Renal Infiltration Research Articles

Daily Low-intensity Pulsed Ultrasound Ameliorates Renal Fibrosis and Inflammation in Experimental Hypertensive and Diabetic Nephropathy.

The estimated morbidity rate of chronic kidney disease is 8% to 16% worldwide, and many patients with chronic kidney disease eventually develop renal failure. Thus, the development of new therapeutic strategies for preventing renal failure is crucial. In this study, we assessed the effects of daily low-intensity pulsed ultrasound (LIPUS) therapy on experimental hypertensive nephropathy and diabetic nephropathy. Unilateral nephrectomy and subcutaneous infusion of angiotensin II via osmotic mini-pumps were used to induce hypertensive nephropathy in mice. Immunohistochemistry revealed that daily LIPUS treatment ameliorated renal fibrosis and infiltration of inflammatory cells induced by angiotensin II. A similar therapeutic effect was also observed in mice with angiotensin II-induced hypertensive nephropathy in which splenectomy was performed. In addition, LIPUS treatment significantly decreased systolic blood pressure after 21 days. Subsequently, db/db mice with unilateral nephrectomy developed proteinuria; daily LIPUS treatment significantly reduced proteinuria after 42 days. In addition, immunohistochemistry revealed that renal fibrosis was significantly ameliorated by LIPUS treatment. Finally, LIPUS stimulation suppressed TGF-β1 (transforming growth factor-β1)-induced phosphorylation of Smad2 and Smad3 in HK-2 (human proximal tubular cell line) cells. LIPUS treatment may be a useful therapy for preventing the progression of renal fibrosis in patients with chronic kidney disease.

Outbreak and management of <i>Salmonella</i> Enteritidis infection in 2-week-old Lohmann brown pullets

Avian salmonellosis has huge economic and public health impact. In this manuscript, a case of S. Enteritidis and its management within Jos Metropolis was reported. Fiftythree carcasses of 2-weeks old pullets were presented at the poultry and fish clinic of the Veterinary Teaching Hospital, University of Jos, Nigeria for investigation. There was persistent mortality despite 5 days medication with 20% Enrofloxacin (Floxinor®, Shijiazhuang Guanghua Pharmaceutical co. Ltd, Hebei, China). Cumulative mortality within 14 days was 203 birds in a flock of 4,000. Necropsy was done and harvested were subjected to microbial analysis for bacterial isolation, identification and antibiotic susceptibility test while portions of these organs were preserved in 10% formalin for histopathology. Necropsy findings were empty crops, hepatitis with petechial hemorrhages, nephritis, congested and consolidated lungs, peritonitis, congested spleens and mild enteritis. Histologically, there were vacuolation and necrosis of renal tubular epithelia cells and interstitial infiltration with heterophils. Severe disorganization of hepatic cords, infiltration with inflammatory cells and mild necrosis of hepatocytes were observed, while there was severe congestion and diffuse hemorrhages in the lungs. Cellular infiltration within the lamina propria of small intestine with stunting and blunting of the villi were observed. Organism isolated on MacConkey agar was identified as Salmonella Enteritidis. Antibiotic susceptibility test showed the organism to be most susceptible to Streptomycin, which was administered via drinking water at dosage of 40mg/kg with good recovery of the flock. It was concluded that the occurrence of Salmonella Enteritidis infection in this flock might be from the hatchery or via ingestion of contaminated feed and water. Day old chicks should be screened for Salmonella infection and strict biosecurity should be instituted on poultry farms.
 Keywords: Mortality, Necrosis, Pullets, Salmonella Enteritidis, streptomycin

Renal Macrophage Infiltration Precedes Macrophage to Myofibroblast Transition and T-Cell Recruitment Following Repeated Low-Dose Cisplatin Treatment

Renal Macrophage Infiltration Precedes Macrophage to Myofibroblast Transition and T-Cell Recruitment Following Repeated Low-Dose Cisplatin Treatment

Glomerulosclerosis predicts poor renal outcome in patients with idiopathic membranous nephropathy.

