Interstitial Expansion Research Articles

Integrin alpha1 beta1 promotes interstitial fibrosis in a mouse model of polycystic kidney disease.

Fibrosis is the cause of end-stage kidney failure in patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD). The molecular and cellular mechanisms involved in fibrosis are complex and anti-fibrotic therapies have so far failed to make an impact on patient welfare. Using unbiased proteomics analysis on the Pkd1 nl/nl mouse, we found that expression of the integrin α1 subunit is increased in this model of ADPKD. In human ADPKD tissue and two single cell RNA kidney disease datasets, ITGA1 was also upregulated. To investigate the functional role of this integrin subunit in ADPKD, we generated a Pkd1 nl/nl Itga1 -/- mouse. We observed a significant reduction in kidney volume and kidney dysfunction in mice lacking the integrin α1 subunit. Kidneys from Pkd1 nl/nl Itga1 -/- mice had smaller cysts and reduced interstitial expansion and tubular atrophy. Picrosirius red staining identified a restriction in collagen staining in the interstitium and the myofibroblast marker α smooth muscle actin was also downregulated. Myofibroblast cell proliferation was reduced in Pkd1 nl/nl Itga1 -/- mice and primary fibroblast cultures demonstrated an abrogated fibrogenic phenotype in integrin α1-depleted fibroblasts. These results highlight a previously unrecognised role for the integrin α1 subunit in kidney fibrosis.

Development of Ti–Zr–Mn–Cr-(V–Fe) based alloys for hydrogen feeding system in hydrogen metallurgy application

AB2-type Ti-based hydrogen storage alloys are considered promising candidates for the hydrogen feeding system in hydrogen-metallurgy application. In this work, Ti0·87Zr0.15MnxCr1.75-xV0.25 (x = 1.25–1.5), Ti0·87Zr0·15Mn1·5Cr0.5-y(VFe)y (y = 0.25–0.43) and Ti0.85+zZr0.15Mn1·5Cr0·07(VFe)0.43 (z = 0–0.05) alloys were synthesized using induction levitation melting, where ferrovanadium VFe consists of 80 wt% V and 20 wt% Fe. Subsequently, their microstructures and hydrogen storage performances were systematically investigated. The results demonstrate that all alloy samples exhibit a single C14 Laves phase structure with uniform element distribution. With the increment of Cr/Mn, VFe/Cr ratio, or Ti stoichiometry, the alloys exhibit enhanced hydrogen storage capacity, accompanied by a decrease in hydrogenation equilibrium pressure because of interstitial volume expansion or hydrogen affinity improvement, which is also supported by density functional theory calculations. Considering the application of hydrogen metallurgy, Ti0·86Zr0·15Mn1·5Cr0·07(VFe)0.43 alloy is regarded as a promising candidate, exhibiting a saturated capacity of 2.01 wt% H2, an effective reversible capacity of 1.91 wt% H2, rapid hydrogenation kinetics, excellent cyclic durability and low costs. This work provides valuable insights into the compositional design of hydrogen storage alloys for the hydrogen feeding system in hydrogen metallurgy applications.

High-Resolution Spatial Lipidomic Profiling of the Kidney During Periods of Cyst Expansion in a Mouse Model of ADPKD

Introduction: The progression of renal pathology in autosomal dominant polycystic kidney disease (ADPKD) involves a complex series of changes including renal cyst formation, interstitial cyst expansion, tubular atrophy, and fibrosis. Changes to in tissue metabolism and cyst fluid metabolite composition have been shown in ADPKD models, however it has been diffcult to discretely localize these compounds to specific regions of the kidney. Further, very little is known about lipid profiles within the kidney during ADPKD. We hypothesized that spatial lipidomic analysis during periods of cyst expansion would reveal new understanding of changes in lipid metabolism during this critical window of pathology. In this study we focused on changes in the mcwPkd1nl/nl mouse, a hypomorphic ADPKD model that rapidly develops a cystic phenotype. Methods: Kidneys were collected from female cystic mcwPkd1nl/nl mice at postnatal days 7, 14 and 28, representing periods preceding, during and at maximal cyst expansion, respectively. Control kidneys were collected from female wild-type littermates at postnatal day 7 and 28. Tissues were rapidly cryoembedded for 10 mm sectioning onto Intellislides (BrukerDaltonik). Slides were scanned on a Reflecta MF-5000 scanner and sprayed with 7 mg/mL CHCA in 70% Acetonitrile, 30% water and 0.1% TFA using a TM Sprayer Model M3 (HTX Technologies, LLC). Mass spec imaging data was acquired with a Bruker timsTOF Flex system (BrukerDaltonik) with a Smartbeam 3D laser at 10kHz and 10 μm resolution. Imaging data analysis was performed in SCiLS Lab software (version 2023b, Bruker). Calculations were performed on data normalized to total ion count (TIC). Spatial segmentation analysis of data was performed using an unsupervised bisecting k-means algorithm and resulting clusters were investigated by ROC. Lipid annotation was performed the Lipid Species annotation tool with MSDial VS68 spectral library in Metaboscape (version 2022b, Bruker). Results: There were vast global differences between lipid composition of wild-type and cystic kidneys at postnatal day 28. When comparing cystic to wild-type kidneys phosphoinositol and ceremide lipid species were decreased and other metabolites, such as thiophene-3-carboxylate and benzothiazine-2-carbonitrile, were increased at both PN7 and PN28. Further numerous lipid compounds were identified only within cystic fluid that have not been previously annotated. Conclusions: The results of this study, for the first time, reveals alterations in lipid molecule profiles throughout the cystic kidney in tandem with morphological changes. This is a major step forward in understanding how lipid metabolism changes in response to cyst expansion during the progression of ADPKD, as well as revealing molecular changes that precede cellular pathology. This work has been supported by Children’s Wisconsin Foundation and Children’s Research Institute. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

