Ageing-Related Alterations in Renal Epithelial Glucose Transport.

The kidney plays a crucial role in glucose homeostasis by regulating glucose transport. We aimed to investigate the impact of alterations in glucose transport on glucose metabolism during ageing. Adult male Sprague Dawley rats were divided into five groups: 3-month, 6-month, and 12-month control groups, and 6- and 12-month groups receiving the hydrogen sulfide donor molecule GYY4137. The study found that, as age increased, daily urinary uric acid and protein levels increased in the 12-month group. Blood sugar level and HOMA-IR index increased in the 12-month group, and were partially improved by GYY4137. The kidney tissue showed mild glomerulosclerosis in the 12-month group, which was diminished by GYY4137. Gene expression analysis showed decreased sirtuin and increased p21 expression in the aging groups. Increased SGLT1 and SGLT2 expression was observed in the 12-month group, which was reversed by GYY4137. Both GLUT1 and GLUT2 expression was increased in the 6- and 12-month groups, and reversed by GYY4137 in the 12-month group. The study concluded that aging was associated with increased blood sugar levels and the HOMA-IR index, and the abundance of renal glucose transporters increased as aging progressed. GYY4137 effectively reversed aging-related alterations in glucose homeostasis and renal epithelial transporters.

No infectious SARS-CoV-2 in breast milk from a cohort of 110 lactating women.

BACKGROUND: Genomic RNA of severe acute respiratory syndrome-associated coronavirus type 2 (SARS-CoV-2) has been detected in the breast milk of lactating women, but its pathological significance has remained uncertain due to the small size of prior studies. METHODS: Breast milk from 110 lactating women was analyzed by reverse transcription-polymerase chain reaction (285 samples) and viral culture (160 samples). Those containing SARS-CoV-2 viral RNA (vRNA) were examined for the presence of subgenomic RNA (sgRNA), a putative marker of infectivity. RESULTS: Sixty-five women had a positive SARS-CoV-2 diagnostic test, 9 had symptoms but negative diagnostic tests, and 36 symptomatic women were not tested. SARS-CoV-2 vRNA was detected in the milk of 7 (6%) women with either a confirmed infection or symptomatic illness, including 6 of 65 (9%) women with a positive SARS-CoV-2 diagnostic test. Infectious virus was not detected in any culture and none had detectable sgRNA. In control experiments, infectious SARS-CoV-2 could be cultured after addition to breastmilk despite several freeze-thaw cycles, as it occurs in the storage and usage of human milk. CONCLUSIONS: SARS-CoV-2 RNA can be found infrequently in the breastmilk after recent infection, but we found no evidence that breastmilk contains an infectious virus or that breastfeeding represents a risk factor for transmission of infection to infants. IMPACT: This article goes beyond prior small studies to provide evidence that infectious SARS-CoV-2 is not present in the milk of lactating women with recent infection, even when SARS-CoV-2 RNA is detected. Recent SARS-CoV-2 infection or detection of its RNA in human milk is not a contraindication to breastfeeding.

Incidence, characteristics and outcomes among inpatient, outpatient and emergency department with reported high critical serum potassium values.

OBJECTIVES: Severe hyperkalemia can cause life-threatening arrhythmia, cardiac arrest, or death. This study aimed to investigate the incidence and the associated factors relevant to critical hyperkalemia (≥6 mmol/L) among inpatients, outpatients, and emergency department. Their clinical outcomes were also analyzed. METHODS: All patients whose high serum potassium values had been reported as critical laboratory values in 2016 were enrolled. Their demographic data, comorbidities, clinical symptoms, biochemical data, and outcomes were reviewed and collected. The Charlson comorbidity score (CCS) and glomerular filtration rate (GFR) were computed to assess the comorbidity burden and renal function. Patients were divided into groups according to different settings, potassium and GFR levels, and their survival. RESULTS: Of the 293,830 total serum potassium tests, 1,382 (0.47%) reports were listed as critical laboratory values. The average reply time was 6.3 min. Their mean age was 67.2 years, while the average GFR was 12.2 mL/min/1.73 m2. The overall mortality rate was 34%. Patients in the emergency department had the highest incidence (0.92%), while inpatients had the worst outcome (51% mortality). The leading cause of mortality was septic shock. The fatal group had higher rates of clinical symptoms, higher potassium values, CCS, and eGFR (all p<0.05). CONCLUSIONS: Most of the responses for the reports were obtained within a short period of time. Patients with reported high critical serum potassium values were characterized by high rates of comorbidity, reduced eGFR, and mortality. The incidence, clinical manifestations, and outcomes varied in the different clinical settings.