This study aimed to investigate the association between the proportion of glomerulosclerosis (focal segmental glomerulosclerosis and/or global glomerulosclerosis) and renal prognosis in patients with idiopathic membranous nephropathy (IMN). A retrospective analysis performed from January 2008 to December 2017 in the First Affiliated Hospital of Shenzhen University by renal biopsy confirmed 200 patients with IMN, and their clinical pathology and prognosis were compared. Patients were divided into three groups on the basis of glomerular sclerosis proportion tertiles: low (Tertile1 group, proportion of glomerulosclerosis, 0-0%), middle (Tertile2 group, proportion of glomerulosclerosis, 0-5.5%) and high (Tertile3 group, proportion of glomerulosclerosis, 5.8-72.7%) tertiles. The follow-up endpoints were decreased estimated glomerular filtration rate (eGFR) by 20%, end-stage renal disease, and all-cause mortality. (1) Both, the Tertile1 and Tertile2, groups had significantly lower albumin level and higher 24-h urine protein level than that in the Tertile3 group. Regarding treatment, as the proportion of glomerulosclerosis increases, a more aggressive treatment with glucocorticoids and immunosuppressants should be provided. (2) Correlation analysis showed that the proportion of glomerulosclerosis was positively associated with age (P < 0.05). However, it was negatively associated with eGFR (P < 0.05). (3) Renal tubular atrophy and renal interstitial inflammatory cell infiltration were considered independent correlative factors for glomerulosclerosis. Kaplan-Meier analysis revealed that renal survival rate was significantly lower in patients with a proportion of glomerulosclerosis ≥ 6.45% than in patients with a proportion of glomerulosclerosis < 6.45%. Cox regression analysis revealed that as the proportion of glomerulosclerosis increases, the risk of renal outcomes increases gradually. Patients in the Tertile3 (higher proportion of glomerulosclerosis) group had more severe renal pathological damage compared to patients in the Tertile1 and Tertile2 groups. Glomerulosclerosis is a risk factor for renal function progression and poor renal prognosis in patients with IMN. As the proportion of glomerulosclerosis increases, the risk of renal endpoint events increases gradually.

The profiles of biopsy-proven renal tubulointerstitial lesions in patients with glomerular disease.

BackgroundRenal tubules and interstitium are vulnerable to injury and play a central role in the progression of various chronic kidney diseases (CKDs). However, high quality epidemiologic study on the profiles of biopsy-proven tubulointerstitial lesions (TILs) is extremely limited.MethodsWe conducted a retrospective renal biopsy series including 62,569 native biopsies at 1,211 hospitals across China from 2015 to 2017. The TILs, including the shedding of tube epithelial, renal tubular atrophy, renal interstitial fibrosis, edema and inflammatory infiltration, were identified from the pathological report. We analyzed the severity and chronicity of TILs stratified by gender, age groups, biopsy indications, and concurrent glomerular diseases. We also examined the correlation between TIL and glomerulosclerosis.ResultsOf 56,880 patients with biopsy-proven glomerular disease, 79.5% had TILs. Renal interstitial inflammatory infiltration was the most common type of TIL (77.7%), followed by renal tubular atrophy (56.0%) and renal interstitial fibrosis (32.8%). Severe and chronic TILs were more common in adults than in children. The three glomerular diseases with the highest proportion of moderate-to-severe and chronic TIL were diabetic nephropathy, immunoglobulin A (IgA) nephropathy and focal segmental glomerulosclerosis. The severity of TILs was moderately correlated with glomerulosclerosis score (r=0.51). Moderate-to-severe and chronic TIL were more common in southern China. After adjusting for age, sex, hospital level, region, biopsy indication and type of concurrent glomerular diseases, adults with renal arteriole injury had a six-fold higher risk of moderate-to-severe TIL [odds ratio (OR), 7.12; 95% confidence interval (CI), 6.42 to 7.91] and a three-fold higher risk of chronic TIL (OR, 4.58; 95% CI, 4.37 to 4.79).ConclusionsTILs were common in patients with biopsy-proven glomerular disease. The type and severity of TILs varied with age, region and concurrent glomerular diseases. Renal arteriole injury and glomerulosclerosis was associated with a significantly increased risk of TIL.