3-D Nanostructure Palladium Synthesis By Electrochemical Deposition for Hydrogen Sensor with Switching Resistance Characteristic in Normal Temperature and Pressure

In the hydrogen industry, it is crucial to detect hydrogen leaks and monitor its concentration due to its highly explosive, flammable, and diffusive properties in the concentration range of 4%-75%. Until now, hydrogen sensors have been focused on oxide materials at high temperature and pressure conditions such as semiconductor and steel processes. However, in the future of the hydrogen industry, it is important to sense hydrogen at normal temperature and pressure (NTP). To develop hydrogen sensors with fast response time and high sensitivity specifically designed for NTP conditions, various material properties and structural aspects such as film, nanostructure, and multilayer are being experimentally explored.Metal resistance hydrogen sensors utilize changes in resistance due to hydrogen adsorption and absorption. Compared to other sensors such as catalytic and thermal conductivity sensors, metal resistance hydrogen sensors have advantages such as excellent sensitivity, response time, and selectivity. Palladium metal exhibits superior characteristics with regard to hydrogen compared to other metals, due to its low activation energy for hydrogen molecule dissociation reaction and high reactivity in absorbing hydrogen at NTP.[1] Also, palladium with 3-D nanostructures exhibits a switching resistance characteristic, where the resistance initially decreases rapidly and then increases because of hydrogen and palladium reaction.[2] This depends on the hydrogen concentration and exposure time, which is due to a phenomenon where the combined effects of characteristics such as hydrogen interstitial, phase transition, and volume expansion lead to different responses of hydrogen and palladium.In this study, we focused on the resistance switching characteristic of palladium, specifically its response to changes in hydrogen concentration and exposure time. We used this characteristic to experiment with both the material and structural properties of palladium nanostructures. We varied impurities and additives in the palladium electrodeposition solution to control the material properties, and varied parameters such as concentration, pH, and voltage using electrochemical methods for structural properties. Structural and material properties were analyzed using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Photoelectron Spectroscopy (XPS). Sensing characteristics were then analyzed using a hand-made sensor platform with a Source Meter.[Reference][1] Dekura, S., Kobayashi, H., Kusada, K., & Kitagawa, H. (2019). Hydrogen in Palladium and Storage Properties of Related Nanomaterials: Size, Shape, Alloying, and Metal‐Organic Framework Coating Effects. ChemPhysChem, 20(10), 1158-1176.[2] Cho, S. Y., Ahn, H., Park, K., Choi, J., Kang, H., & Jung, H. T. (2018). Ultrasmall grained Pd nanopattern H2 sensor. ACS sensors, 3(9), 1876-1883.

Assessment of reproductive toxicity in adult zebrafish (Danio rerio) following sublethal exposure to penthiopyrad

Penthiopyrad (PO), a succinate dehydrogenase inhibitor (SDHI) fungicide, poses a potential risk to fish. Here, we investigated the adverse effects of PO on endocrine regulation and reproductive capacity in zebrafish during a 21-d sublethal exposure to PO concentrations ranging from 0.02 to 2.00 mg/L. Following exposure to PO (0.20 and 2.00 mg/L), female-specific effects including follicle necrosis, structural disturbance of the yolk follicle, fusion of cortical follicles appeared in ovarian tissue of adult females, which led to a significant reduction in fertility. Correspondingly, 0.20 and 2.00 mg/L PO led to a marked reduction in the GSI values of females, and 2.00 mg/L PO caused a 31% decline in the proportion of perinucleolar oocytes (PCO) in oocytes. In addition, testosterone (T) level was obviously suppressed and 17β-estradiol (E2) level was increased in females after exposure to 2.00 mg/L PO. Male zebrafish treated with 0.20 and 2.00 mg/L of PO exhibited significant interstitial enlargement, edema in the testes, and reduced diameter of seminiferous tubules, along with a thinner basement membrane. The effects of PO on males were associated with significant increase in E2 level, suggesting that PO has an estrogenic effect on male fish. Greater E2 levels in serum were further supported by increased transcription levels of genes linked to the hypothalamic-pituitary-gonad-liver (HPGL) axis. Notably, transcription levels of cyp19a, er2b, era, and cyp19b was remarkably increased, exhibiting a clear link with variations in E2 levels. Overall, the present study demonstrates that PO induces reproductive impairment in zebrafish by promoting steroidogenesis.

