Interstitial Expansion Research Articles

Myocardial edema, interstitial expansion and clinical correlates in takotsubo syndrome: a cardiac magnetic resonance tissue mapping study

Abstract Funding Acknowledgements Type of funding sources: None. Background takotsubo syndrome (TTS) is an acute heart failure syndrome characterized by transient systolic dysfunction, widespread myocardial edema and not trivial rate of in-hospital complications. Tissue mapping by cardiac magnetic resonance (CMR) imaging provides measure of myocardial interstitial expansion. Few studies to date comprehensively examined native T1, T2 and extracellular volume (ECV) quantification by CMR in TTS. Purpose to describe T1 and T2 mapping findings by cardiac magnetic resonance (CMR) imaging in a cohort of TTS patients and control subjects. Methods we performed CMR imaging with native T1 and T2 mapping assessment as well as ECV and late gadolinium enhancement (LGE) imaging in n = 14 TTS patients at a median of 4 (3, 7) days after the acute event. Control group consisted of n = 14 healthy individuals with no known prior acute cardiac events. Extracellular-volume (ECV) fraction estimate was derived from native and post-contrast T1 of myocardium and blood pool corrected for hematocrit as reported in literature. All mapping measurements were performed in the interventricular septum from the mid-short-axis view. Results median age of the study population was 72 years, 84% female. Typical apical ballooning was present in 72% of the patients, atypical in 28%, with median left ventricular ejection fraction (LVEF) of 45%; mid interventricular septum was involved in all patients based on the presence of wall motion abnormalities at hospital admission. Median native T1, T2 and ECV were 1078 msec vs 965 msec, 55 msec vs 47 msec and 29% vs 25% in TTS and controls respectively (p < 0.001 for all). A significant direct correlation was found between T2 and both native T1 and ECV in TTS (r = 0.759, p = 0.002 and r = 0.630, p = 0.018 respectively) but not in controls. Moreover, in TTS patients, native T2 inversely correlated with LVEF as assessed at hospital admission (r=-0.563, p = 0.037), whereas non-significant trends were observed between admission LVEF and both native T1 and ECV. No LGE was detected neither in TTS patients nor in controls. Conclusions myocardial edema, as signified by increased T2, is a prominent feature of TTS, likely driving interstitial expansion and increase of native T1 and ECV in the acute phase. Correlation of T2 with LVEF on admission suggests that CMR-based parametric assessment of myocardial edema could contribute to better characterize disease severity in TTS.

Quantitative Assessment of Neuroinflammation, Myelinogenesis, Demyelination, and Nerve Fiber Regeneration in Immunostained Sciatic Nerves From Twitcher Mice With a Tissue Image Analysis Platform.

Scoring demyelination and regeneration in hematoxylin and eosin-stained nerves poses a challenge even for the trained pathologist. This article demonstrates how combinatorial multiplex immunohistochemistry (IHC) and quantitative digital pathology bring new insights into the peripheral neuropathogenesis of the Twitcher mouse, a model of Krabbe disease. The goal of this investigational study was to integrate modern pathology tools to traditional anatomic pathology microscopy workflows, in order to generate quantitative data in a large number of samples, and aid the understanding of complex disease pathomechanisms. We developed a novel IHC toolkit using a combination of CD68, periaxin-1, phosphorylated neurofilaments and SOX-10 to interrogate inflammation, myelination, axonal size, and Schwann cell counts in sciatic nerves from 17-, 21-, 25-, and 35-day-old wild-type and Twitcher mice using self-customized digital image algorithms. Our quantitative analyses highlight that nerve macrophage infiltration and interstitial expansion are the earliest detectable changes in Twitcher nerves. By 17 days of age, while the diameter of axons is small, the number of myelinated axons is still normal. However, from 21 days onward Twitcher nerves contain 75% of wild-type myelinated nerve fiber numbers despite containing 3 times more Schwann cells. In 35-day-old Twitcher mice when demyelination is detectable, nerve myelination drops to 50%.

Cardiac biomarkers in chronic kidney disease are independently associated with myocardial edema and diffuse fibrosis by cardiovascular magnetic resonance

