Genetic Deletion of Vasohibin-2 Exacerbates Ischemia-Reperfusion-Induced Acute Kidney Injury

Acute kidney injury (AKI) has been increasingly recognized as a risk factor for transition to chronic kidney disease. Recent evidence suggests that endothelial damage in peritubular capillaries can accelerate the progression of renal injury. Vasohibin-2 (VASH2) is a novel proangiogenic factor that promotes tumor angiogenesis. However, the pathophysiological roles of VASH2 in kidney diseases remain unknown. In the present study, we examined the effects of VASH2 deficiency on the progression of ischemia-reperfusion (I/R) injury-induced AKI. I/R injury was induced by bilaterally clamping renal pedicles for 25 min in male wild-type (WT) andVash2homozygous knockout mice. Twenty-four hours later, I/R injury-induced renal dysfunction and tubular damage were more severe in VASH2-deficient mice than in WT mice, with more prominent neutrophil infiltration and peritubular capillary loss. After induction of I/R injury, VASH2 expression was markedly increased in injured renal tubules. These results suggest that VASH2 expression in renal tubular epithelial cells might be essential for alleviating I/R injury-induced AKI, probably through protecting peritubular capillaries and preventing inflammatory infiltration

Differences in coronary plaque characteristics between patients with and those without peripheral arterial disease.

INTRODUCTION Cardiovascular mortality of patients with combined peripheral arterial disease (PAD) and coronary artery disease (CAD) is twice as high as that in those with either disease alone. It is known that patients with PAD undergoing percutaneous coronary intervention have a higher incidence of adverse cardiac events such as myocardial infarction or target vessel revascularization. OBJECTIVE In this study, we compared the detailed characteristics of culprit and nonculprit plaques between patients with and those without PAD using optical coherence tomography. PATIENTS AND METHODS We performed propensity score matching using the following variables: (i) age; (ii) sex; (iii) clinical presentation; (iv) diabetes mellitus; (v) hyperlipidemia; (vi) smoking; (vii) hypertension; (viii) BMI; and (ix) coronary lesion location. Finally, we matched 34 culprit lesions and 30 nonculprit lesions in patients with PAD to 68 culprit lesions and 60 nonculprit lesions in patients without PAD (1 : 2 ratio). RESULTS In culprit lesions, PAD patients when compared with those without PAD had a higher prevalence of lipid-rich plaque (73.5 vs. 51.5%; P=0.033), higher lipid index (1744±1110 vs. 1246±656; P=0.043), calcification (79.4 vs. 58.8%; P=0.039), macrophage accumulation (70.6 vs. 48.5%; P=0.034), and cholesterol crystals (32.4 vs. 10.3%; P=0.006). In nonculprit lesions, PAD patients had a higher prevalence of calcification (76.7 vs. 55.0%; P=0.046), macrophage accumulation (63.3 vs. 38.3%; P=0.025), and cholesterol crystals (36.7 vs. 16.7%; P=0.034). CONCLUSION Our study suggests greater coronary plaque vulnerability in both culprit and nonculprit lesions in patients with PAD. This observation underscores the need for more aggressive risk management in patients with combined PAD and coronary artery disease

Silica-associated systemic lupus erythematosus with lupus nephritis and lupus pneumonitis A case report and a systematic review of the literature

Introduction Several epidemiological studies have shown that silica exposure triggers the onset of systemic lupus erythematosus (SLE); however, the clinical characteristics of silica-associated SLE have not been well studied. Patient concerns A 67-year-old man with silicosis visited a primary hospital because of a fever and cough. His respiratory condition worsened, regardless of antibiotic medication, and he was referred to our hospital. Diagnosis The patient showed leukopenia, lymphopenia, serum creatinine elevation with proteinuria and hematuria, decreased serum C3 level, and was positive for anti-double stranded DNA antibody, anti-nuclear antibody, and direct Coombs test. He was diagnosed with SLE. Renal biopsy was performed, and the patient was diagnosed with lupus nephritis (class IV-G(A/C) + V defined by the International Society of Nephrology/Renal Pathology Society classification). Computed tomography revealed acute interstitial pneumonitis, bronchoalveolar lavage fluid showed elevation of the lymphocyte fraction, and he was diagnosed with lupus pneumonitis. Interventions Prednisolone (50 mg/day) with intravenous cyclophosphamide (500 mg/body) were initiated. Outcomes The patient showed a favorable response to these therapies. He was discharged from our hospital and received outpatient care with prednisolone slowly tapered off. He had cytomegalovirus and herpes zoster virus infections during treatment, which healed with antiviral therapy. Review: We searched for the literature on sSLE, and selected 11 case reports and 2 population-based studies. The prevalence of SLE manifestations in sSLE patients were comparative to that of general SLE, particularly that of elderly-onset SLE. Our renal biopsy report and previous reports indicate that lupus nephritis of sSLE patients show as various histological patterns as those of general SLE patients. Among the twenty sSLE patients reported in the case articles, three patients developed lupus pneumonitis and two of them died of it. Moreover, two patients died of bacterial pneumonia, one developed aspergillus abscesses, one got pulmonary tuberculosis, and one developed lung cancer. Conclusion Close attention is needed, particularly for respiratory system events and infectious diseases, when treating patients with silica-associated SLE using immunosuppressive therapies