Effects of Renin–Angiotensin Blockade on the Components of Early Interstitial Expansion in Patients with Type 1 Diabetes

Interstitial expansion is associated with glomerular filtration rate (GFR) loss in many renal diseases, including diabetic nephropathy. The Renin–Angiotensin System Study (RASS) tested whether a 5-year renin–angiotensin system (RAS) blockade with enalapril or losartan versus placebo slowed progression of early diabetic nephropathy lesions in 285 normoalbuminuric, normotensive, normal/high GFR patients with type 1 diabetes. RASS found no benefit to the RAS blockade on diabetic glomerular lesions but observed an unexpected 50% increase in the fractional volume of the renal cortex which is the interstitium. The effects of the RAS blockade on individual interstitial components––striated collagen, interstitial cells, and peritubular capillaries––were not assessed. We evaluated by electron microscopy changes in fractional volume of each component in seven patients from each group between baseline and five years. At baseline, 49% of the interstitium was collagen, 12% cells, 26% peritubular capillaries, 7% space, and 2% artifact. There was no overall change in the interstitial composition during the RASS. There were no statistically significant effects of treatment group on any interstitial components. Renal volume remained stable in all groups. The RAS blockade affected neither the approximately 50% increase in interstitium fractional volume per cortex nor the parallel increase in all interstitial components that occurred over the five years of the RASS.

Greater renal interstitial expansion and inflammation in older male versus older female rats following a four-day simulated heatwave

Acute kidney injury (AKI) is an emerging cause of morbidity during heatwaves worldwide and is associated with negative health outcomes. Older age increases the likelihood of AKI, which is a top cause of hospitalization during heatwaves in older adults. Further, biological sex likely affects the severity of, and prognosis following, AKI. Moreover, recent observations suggest that older women are at greater risk of AKI during heatwaves compared to older men. Whether this observation can be directly attributed to biological sex is unclear. Therefore, we tested the hypothesis that older female rats experience more severe kidney injury during a four-day simulated heatwave, compared to older male rats.To test this hypothesis, older (18-22 month old) male (M) and female (F) Wistar rats were exposed to a 36°C (M: n=5; F: n=8) or a 21°C (M: n=2; F: n=2) environment for three hours over four consecutive days. During, and for five hours following heat exposure, the rats did not have access to food or water, but otherwise were housed in standard housing conditions with free access to food and water. Core temperature (Tc) was continuously monitored and rats were removed from the heat if Tc reached 40.5℃, a safeguard put in place to prevent heatstroke. Data are presented as mean±SD.Male and females did not differ in the amount of time exposed to heat during each day (average duration - M: 39.3±4.0, F: 42.3±5.2 minutes, P=0.86) or body weight loss during heat exposure (average body weight loss - M: -2.0±0.1, F: -2.5±0.1% P=0.93). Serum creatinine concentration did not differ between heat exposed males and females on Day 1 (pre- M: 0.4±0.2, F: 0.4±0.1; post- M: 0.5±0.2, F: 0.4±0.2 mg/dL) or Day 4 (post- M: 0.4±0.1, F:0.3±0.1 mg/dL; P=0.86) Heat exposure resulted in cortical interstitial expansion and immune cell infiltration in aged male, but not female rats (M Heat: 77.2±36.1, F Heat: 12.1±16.5, M Control: 18.2±17.5, F Control: 13.4±19.0 dots per image, P=0.002). Only older male rats displayed greater interstitial immune cell infiltration than older controls in response to heating (P=0.04). Immunohistochemistry demonstrated distinct populations of CD3e+ T cells, CD20+ B cells and CD68+ macrophages within the interstitial immune cell infiltration in the older male rats. Kidney expression of kidney injury molecule 1 (KIM1, P=0.41) and neutrophil gelatinase associated lipocalin (NGAL, P=0.12) did not differ between older male and female rats exposed to heat or control conditions. Compared to older female rats, older male rats display increased cortical interstitial expansion and inflammation following a four-day simulated heatwave. UL1TR002529, T32DK120524 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The protective effects of a novel AT2 receptor agonist, β-Pro7Ang III in ischemia-reperfusion kidney injury