BackgroundHigh sensitivity cardiac troponin T (hs-cTnT) and NT-pro-brain natriuretic peptide (NT-pro BNP) are often elevated in chronic kidney disease (CKD) and associated with both cardiovascular remodeling and outcome. Relationship between these biomarkers and quantitative imaging measures of myocardial fibrosis and edema by T1 and T2 mapping remains unknown.MethodsConsecutive patients with established CKD and estimated glomerular filtration rate (eGFR) < 59 ml/min/1.73 m2 (n = 276) were compared to age/sex matched patients with eGFR ≥ 60 ml/min/1.73 m2 (n = 242) and healthy controls (n = 38). Comprehensive cardiovascular magnetic resonance (CMR) with native T1 and T2 mapping, myocardial ischemia and scar imaging was performed with venous sampling immediately prior to CMR.ResultsPatients with CKD showed significant cardiac remodeling in comparison with both healthy individuals and non-CKD patients, including a stepwise increase of native T1 and T2 (p < 0.001 between all CKD stages). Native T1 and T2 were the sole imaging markers independently associated with worsening CKD in patients [B = 0.125 (95% CI 0.022–0.235) and B = 0.272 (95% CI 0.164–0.374) with p = 0.019 and < 0.001 respectively]. At univariable analysis, both hs-cTnT and NT-pro BNP significantly correlated with native T1 and T2 in groups with eGFR 30–59 ml/min/1.73 m2 and eGFR < 29 ml/min/1.73 m2 groups, with associations being stronger at lower eGFR (NT-pro BNP (log transformed, lg10): native T1 r = 0.43 and r = 0.57, native T2 r = 0.39 and r = 0.48 respectively; log-transformed hs-cTnT(lg10): native T1 r = 0.23 and r = 0.43, native T2 r = 0.38 and r = 0.58 respectively, p < 0.001 for all, p < 0.05 for interaction). On multivariable analyses, we found independent associations of native T1 with NT-pro BNP [(B = 0.308 (95% CI 0.129–0.407), p < 0.001 and B = 0.334 (95% CI 0.154–0.660), p = 0.002 for eGFR 30–59 ml/min/1.73 m2 and eGFR < 29 ml/min/1.73 m2, respectively] and of T2 with hs-cTnT [B = 0.417 (95% CI 0.219–0.650), p < 0.001 for eGFR < 29 ml/min/1.73 m2].ConclusionsWe demonstrate independent associations between cardiac biomarkers with imaging markers of interstitial expansion, which are CKD-group specific. Our findings indicate the role of diffuse non-ischemic tissue processes, including excess of myocardial fluid in addition to diffuse fibrosis in CKD-related adverse remodeling.

Multimodality Imaging for Atrial Fibrosis Detection in the Era of Precision Medicine.

In recent years, atrial fibrillation (AF) has increasingly become a focus of attention because it represents the most encountered arrhythmia in clinical practice and a major cause of morbidity and mortality. Issues underlying AF have long been debated; nevertheless, electrical, contractile, and structural remodeling is demonstrated to be the pivotal contributor to arrhythmic substrate. Fibrosis is a hallmark of arrhythmogenic structural remodeling, resulting from an accumulation of fibrillar collagen deposits, as a reparative process to replace degenerating myocardium with concomitant reactive fibrosis, which causes interstitial expansion. Although the precise role of fibrosis in AF initiation and maintenance remains to be fully elucidated, a better definition of its extent and distribution may assist in designing individually tailored ablation approaches and improving procedure outcomes by targeting the fibrotic substrates with an organized strategy employing imaging resources. A deep comprehension of the mechanisms underlying atrial fibrosis could be crucial to setting up improved strategies for preventing AF-promoting structural remodeling. Imaging modalities such as echocardiography, cardiac computed tomography, and cardiac magnetic resonance, combined sometimes with invasive electroanatomical mapping, could provide valuable information for the optimal patients’ management if their use is not limited to cardiac anatomy study but extended to characterize abnormal left atrial substrate. Although pulmonary vein isolation is usually efficacious in treating paroxysmal AF, it is not sufficient for many patients with nonparoxysmal arrhythmias, particularly those with longstanding persistent AF. Noninvasive imaging techniques play a pivotal role in the planning of arrhythmic substrates ablation and show a strong correlation with electro-anatomic mapping, whose novel multipolar mapping catheters allow nowadays a more precise comprehension of atrial substrate. This review aims to explore the impact of the various imaging modalities for the detection of atrial fibrosis and their role in the management of AF.

Deep Learning-Based Segmentation and Quantification in Experimental Kidney Histopathology.

Nephropathologic analyses provide important outcomes-related data in experiments with the animal models that are essential for understanding kidney disease pathophysiology. Precision medicine increases the demand for quantitative, unbiased, reproducible, and efficient histopathologic analyses, which will require novel high-throughput tools. A deep learning technique, the convolutional neural network, is increasingly applied in pathology because of its high performance in tasks like histology segmentation. We investigated use of a convolutional neural network architecture for accurate segmentation of periodic acid-Schiff-stained kidney tissue from healthy mice and five murine disease models and from other species used in preclinical research. We trained the convolutional neural network to segment six major renal structures: glomerular tuft, glomerulus including Bowman's capsule, tubules, arteries, arterial lumina, and veins. To achieve high accuracy, we performed a large number of expert-based annotations, 72,722 in total. Multiclass segmentation performance was very high in all disease models. The convolutional neural network allowed high-throughput and large-scale, quantitative and comparative analyses of various models. In disease models, computational feature extraction revealed interstitial expansion, tubular dilation and atrophy, and glomerular size variability. Validation showed a high correlation of findings with current standard morphometric analysis. The convolutional neural network also showed high performance in other species used in research-including rats, pigs, bears, and marmosets-as well as in humans, providing a translational bridge between preclinical and clinical studies. We developed a deep learning algorithm for accurate multiclass segmentation of digital whole-slide images of periodic acid-Schiff-stained kidneys from various species and renal disease models. This enables reproducible quantitative histopathologic analyses in preclinical models that also might be applicable to clinical studies.

Inward collapse of the nasal cavity: Perinatal consolidation of the midface and cranial base in primates.