Clinical and laboratory predictors for plaque erosion in patients with acute coronary syndromes

Background-—Plaque erosion is responsible for 25% to 40% of patients with acute coronary syndromes (ACS). Recent studies suggest that anti-thrombotic therapy without stenting may be an option for this subset of patients. Currently, however, an invasive procedure is required to make a diagnosis of plaque erosion. The aim of this study was to identify clinical or laboratory predictors of plaque erosion in patients with ACS to enable a diagnosis of erosion without additional invasive procedures. Methods and Results-—Patients with ACS who underwent optical coherence tomography imaging were selected from 11 institutions in 6 countries. The patients were classified into plaque rupture, plaque erosion, or calcified plaque, and predictors were identified using multivariable logistic modeling. Among 1241 patients with ACS, 477 (38.4%) patients were found to have plaque erosion. Plaque erosion was more frequent in non–ST-segment elevation-ACS than in ST-segment–elevation myocardial infarction (47.9% versus 29.8%, P=0.0002). Multivariable logistic regression models showed 5 independent parameters associated with plaque erosion: age 15.0 g/dL, and normal renal function. When all 5 parameters are present in a patient with non–ST-segment elevation-ACS, the probability of plaque erosion increased to 73.1%. Conclusions-—Clinical and laboratory parameters associatedwith plaque erosion are explored in this retrospective registry study. These parametersmay be useful to identify the subset ofACS patients with plaque erosion and guide themto conservativemanagement without invasive procedures. The results of this exploratory analysis need to be confirmed in large scale prospective clinical studiesDr. Jang has received an educational grant from Abbott Vascular and Medicure. Dr. Adriaenssens has received grants and consulting fees from Abbott Vascula

Age‐related changes in the coronary microcirculation influencing the diagnostic performance of invasive pressure‐based indices and long‐term patient prognosis

Objectives Investigate age-related changes in coronary microvascular function, its effect on hyperemic and non-hyperemic indices of stenosis relevance, and its prognostic implications. Background Evidence assessing the effect of age on fractional flow reserve (FFR), resting mean distal intracoronary pressure/mean aortic pressure (Pd/Pa), and microcirculatory function remains scarce. Methods This is a post hoc study of a large prospective international registry (NCT03690713) including 1134 patients (1326 vessels) with coronary stenoses interrogated with pressure and flow guidewires. Age-dependent correlations with functional indices were analyzed. Prevalences of FFR, resting Pd/Pa, and coronary flow reserve (CFR) classification agreement were assessed. At 5 years follow-up, the relation between resting Pd/Pa, CFR, and their age-dependent implications on FFR-guided percutaneous coronary intervention (PCI) deferral (deferred if FFR > 0.80) were investigated using vessel-oriented composite outcomes (VOCO) composed of death, myocardial infarction, and repeated revascularization. Results Age correlated positively with FFR (r = 0.08, 95% confidence interval [CI]: 0.03 to 0.13, p =  0.005), but not with resting Pd/Pa (r = −0.03, 95% CI:−0.09 to 0.02, p = 0.242). CFR correlated negatively with age (r = −0.15, 95% CI: −0.21 to −0.10, p < 0.001) due to a significant decrease in maximal hyperemic flow in older patients. Patients over 60 years of age with FFR-guided deferred-PCI abnormal resting Pd/Pa or abnormal CFR had increased risk of VOCO (hazard ratio [HR]: 2.10, 95% CI: 1.15 to 4.36, p = 0.048; HR: 2.46, 95% CI:1.23 to 4.96, p = 0.011; respectively). Conlusions Aging is associated with decrease in microcirculatory vasodilation, as assessed with adenosine-based methods like CFR. In patients older than 60 years in whom PCI is deferred according to FFR > 0.80, CFR and resting Pd/Pa have an incremental value in predicting future vessel-oriented patient outcomes

