Citations

Despite proven efficacy, ARB therapy reduces glomerular filtration in patients with unilateral renal artery stenosis (RAS). The objective of this study was to determine whether ARB exacerbates renal injury in 2K1C hypertension. RAS was established in mice by placement of a cuff on the right renal artery, which reduces blood flow by 70%. Both Hydralazine (H) and Valsartan (ARB) reduced blood pressure to a similar extent. RAS‐mediated cardiac hypertrophy (heart weight 134% sham (S) p<0.001) was prevented by ARB (102% S, p=ns) but not H (116% S, p=0.03); cardiac fibrosis was prevented in both ARB and H. Although ARB did not exacerbate renal atrophy (91.4 ± 2.1% atrophy vehicle (V) vs 75.3 ± 9.5% ARB, p=ns), H reduced renal atrophy (91.4 ± 2.1% V vs 28.4 ± 13.5% H, p<0.01). The contralateral kidney underwent compensatory hyperplasia (123% S; p<0.001), which was blunted with ARB or H treatment. No significant histopathologic alterations were observed in the contralateral kidneys of any group. RAS induced proteinuria in V mice. Urine protein excretion in ARB RAS mice was reduced to levels observed in S mice; H did not significantly alter urine protein excretion. Severe renal atrophy was observed in the cuffed kidneys of V mice, which was not exacerbated by ARB. However, ARB reduced proteinuria to baseline levels, indicating that ARB may protect overall renal function in unilateral RAS. These studies were supported by NIH grant P01 HL85307.

Recent studies have implicated CCR2 ‐ CCL2 signaling in macrophage influx and development of chronic renal disease in human and experimental renal artery stenosis (RAS). We sought to test the hypothesis that development of chronic renal disease would be abrogated in CCR2 knockout (KO) mice. We established RAS in CCR2 KO and WT mice (n=10) through placement of a cuff on the right renal artery We have shown that the cuff reproducibly reduces blood flow by 65% to the kidney. Sham mice underwent manipulation of the right renal artery without cuff placement. Both CCR2 KO and WT mice developed hypertension, which persisted throughout the 4 week study. There was no difference in renal atrophy between CCR2 KO (53+//‐14.6% cortical surface area) and WT (61.2%+/‐14%) mice. Furthermore, there were no significant differences in F4/80+ macrophage infiltration (12.78+/‐4.9% surface area for CCR2 KO mice and 13.13+/‐ 3.1% for WT mice) or CD3+ T cell infiltration. Infiltrating macrophages were predominantly iNOS+ M1 phenotype; few arginase+ cells were observed in any group. Urine protein excretion was similar in CCR2 KO and WT mice. CCL was induced to a similar extent in CCR2 KO and WT mice. Furthermore, no differences in CCL5, CCL7, CCR5, CCR1, or iNOS expression was observed between CCR2 KO and WT mice. We conclude that macrophage infiltration and chronic renal damage occurs in mice with deletion of CCR2. Future studies will identify signaling pathway(s) responsible for macrophage influx and chronic renal damage in this model. Grant Funding Source : AI‐100911

Abstract Basilar artery occlusions (BAOs) are devastating ischemic strokes that account for 1% of all strokes with high morbidity and mortality; however, neuroendovascular techniques such as ADAPT have recently revolutionized the clinical outcomes of these patients. 1-3 Common underlying pathology in patients with BAO include intracranial atherosclerotic disease (ICAD) as well as thromboembolic origin. 4 Basilar artery ICAD in a setting of acute stroke portends a poor prognosis and post-thrombectomy residual critical flow limiting stenosis treatment options, including balloon angioplasty with or without stent placement. 5-7 We present a video illustration of neuroendovascular technique and challenges encountered when managing this pathology. Image at 5:42 reprinted with permission from Alawieh et al, Lessons learned over more than 500 stroke thrombectomies using ADAPT with increasing aspiration catheter size, Neurosurgery , 86(1), 2020, pp. 61-70, with permission from the Congress of Neurological Surgeons. 1

We have previously demonstrated that, in vitro, c‐AMP specific PDE3 inhibitors block mitogenesis of mesangial cells (Am J Physiol Renal Physiol, 2004) and PDE4 inhibitors block cytokine stimulated MCP‐1 expression (Am J Physiol Cell Physiol, 2005). The in vivo relevance of these findings has not been previously established. Mice were treated with the nonselective cAMP PDE inhibitor pentoxifylline (PTX) prior to bilateral clamping of the renal arteries for 30 minutes, followed by reperfusion for 1 and 4 days. PTX blunted the increase in BUN and creatinine after 1 day (−38% and −43%, respectively, p<0.05), and after 4 days (−80% and −44%, respectively, p<0.05). PTX reduced the extent of tubular necrosis (1 day: 39.13% vs. 52.5%; 4 days: 2.5% vs. 23.33%, p<0.05, p=NS. % cortical area in PTX vs. IR). PTX reduced PCNA expression 4 days after IR, as assessed by Western blot (−43%, p<0.05), and reduced caspase 3 activity one day after IR (−43%, p<0.05). PTX markedly reduced expression of MMP10 and Cox‐2 one day after IR (26 and 4 folds, respectively, p<0.05), which are induced in response to acute inflammation. PTX significantly reduced cyclin F, cyclin A2 and Ki67 expression 4 days after IR (124, 7 and 9 folds, respectively, p<0.05), which are induced in response to proliferation. We conclude that PTX ameliorates IR injury through c‐AMP mediated reduction in proliferative and inflammatory responses to acute injury.