Living primates show a complex trend in reduction of nasal cavity spaces and structures due to moderate to severe constraint on interorbital breadth. Here we describe the ontogeny of the posterior end of the primate cartilaginous nasal capsule, the thimble shaped posterior nasal cupula (PNC), which surrounds the hind end of the olfactory region. We used a histologically sectioned sample of strepsirrhine primates and two non-primates (Tupaia belangeri, Rousettus leschenaulti), and histochemical and immunohistochemical methods to study the PNC in a perinatal sample. At birth, most strepsirrhines possess only fragments of PNC, and these lack a perichondrium. Fetal specimens of several species reveal a more complete PNC, but the cartilage exhibits uneven or weak reactivity to type II collagen antibodies. Moreover, there is relatively less matrix than in the septal cartilage, resulting in clustering of chondrocytes, some of which are in direct contact with adjacent connective tissues. In one primate (Varecia spp.) and both non-primates, the PNC has a perichondrium at birth. In older, infant Varecia and Rousettus, the perichondrium of the PNC is absent, and PNC fragmentation at its posterior pole has occurred in the former. Loss of the perichondrium for the PNC appears to precede resorption of the posterior end of the nasal capsule. These results suggest that the consolidation of the basicranial and facial skeletons happens ontogenetically earlier in primates than other mammals. We hypothesize that early loss of cartilage at the sphenoethmoidal articulation limits chondral mechanisms for nasal complexity, such as interstitial expansion or endochondral ossification.

PNEUMONIA OR LYMPHOMA? DO NOT BE FOOLED!

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Mucosa-associated lymphoid tissue (MALT) Lymphoma, also known as Extranodal Marginal Zone B cell lymphoma (EMZL), is a rare type of non-Hodgkin’s lymphoma with an incidence rate of 18.3 cases per 1 million in the United States. The objective of this case is to describe a challenging case of EMZL presenting as persistent localized lung consolidation that was mistaken for pneumonia. CASE PRESENTATION: 77-year-old male, former smoker who presented with complains of nonproductive cough for several weeks, chest-x-ray (CXR) showed a 4.3 cm rounded hazy right parahilar mass. A follow up computed tomography (CT) of the chest revealed 4.7 x2.8 cm consolidative opacity along the interlobar fissure in the right upper lobe (RUL). Reviewing back a year ago, CT scan done for nonspecific chest pain, showed the mass size was unchanged but appeared to be less solid compared to the current scan. Patient underwent a Fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan which showed elevated FDG activity SUV 3.0 associated with a consolidative pulmonary opacity in the posterior portion of the right upper lobe silhouetting the major fissure. The patient subsequently underwent a CT guided percutaneous biopsy of the right upper lobe airspace consolidation. Histologic sections showed interstitial expansion and bronchial epithelium involvement by small monocytoid- appearing lymphocytes and significant amount of plasma cells (Figure 1). Immunohistochemistry was positive for CD20 and BCL-2 and negative for BCL-6 and CD10. CD138 which highlights plasma cell component was positive. Immunostaining for kappa and lambda showed findings most suggestive of monotypic lambda expression. Fluorescence in situ hybridization (FISH) studies for MALT1 (18q21) rearrangement identified a MALT1 gene rearrangement and B cell clonality studies done by PCR were positive for a clonal rearrangement. Therefore, the final diagnosis was small B-cell non-hodgkin lymphoma consistent with extranodal MALT. In retrospect the lymphoma was likely present a year ago however mistaken as a pneumonia. Given the lack of symptoms and minimal progression of over one year, was consistent with the indolent clinical behavior of the tumor. Decision was made not to treat at this point by the physician and patient. Till date patient remain asymptomatic. DISCUSSION: EMZL has been associated with persistent inflammatory state, either infectious or autoimmune in nature. EMZL can present in various ways from an incidental finding on imaging to ambiguous symptoms such as dyspnea, chest pain, cough, and rarely hemoptysis. Prognosis in MALT-type lymphomas is generally good with mean survival of more than 10 years. CONCLUSIONS: In conclusion, EMZL of the lung is uncommon and unique therefore a collaborative effort addressing early diagnosis and less invasive diagnostic testing for these high-risk EMZL patients are needed. Reference #1: Khalil MO, Morton LM, Devesa SS, et al. Incidence of marginal zone lymphoma in the United States, 2001 to 2009 with a focus on primary anatomic stie. Br J Haematol 2014; 165:67 Reference #2: Santos IG, Marchiori E, Zanetti G, Mano CM, SarcielliLuz B, Vianna FG. Primary pulmonary mucosaasociated lymphoid tissue lymphoma computed tomography findings: A case report. Cases J. 2009;2:6329. [PMCID:PMC2740136] [PubMed: 19829788] DISCLOSURES: No relevant relationships by Hussein Hussein, source=Web Response No relevant relationships by Ahmad JABRI, source=Web Response No relevant relationships by Sonya Joshi, source=Web Response No relevant relationships by Sujith Modugula, source=Web Response No relevant relationships by Elizabeth Verghese, source=Web Response