A Patient with Type 3 Autoimmune Polyglandular Syndrome who Developed Systemic Lupus Erythematosus 8 years after the Diagnosis of Autoimmune Hepatitis

Eight years prior to her present admission, a 61-year-old Japanese woman was diagnosed with autoimmune hepatitis, slowly progressive insulin-dependent diabetes mellitus, and chronic thyroiditis; she had been treated with oral prednisolone (PSL). After she suddenly discontinued PSL, she newly developed systemic lupus erythematosus. A combination therapy of oral PSL and intravenous cyclophosphamide resulted in remission. She was finally diagnosed with autoimmune polyglandular syndrome (APS) type 3 (3A ,3B, 3D), complicated with four different autoimmune diseases. Since patients with type 3 APS may present many manifestations over a long period of time, they should be carefully monitored

Management of corticosteroid-dependent eosinophilic interstitial nephritis A case report

Introduction: Drug-induced acute interstitial nephritis (DI-AIN) is an important cause of acute kidney injury. In renal biopsy specimens, tubulitis with eosinophilic infiltration is suggestive of DI-AIN. Although corticosteroid therapy and discontinuation of the offending drug can improve renal dysfunction in most cases of DI-AIN, some patients experience AIN recurrence, leading to corticosteroid dependency. Corticosteroid-dependent eosinophilic interstitial nephritis presents a difficult dilemma in diagnosis and information regarding optimum management is limited. Patient concerns: A 25-year-old man, who received treatment with carbamazepine, zonisamide, valproate, and lacosamide for temporal lobe epilepsy, showed an increase in serum creatinine level from 0.98 to 1.29 mg/dL over a period of 6 months. Although he exhibited no symptoms, his serum creatinine level continued to increase to 1.74 mg/dL. Diagnosis: Renal biopsy revealed tubulitis and interstitial inflammatory infiltrates with eosinophils. Immunological and ophthalmological examinations showed no abnormal findings, and thus, his renal dysfunction was presumed to be caused by DI-AIN. Although oral prednisolone (PSL) administration (40 mg/d) and discontinuation of zonisamide immediately improved his renal function, AIN recurred 10 months later. The increase in PSL dose along with discontinuation of valproate and lacosamide improved renal function. However, 10 months later, recurrent AIN with eosinophilic infiltration was confirmed by further biopsy. The patient was therefore diagnosed with corticosteroid-dependent eosinophilic interstitial nephritis. Interventions: To prevent life-threatening epilepsy, carbamazepine could not be discontinued; hence, he was treated with an increased dose of PSL (60 mg/d) and 1500 mg/d of mycophenolate mofetil (MMF). Outcomes: MMF was well tolerated and PSL was successfully tapered to 5 mg/d; renal function stabilized over a 20-month period. Lessons: The presence of underdetermined autoimmune processes and difficulties in discontinuing the putative offending drug discontinuation are contributing factors to corticosteroid dependency in patients with eosinophilic interstitial nephritis. MMF may be beneficial in the management of corticosteroid-dependent eosinophilic interstitial nephritis by reducing the adverse effects related to high-dose and long-term corticosteroid use

Vasohibin-1 has α-tubulin detyrosinating activity in glomerular podocytes

Podocytes are highly specialized epithelial cells in glomeruli, with a complex morphology composed of a cell body, primary processes, and foot processes, which maintain barrier function in glomerular filtration. The microtubule-based cytoskeleton is necessary for podocyte morphology. Microtubule structure and function can be affected by post-translational modification of tubulin, including detyrosination. Recent studies have shown that vasohibin-1 (VASH1), an antiangiogenic factor, has tubulin carboxypeptidase activity that causes detyrosination of α-tubulin. We aimed to examine the role of VASH1 in regulating α-tubulin detyrosination in podocytes and the potential involvement of VASH1 deficiency in renal morphology. In normal mouse kidneys, detyrosinated α-tubulin was mainly identified in glomeruli, especially in podocytes; meanwhile, in cultured immortalized podocytes, α-tubulin detyrosination was promoted with cell differentiation. Notably, α-tubulin detyrosination in glomeruli was diminished in Vash1 homozygous knockout (Vash1−/−) mice, and knockdown of VASH1 in cultured podocytes prevented α-tubulin detyrosination. Although VASH1 deficiency-induced downregulation of detyrosination caused no remarkable glomerular lesions, urinary albuminuria excretion and glomerular volume were significantly higher in Vash1−/− mice than in wild-type mice. Furthermore, decreased glomerular nephrin expression and narrower slit diaphragms width were observed in Vash1−/− mice. Taken together, we demonstrated that α-tubulin detyrosination in podocytes was mainly regulated by VASH1 and that VASH1 deficiency-mediated decreases in α-tubulin detyrosination led to minor alterations in podocyte morphology and predisposition to albuminuria. VASH1 expression and α-tubulin detyrosination may be novel targets for maintaining glomerular filtration barrier integrity