Dapagliflozin and xanthine oxidase inhibitors improve insulin resistance and modulate renal glucose and urate transport in metabolic syndrome.

Disturbance in glucose and uric acid metabolism is the major disorder of metabolic syndrome (MetS). The kidneys play an important role in the management of glucose and uric acid. The aim of our study was to investigate alterations in renal glucose and uric acid transporters in animals with MetS after treatment with dapagliflozin and xanthine oxidase inhibitors (allopurinol and febuxostat). Sprague-Dawley rats were fed normal chow or a high fructose diet for the first 3 months. The fructose-fed animals were then treated with dapagliflozin, allopurinol, febuxostat, or no treatment for the next 3 months. Fasting glucose, insulin resistance, and hyperuricaemia were improved in all treatment groups except that in the fructose group (all p < 0.05). Both allopurinol and febuxostat reversed the increase in levels of sodium glucose cotransporter (SGLT) 1, SGLT2, and glucose transporter (GLUT) 2 (all p < 0.05). Dapagliflozin alleviated hyperuricaemia and induced uricosuria without affecting serum xanthine oxidase activity. Dapagliflozin suppressed the expression of GLUT9, urate transporter, and urate anion exchanger 1 (all p < 0.05), which was similar to the effects of allopurinol and febuxostat. The results suggest that treatment with dapagliflozin and xanthine oxidase inhibitors improved insulin resistance and reversed the increased expression of glucose and urate transporters in the kidney.

Cross-Reactivity against Multiple HIV-1 Epitopes Is Characteristic of HIV-1-Specific Cytotoxic T Lymphocyte Clones.

Although a high level of promiscuity for heterologous epitopes is believed to exist for cellular immunity, limited data explore this issue for human immunodeficiency virus type 1 (HIV-1)-specific CD8+ T lymphocyte (CTL) responses. Here, we found an unexpected degree of heterologous cross-reactivity against HIV-1 epitopes, in addition to the targeted index epitope. Most CTL clones screened cross-reacted against other known HIV-1 epitopes of the same major histocompatibility complex type I (MHC-I) restriction, up to 40% of tested nonindex epitopes in some cases. The observed cross-reactivity was universally lower avidity than recognition of the index epitope when examined for several A*02- and B*57-restricted CTL clones, demonstrating that the high concentrations of exogenous epitope typically used for screening of CTL responses are prone to detect such cross-reactivity spuriously. In agreement with this, we found that these cross-reactive responses do not appear to mediate CTL activity against HIV-1-infected cells. Overall, our data indicate that low-level cross-reactivity is remarkably common for HIV-1-specific CTLs. The role of this phenomenon is unclear, but low-avidity interactions have been shown to foster homeostatic proliferation of memory T cells.IMPORTANCE This study raises two issues related to HIV-1-specific CTL responses. These are key immune responses that retard disease progression in infected persons that are highly relevant to immunotherapies and vaccines for HIV-1. First, we make the novel observation that these responses are promiscuous and that CTLs targeting one epitope may cross-recognize other, completely distinct epitopes in the virus. While these are low-avidity interactions that do not appear to contribute directly to the antiviral activity of CTLs, this raises interesting biologic implications regarding the purpose of the phenomenon, such as providing a stimulus for these responses to persist long term. Second, the data raise a technical caveat to detection of CTL responses against particular epitopes, suggesting that some methodologies may unintentionally detect cross-reactivity and overestimate responses against an epitope.

HIV-1 epitopes presented by MHC class I types associated with superior immune containment of viremia have highly constrained fitness landscapes.