KLFs (Kruppel‐like factors) comprise a family of over 17 distinct transcription factors that have been shown to regulate cell metabolism and renal function, including podocyte differentiation and maintenance of the glomerular filtration barrier. In non‐renal systems, KLF11 has been shown to regulate fibrosis. However, no previous studies have established a potential role for KLF11 in renal pathophysiology. We sought to test the hypothesis that KLF11 regulates renal fibrosis in unilateral ureteral obstruction, a well‐established murine model of renal fibrosis. Mice with homozygous deletion of the KLF11 gene (KO) and wild‐type (WT) mice were subjected to unilateral ureteral obstruction (UUO; n=8 per group); sham controls (n=4 per group) were subjected to manipulation of the ureter without ligation. Kidneys were harvested at 9 days following surgery,. Semiquantitative histopathologic analysis of interstitial fibrosis, tubular atrophy, and interstitial inflammation was performed in a blinded fashion. Analysis of gene expression was performed on renal cortex using Pathway Detect RNA arrays and by RNASeq. Histopathologic analysis of sham controls revealed no significant alterations. However, expression of several elements of the TGF‐beta signaling pathway was significantly higher in KLF11 KO sham mice, compared to WT mice, including TGF‐beta receptors type I and type II, Smad2, Smad 7, Bmpr1B, and Bmpr2R, and the KLF‐related transcription factor Sp1 (all p<0.05). In mice subjected to UUO, interstitial fibrosis, tubular atrophy, and interstitial inflammation were significantly greater in KLF11 KO mice compared to WT mice. Interstitial inflammation was associated with influx of alternatively activated macrophages, as assessed by quantitative analysis of CD206+ infiltrating cells (p<0.05); no significant increase in CD3+ T cell numbers were noted. Expression of several members of the TGF‐beta signaling pathway were significantly increased in KLF11 KO UUO mice, compared to WT UUO mice, including TGF‐beta 1, TGF‐beta‐2, and TGF‐beta3, TGF‐beta receptors type I and type II, and Smad 1,2,3,4, and 5 (all p<0.05). Conversely, expression of the transcription factor JunB was markedly increased in WT UUO mice compared to WT sham mice (12.2 ‐fold; p<0.0001). However, JunB expression was markedly decreased in KLF11 KO mice (both sham and UUO). Although MMP expression was not significantly different in KO versus WT mice, TIMP3 expression was higher in KO mice compared to WT mice. In conclusion, we found that renal damage is exacerbated in KLF11 KO mice subjected to UUO, compared to WT UUO mice and is associated with influx of potentially pro‐fibrotic, alternatively activated M2 macrophages. KLF11 appears to be a critical regulator of TGF‐beta signaling, as KLF11 deficiency is associated with increased expression of TGF‐beta and signaling intermediates of this fibrogenic pathway.

Abstract In-stent stenosis has a reported prevalence of 14% to 19% at 1-yr follow-up after carotid stenting and is associated with an increased risk of acute ischemic stroke. 1,2 Risk factors include female sex, diabetes, and dyslipidemia. Cutting balloon angioplasty is a safe and effective treatment modality for the treatment of carotid in-stent stenosis, and alternative treatment options include observation with medical management and placement of another stent. 3,4 The authors present the case of a 61-yr-old man with carotid in-stent restenosis and progressive worsening on serial imaging with ultrasound. The patient had a history of carotid stenting for symptomatic stenosis 6 mo prior and was maintained on aspirin and clopidogrel. In light of the progressive worsening, the in-stent stenosis was confirmed on computed tomography (CT) angiogram. The options were discussed with the patient and he consented for treatment with cutting balloon angioplasty. Final angiogram showed improvement of the luminal diameter with a residual stenosis of 15%. The patient tolerated the procedure well and was discharged home on postoperative day 1. Follow-up ultrasound demonstrated moderate improvement in peak systolic velocities, and the plan is to continue observation with a clinical follow-up and repeat carotid Dopplers at 3 mo.