Management of corticosteroid-dependent eosinophilic interstitial nephritis A case report

Introduction: Drug-induced acute interstitial nephritis (DI-AIN) is an important cause of acute kidney injury. In renal biopsy specimens, tubulitis with eosinophilic infiltration is suggestive of DI-AIN. Although corticosteroid therapy and discontinuation of the offending drug can improve renal dysfunction in most cases of DI-AIN, some patients experience AIN recurrence, leading to corticosteroid dependency. Corticosteroid-dependent eosinophilic interstitial nephritis presents a difficult dilemma in diagnosis and information regarding optimum management is limited. Patient concerns: A 25-year-old man, who received treatment with carbamazepine, zonisamide, valproate, and lacosamide for temporal lobe epilepsy, showed an increase in serum creatinine level from 0.98 to 1.29 mg/dL over a period of 6 months. Although he exhibited no symptoms, his serum creatinine level continued to increase to 1.74 mg/dL. Diagnosis: Renal biopsy revealed tubulitis and interstitial inflammatory infiltrates with eosinophils. Immunological and ophthalmological examinations showed no abnormal findings, and thus, his renal dysfunction was presumed to be caused by DI-AIN. Although oral prednisolone (PSL) administration (40 mg/d) and discontinuation of zonisamide immediately improved his renal function, AIN recurred 10 months later. The increase in PSL dose along with discontinuation of valproate and lacosamide improved renal function. However, 10 months later, recurrent AIN with eosinophilic infiltration was confirmed by further biopsy. The patient was therefore diagnosed with corticosteroid-dependent eosinophilic interstitial nephritis. Interventions: To prevent life-threatening epilepsy, carbamazepine could not be discontinued; hence, he was treated with an increased dose of PSL (60 mg/d) and 1500 mg/d of mycophenolate mofetil (MMF). Outcomes: MMF was well tolerated and PSL was successfully tapered to 5 mg/d; renal function stabilized over a 20-month period. Lessons: The presence of underdetermined autoimmune processes and difficulties in discontinuing the putative offending drug discontinuation are contributing factors to corticosteroid dependency in patients with eosinophilic interstitial nephritis. MMF may be beneficial in the management of corticosteroid-dependent eosinophilic interstitial nephritis by reducing the adverse effects related to high-dose and long-term corticosteroid use

Vasohibin-1 has α-tubulin detyrosinating activity in glomerular podocytes

Podocytes are highly specialized epithelial cells in glomeruli, with a complex morphology composed of a cell body, primary processes, and foot processes, which maintain barrier function in glomerular filtration. The microtubule-based cytoskeleton is necessary for podocyte morphology. Microtubule structure and function can be affected by post-translational modification of tubulin, including detyrosination. Recent studies have shown that vasohibin-1 (VASH1), an antiangiogenic factor, has tubulin carboxypeptidase activity that causes detyrosination of α-tubulin. We aimed to examine the role of VASH1 in regulating α-tubulin detyrosination in podocytes and the potential involvement of VASH1 deficiency in renal morphology. In normal mouse kidneys, detyrosinated α-tubulin was mainly identified in glomeruli, especially in podocytes; meanwhile, in cultured immortalized podocytes, α-tubulin detyrosination was promoted with cell differentiation. Notably, α-tubulin detyrosination in glomeruli was diminished in Vash1 homozygous knockout (Vash1−/−) mice, and knockdown of VASH1 in cultured podocytes prevented α-tubulin detyrosination. Although VASH1 deficiency-induced downregulation of detyrosination caused no remarkable glomerular lesions, urinary albuminuria excretion and glomerular volume were significantly higher in Vash1−/− mice than in wild-type mice. Furthermore, decreased glomerular nephrin expression and narrower slit diaphragms width were observed in Vash1−/− mice. Taken together, we demonstrated that α-tubulin detyrosination in podocytes was mainly regulated by VASH1 and that VASH1 deficiency-mediated decreases in α-tubulin detyrosination led to minor alterations in podocyte morphology and predisposition to albuminuria. VASH1 expression and α-tubulin detyrosination may be novel targets for maintaining glomerular filtration barrier integrity