compensatory response to acute respiratory alkalosis in panic disorder is induced by increased lactic acid production.

BACKGROUND: In acute respiratory alkalosis, the severity of alkalaemia is ameliorated by a decrease in plasma [HCO(3)(-)] of 0.2 mEq/L for each 1 mmHg decrease in PaCO(2). Although hyperventilation in panic disorder patients is frequently encountered in outpatients, the drop in plasma [HCO(3)(-)] sometimes surpasses the expectation calculated from the above formula. The quantitative relationship between reduced PaCO(2) and plasma [HCO(3)(-)] in acute respiratory alkalosis has not been studied in panic disorder patients. Our objective was to provide reference data for the compensatory metabolic changes in acute respiratory alkalosis in panic disorder patients. METHODS: In 34 panic disorder patients with hyperventilation attacks, we measured arterial pH, PaCO(2), plasma [HCO(3)(-)] and lactate on arrival at the emergency room. RESULTS: For each decrease of 1 mmHg in PaCO(2), plasma [HCO(3)(-)] decreased by 0.41 mEq/L. During hypocapnia, panic disorder patients exhibited larger increases in serum lactate levels (mean +/- SD; 2.59 +/- 1.50 mmol/L, range; 0.78-7.78 mmol/L) than previously reported in non-panic disorder subjects. Plasma lactate accumulation was correlated with PaCO(2) (P < 0.001). CONCLUSIONS: These results suggest that the compensatory metabolic response to acute respiratory alkalosis is exaggerated by increased lactic acid production in panic disorder patients. Here, we call attention to the diagnosis of acid-base derangements by means of plasma [HCO(3)(-)] and lactate concentration in panic disorder patients.