Background and purposeThis study investigated the reno-protective effects of a highly selective AT2R agonist peptide, β-Pro7Ang III in a mouse model of acute kidney injury (AKI). MethodsC57BL/6 J mice underwent either sham surgery or unilateral kidney ischemia-reperfusion injury (IRI) for 40 min. IRI mice were treated with either β-Pro7Ang III or perindopril and at 7 days post-surgery the kidneys analysed for histopathology and the development of fibrosis and matrix metalloproteinase (MMP)-2 and -9 activity. The association of the therapeutic effects of β-Pro7Ang III with macrophage number and phenotype was determined in vivo and in vitro. Key resultsDecreased kidney tubular injury, interstitial matrix expansion and reduced interstitial immune cell infiltration in IRI mice receiving β-Pro7Ang III treatment was observed at day 7, compared to IRI mice without treatment. This correlated to reduced collagen accumulation and MMP-2 activity in IRI mice following β-Pro7Ang III treatment. FACS analysis showed a reduced number and proportion of CD45+CD11b+F4/80+ macrophages in IRI kidneys in response to β-Pro7Ang III, correlating with a significant increase in M2 macrophage markers and decreased M1 markers at day 3 and 7 post-IR injury, respectively. In vitro analysis of cultured THP-1 cells showed that β-Pro7Ang III attenuated lipopolysaccharide (LPS)-induced tumour necrosis factor-α (TNF-α) and interleukin (IL)− 6 production but increased IL-10 secretion, compared to LPS alone. ConclusionAdministration of β-Pro7Ang III via mini-pump improved kidney structure and reduced interstitial collagen accumulation, in parallel with an alteration of macrophage phenotype and anti-inflammatory cytokine release, therefore mitigating the downstream progression of ischemic AKI.

Myocardial oedema contributes to interstitial expansion and associates with mechanical and electrocardiographic changes in takotsubo syndrome: a CMR T1 and T2 mapping study.

myocardial oedema is largely represented in takotsubo syndrome (TTS) and may contribute to alter the myocardium morphology and function. The aim of the study is to describe relationships between oedema, mechanical, and electrical abnormalities in TTS. the study included n = 32 hospitalized TTS patients and n = 23 controls. Cardiac magnetic resonance (CMR) with tissue mapping and feature tracking was performed with concomitant 12-lead electrocardiogram (ECG) recording. Mean age of TTS was 72 ± 12 years old, 94% women. Compared with controls, patients had higher left ventricular (LV) mass, worse systolic function, higher septal native T1 (1116 ± 73 msec vs. 970 ± 23 msec, P < 0.001), T2 (56 ± 5 msec vs. 46 ± 2 msec, P < 0.001), and extracellular volume (ECV) fraction (32 ± 5% vs. 24 ± 1%, P < 0.001). TTS patients had higher apicobasal gradient of T2 values (12 ± 6 msec vs. 2 ± 6 msec, P < 0.001); basal LV wall displayed higher native T1, T2, and ECV (all P < 0.002) but similar circumferential strain against controls (-23 ± 3% vs. -24 ± 4%, P = 0.351). In the TTS cohort, septal T2 values showed significant correlations with native T1 (r = 0.609, P < 0.001), ECV (r = 0.689, P < 0.001), left ventricular ejection fraction (r = -0.459, P = 0.008) and aVR voltage (r = -0.478, P = 0.009). Negative T-wave voltage and QTc length correlated with apicobasal T2 mapping gradient (r = 0.499, P = 0.007 and r = 0.372, P = 0.047, respectively) but not with other tissue mapping measurements. CMR T1 and T2 mapping demonstrated increased myocardial water content conditioning interstitial expansion in acute TTS, detected even outside areas of abnormal wall motion. Oedema burden and distribution associated with mechanical and electrocardiographic changes, making it a potential prognostic marker and therapeutic target in TTS.

Differences in Myocardial Remodeling and Tissue Characteristics in Chronic Isolated Aortic and Mitral Regurgitation.

The left ventricular hemodynamic load differs between aortic regurgitation (AR) and primary mitral regurgitation (MR). We used cardiac magnetic resonance to compare left ventricular remodeling patterns, systemic forward stroke volume, and tissue characteristics between patients with isolated AR and isolated MR. We assessed remodeling parameters across the spectrum of regurgitant volume. Left ventricular volumes and mass were compared against normal values for age and sex. We calculated forward stroke volume (planimetered left ventricular stroke volume-regurgitant volume) and derived a cardiac magnetic resonance-based systemic cardiac index. We assessed symptom status according to remodeling patterns. We also evaluated the prevalence of myocardial scarring using late gadolinium enhancement imaging, and the extent of interstitial expansion via extracellular volume fraction. We studied 664 patients (240 AR, 424 primary MR), median age of 60.7 (49.5-69.9) years. AR led to more pronounced increases in ventricular volume and mass compared with MR across the spectrum of regurgitant volume (P<0.001). In ≥moderate regurgitation, AR patients had a higher prevalence of eccentric hypertrophy (58.3% versus 17.5% in MR; P<0.001), whereas MR patients had normal geometry (56.7%) followed by myocardial thinning with low mass/volume ratio (18.4%). The patterns of eccentric hypertrophy and myocardial thinning were more common in symptomatic AR and MR patients (P<0.001). Systemic cardiac index remained unchanged across the spectrum of AR, whereas it progressively declined with increasing MR volume. Patients with MR had a higher prevalence of myocardial scarring and higher extracellular volume with increasing regurgitant volume (P value for trend <0.001), whereas they were unchanged across the spectrum of AR (P=0.24 and 0.42, respectively). Cardiac magnetic resonance identified significant heterogeneity in remodeling patterns and tissue characteristics at matched degrees of AR and MR. Further research is needed to examine if these differences impact reverse remodeling and clinical outcomes after intervention.