Abstract MP15: Treatment With IL-25 Slows The Early Progression Of Proteinuria In Obese Dahl Salt-sensitive Rats

Recently, we reported that the early progression of proteinuria in the obese Dahl salt-sensitive (SS LepR mutant) strain was associated with increased renal macrophage infiltration in the absence of hyperglycemia and elevations in arterial pressure. Macrophages (MØ) can be divided into two distinct phenotypes: M1-macrophages (classical; pro-inflammatory), and M2-macrophages (alternative; anti-inflammatory). M1-macrophages induce renal inflammation and fibrosis whereas M2-macrophages reduce renal inflammation and fibrosis. Moreover, previous studies have demonstrated that interlukin-25 (IL-25) converts resting MØ and M1 macrophages into M2 macrophages. Therefore, the objective of the current study was to examine whether treatment with IL-25 would reduce the early progression of proteinuria in SS LepR mutant rats by increasing renal M2 macrophages. Four week-old SS LepR mutant rats were separated into two groups (n=5/group): (1) vehicle (PBS) and (2) IL-25 (1μg/day, i.p.) for the first 10 days of the study. At baseline, proteinuria was similar in vehicle and IL-25 treated rats (81±18 vs. 66±8 mg/day, respectively). After 2 weeks, proteinuria was markedly reduced in the IL-25-treated group compared to the values measured in the vehicle treated rats (191±37 vs. 365±55 mg/day respectively; p&lt;0.05 vs. vehicle). Interestingly, treatment with IL-25 was no longer effective in inhibiting the progression of proteinuria after 4 weeks (508±83 and 521±73 mg/day). When examining the possible phenotypes of the infiltrated macrophages in the kidneys, we did not detect any differences in M1 versus M2 macrophages between vehicle and IL-25 treated groups after 4 weeks. However, after 2 weeks of treatment, we did observe a tendency for M2 macrophages to be elevated in the kidneys of the IL-25 group. Overall, these data support our previous finding that the early progression of proteinuria in the obese SS LepR mutant strain is associated with renal macrophage infiltration and also suggest that IL-25 may be considered a therapeutic target for renal disease associated with obesity. This study was supported by DK109133. Key Words: Obesity, Renal Disease, Macrophages, IL-25

Abstract P132: A Kidney-Targeted Nanoparticle To Augment Renal Lymphatic Density Decreases Blood Pressure In Mice With L-NAME- And Angiotensin II-Induced Hypertension

Chronic interstitial inflammation and renal infiltration of activated immune cells play an integral role in hypertension. Lymphatic vessels attenuate inflammation by trafficking activated immune cells and excess fluid from the interstitial space to lymph nodes. Previously, our laboratory demonstrated that genetically inducing renal lymphangiogenesis could treat hypertension in three different mouse models. In an effort to translate these findings into a clinical treatment, we hypothesized that a targeted nanoparticle could deliver the pro-lymphangiogenic factor VEGF-C156S to the kidney, induce lymphangiogenesis, and lower blood pressure in hypertensive mice. A micellar nanoparticle was developed with the capacity to deliver protein to the kidney, as demonstrated through delivery trials. This nanoparticle was loaded with VEGF-C156S and injected into mice with LNAME-induced hypertension (LHTN) or angiotensin II-induced hypertension (AIIHTN) via tail vein every 3 days. Compared to hypertensive mice injected with VEGF-C156S only (no nanoparticle) every 3 days, nanoparticle-treated mice exhibited a significantly lower systolic blood pressure (SBP) after 4 injections (LHTN SBP: 160±5 vs. 120±3 mmHg, p&lt;0.001; AIIHTN SBP: 150±8 vs. 126±6 mmHg, p=0.03). Immunolabeled kidney sections from nanoparticle-treated LHTN mice showed a significant increase in podoplanin+ pixels, corresponding to an increase in lymphatic vessel density (p&lt;0.01). A 5-fold increase in renal gene expression of podoplanin in nanoparticle-treated LHTN mice further supported this finding (p=0.01). Flow cytometric analysis of the nanoparticle-treated LHTN mice showed decreased renal CD45+F4/80+CD11c- cells, while AIIHTN mice revealed decreased levels of renal CD45+CD3e+, CD45+CD4+CD8-, and CD45+F4/80+CD11c+ cells (p&lt;0.01, p=0.03, and p&lt;0.001, respectively) when compared to their respective hypertensive groups. These data support our previous findings that expanding the renal lymphatic vasculature can treat existing hypertension by reducing renal immune cells. The results of this study may provide clinicians with a renal lymphatic-targeted therapeutic for treating hypertensive patients.