NMDA receptor-mediated CaMKII/ERK activation contributes to renal fibrosis

BackgroundThis study aimed to understand the mechanistic role of N-methyl-D-aspartate receptor (NMDAR) in acute fibrogenesis using models of in vivo ureter obstruction and in vitro TGF-β administration.MethodsAcute renal fibrosis (RF) was induced in mice by unilateral ureteral obstruction (UUO). Histological changes were observed using Masson’s trichrome staining. The expression levels of NR1, which is the functional subunit of NMDAR, and fibrotic and epithelial-to-mesenchymal transition markers were measured by immunohistochemical and Western blot analysis. HK-2 cells were incubated with TGF-β, and NMDAR antagonist MK-801 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93 were administered for pathway determination. Chronic RF was introduced by sublethal ischemia–reperfusion injury in mice, and NMDAR inhibitor dextromethorphan hydrobromide (DXM) was administered orally.ResultsThe expression of NR1 was upregulated in obstructed kidneys, while NR1 knockdown significantly reduced both interstitial volume expansion and the changes in the expression of α-smooth muscle actin, S100A4, fibronectin, COL1A1, Snail, and E-cadherin in acute RF. TGF-β1 treatment increased the elongation phenotype of HK-2 cells and the expression of membrane-located NR1 and phosphorylated CaMKII and extracellular signal–regulated kinase (ERK). MK801 and KN93 reduced CaMKII and ERK phosphorylation levels, while MK801, but not KN93, reduced the membrane NR1 signal. The levels of phosphorylated CaMKII and ERK also increased in kidneys with obstruction but were decreased by NR1 knockdown. The 4-week administration of DXM preserved renal cortex volume in kidneys with moderate ischemic–reperfusion injury.ConclusionsNMDAR participates in both acute and chronic renal fibrogenesis potentially via CaMKII-induced ERK activation.

Paeoniflorin Improves Acute Lung Injury in Sepsis by Activating Nrf2/Keap1 Signaling Pathway

To investigate the effect of paeoniflorin (PF) on sepsis-induced acute lung injury and its relationship with nuclear factor erythyroid 2-related factor 2 (Nrf2)/Kelch-like ECH2 associated protein 1 (Keap1) signaling pathway. Cecal ligation and puncture (CLP) was used to induce the sepsis rat model. Rats were randomly divided into 5 groups (n=10): sham group (Sham), model group (Model), low dose PF group (L-PF group, 50 mg/kg PF), high dose PF group (H-PF group, 150 mg/kg PF) and high dose PF+Nrf2 inhibitor group (H-PF+ML385 group, 150 mg/kg PF+30 mg/kg ML385). The severity of sepsis in rats was scored according to the improved severity scale of sepsis; the pathological changes of lung tissue were observed by HE staining; the activity of superoxide dismutase (SOD) in lung tissue was determined by xanthine oxidase method; the content of malondialdehyde (MDA) in lung tissue was measured by thiobarbituric acid method; and the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in lung tissues were detected by ELISA. Western blot was used to detect the expression of Nrf2, Keap1 and HO-1 proteins in lung tissues. Compared with Sham group, the sepsis symptoms in Model group were more serious, severe inflammatory infiltration in lung tissue, macrophages and interstitial enlargement, and the contents of pro-inflammatory factors IL-1β, TNF-α, IL-6 and oxidative index MDA in lung tissues were significantly increased (P<0.05), while the activity of antioxidant index SOD were significantly decreased (P<0.05). The protein and mRNA expression levels of Nrf2 and HO-1 were significantly decreased (P<0.05), while the protein and mRNA expression levels of Keap1 were markedly increased (P<0.05). Compared with the Model group, the severity of sepsis in PF groups was decreased, the lung tissue injury was improved, the contents of IL-1β, TNF-α, IL-6 and MDA in lung tissue were significantly decreased (P<0.05), the activity of SOD was markedly increased (P<0.05), the protein and mRNA expression levels of Nrf2 and HO-1 were significantly increased (P<0.05), and the expression levels of Keap1 protein and mRNA were significantly decreased (P<0.05). Compared with the H-PF group, Nrf2 inhibitor ML385 significantly inhibited the improvement of PF on lung injury in sepsis rats. PF can reduce oxidative stress and inflammation by activating Nrf2/Keap1 signaling pathway, and improve sepsis-induced acute lung injury.

Identifying Cardiac Amyloid in Aortic Stenosis: ECV Quantification by CT in TAVR Patients

ObjectivesThe purpose of this study was to validate computed tomography measured ECV (ECVCT) as part of routine evaluation for the detection of cardiac amyloid in patients with aortic stenosis (AS)-amyloid. BackgroundAS-amyloid affects 1 in 7 elderly patients referred for transcatheter aortic valve replacement (TAVR). Bone scintigraphy with exclusion of a plasma cell dyscrasia can diagnose transthyretin-related cardiac amyloid noninvasively, for which novel treatments are emerging. Amyloid interstitial expansion increases the myocardial extracellular volume (ECV). MethodsPatients with severe AS underwent bone scintigraphy (Perugini grade 0, negative; Perugini grades 1 to 3, increasingly positive) and routine TAVR evaluation CT imaging with ECVCT using 3- and 5-min post-contrast acquisitions. Twenty non-AS control patients also had ECVCT performed using the 5-min post-contrast acquisition. ResultsA total of 109 patients (43% male; mean age 86 ± 5 years) with severe AS and 20 control subjects were recruited. Sixteen (15%) had AS-amyloid on bone scintigraphy (grade 1, n = 5; grade 2, n = 11). ECVCT was 32 ± 3%, 34 ± 4%, and 43 ± 6% in Perugini grades 0, 1, and 2, respectively (p < 0.001 for trend) with control subjects lower than lone AS (28 ± 2%; p < 0.001). ECVCT accuracy for AS-amyloid detection versus lone AS was 0.87 (0.95 for 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid Perugini grade 2 only), outperforming conventional electrocardiogram and echocardiography parameters. One composite parameter, the voltage/mass ratio, had utility (similar AUC of 0.87 for any cardiac amyloid detection), although in one-third of patients, this could not be calculated due to bundle branch block or ventricular paced rhythm. ConclusionsECVCT during routine CT TAVR evaluation can reliably detect AS-amyloid, and the measured ECVCT tracks the degree of infiltration. Another measure of interstitial expansion, the voltage/mass ratio, also performed well.