66 MYOCARDIAL EDEMA CONTRIBUTES TO INTERSTITIAL EXPANSION AND ASSOCIATES WITH MECHANICAL AND ELECTROCARDIOGRAPHIC CHANGES IN TAKOTSUBO SYNDROME: A CMR T1 AND T2 MAPPING STUDY

Abstract Background myocardial edema has a central role in takotsubo syndrome (TTS). Relationships between edema, mechanical and electrical abnormalities in TTS are still elusive. Methods n=32 hospitalized TTS patients and n=23 controls were analyzed. We performed cardiac magnetic resonance (CMR) with tissue mapping for the assessment of edema and interstitial expansion, global longitudinal (GLS) and circumferential strain (GCS) were evaluated by CMR feature-tracking. Twelve-lead ECGs were recorded at the time of CMR in TTS patients, aVR voltage, negative T-wave voltage and QTc length were calculated. Results mean age of the TTS cohort was 72±12-year-old, 94% women, undergoing CMR at a median of 4 days (interquartile range 2, 6) after hospital admission. Compared with controls, patients had increased LV mass (55±11 g/m2 vs 46±8 g/m2, p&amp;lt;0.001), worse left ventricular ejection fraction (LVEF), GLS and GCS (all p&amp;lt;0.001), higher septal native T1 (1116±73 msec vs 970±23 msec, p&amp;lt;0.001), T2 (56±5 msec vs 46±2 msec, p&amp;lt;0.001) and extra-cellular volume (ECV) fraction (32±5% vs 24±1%, p&amp;lt;0.001). TTS patients had higher apicobasal gradient of T2 values (12±6 msec vs 2±6 msec, p&amp;lt;0.001), basal LV wall displayed higher native T1, T2 and ECV (all p&amp;lt;0.002) but similar circumferential strain against controls (-23±3% vs -24±4%, p=0.351). In the TTS cohort, septal T2 value showed significant correlations with native T1 (r=0.609, p&amp;lt;0.001), ECV (r=0.689, p&amp;lt;0.001), LVEF (r=-0.459, p=0.008) and aVR voltage (r=-0.437, p&amp;lt;0.05). Negative T waves voltage and QTc length significantly correlated with apicobasal T2 mapping gradient (r=0.499, p=0.007 and r=0.372, p=0.047 respectively) but not with other tissue mapping measurements. Conclusions CMR T1 and T2 mapping demonstrated increased myocardial water content conditioning interstitial expansion in acute TTS. Myocardial edema was detected even outside areas of abnormal wall motion, its burden and distribution associated with mechanical and electrocardiographic changes, making it a potential prognostic marker and therapeutic target in TTS.

Diffuse Pulmonary Meningotheliomatosis: A Case Report

Abstract Introduction/Objective Diffuse pulmonary meningotheliomatosis (DPM) is a pulmonary disease characterized by the presence of widespread bilateral minute pulmonary meningothelial-like nodules (MPMNs). It is exceedingly rare and predominantly seen in females. The nodules are typically asymptomatic and detected incidentally on imaging. Methods/Case Report We present a case of a 57-year-old woman with a history of chronic cough and CT imaging findings of bilateral multiple ground-glass nodules. Wedge resections from the right upper and right lower lobes were obtained, which revealed gross changes suggestive of interstitial lung disease. Histologic evaluation of the wedges showed similar morphology, consisting of discrete areas with variable interstitial expansion of the stroma with ovoid/spindle cells, collagen, elastosis, and mild chronic inflammatory cells, in a somewhat perivascular pattern. Some areas were also cystic. This appeared in a background of emphysematous change and focal foreign body giant cell reaction to non-polarizable material. Immunohistochemical stains were diffusely positive for vimentin, EMA , and PR, and CD163 highlighted increased cells that were S100 and CD1a negative. Additionally, the ovoid/spindle cells were negative for desmin, SMM, HMB-45, HHV8, pan-CK, chromogranin, and multiplex SOX10-MART1. Results (if a Case Study enter NA) NA Conclusion Diffuse pulmonary meningotheliomatosis is a rare entity that requires sufficient histological evaluation to identify the ovoid/spindle cell component histologically and immunohistochemically. This disease should be considered in the differential for cases of diffuse interstitial pulmonary infiltrates. Few cases have been reported in the literature, requiring further research to understand the mechanisms of this disease and its clinical significance.