Abstract P036: Salt-inducible Kinase (SIK): A Pharmacological Target Of Salt-sensitive Hypertension

Salt-inducible kinase (SIK) is a serine/threonine kinase involved in intracellular sensing network. However, its role in the development of salt-sensitive hypertension remains uncertain. We used a mouse model of salt-sensitive hypertension to test the hypothesis that SIK inhibition decreases systolic blood pressure (SBP) and renal injury. Male C57BL/6J mice (20-25g) were randomly fed either normal salt (NS; 0.5% NaCl) or high salt (HS; 4% NaCl) diet and daily treated or not with a SIK inhibitor (iSIK, YKL-05-099, 20 mg/Kg, via IP; n=6/group; CEUA: 013/19). In these mice: 1) SBP was measured by telemetry for 15 days; 2) Urine metabolic collection for 24 h was performed on day 14; and 3) Blood and kidney samples were collected after euthanasia on day 15. HS diet increased SBP during both day and night times (Day: from 114±1 to 136±1 mmHg; Night: from 127±3 to 141±4 mmHg; p&lt;0.0001). Treatment with iSIK prevented increases in SBP (Day: 112±1 and Night: 123±2 mmHg). iSIK did not change SBP nor renal Na + handling in NS diet. In HS mice, iSIK prevented the augmentation of urine osmolality (HS: 1692±14 vs. HS+iSIK: 1104±34 mOsm/Kg H 2 O; p=0.0019) but did not change increases in urine volume and Na + excretion neither decreases in urine creatinine. Moreover, HS mice displayed glomerular segmentation, tubular interstitial disruption, infiltration of inflammatory cells and collagen accumulation. These responses were attenuated by iSIK. Increased kidney SIK activity in HS mice were sensitive to iSIK (HS: 222.8±45 vs. HS+iSIK: 19.10±15 pmol.mg -1 .min -1 ; p=0.0026). The augmentation of (Na + +K + )ATPase activity in HS mice was exacerbated during iSIK (HS: 517±112 and HS+SIKi: 763±18 mmol.mg -1 ;.min -1 p&lt;0.0001). Equally important, SIK inhibition in HS mice: 1) Decreased plasma MCP-1 levels (HS: 79±7 vs. HS+iSIK: 51±2 pg/dL; p=0.0019); 2) Prevented HS-dependent macrophages renal infiltration; 3) Decreased kidney ROS; and 4) Decreased kidney TGF-β protein expression (HS: 1.9±0.01 vs. HS+iSIK: 1.4±0.3 au. p=0.0007). Thus, the data indicate that SIK inhibition attenuates salt-sensitive hypertension and prevents kidney injury, without altering Na + handling in response to HS. In perspective, SIK might be a pharmacological target for salt-sensitive hypertension treatment.

Histone Deacetylase Inhibitor-loaded Calcium Alginate Microspheres for Acute Kidney Injury Treatment.

The protective effects of histone deacetylase (HDAC) inhibitors were highlighted in the treatment of kidney diseases, especially acute kidney injury (AKI). However, the currently available HDAC inhibitor cannot be delivered to the kidney properly because of its poor solubility in aqueous solutions. Therefore, calcium alginate (Ca-ALG) microspheres were proposed as microcarriers for the delivery of HDAC inhibitors in this study. First, Ca-ALG microspheres with high sphericity were obtained by a single-emulsion microfluidic strategy. Then, we selected suitable Ca-ALG microspheres for HDAC inhibitor loading by analyzing the swelling ratio and the release property using different parameters. Besides, thermal stimulation will change the drug release property of Ca-ALG microspheres in in vitro experiments. Furthermore, the HDAC inhibitor-loaded microspheres were delivered to the kidney by renal subcapsular injection for evaluating the treatment effects in mice with ischemia-reperfusion-induced AKI. The in vivo results showed that the HDAC inhibitor-loaded Ca-ALG microspheres could effectively reduce the renal regional inflammatory response and macrophage infiltration. Taken together, we proposed a promising therapy with an effective kidney-targeted drug delivery for the treatment of AKI.