P0337PROTEOME CHANGES IN TUBULOINTERSTITIAL TISSUE OF PROGRESSIVE VS NON-PROGRESSIVE IGAN

Abstract Background and Aims IgA nephropathy (IgAN), a common glomerulonephritis worldwide, is associated with a significant risk of progression to end-stage renal failure. In the Oxford classification, tubular atrophy is an established important risk factor for the risk of progression but few studies have investigated possible tubulointerstitial markers and the mechanisms of progression in IgAN. The present study investigated changes in the tubulointerstitial proteome from patients with IgAN. Method Based on data from the Norwegian Kidney Biopsy Registry and the Norwegian Renal Registry, two groups were included: IgAN patients with (n=9) or without (n=16) progression to ESRD during 10 years. Tubulointerstitial tissue without discernible interstitial expansion or pronounced tubular alterations were microdissected, proteome was analysed using mass spectrometry and protein abundances were compared between groups. Results: Proteomic analyses quantified 2562 proteins with 2 or more unique peptides . Of these, 201 proteins had significant different abundance between progressive and non-progressive IgAN patients, 96 were more abundant and 105 less abundant. Periostin was the protein with the highest fold change between progressive and non progressive IgAN (fc 9.59, p&amp;lt;0.05). Proteins related to inflammation were more abundant and proteins involved in the aerobic energy metabolism and energy demanding ion channels were significantly less abundant in progressive vs non-progressive patients. Conclusion Our study describes extensive proteome changes of tubulo-interstitial tissue in patients with progressive IgAN and indicates several proteins and pathways that are important in the progression of the disease.

P0722VITAMIN D-DEFICIENT RATS RECOVER RENAL ALTERATIONS AFTER VITAMIN D REPLACEMENT FOLLOWING ISCHEMIA-REPERFUSION INJURY

Abstract Background and Aims Several studies have been linking vitamin D deficiency (VDD) as a non-traditional risk factor to acute kidney injury (AKI). It has been shown that VDD associated with AKI potentiates the injury and may accelerate the progression of kidney disease. Conversely, some lines of evidence have been describing that vitamin D sufficiency can be considered as a renal protective factor. Thus, we aimed to verify the effect of vitamin D replacement (R) on the renal disease progression post ischemia-reperfusion injury (IRI) in vitamin D deficient rats. Method We performed bilateral 45 min IRI on day 30 in all animal groups. Male Wistar rats were randomized into three groups: 1- IRI (fed a standard diet for 120 days); 2- VDD+IRI (fed a vitamin D-free diet for 120 days); and 3- VDD+IRI+R (fed a vitamin D-free diet for 30 days and just after IRI, on day 31, we reintroduced the standard diet for more 90 days). We evaluated inulin clearance (Cin); mean arterial pressure (MAP); renal blood flow (RBF); plasma levels of Vitamin D2+D3 [25(OH)D] and Parathormone (PTH) by ELISA. In addition, we performed histomorphometrical studies for CD3+ cells, fibronectin and vimentin as well as the fractional interstitial area (FIA). Moreover, we run qPCR studies and immunoblotted for vitamin D receptor (VDR) and Klotho. All the results are described in table 1. Results Vitamin D replacement restored the plasma levels of 25(OH)D and PTH in VDD+IRI+R group. Also, VDD+IRI+R presented an improvement of renal function and hemodynamic parameters. In addition, we observed more evident alterations in tubulointerstitial compartment, featuring interstitial expansion (renal fibrosis and inflammatory cell infiltrates) and fibronectin and vimentin expression in VDD+IRI rats. These alterations were recovered by vitamin D replacement. Concerning VDR and Klotho data, our results revealed a decreased expression of these targets in VDD+IRI group. On the other hand, vitamin D replacement retrieved the expression of VDR and Klotho. Conclusion Our study suggests that vitamin D replacement improved the recovery of renal function, hemodynamics, inflammatory and morphological alterations. In addition, vitamin D replacement was able to reestablish the expression of VDR and Klotho in IRI-AKI associated with vitamin D deficiency. Thus, it is recommendable that vitamin D levels should be observed as well as its reposition should be taken into account in renal patients.