Certain Major Histocompatibility-I (MHC-I) types are associated with superior immune containment of HIV-1 infection by CD8+ cytotoxic T lymphocytes (CTLs), but the mechanisms mediating this containment are difficult to elucidate in vivo. Here we provide controlled assessments of fitness landscapes and CTL-imposed constraints for immunodominant epitopes presented by two protective (B*57 and B*27) and one non-protective (A*02) MHC-I types. Libraries of HIV-1 with saturation mutagenesis of CTL epitopes are propagated with and without CTL selective pressure to define the fitness landscapes for epitope mutation and escape from CTLs via deep sequencing. Immunodominant B*57- and B*27- present epitopes are highly limited in options for fit mutations, with most viable variants recognizable by CTLs, whereas an immunodominant A*02 epitope-presented is highly permissive for mutation, with many options for CTL evasion without loss of viability. Generally, options for evasion overlap considerably between CTL clones despite highly distinct T cell receptors. Finally, patterns of variant recognition suggest population-wide CTL selection for the A*02-presented epitope. Overall, these findings indicate that these protective MHC-I types yield CTL targeting of highly constrained epitopes, and underscore the importance of blocking public escape pathways for CTL-based interventions against HIV-1.

Goal attainment and renal outcomes in patients enrolled in the chronic kidney disease care program in Taiwan: a 3-year observational study.

OBJECTIVE: To analyze the effects of chronic kidney disease (CKD) care programs on clinical outcomes. DESIGN: An observational, retrospective study with medical record review. SETTING: Kaohsiung Chang Gung Memorial Hospital. PARTICIPANTS: Patients diagnosed with CKD. INTERVENTIONS: CKD care programs conducted by nephrologists-based team from 2006 to 2013 in our hospital. MAIN OUTCOME MEASURES: We set 10 goals with treatment target ranges based on the guidelines suggested by the following organizations: Kidney Disease Improving Global Outcomes (2012) and the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (2003). RESULTS: In total, 1486 patients were enrolled. Their average estimated glomerular filtration rate (ml/min/1.73 m2) was 31.9 at baseline and declined to 28.9 in Year 3 (P < 0.001). The all-goals attainment rate increased from 59.4% at baseline to 60.5% in Year 3, with an especially significant improvement for low-density lipoprotein (from 46.8% to 67.0%) and glycated hemoglobin (from 55.0% to 64.0%). Achievement rates decreased for hemoglobin (from 34.2% to 31.0%), calcium (from 94.6% to 92.3%) and phosphate (from 89.9% to 82.5%) between baseline and Year 3. Albuminuria was the least achieved goal (from 23.4% to 24.0%). Subgroup analysis revealed that estimated glomerular filtration rate did not decline in patients who had a good achievement rate, but decreased significantly in patients with a poor achievement rate. CONCLUSION: Enrolment in CKD care programs resulted in a significant improvement in goal attainment by patients. Further, a good achievement rate was associated with better preservation of residual renal function.

Highly Attenuated Infection With a Vpr-Deleted Molecular Clone of Human Immunodeficiency Virus-1.

A 48-year-old woman was infected with a vpr-defective human immunodeficiency virus (HIV)-1 molecular clone. Seroconversion was markedly delayed, and without treatment she had durably suppressed viremia and normal T-cell levels. Neutralizing antibody and CD8+ T-cell immune responses against HIV-1 were unremarkable. Viral sequences confirmed the source but evolved defective nef, suggesting an unknown mechanistic link to vpr. There were subtle qualitative defects in T and B cells. To our knowledge, this is the only case of human infection with a characterized defective HIV-1 molecular clone, which furthermore recapitulated live-attenuated vaccination in macaque models of HIV-1 vaccine research.

HIV-1 Epitope Variability Is Associated with T Cell Receptor Repertoire Instability and Breadth.