Anti-Inflammatory, Antioxidant, and Antifibrotic Effects of Kefir Peptides on Salt-Induced Renal Vascular Damage and Dysfunction in Aged Stroke-Prone Spontaneously Hypertensive Rats.

The increased prevalence of renal dysfunction and chronic kidney disease (CKD) and the high costs and poor outcomes of treatment are a significant health issue. The consequence of chronic high blood pressure is the increased prevalence of target organ end-stage renal disease, which has been proven to be a strong independent risk factor for adverse cardiovascular disease. A previous study showed that kefir products have anti-inflammatory and anti-hypertensive activities and immunological modulation functions. However, no data regarding the beneficial effects of kefir peptides (KPs) on salt-induced renal damage or related kidney diseases are available. In this study, KPs were orally administered to aged salt-induced stroke-prone spontaneously hypertensive (SHRSP) rats, and the effects of KPs against inflammation and oxidative stress and their ability to protect against renal dysfunction were evaluated. Fifty-five-week-old SHRSP rats under induction with 1% NaCl in drinking water for 4 weeks showed multiple renal injuries with increased renal inflammation, fibrosis, oxidative stress, tubular atrophy, and glomerulosclerosis. In contrast, oral gavage with KPs reduced the urine protein to creatinine (UPC) ratio, the fractional excretion of electrolytes (FeNa and FeCl), extracellular matrix deposition, and the interstitial fibrotic α-smooth muscle actin (α-SMA) levels in salt-induced SHRSP rats. The renal infiltration of inflammatory cells; the release of monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), endothelin-1 (ET-1), and the cytokine nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) and transforming growth factor-β (TGF-β); the reactive oxygen species (ROS) levels; and histopathological lesions were also decreased in salt-induced SHRSP rats. Furthermore, KP treatment significantly increased the renal superoxide dismutase (SOD) activity and the glomerular filtration rate (GFR), which exerted potent protection against salt-induced chronic kidney disease in SHRSP rats. The results of this study suggest that KPs ameliorate salt-induced renal damage, tubular atrophy, and glomerular dysfunction through anti-inflammatory, antioxidative stress, and antifibrotic activities, and might be a promising protective agent against high salt-induced renovascular-related diseases.

Synergistic Inhibition of Renal Fibrosis by Nintedanib and Gefitinib in a Murine Model of Obstructive Nephropathy

Background: Our recent studies demonstrated that both nintedanib, an FDA-approved quadruple kinase inhibitor, and gefitinib, an epidermal growth factor receptor (EGFR) inhibitor, protect against obstructive kidney disease. It remains unknown whether they have a synergistic effect. Methods: In this study, we investigated the effect of combined administration of nintedanib and gefitinib on renal fibrosis in a murine model of renal fibrosis induced by unilateral ureteral obstruction (UUO). Results: Combined treatment with nintedanib and gefitinib after UUO resulted in a greater antifibrotic effect compared with their individual application. Mechanistically, administration of nintedanib blocked UUO-induced phosphorylation of multiple kinase receptors associated renal fibrosis, including platelet-derived growth factor receptors, fibroblast growth factor receptors, vascular endothelial growth factor receptors, and Src family kinase, while gefitinib inhibited EGFR phosphorylation. Their combination also exhibited a more pronounced effect in reducing expression of tissue inhibitors of metalloproteinase-2 (TIMP-2), increasing expression of matrix metalloproteinase-2 (MMP-2), and suppressing renal proinflammatory cytokine expression and macrophage infiltration in the injured kidney. Furthermore, simultaneous administration of nintedanib and gefitinib was more potent in inhibiting UUO-induced renal phosphorylation of signal transducer and activator of transcription-3 (STAT3), nuclear factor-κB, and Smad-3 compared with monotherapy. In cultured renal interstitial fibroblasts, cotreatment with these 2 inhibitors also had synergistic effects in abrogating transforming growth factor β1-induced activation of renal fibroblasts and phosphorylation of Akt, STAT3, and Smad3. Conclusions: Combined application of nintedanib and gefitinib has a synergistic antifibrotic effect in the kidney and may hold translational potential for the treatment of chronic kidney disease.