Donor and Recipient Characteristics in Heart Transplantation Are Associated with Altered Myocardial Tissue Structure and Cardiac Function

To use structure-function cardiac MRI in the evaluation of relationships between donor and heart transplantation (HTx) recipient characteristics and changes in cardiac tissue structure and function. HTx candidates and donor hearts are evaluated for donor-recipient matches to improve survival, but the impact of donor and recipient characteristics on changes in myocardial tissue and function in the transplanted heart is not fully understood. Cardiac MRI at 1.5 T was performed from August 2014 to June 2017 in 58 HTx recipients (mean age, 51.1 years ± 12.6 [standard deviation], 26 female patients) and included T2 mapping (to evaluate edematous and/or inflammatory changes), precontrast and postcontrast T1 mapping (allowing the calculation of extracellular volume fraction [ECV] to estimate interstitial expansion), and tissue phase mapping (allowing the calculation of myocardial velocities and twist). Donor and recipient demographics (age, sex, height, weight, and body mass index [BMI]) and comorbidities (hypertension, diabetes, and smoking history) were evaluated for relationships with cardiac MRI measures. Sex-influenced cardiac MRI measures of myocardial tissue and function are as follows: Female HTx recipients demonstrated increased precontrast T1 (P = .002) and reduced systolic peak long-axis velocities (P = .015). Increased age of the donor heart was associated with elevated T2 (r = 0.32; P < .05) and ECV (r = 0.47; P < .01), indicating increased edema and interstitial expansion, as well as impaired diastolic peak long-axis velocities (r = 0.41; P < .01). Recipient-donor differences in age, weight, and BMI were significantly associated with elevated ECV (r = 0.36-0.48; P < .05). Hypertension in donors resulted in increased ECV (31.0% ± 4.2 vs 26.0% ± 3.3; P = .001). Donor and HTx recipient characteristics were significantly associated with cardiac MRI-derived measures of myocardial tissue structure and function.© RSNA, 2019.

Additional evidence that the rat renal interstitium contracts in vivo.

We recently provided highly suggestive preliminary evidence that the renal interstitium contracts reactively in vivo. We demonstrated that renal medullary direct interstitial volume expansion (rmDIVE = 100 μl bolus infusion of 0.9% saline (SS)/30 s) brought about a biphasic renal interstitial hydrostatic pressure (RIHP) response which was abolished when dibutyryl-cAMP was concomitant and interstitially infused. To assess more deeply the feasibility of the concept that the renal interstitium contracts in vivo, two experimental series (S1, S2) were performed in hydropenic rats subjected to acute left renal-denervation, hormonal clamping, and control of renal arterial pressure. In S1, RIHP and renal outer medullary blood flow (RoMBF) were continuously measured before and after a sudden micro-bolus (5μl) injection, into the renal medullary interstitium, of SS containing α-trinositol (α-TNS, anti-inflammatory drug) to either two doses 2 or 4 mM (SS + 2 α-TNS and SS + 4 α-TNS groups). No overall differences between groups in either ΔRIHP or %ΔRoMBF time courses were found; however, in the SS + 2 α-TNS group the data were less scattered and the ΔRIHP time course tended to peak faster and then persisted there, so that, this α-TNS dose was selected for S2. In S2, RIHP and RoMBF were similarly measured in rats randomly assigned to three groups: the CTR group (sham time-control), SS group (SS alone), and SS + α-TNS group. The micro-bolus injection of SS alone (SS group) was unable to increase ΔRIHP. The group with no micro-bolus injection (CTR group) experienced a decrease in ΔRIHP. The micro-bolus injection of SS + 2 α-TNS was accompanied by a differential increase in ΔRIHP (vs. CTR and SS groups). These responses were not associated with differential changes among groups in %ΔRoMBF or hemodilution parameters. These results provide additional evidence that the renal interstitium contracts in vivo.

Perioperative Interstitial Fluid Expansion Predicts Major Morbidity Following Pancreatic Surgery: Appraisal by Bioimpedance Vector Analysis.

To evaluate whether perioperative bioimpedance vector analysis (BIVA) predicts the occurrence of surgery-related morbidity. BIVA is a reliable tool to assess hydration status and compartimentalized fluid distribution. The BIVA of patients undergoing resection for pancreatic malignancies was prospectively measured on the day prior to surgery and on postoperative day (POD)1. Postoperative morbidity was scored per the Clavien-Dindo classification (CDC), and the Comprehensive Complication Index (CCI). Out of 249 patients, the overall and major complication rates were 61% and 16.5% respectively. The median CCI was 24 (IQR 0.0-24.2), and 24 patients (9.6%) had a complication burden with CCI≥40. At baseline the impedance vectors of severe complicated patients were shorter compared to the vectors of uncomplicated patients only for the female subgroup (P=0.016). The preoperative extracellular water (ECW) was significantly higher in patients who experienced severe morbidity according to the CDC or not [19.4L (17.5-22.0) vs. 18.2L (15.6-20.6), P=0.009, respectively] and CCI≥40, or not [20.3L (18.5-22.7) vs. 18.3L (15.6-20.6), P=0.002, respectively]. The hydration index on POD1 was significantly higher in patients who experienced major complications than in uncomplicated patients (P=0.020 and P=0.025 for CDC and CCI, respectively).At a linear regression model, age (β=0.14, P=0.035), sex female (β=0.40, P<0.001), BMI (β=0.30, P<0.001), and malnutrition (β=0.14, P=0.037) were independent predictors of postoperative ECW. The amount of extracellular fluid accumulation predicts major morbidity after pancreatic surgery. Female, obese and malnourished patients were at high risk of extracellular fluid accumulation.