8049 Background: The treatment paradigm of Waldenström macroglobulinemia (WM) continues to evolve as new therapies expand our options for this indolent and incurable disease. While more profound responses are generally associated with longer treatment-free intervals, the impact of depth of response from fixed duration therapy in WM patients' survival needs further evaluation. In this international, multicenter cohort study, we report the prognostic impact of depth of response in WM. Methods: 319 WM patients treated with frontline fixed duration therapy [Dexamethasone/Rituximab/Cyclophosphamide (DRC), Bendamustine/Rituximab (BR), or Bortezomib/Dexamethasone/Rituximab (BDR)] were included. Response at the completion of therapy (6 months) was used in a landmark analysis for progression-free survival (PFS), time to next treatment (TTNT), and overall survival (OS) (defined as time from 6 months post treatment response to event or censor). Response was defined by modified IWWM-6 criteria. Associations between clinical variables and outcomes were evaluated using Cox proportional-hazard models. Results: The median age at the time of treatment initiation was 64 years (range: 29-94), 59% were men, and risk category by International Prognostic Scoring System (IPSS)-WM was low (n=67, 23%), intermediate (n=83, 29%), and high-risk (n=141, 48%). Evaluable responses at 6 months from frontline therapy [DRC (n=105; 41%), BR (n=83; 32%), BDR (n=68; 27%)] were available in 256 patients and included in the landmark analysis. Median follow-up was 63 months (95% CI: 59-70). The rate of major response (PR or better) at 6 months was 74% for the entire cohort. Five-year PFS rates from completion of therapy for patients who attained major response vs. those who did not were 71% and 43%, respectively (p<0.001). Five-year TTNT rates for patients who attained major response vs. not were 84% and 54%, respectively (p<0.001). Five-year OS rates for patients who attained major response vs. not were 92% and 77%, respectively (p<0.001). In multivariable analyses including other WM prognostic factors evaluated at initiation of frontline therapy, attaining a major response at 6 months was associated with superior PFS (HR 0.33, p<0.001), TTNT (HR 0.23, p<0.001), and OS (HR 0.31, p=0.001–Table). Conclusions: Achieving a major response at 6 months after frontline chemoimmunotherapy emerges as a significant prognostic factor for PFS, TTNT and OS in patients with WM.[Table: see text]

Abstract Background and Aims Kruppel-like factors (KLFs) comprise a family of zinc-finger transcription factors that play a critical role in development, proliferation, and regeneration following injury. There are over 17 members of this family; recent studies have shown that KLF family members regulate podocyte differentiation, preservation of the glomerular filtration barrier, and regulation of mitochondrial function. However, a role for KLF11 in renal pathophysiology has not been previously established. Method Wild-type (WT) and KLF11 knockout (KO) mice were subjected to unilateral ureteric obstruction (UUO), a well-established model of renal inflammation and fibrosis; controls included mice subjected to manipulation of the ureter without ligation. Kidneys were harvested after 9 days (n=8 animals per group). Semiquantitative histopathologic analysis of renal atrophy, fibrosis, and inflammation was performed in a blinded fashion. Gene expression analysis was performed on renal cortex employing the Pathway Detect RNA array and RNASeq. Results In UUO, renal atrophy was more severe in KLF11 KO mice than WT mice (p&lt;0.001). Deposition of collagen, as assessed by quantitative analysis of Sirus Red stained sections, was greater in KLF11 KO mice, compared to WT mice subjected to UUO; COL3A1 expression was also increased (p&lt;0.05). Atrophy was associated with an increase in F4/80+ (p&lt;0.01) and CD206+ macrophages (p&lt;0.05), but not CD3+ T cells in KLF11 KO vs. WT mice. Induction of CC chemokines, including CCL2, CCL5, CCL7, CCL12, and CCL2 as well as CCR2 was significantly higher in KLF11 KO versus WT mice subjected to UUO (all p&lt;0.001). Expression of NF-kB (p&lt;0.01) and TNF alpha (p&lt;0.01), but not IL-1 beta, IL-6, or IL-10 were significantly higher in KLF11 KO than WT mice with UUO. Expression of TGF-beta 1, Smad2, and Smad3 were also higher in KLF11 KO mice than WT mice with UUO (p&lt;0.05). Conclusion Renal injury in UUO is exacerbated in KLF11 KO mice, compared to WT mice. Injury is associated with increased macrophage influx and production of pro-inflammatory chemokines. Future studies will determine how KLF11 deficiency directs transcription of pro-inflammatory and pro-fibrotic genes.

AbstractGaucher disease (GD), one of the most common lysosomal disorders, is caused by deficiency of β‐glucocerebrosidase. Based on the presence and severity of neurological complications, GD is classified into types I, II (the most severe form), and III. Abnormalities in systemic markers of vitamin B12 (B12) metabolism have been reported in GD type I patients, suggesting a higher prevalence of B12 deficiency in these patients. A 2‐month‐old male with GD type II was admitted to the hospital presenting jaundice, hepatosplenomegaly, and ichthyosis. At admission, cholestasis and ascites, abnormal liver function enzymes, prolonged prothrombin time, and high levels of B12 were confirmed. Analysis of biomarkers of B12 status revealed elevated B12 and holo‐transcobalamin (holo‐TC) levels. The B12 profile found in our patient is the opposite to what is described for GD type I patients. Holo‐TC may increase in inflammatory states or due to liver diseases. In GD, the accumulation of glucocerebroside may be a trigger that initiates a systemic inflammatory reaction, characterized by macrophage activation. We suggest higher levels of holo‐TC could be associated with a more severe (neuronopathic) GD, and be a biomarker of GD type II.