Proliferation of HIV-infected renal epithelial cells following virus acquisition from infected macrophages.

HIV-1 can infect and persist in different organs and tissues, resulting in the generation of multiple viral compartments and reservoirs. Increasing evidence supports the kidney as such a reservoir. Previous work demonstrated that HIV-1 infected CD4 T-cells transfer virus to renal tubule epithelial (RTE) cells through cell-to-cell contact. In addition to CD4 T cells, macrophages represent the other major target of HIV-1. Renal macrophages induce and regulate inflammatory responses and are critical to homeostatic regulation of the kidney environment. Combined with their ability to harbour virus, macrophages may also play an important role in the spread of HIV-1 infection in the kidney. Multiparametric histochemistry analysis was performed on kidney biopsies from individuals with HIV-1 associated nephropathy (HIVAN). Primary monocyte-derived macrophages were infected with a GFP-expressing replication competent HIV-1. HIV-1 transfer from macrophages to RTE cells was carried out in a coculture system and evaluated by fluorescence-microscopy and flow-cytometry. Live imaging was performed to assess the fate of HIV-1 infected RTE cells over time. We show that macrophages are abundantly present in the renal inflammatory infiltrate of individuals with HIVAN. We observed contact-dependent HIV-1 transfer from infected macrophages to both primary and immortalized renal cells. Live imaging of HIV-1 infected RTE cells revealed four different fates: proliferation, hypertrophy, latency and cell death. Our study suggests that macrophages may play a role in the dissemination of HIV-1 in the kidney and that proliferation of infected renal cells may contribute to HIV-1 persistence in this compartment.

Melatonin pretreatment alleviates renal ischemia-reperfusion injury by promoting autophagic flux via TLR4/MyD88/MEK/ERK/mTORC1 signaling.

Autophagy is an important mechanism for cellular homeostasis and survival during pathologic stress conditions in the kidney, such as ischemia-reperfusion (IR) injury. In this study, renal IR was induced in female C57BL/6 mice after melatonin administration. Renal function, histological damage, inflammatory infiltration, cytokine production, oxidative stress, antioxidant capacity, autophagy changing, apoptosis levels, and autophagy-associated intracellular signaling pathway were assessed to evaluate the impact of antecedent melatonin treatment on IR-induced renal injury. The administration of melatonin resulted in significantly preserved renal function, and the protective effect was associated with ameliorated oxidative stress, limited pro-inflammatory cytokine production, and neutrophil and macrophage infiltration. Moreover, autophagic flux was increased after melatonin administration while the apoptosis levels were decreased in the melatonin-pretreated mice. Using TAK-242 and CRX-527, we confirmed that MyD88-dependent TLR4 and MEK/ERK/mTORC1 signaling participated in melatonin-induced autophagy in IR mice. Collectively, our results provide novel evidence that antecedent melatonin treatment provides protection for the kidney against IR injury by enhancing autophagy, as regulated by the TLR4/MyD88/MEK/ERK/mTORC1 signaling pathway. Therefore, melatonin preconditioning offers a potential therapeutic approach to prevent renal IR injury related to various clinical conditions.

A synthetic retinoic acid receptor agonist Am80 ameliorates renal fibrosis via inducing the production of alpha-1-acid glycoprotein

Renal fibrosis is a major factor in the progression of chronic kidney disease and the final common pathway of kidney injury. Therefore, the effective therapies against renal fibrosis are urgently needed. The objective of this study was to investigate the effect of Am80, a synthetic retinoic acid receptor (RAR) agonist, in the treatment of renal interstitial fibrosis using unilateral ureteral obstruction (UUO) mice. The findings indicate that Am80 treatment suppressed renal fibrosis and inflammation to the same degree as the naturally-occuring retinoic acid, all-trans retinoic acid (atRA). But the adverse effect of body weight loss in Am80-treated mice was lower compared to the atRA treatment. The hepatic mRNA levels of alpha-1-acid glycoprotein (AGP), a downstream molecule of RAR agonist, was increased following administration of Am80 to healthy mice. In addition, increased AGP mRNA expression was also observed in HepG2 cells and THP-1-derived macrophages that had been treated with Am80. AGP-knockout mice exacerbated renal fibrosis, inflammation and macrophage infiltration in UUO mice, indicating endogenous AGP played an anti-fibrotic and anti-inflammatory role during the development of renal fibrosis. We also found that no anti-fibrotic effect of Am80 was observed in UUO-treated AGP-knockout mice whereas atRA treatment tended to show a partial anti-fibrotic effect. These collective findings suggest that Am80 protects against renal fibrosis via being involved in AGP function.