Mutational escape of HIV-1 from HIV-1-specific CD8+ T lymphocytes (CTLs) is a major barrier for effective immune control. Each epitope typically is targeted by multiple clones with distinct T cell receptors (TCRs). While the clonal repertoire may be important for containing epitope variation, determinants of its composition are poorly understood. We investigate the clonal repertoire of 29 CTL responses against 23 HIV-1 epitopes longitudinally in nine chronically infected untreated subjects with plasma viremia of <3,000 RNA copies/ml over 17 to 179 weeks. The composition of TCRs targeting each epitope varied considerably in stability over time, although clonal stability (Sorensen index) was not significantly time dependent within this interval. However, TCR stability inversely correlated with epitope variability in the Los Alamos HIV-1 Sequence Database, consistent with TCR evolution being driven by epitope variation. Finally, a robust inverse correlation of TCR breadth against each epitope versus epitope variability further suggested that this variability drives TCR repertoire diversification. In the context of studies demonstrating rapidly shifting HIV-1 sequences in vivo, our findings support a variably dynamic process of shifting CTL clonality lagging in tandem with viral evolution and suggest that preventing escape of HIV-1 may require coordinated direction of the CTL clonal repertoire to simultaneously block escape pathways.IMPORTANCE Mutational escape of HIV-1 from HIV-1-specific CD8+ T lymphocytes (CTLs) is a major barrier to effective immune control. The number of distinct CTL clones targeting each epitope is proposed to be an important factor, but the determinants are poorly understood. Here, we demonstrate that the clonal stability and number of clones for the CTL response against an epitope are inversely associated with the general variability of the epitope. These results show that CTLs constantly lag epitope mutation, suggesting that preventing HIV-1 escape may require coordinated direction of the CTL clonal repertoire to simultaneously block escape pathways.

Alterations of Renal Epithelial Glucose and Uric Acid Transporters in Fructose Induced Metabolic Syndrome.

BACKGROUND/AIMS: Hyperglycemia and hyperuricemia are two major disorders of Metabolic syndrome. Kidney plays a crucial role in maintaining the homeostasis of uric acid and glucose. The aim of the study was to examine the changes of renal glucose and uric acid transporters in animals with metabolic syndrome. METHODS: Sprague-Dawley rats were fed with high fructose diet (60%) for 3 months (FR-3) and 5 months (FR-5). At the end study, serum and urine biochemical data were compared. Gene expression and protein abundance of renal GLUT1, GLUT2, GLUT9, SGLT1, SGLT2, UAT and URAT1 was investigated by using RT-PCR and immunohistochemical staining. RESULTS: Metabolic syndrome was induced by high-fructose diet. Systolic blood pressure and proteinuria was significantly increased in FR-5 animals. In kidney tissue, gene expression of GLUT2 and SGLT2 increased significantly in a time dependent manner. GLUT9, SGLT1 and UAT were also significantly upregulated in FR-5. Immunohistochemical study showed a significant increase of SGLT1 in both FR-3 (413.5 ± 88.3% of control, p< 0.001) and FR-5 (677.6 ± 26.5% of control, p< 0.001). Also, SGLT2 protein was increased in both FR-3 (643.1 ± 41.3% of control, p< 0.001) and FR-5 (563.3 ± 21.7% of control, p< 0.001). Fructose rich food also induced increase of UAT by nearly 5-fold in both FR-3 and FR-5 (both p< 0.05) and more than 3-fold of GLUT-9 in FR-3 and FR-5 (both p< 0.05). CONCLUSION: Long term high fructose diet induced metabolic syndrome with increased blood pressure and proteinuria in rats. Metabolic syndrome was associated with dual increase in renal glucose and uric acid transporters, including SGLT1, SGLT2, GLUT2, GLUT9 and UAT.

C-reactive protein variability is associated with vascular access outcome in hemodialysis patients.