Protective effect and mechanism of electroacupuncture of "Biao-Ben" acupoints combination for mitochondrial dysfunction in diabetic nephropathy rats

To study the protective effect of electroacupuncture (EA) at "Biao"-acupoints, "Fenglong"(ST40) and "Zhongwan"(CV12), used for treating symptoms of the disease, and "Ben"-acupoints, "Zusanli"(ST36) and "Guanyuan"(CV4), for treating the root cause of the disease on oxidative stress injury of renal mitochondria through SIRT1/PGC-1α signal pathway in rats with diabetic nephropathy (DN). A total of 33 male Wistar rats were randomized into normal (n=10), model (n=12) and EA (n=11) groups.The DN model was established by feeding the rats with high-sugar and high-fat diet for 6 weeks combined with streptozotocin (STZ, 35 mg/kg, i.p.). EA (4 Hz/60 Hz, 1 mA)was applied to ST36-ST40 and CV4-CV12 for 15 min, once every other day for 8 weeks. The rats' body weight was recorded, urine in 24 hours (24-h UP) was collected to measure the urine protein level, and the fasting blood glucose (FBG) level detected by using a glucometer. The levels of serum glycosylated hemoglobin (HbA1c), creatinine (Scr) and urea nitrogen (BUN) were assayed using immunoturbidi-metry, picric acid method and urease method, respectively, and those of serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) detected using an automatic biochemical analyzer. The kidney tissue was collected for assaying the activity of superoxide dismutase (SOD) with xanthine oxidase method, glutathione (GSH) activity with dithio-dinitrobenzoic acid method, catalase （CAT） activity with ammonium molybdate spectrometric method, and malondialdehyde (MDA) content with thiobarbituric acid method. Histopathological changes of the kidney tissue were observed by microscope after hematoxylin-eosin staining (HE), periodate Schiff staining (PAS) and Masson staining, separately, and its subcellular structure was observed under transmission electron microscopy. The expression levels of renal SIRT1 and PGC-1α mRNAs and proteins were detected by quantitative real-time PCR and Western blot, and the immunoactivity of renal α-smooth muscle actin (α-SMA), and immunofluorescence density of renal collagen Ⅰ (Col Ⅰ), collagen Ⅳ(Col Ⅳ) and fibronec-tin (FN) detected by immunohistochemistry and immunofluorescence assay, respectively. Compared with the normal group, the levels of FBG, HbA1c, BUN, Scr, 24-h UP, TG, TC, LDL-C, MDA, α-SMA, Col Ⅰ, Col Ⅳ and FN proteins were significantly increased (P<0.01), and the levels of body weight, HDL-C, SOD, GSH, CAT, SIRT1 and PGC-1α mRNAs and proteins were decreased in the model group (P<0.01, P<0.05). In comparison with the model group, the levels of FBG, HbA1c, BUN, Scr, 24-h UP, TG, TC, LDL-C and MDA, and the expressions of α-SMA, Col Ⅰ, Col Ⅳ and FN proteins were markedly down-regulated (P<0.05, P<0.01), and those of body weight, HDL-C, SOD, GSH, CAT, and the expressions of SIRT1 and PGC-1α mRNAs and proteins significantly up-regulated (P<0.01, P<0.05) in the EA group. HE staining showed mesangial dilatation, glomerular hypertrophy and mesangial matrix accumulation; PAS staining showed an increase of the glomerular extracellular matrix deposition; and Masson staining displayed an enhancement of glomerular fibrosis and interstitial space expansion; and electron microscope revealed foot process fusion, basement membrane thickening and organelle injury in the rat's kidney of the model group, which were relatively milder in the EA group. EA of ST36-ST40 and CV4-CV12, "Biao-Ben" acupoints combination, can alleviate oxidative stress and mitochondrial dysfunction in DN rats, which may be associated with its functions in up-regulating SIRT1/PGC-1α signaling, and decreasing renal fibrosis.

Mesenchymal Stem Cells Alleviate Renal Fibrosis and Inhibit Autophagy via Exosome Transfer of miRNA-122a.

Exosomes derived from mesenchymal stem cell (MSC) alleviate kidney damage through autophagy. This study determined whether MSCs relieve renal fibrosis and inhibit autophagy by exosome transfer of miRNA-122a. The gene expression involved in the mTOR signaling pathway and autophagy was assessed in TGF-β1-treated human renal tubular epithelial cells (HK-2) and unilateral ureteral obstruction (UUO) mice before and after MSC-derived exosomes and miRNA-122a mimic treatment. Small RNA (sRNA) next-generation sequencing was also performed on TGF-β1-treated HK-2 cells. MSC-derived exosomes relieve fibrosis caused by TGFβ in HK-2 via regulation of the mTOR signaling pathway and downstream autophagy. Furthermore, we found that MSC-derived exosomes mediate miRNA-122a to relieve renal fibrosis in HK-2 cells in response to TGF-β1 through the regulation of mTOR signaling and autophagy. In the UUO mouse model, miRNA-122a mimic-transfected MSC treatment and its combination with 3-MA both recapitulated the same results as the in vitro experiments, along with reduced expansion of renal tubule, interstitial expansion, and preservation of kidney architecture. The antifibrotic activity of MSC-derived exosomes after renal fibrosis occurs partially by autophagy suppression via excreted exosomes containing mainly miRNA-122a. These findings indicate that the export of miRNA-122a via MSC-derived exosomes represents a novel strategy to alleviate renal fibrosis.