Amphiregulin Aggravates Glomerulonephritis via Recruitment and Activation of Myeloid Cells.

Recent studies have identified the EGF receptor (EGFR) ligand amphiregulin (AREG) as an important mediator of inflammatory diseases. Both pro- and anti-inflammatory functions have been described, but the role of AREG in GN remains unknown. The nephrotoxic nephritis model of GN was studied in AREG-/- mice after bone marrow transplantation, and in mice with myeloid cell-specific EGFR deficiency. Therapeutic utility of AREG neutralization was assessed. Furthermore, AREG's effects on renal cells and monocytes/macrophages (M/M) were analyzed. Finally, we evaluated AREG expression in human renal biopsies. Renal AREG mRNA was strongly upregulated in murine GN. Renal resident cells were the most functionally relevant source of AREG. Importantly, the observation that knockout mice showed significant amelioration of disease indicates that AREG is pathogenic in GN. AREG enhanced myeloid cell responses via inducing chemokine and colony stimulating factor 2 (CSF2) expression in kidney resident cells. Furthermore, AREG directly skewed M/M to a proinflammatory M1 phenotype and protected them from apoptosis. Consequently, anti-AREG antibody treatment dose-dependently ameliorated GN. Notably, selective abrogation of EGFR signaling in myeloid cells was sufficient to protect against nephritis. Finally, strong upregulation of AREG expression was also detected in kidneys of patients with two forms of crescentic GN. AREG is a proinflammatory mediator of GN via (1) enhancing renal pathogenic myeloid cell infiltration and (2) direct effects on M/M polarization, proliferation, and cytokine secretion. The AREG/EGFR axis is a potential therapeutic target for acute GN.

Immunity and Hypertension.

Hypertension is the primary cause of cardiovascular mortality. Despite multiple existing treatments, only half of those with the disease achieve adequate control. Therefore, understanding the mechanisms causing hypertension is essential for the development of novel therapies. Many studies demonstrate that immune cell infiltration of the vessel wall, kidney and central nervous system, as well as their counterparts of oxidative stress, the renal renin-angiotensin system (RAS) and sympathetic tone play a critical role in the development of hypertension. Genetically modified mice lacking components of innate and/or adaptive immunity confirm the importance of chronic inflammation in hypertension and its complications. Depletion of immune cells improves endothelial function, decreases oxidative stress, reduces vascular tone and prevents renal interstitial infiltrates, sodium retention and kidney damage. Moreover, the ablation of microglia or central nervous system perivascular macrophages reduces RAS-induced inflammation and prevents sympathetic nervous system activation and hypertension. Therefore, understanding immune cell functioning and their interactions with tissues that regulate hypertensive responses may be the future of novel antihypertensive therapies.

MRI Findings of Renal Infiltration Observed in a Child with Leukemia

MRI Findings of Renal Infiltration Observed in a Child with Leukemia

Sphingosine-1-phosphate receptor modulator FTY720 attenuates experimental myeloperoxidase-ANCA vasculitis in a T cell-dependent manner.

Sphingosine-1-phosphate (S1P) is a pleiotropic lysosphingolipid derived from the metabolism of plasma membrane lipids. The interaction between S1P and its ubiquitously expressed G-protein-coupled receptors (S1PR1-5) is crucial in many pathophysiological processes. Emerging evidence suggested a potential role for S1P receptors in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). In the present study, we investigated the effects of three different S1P receptors modulators (FTY720, SEW2871 and TY52156) in a recognized rat model of experimental autoimmune vasculitis (EAV). The effects of treatments were evaluated with clinico-pathological parameters including hematuria, proteinuria, crescent formation, pulmonary hemorrhage, etc. In vitro functional studies were performed in a Jurkat T-cell line following stimulations of serum from myeloperoxidase-AAV patients. We found that only the FTY720 treatment significantly alleviated hematuria and proteinuria, and diminished glomerular crescent formation, renal tubulointerstitial lesions and pulmonary hemorrhage in EAV. The attenuation was accompanied by less renal T-cell infiltration, up-regulated mRNA of S1PR1 and down-regulated IL-1β in kidneys, but not altered circulating ANCA levels, suggesting that the therapeutic effects of FTY720 were B-cell independent. Further in vitro studies demonstrated that FTY720 incubation could significantly inhibit the proliferation, adhesion, and migration, and increase apoptosis of T cells. In conclusion, the S1P modulator FTY720 could attenuate EAV through the reduction and inhibition of T cells, which might become a novel treatment of ANCA-associated vasculitis.