BACKGROUND: Hemodialysis (HD) vascular access failure is one of the most important causes of morbidity and contributes to the cost of dialysis care. There is paucity of data evaluating long-term monitoring of C-reactive protein (CRP) on outcome of HD vascular access. METHODS: We conducted a retrospective study to investigate whether variability of serum CRP level was associated with vascular access failure rate over a 7-year period. A total of 318 HD patients were included. Their demographic data, co-morbidities and biochemical data were reviewed and collected. Serum high-sensitivity CRP (hs-CRP) level was measured every 6 months. Patients were divided into three groups according to their serial hs-CRP levels. Patients with their hs-CRP below 2 mg/L were defined as low group (n=65, 20.4%) and those with higher than 4 mg/L were defined as high (n=39, 12.3%). The rest were classified as fluctuated hs-CRP group (n=214, 67.3%). Treatment of vascular access failure includes angioplasty and access re-creation. RESULTS: Their body mass index, indicators of dialysis adequacy and serum albumin and hs-CRP levels differed significantly among three groups. The annual vascular access failure rate was significantly higher in fluctuated hs-CRP group than in high hs-CRP group (0.41 vs 0.36, P=.037). Serum albumin was a significant associate of vascular access failure. Kaplan-Meier survival analysis indicated patients with high or fluctuated hs-CRP had shorter free interval of vascular access failure than low hs-CRP group. CONCLUSIONS: HD patients with fluctuated hs-CRP levels were associated with increased vascular access failure.

HIV-1-Specific Chimeric Antigen Receptors Based on Broadly Neutralizing Antibodies.

UNLABELLED: Although the use of chimeric antigen receptors (CARs) based on single-chain antibodies for gene immunotherapy of cancers is increasing due to promising recent results, the earliest CAR therapeutic trials were done for HIV-1 infection in the late 1990s. This approach utilized a CAR based on human CD4 as a binding domain and was abandoned for a lack of efficacy. The growing number of HIV-1 broadly neutralizing antibodies (BNAbs) offers the opportunity to generate novel CARs that may be more active and revisit this modality for HIV-1 immunotherapy. We used sequences from seven well-defined BNAbs varying in binding sites and generated single-chain-antibody-based CARs. These CARs included 10E8, 3BNC117, PG9, PGT126, PGT128, VRC01, and X5. Each novel CAR exhibited conformationally relevant expression on the surface of transduced cells, mediated specific proliferation and killing in response to HIV-1-infected cells, and conferred potent antiviral activity (reduction of viral replication in log10 units) to transduced CD8(+) T lymphocytes. The antiviral activity of these CARs was reproducible but varied according to the strain of virus. These findings indicated that BNAbs are excellent candidates for developing novel CARs to consider for the immunotherapeutic treatment of HIV-1. IMPORTANCE: While chimeric antigen receptors (CARs) using single-chain antibodies as binding domains are growing in popularity for gene immunotherapy of cancers, the earliest human trials of CARs were done for HIV-1 infection. However, those trials failed, and the approach was abandoned for HIV-1. The only tested CAR against HIV-1 was based on the use of CD4 as the binding domain. The growing availability of HIV-1 broadly neutralizing antibodies (BNAbs) affords the opportunity to revisit gene immunotherapy for HIV-1 using novel CARs based on single-chain antibodies. Here we construct and test a panel of seven novel CARs based on diverse BNAb types and show that all these CARs are functional against HIV-1.

The role of calbindin-D28k on renal calcium and magnesium handling during treatment with loop and thiazide diuretics.

Calbindin-D28k (CBD-28k) is a calcium binding protein located in the distal convoluted tubule (DCT) and plays an important role in active calcium transport in the kidney. Loop and thiazide diuretics affect renal Ca and Mg handling: both cause Mg wasting, but have opposite effects on Ca excretion as loop diuretics increase, but thiazides decrease, Ca excretion. To understand the role of CBD-28k in renal Ca and Mg handling in response to diuretics treatment, we investigated renal Ca and Mg excretion and gene expression of DCT Ca and Mg transport molecules in wild-type (WT) and CBD-28k knockout (KO) mice. Mice were treated with chlorothiazide (CTZ; 50 mg · kg(-1) · day(-1)) or furosemide (FSM; 30 mg · kg(-1) · day(-1)) for 3 days. To avoid volume depletion, salt was supplemented in the drinking water. Urine Ca excretion was reduced in WT, but not in KO mice, by CTZ. FSM induced similar hypercalciuria in both groups. DCT Ca transport molecules, including transient receptor potential vanilloid 5 (TRPV5), TRPV6, and CBD-9k, were upregulated by CTZ and FSM in WT, but not in KO mice. Urine Mg excretion was increased and transient receptor potential subfamily M, member 6 (TRPM6) was upregulated by both CTZ and FSM in WT and KO mice. In conclusion, CBD-28k plays an important role in gene expression of DCT Ca, but not Mg, transport molecules, which may be related to its being a Ca, but not a Mg, intracellular sensor. The lack of upregulation of DCT Ca transport molecules by thiazides in the KO mice indicates that the DCT Ca transport system is critical for Ca conservation by thiazides.