Metabolomics-based safety evaluation of acute exposure to electronic cigarettes in mice

IntroductionA growing number of epidemiological evidence reveals that electronic cigarettes (E-cigs) were associated with pneumonia, hypertension and atherosclerosis, but the toxicological evaluation and mechanism of E-cigs were largely unknown. ObjectiveOur study was aimed to explore the adverse effects on organs and metabolomics changes in C57BL/6J mice after acute exposure to E-cigs. Methods and resultsHematoxylin and eosin (H&E) staining found pathological changes in tissues after acute exposure to E-cigs, such as inflammatory cell infiltration, nuclear pyknosis, and intercellular interstitial enlargement. E-cigs could increase apoptosis-positive cells in a time-dependent way using Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Oxidative damage indicators of reactive oxygen species (ROS), malondialdehyde (MDA) and 4-hydroxynonena (4-HNE) were also elevated after E-cigs exposure. There was an increasing trend of total glycerol and cholesterol in serum, while the glucose and liver enzymes including alanine aminotransferase (ALT), aspartate transaminase (AST), gamma-glutamyltranspeptidase (γ-GT) had no significant change compared to that of control. Further, Q Exactive high field (HF) mass spectrometer was used to conduct metabolomics, which revealed that differential metabolites including l-carnitine, Capryloyl glycine, etc. Trend analysis showed the type of compounds that change over time. Pathway enrichment analysis indicated that E-cigs affected 24 metabolic pathways, which were mainly regulated amino acid metabolism, further affected the tricarboxylic acid (TCA) cycle. Additionally, metabolites-diseases network analysis found that the type 2 diabetes mellitus, propionic acidemia, defect in long-chain fatty acids transport and lung cancer may be related to E-cigs exposure. ConclusionsOur findings provided important clues for metabolites biomarkers of E-cigs acute exposure and are beneficial for disease prevention.

Proteomic signature of tubulointerstitial tissue predicts prognosis in IgAN

BackgroundIgA nephropathy (IgAN) is associated with a significant risk of progression to kidney failure. Tubular atrophy is an established important risk factor for progressive disease, but few studies have investigated tubulointerstitial molecular markers and mechanisms of progression in IgAN.MethodsBased on data from the Norwegian Renal Registry, two groups were included: IgAN patients with (n = 9) or without (n = 18) progression to kidney failure during 10 years of follow-up. Tubulointerstitial tissue without discernible interstitial expansion or pronounced tubular alterations was microdissected, proteome was analysed using tandem mass spectrometry and relative protein abundances were compared between groups. ResultsProteome analyses quantified 2562 proteins with at least 2 unique peptides. Of these, 150 proteins had significantly different abundance between progressive and non-progressive IgAN patients, 67 were more abundant and 83 less abundant. Periostin was the protein with the highest fold change between progressive and non-progressive IgAN (fold change 8.75, p < 0.05) and periostin staining was also stronger in patients with progressive vs non-progressive IgAN. Reactome pathway analyses showed that proteins related to inflammation were more abundant and proteins involved in mitochondrial translation were significantly less abundant in progressive vs non-progressive patients.ConclusionsMicrodissection of tubulointerstitial tissue with only mild damage allowed for identification of proteome markers of early progressive IgAN. Periostin abundance showed promise as a novel and important risk marker of progression.

R213G Variant of Extracellular Superoxide Dismutase (EC-SOD) Alters Interstitial Macrophage Subset Expansion During Hypoxia

R213G Variant of Extracellular Superoxide Dismutase (EC-SOD) Alters Interstitial Macrophage Subset Expansion During Hypoxia

Longitudinal systolic dysfunction in hypertensive cardiomyopathy with normal ejection fraction