Peptidylarginine Deiminase 4 Promotes the Renal Infiltration of Neutrophils and Exacerbates the TLR7 Agonist-Induced Lupus Mice

Peptidylarginine deiminase 4 (PAD4), encoded by PADI4, plays critical roles in the immune system; however, its contribution to the pathogenesis of lupus nephritis remains controversial. The pathological roles of PAD4 were investigated in lupus model mice. An imiquimod (IMQ)-induced lupus model was analyzed in wild-type (WT) and Padi4-knockout (KO) mice. Proteinuria, serum anti-double stranded DNA (anti-dsDNA) antibody, and renal infiltrated cells were evaluated. Neutrophil migration and adhesion were assessed using adoptive transfer and adhesion assay. PAD4-regulated pathways were identified by RNA-sequencing of Padi4 KO neutrophils. Padi4 KO mice exhibited significant improvements in proteinuria progression compared with WT mice, whereas, serum anti-dsDNA antibody and immune complex deposition in the glomeruli showed no difference between both mice strains. Padi4 KO mice showed decreased neutrophil infiltration in the kidneys. Adoptively transferred Padi4 KO neutrophils showed decreased migration to the kidneys of IMQ-treated WT mice, and adhesion to ICAM-1 was impaired in Padi4 KO neutrophils. Padi4 KO neutrophils exhibited reduced upregulation of p38 mitogen-activated protein kinase (MAPK) pathways. Toll-like receptor 7 (TLR7)-primed Padi4 KO neutrophils demonstrated reduced phosphorylation of p38 MAPK and lower expression of JNK-associated leucine zipper protein (JLP), a p38 MAPK scaffold protein. Neutrophils from heterozygous Jlp KO mice showed impaired adhesion to ICAM-1 and decreased migration to the kidneys of IMQ-treated WT mice. These results indicated a pivotal role of PAD4-p38 MAPK pathway in renal neutrophil infiltration in TLR7 agonist-induced lupus nephritis, and the importance of neutrophil-mediated kidney inflammation. Inhibition of the PAD4-p38 MAPK pathway may help in formulating a novel therapeutic strategy against lupus nephritis.

Proinflammatory P2Y14 receptor inhibition protects against ischemic acute kidney injury in mice.

Ischemic acute kidney injury (AKI), a complication that frequently occurs in hospital settings, is often associated with hemodynamic compromise, sepsis, cardiac surgery, or exposure to nephrotoxins. Here, using a murine renal ischemia/reperfusion injury (IRI) model, we show that intercalated cells (ICs) rapidly adopted a proinflammatory phenotype after IRI. Wwe demonstrate that during the early phase of AKI either blockade of the proinflammatory P2Y14 receptor located on the apical membrane of ICs or ablation of the gene encoding the P2Y14 receptor in ICs (a) inhibited IRI-induced increase of chemokine expression in ICs, (b) reduced neutrophil and monocyte renal infiltration, (c) reduced the extent of kidney dysfunction, and (d) attenuated proximal tubule damage. These observations indicate that the P2Y14 receptor participates in the very first inflammatory steps associated with ischemic AKI. In addition, we show that the concentration of the P2Y14 receptor ligand UDP-glucose (UDP-Glc) was higher in urine samples from intensive care unit patients who developed AKI compared with patients without AKI. In particular, we observed a strong correlation between UDP-Glc concentration and the development of AKI in cardiac surgery patients. Our study identifies the UDP-Glc/P2Y14 receptor axis as a potential target for the prevention and/or attenuation of ischemic AKI.