Gelsolin and Progression of Aortic Arch Calcification in Chronic Hemodialysis Patients.

BACKGROUND: Vascular calcification (VC) is a key process associated with cardiovascular mortality in dialysis patients. Gelsolin is an actin-binding protein that can modulate inflammation, correlated inversely with hemodialysis (HD) mortality and involved in bone calcification homeostasis. In this report, we aim to characterize progression in aortic arch calcification (AAC) and investigate its association with gelsolin. METHODS: 184 HD patients were enrolled and their annual posterior-anterior chest X-ray films (CXR) in 2009 and 2013 were examined. The severity of AAC was classified as grade 0 to 3. Blood levels of gelsolin were measured by ELISA kits. Biographic and biochemical data at baseline were analyzed with status of AAC at baseline and changes after 4 years. RESULTS: At baseline, 60% of the patients had detectable AAC on CXR. After 4 years, 77% had AAC. Patients with grade 1 and 2 AAC had increased risk of progression (Odds ratio [OR] 2~3, P=0.001) compared to those with grade 0 at baseline. Compared to those with no AAC, patients with AAC progression had older age, lower gelsolin, higher waist circumference and prevalence of vascular disease. Regression analysis confirmed baseline gelsolin (odds ratio 0.845, 95% confidence interval [0.734-0.974]) and waist circumference as the independent factors associated with AAC progression. Gelsolin is positively correlated with serum albumin and negatively with tumor necrosis factor-alpha. CONCLUSION: Our study demonstrated that HD patients with grades 1 or 2 baseline AAC are at increased risk of further progression compared to those with grade 0. We also found lower blood levels of gelsolin associated with progressive AAC. Further investigation into the mechanistic roles of gelsolin in vascular calcification may provide new understanding of this key process.

Ectopic expression of anti-HIV-1 shRNAs protects CD8(+) T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation.

Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8(+) T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8(+) T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8(+) T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24(Gag) in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8(+) T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8(+) T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8(+) T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance.

Ineffectual targeting of HIV-1 Nef by cytotoxic T lymphocytes in acute infection results in no functional impairment or viremia reduction.

The human immunodeficiency virus type 1 (HIV-1) accessory protein Nef is heavily targeted by CD8(+) T lymphocytes (CTLs) during acute infection and therefore is included in many candidate vaccines. We investigated whether CTL targeting of Nef during acute infection contributes to immune control by disrupting the function of Nef. The sequence and function of Nef in parallel with CTL responses were assessed longitudinally from peak viremia until the viremia set point in a cohort of six subjects with acute infection. All but one individual had a single founder strain. Nef-specific CTL responses were detected in all subjects and declined in magnitude over time. These responses were associated with mutations, but none of the mutations were detected in important functional motifs. Nef-mediated downregulation of CD4 and major histocompatibility complex (MHC) class I molecules was better preserved in acute infection than in chronic infection. Finally, Nef-specific CTL responses were not associated with a reduction in viremia from its acute-phase peak. Our results indicate that CTLs targeting Nef epitopes outside critical functional domains have little effect on the pathogenic functions of Nef, rendering these responses ineffective in acute infection. Importance: These data indicate that using the whole Nef protein as a vaccine immunogen likely allows immunodominance that leads to targeting of CTL responses that are rapidly escaped with little effect on Nef-mediated pathogenic functions. Pursuing vaccination approaches that can more precisely direct responses to vulnerable areas would maximize efficacy. Until vaccine-induced targeting can be optimized, other approaches, such as the use of Nef function inhibitors or the pursuit of immunotherapies such as T cell receptor gene therapy or adoptive transfer, may be more likely to result in successful control of viremia.