Inverse correlation of kidney interstitial cells expansion with hemoglobin level and erythropoietin expression in single and repeated kidney ischemic/reperfusion injury in mice

Ischemic/reperfusion injury (IRI) causes acute kidney injury that may lead to chronic kidney disease. We investigated the correlation between kidney interstitial cells expansion, hemoglobin level, and erythropoietin expression as the chronic effects of single and repeated kidney IRI in mice. We created an IRI model using male Swiss mice by clamping the bilateral renal pedicles. Subjects were divided into four groups that contained six mice each: control/sham operation, single acute IRI, single chronic IRI, and repeated IRI. Our results showed that the single chronic and repeated IRI groups significantly increased the tubular injury score, decreased the hemoglobin level, and increased erythropoietin expression compared with the control. Lower hemoglobin levels in all of the groups compared with the control was associated with erythropoietin resistance. In single chronic and repeated kidney IRI, there were decreased creatinine levels compared with the control. The decreased creatinine levels from the single acute IRI group to the single chronic IRI group, suggesting a repair phase of IRI starting on day 7 occurred in the single chronic IRI group. A macrophage marker, CD68, and an inflammatory mediator marker, MCP-1, significantly increased in all IR groups, indicating inflammation occurred due to IRI. In conclusion, chronic and repeated kidney IRI induced interstitial cells expansion and inflammation associated with anemia.

Mesenchymal stem cells improve renal injury in diabetic rats by inhibiting CD103+DCs maturation to decline CD8 + T cell responses

BackgroundDiabetic nephropathy (DN) caused by the consistent high levels of blood glucose often leads to end‐stage renal disease (ESRD). Studies have shown that CD103 + dendritic cells (DCs) display a pathogenic role in murine CKD via activation of CD8 + T cells in kidney. Mesenchymal stem cells (MSCs) were reported to be able to improve DN, affect maturation of DCs and inhibit activation and proliferation of T cells. Here we examined the effects of MSCs on DN and explored the underlying mechanism though CD103+ DCs in rat DN.Methods30 rats were randomly assigned into normal control group (NC, n=6, healthy rats without treatment); diabetic nephropathy group (DN, n=13, diabetic rats receiving injection of 0.5 ml 0.9% saline); BMSCs treatment group (DN‐MSCs, n=11, diabetic rats receiving injection of BMSCs). Male diabetic rats were intraperitoneally injected with 55 mg/kg body weight of streptozotocin(STZ, Sigma)once causing a fasting blood glucose (FBG) level ≥16.7 mM for 6 weeks. Then 1×107 cells/kg body weight MSCs were transplanted to rats via tail vein injection weekly for 6 weeks. At the 13th week, the rats were sacrificed and blood, urine, kidney were collected for further detection. The concentrations of FBG, blood urea nitrogen (BUN), urinary albumin, urinary creatinine and albumin to creatinine ratio (ACR) were determined. RT‐qPCR for IL‐1β, IL‐6, TNF‐α, BATF3, FLT‐3, ID2 was performed. Renal pathology (HE and Massion staining) and immunofluorescence (IF) for CD103, CD11c, CD8 were also performed. Fluorescence activated Cell Sorting (FACS) was performed to analysis or sort of kidney samples and to characterize the phenotype of renal mononuclear phagocytes (rMPs). A combination of markers including CD45, MHC‐II, lineage (lin) makers (CD3, CD19, T cell receptor [TCR]‐β, TCR‐γδ, and CD49b), CD11c, CD68, CD11b and CD103 was used.ResultDN rats showed dyslipidemia and increased 24‐h proteinuria. After six times BMSCs transplantation, BUN, urinary albumin, urinary creatinine and ACR were significantly lower than in rats with DN alone (p&lt;0.01). In respect of renal pathology, DN rats showed increased inflammatory cell infiltration, renal tubular epithelial cells injury, tubular atrophy, interstitial expansion. BMSCs treatment downregulated the genes expression of inflammatory‐related cytokines such as IL‐6, TNF‐α and IL‐1β, and reduced the other symptoms of DN‐alone rats. Next we found that the number of kidney CD103 + DCs was significantly higher in DN than in normal rat. Kidney CD103 + DCs preferentially elicited CD8 + T cells to exacerbate kidney injury in DN rats. BMSCs transplantation Significantly downregulated the genes expression of transcription factors (Batf3) and growth factor receptors (Flt3) which are necessary for the development of CD103 + DCs. Furthermore, BMSCs transplantation impaired activation and proliferation of CD8 + T cells and prevented the exacerbation of kidney injury.ConclusionBMSCs were able to improve DN kidney injury through inhibiting CD103 + DCs maturation to decline CD8 + T cell responses.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Therapeutic effect of quinolone oxizime on fibrotic kidney diseases