The left ventricle (LV) journey in their transition from hypertrophy to heart failure is marked by many subcellular events partially understood yet. The moment in which the structural abnormalities reach the umbral to induce myocardial dysfunction remains elusive. To evaluate the anatomic-functional relationship between LV wall thickness and longitudinal systolic dysfunction. We prospectively performed clinical assessment and transthoracic echocardiogram on healthy individuals and hypertensive patients with left ventricle ejection fraction (LVEF) ≥50% and absence of heart failure symptoms. A total of 226 patients and 101 healthy individuals were recruited. The distribution for sex was similar between groups. The mean age was 67±13 years old in the patients, and 44% had concentric LV hypertrophy. LVEF was identical in both groups (63±6%); in contrast, global longitudinal strain (GLS) (-18.8±2.5%vs -20.4±2%) and mitral annulus plane systolic excursion (MAPSE) (13.8±2.8vs 15.5±2mm) were lower. ROC curve optimally classified decreased GLS with LV septum thickness ≥13mm and decreased MAPSE with thickness ≥14mm. Multivariable logistic regression found that LV septum thickness is the only variable associated with longitudinal systolic dysfunction (OR=1.1, CI95% = 1.05 - 1.15, P=0.001, R squared=.38). A progressive increase in LV wall thickness due to myocyte hypertrophy and interstitial expansion is associated with LV systolic longitudinal dysfunction. Patients with moderate or severe ventricular hypertrophy (septum ≥13mm) had longitudinal systolic dysfunction, GLS decreases with minor structural change than MAPSE, and LVEF is insensitive in detecting longitudinal myocardial dysfunction in patients with hypertension.

Feasibility of Hepatic T1-Mapping and Extracellular Volume Quantification on Routine Cardiac Magnetic Resonance Imaging in Patients with Infiltrative and Systemic Disorders

Cardiac magnetic resonance imaging (CMR) is commonly obtained to evaluate for myocardial infiltrative disorders and fibrosis. Pre- and post-Gadolinium contrast T1-mapping sequences are employed to estimate interstitial expansion using extracellular volume fraction (ECV). Given the proximity of the liver to the heart, T1 and ECV quantification of the liver is feasible on CMR. The purpose of this study was to evaluate for hepatic measures of fibrosis and interstitial expansion in patients with amyloidosis or systemic disease on CMR. Myocardial and hepatic native T1 values were measured retrospectively using a cardiac short axis modified Look-Locker inversion recovery sequence. Myocardial and hepatic ECV were calculated using pre- and post-contrast T1 and blood pool values according to the following formula: ECV=(Δ(1/T1) myocardium or liver and/or Δ(1/T1) blood)x(1 - hematocrit). Patients were divided into three cohorts by final diagnosis: amyloidosis, systemic disease (e.g. sarcoid, scleroderma), and controls (EF > 50, no ischemia). Of the 135 patients who underwent CMR, 22 had cardiac amyloidosis (age 59.9 ± 12.6 yrs, 41% female), 20 had systemic disease (age 50.9 ± 13.4 yrs, 35% female), and 93 were controls (age 49.5 ± 17.3 yrs, 50% female). Myocardial T1 and ECV values were highest for patients with amyloid, second highest for systemic disease, and least for controls (T1: 1169 ± 92 vs 1101 ± 53 vs 1027 ± 73 ms, p < 0.0001; ECV: 0.47 ± 0.11 vs 0.31 ± 0.05 vs 0.27 ± 0.04, p < 0.0001). Hepatic T1 and ECV were similarly higher in patients with amyloid and systemic disease compared to controls (T1: 646 ± 101 vs 660 ± 93 vs 595 ± 58 ms, p < 0.0001; ECV: 0.38 ± 0.08 vs 0.37 ± 0.05 vs 0.31 ± 0.03, p < 0.0001). There was a positive correlation between hepatic T1 and ECV (R2=0.282, p < 0.0001). No patients had abnormal liver function tests or clinical liver disease. Hepatic ECV quantification on CMR in patients with amyloidosis and systemic disorders is feasible. Further longitudinal investigation regarding detection of early or subclinical liver disease is warranted.

Interstitial washdown and vascular albumin refill during fluid infusion: novel kinetic analysis from three clinical trials

Background and aimsIncreased capillary filtration may paradoxically accelerate vascular refill of both fluid and albumin from the interstitial space, which is claimed to be edema-preventing. We characterized this proposed mechanism, called “interstitial washdown”, by kinetic analyses of the hemodilution induced by intravenous infusion of crystalloid fluid during 3 distinct physiological states.MethodsGreater plasma dilution of hemoglobin as compared to albumin during fluid therapy indicated recruitment of albumin, which was compared to the flow of interstitial fluid to the plasma as indicated by population volume kinetic analysis. Data for the comparison were derived from 24 infusions of crystalloid fluid in conscious volunteers, 30 in anesthetized patients, and 31 in patients with ketoacidosis from hyperglycemia.Results“Interstitial washdown” increased the plasma albumin concentration by between 0.3 and 1.0 g/L in the three series of infusions. The initial albumin concentration in the interstitial fluid returning to the plasma was estimated to between 22 g/L and 29 g/L, which decreased to an average of 50–75% lower during the subsequent 2–3 h. Kinetic simulations show that pronounced washdown was associated with increased capillary filtration (high k12) and, in conscious subjects, with greater plasma and interstitial volume expansion and restricted urine flow. During anesthesia, the main effect was an increase in the non-exchangeable fluid volume (“third-spacing”).ConclusionsCrystalloid fluid accelerates lymphatic flow that moderately increases plasma albumin, but more clearly helps to maintain the intravascular volume. This “interstitial washdown” mechanism becomes exhausted after a few hours.