Rosiglitazone attenuates indoxyl sulphate-induced endothelial dysfunction.

Indoxyl sulphate is a protein-bound uraemic toxin that has deleterious effects on the cardiovascular system. Rosiglitazone (RGZ) is an insulin sensitizer used for glycaemic control in type 2 diabetes. Rosiglitazone has been shown to be beneficial for cardiovascular disease because of its pleiotropic effects. Whether RGZ can improve indoxyl sulphate-induced endothelial damage has not been investigated. In the present in vitro study, we examined the effects of RGZ on indoxyl sulphate-induced endothelial injury. Endothelial cells were exposed to RGZ (5 and 10 µmol/L) and then treated with indoxyl sulphate (100 and 1000 µmol/L) for 48 h. Indoxyl sulphate upregulated intracellular cell adhesion molecule-1, vascular cell adhesion molecule-1 and monocyte chemotactic protein-1 expression. Indoxyl sulphate also increased the abundance of NADPH oxidase 4 (NOX4) and nuclear factor (NF)-κB. Both extracellular signal-regulated kinase (ERK) 1/2 and p38 mitogen-activated protein kinase (MAPK) signalling pathways were activated after 48 h treatment with indoxyl sulphate. Pretreatment of cells with both concentrations of RGZ improved indices of endothelial injury. In addition, RGZ attenuated the increase in NOX4 and NF-κB and prevented the activation of the ERK1/2 and p38 MAPK signalling pathways. We conclude that RGZ ameliorates indoxyl sulphate-induced endothelial injury.

Gelsolin and adipokines are associated with protein-energy wasting in hemodialysis patients.

Protein-energy wasting (PEW) contributes to mortality in hemodialysis (HD) patients. Adipokines regulate energy homeostasis and body weight. Circulating gelsolin can modulate inflammation and is correlated with HD mortality. Whether adipokines and gelsolin play important roles in PEW remains unclear. Based on the criteria proposed by the International Society of Renal Nutrition and Metabolism, we examined the associations between PEW and biomarkers (gelsolin, leptin, adiponectin, interleukin-6, tumor necrosis factor alpha [TNF-α]) in 188 stable HD patients. Patients with PEW had significantly lower serum leptin levels, and tended to have higher adiponectin, TNF-α, and lower gelsolin levels. Logistic regression analysis revealed that gelsolin, leptin, adiponectin, and blood urea nitrogen were independently associated with PEW score. Serum creatinine, TNF-α, gender, renin-angiotensin system (RAS) blockade, and lipid-lowering agents were not associated with PEW score. Patients on lipid-lowering agents had lower PEW scores and those with RAS blockade had higher PEW scores. Our study confirms that gelsolin, adiponectin, and leptin are significant associates with PEW in HD patients. Further understanding of how these factors contribute to PEW may help design novel therapeutic strategies for PEW in chronic kidney disease.

Indoxyl sulfate upregulates prorenin expression via nuclear factor-κB p65, signal transducer and activator of transcription 3, and reactive oxygen species in proximal tubular cells.

We have recently found that indoxyl sulfate induces prorenin expression in proximal tubular cells. The present study aimed to determine whether nuclear factor-κB (NF-κB) p65, signal transducer and activator of transcription 3 (Stat3), and reactive oxygen species are involved in indoxyl sulfate-induced prorenin expression in cultured human proximal tubular cells (HK-2 cells). Effects of indoxyl sulfate on prorenin expression were determined using HK-2 cells with small interfering RNAs (siRNAs) specific to NF-κB p65 and Stat3, N-acetylcysteine, an antioxidant, and diphenyleneiodonium, an inhibitor of nicotinamide adenine dinucleotide phosphate oxidase. Indoxyl sulfate increased prorenin expression in HK-2 cells. siRNAs specific to NF-κB p65 and Stat3 inhibited indoxyl sulfate-induced prorenin expression. Both N-acetylcysteine and diphenyleneiodonium suppressed indoxyl sulfate-induced prorenin expression. Indoxyl sulfate upregulates the expression of prorenin via NF-κB p65, Stat3, and reactive oxygen species in proximal tubular cells.