Purpose: To investigate the anti-fibrotic effect and mechanism of action of quinolone oxizime in vitro and in vivo.Methods: Proliferation of renal fibroblasts was determined using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while laser confocal fluorescence microscope was used for immuno-cytochemical studies. Total TGF β1 was determined by enzyme linked immunosorbent assay (ELISA).Results: Quinolone oxizime decreased the proliferation of renal fibroblasts in a dose-dependent manner (p < 0.05) in vitro. Proliferation of renal fibroblasts was 39, 63, 82, 95, 97 and 99 % on treatment with quinolone oxizime at doses of 10, 8, 6, 4, 2 and 1 μM, respectively, after 48 h. The expression of TGF β1 in the peripheral blood lymphocytes was reduced significantly by quinolone oxizime treatment. In the animal model of renal fibrosis, quinolone oxizime treatment decreased development of lesions, prevented tubular dilation and expansion of interstitium. After 30 days of quinolone oxizime treatment, tubulo-interstitial lesions were completely absent in rats in the 5 mg/kg treatment group. Moreover, quinolone oxizime treatment for 30 days inhibited accumulation of extracellular matrix and prevented renal injury in rats.Conclusion: These results show that quinolone oxizime exhibits anti-fibrotic effects through targeting the expression of TGF β1. Therefore, quinolone can potentially be used for the treatment of fibrotic kidney diseases but further studies are required to ascertain this.Keywords: Quinolone oxizime, Anti-fibrosis, Tubulo-interstitium, Interstitium, Fibroblasts

Arterial Properties as Determinants of Left Ventricular Mass and Fibrosis in Severe Aortic Stenosis: Findings From ACRIN PA 4008.

BackgroundThe role of arterial load in severe aortic stenosis is increasingly recognized. However, patterns of pulsatile load and their implications in this population are unknown. We aimed to assess the relationship between the arterial properties and both (1) left ventricular remodeling and fibrosis and (2) the clinical course of patients with severe aortic stenosis undergoing aortic valve replacement (AVR).Methods and ResultsWe enrolled 38 participants with symptomatic severe aortic stenosis scheduled to undergo surgical AVR. Aortic root characteristic impedance, wave reflections parameters (reflection magnitude, reflected wave transit time), and myocardial extracellular mass were measured with cardiac magnetic resonance imaging and arterial tonometry Cardiac magnetic resonance imaging was repeated at 6 months in 30 participants. A reduction in cellular mass (133.6 versus 113.9 g; P=0.002) but not extracellular mass (42.3 versus 40.6 g; P=0.67) was seen after AVR. Participants with higher extracellular mass exhibited greater reflection magnitude (0.68 versus 0.54; P=0.006) and lower aortic root characteristic impedance (56.3 versus 96.9 dynes/s per cm5; P=0.006). Reflection magnitude was a significant predictor of smaller improvement in the quality of life (Kansas City Cardiomyopathy Questionnaire score) after AVR (R=−0.51; P=0.0026). The 6‐minute walk distance at 6 months after AVR was positively correlated with the reflected wave transit time (R=0.52; P=0.01).ConclusionsConsistent with animal studies, arterial wave reflections are associated with interstitial volume expansion in severe aortic stenosis and predict a smaller improvement in quality of life following AVR. Future trials should assess whether wave reflections represent a potential therapeutic target to mitigate myocardial interstitial remodeling and to improve the clinical status of this patient population.

Left ventricular extracellular volume fraction and atrioventricular interaction in hypertension.

Left atrial enlargement (LAE) predicts cardiovascular morbidity and mortality. Impaired LA function also confers poor prognosis. This study aimed to determine whether left ventricular (LV) interstitial fibrosis is associated with LAE and LA impairment in systemic hypertension. Following informed written consent, a prospective observational study of 86 hypertensive patients (49 ± 15 years, 53% male, office SBP 168 ± 30 mmHg, office DBP 97 ± 4 mmHg) and 20 normotensive controls (48 ± 13 years, 55% male, office SBP 130 ± 13 mmHg, office DBP 80 ± 11 mmHg) at 1.5-T cardiovascular magnetic resonance was conducted. Extracellular volume fraction (ECV) was calculated by T1-mapping. LA volume (LAV) was measured with biplane area-length method. LA reservoir, conduit and pump function were calculated with the phasic volumetric method. Indexed LAV correlated with indexed LV mass (R = 0.376, p < 0.0001) and ECV (R = 0.359, p = 0.001). However, ECV was the strongest significant predictor of LAE in multivariate regression analysis (odds ratio [95th confidence interval] 1.24 [1.04-1.48], p = 0.017). Indexed myocardial interstitial volume was associated with significant reductions in LA reservoir (R = -0.437, p < 0.0001) and conduit (R = -0.316, p = 0.003) but not pump (R = -0.167, p = 0.125) function. Multiple linear regression, correcting for age, gender, BMI, BP and diabetes, showed an independent decrease of 3.5% LA total emptying fraction for each 10 ml/m2 increase in myocardial interstitial volume (standard β coefficient -3.54, p = 0.002). LV extracellular expansion is associated with LAE and impaired LA reservoir and conduit function. Future studies should identify if targeting diffuse LV fibrosis is beneficial in reverse remodelling of LA structural and functional pathological abnormalities in hypertension. • Left atrial enlargement (LAE) and impairment are markers of adverse prognosis in systemic hypertension but their pathophysiology is poorly understood. • Left ventricular extracellular volume fraction was the strongest independent multivariate predictor of LAE and was associated with impaired left atrial reservoir and conduit function. • LV interstitial expansion may play a central role in the pathophysiology of adverse atrioventricular interaction in systemic hypertension.