20 research outputs found
NLRP3 Gene Silencing Ameliorates Diabetic Cardiomyopathy in a Type 2 Diabetes Rat Model
<div><p>Background</p><p>Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome is associated with metabolic disorder and cell death, which are important triggers in diabetic cardiomyopathy (DCM). We aimed to explore whether NLRP3 inflammasome activation contributes to DCM and the mechanism involved.</p><p>Methods</p><p>Type 2 diabetic rat model was induced by high fat diet and low dose streptozotocin. The characteristics of type 2 DCM were evaluated by metabolic tests, echocardiography and histopathology. Gene silencing therapy was used to investigate the role of NLRP3 in the pathogenesis of DCM. High glucose treated H9c2 cardiomyocytes were used to determine the mechanism by which NLRP3 modulated the DCM. The cell death in vitro was detected by TUNEL and EthD-III staining. TXNIP-siRNA and pharmacological inhibitors of ROS and NF-kB were used to explore the mechanism of NLRP3 inflammasome activation.</p><p>Results</p><p>Diabetic rats showed severe metabolic disorder, cardiac inflammation, cell death, disorganized ultrastructure, fibrosis and excessive activation of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), pro-caspase-1, activated caspase-1 and mature interleukin-1β (IL-1β). Evidence for pyroptosis was found <i>in vivo</i>, and the caspase-1 dependent pyroptosis was found <i>in vitro</i>. Silencing of NLRP3 <i>in vivo</i> did not attenuate systemic metabolic disturbances. However, NLRP3 gene silencing therapy ameliorated cardiac inflammation, pyroptosis, fibrosis and cardiac function. Silencing of NLRP3 in H9c2 cardiomyocytes suppressed pyroptosis under high glucose. ROS inhibition markedly decreased nuclear factor-kB (NF-kB) phosphorylation, thioredoxin interacting/inhibiting protein (TXNIP), NLRP3 inflammasome, and mature IL-1β in high glucose treated H9c2 cells. Inhibition of NF-kB reduced the activation of NLRP3 inflammasome. TXNIP-siRNA decreased the activation of caspase-1 and IL-1β.</p><p>Conclusion</p><p>NLRP3 inflammasome contributed to the development of DCM. NF-κB and TXNIP mediated the ROS-induced caspase-1 and IL-1β activation, which are the effectors of NLRP3 inflammasome. NLRP3 gene silencing may exert a protective effect on DCM.</p></div
NLRP3 gene silencing did not attenuate metabolic abnormalities.
<p>The blood samples were collected at the end of the experiment. Ctrl, control; DM, diabetes mellitus; Blood glucose, blood glucose tested at the end of the experiment; TG, triglyceride; TC, total cholesterol; INS, insulin tested at the end of the experiment; ISI, insulin sensitivity index. Data are mean±SEM, n = 6–8 per group.</p><p>**p<0.01 vs. control.</p
Primer sequences for real-time RT-PCR.
<p>TXNIP, thioredoxin interacting/inhibiting protein; NLRP3, Nucleotide-binding oligomerization domain-like receptor protein 3; ASC, apoptosis-associated speck-like protein containing a caspase recruitment domain; IL-1β, interleukin-1β.</p
Dual-Mode Electronic Skin with Integrated Tactile Sensing and Visualized Injury Warning
Mimicking the pressure-sensing
behavior of biological skins using electronic devices has profound
implications for prosthetics and medicine. The developed electronic
skins based on single response mode for pressure sensing suffer from
a rapid decrease in sensitivity with the increase of pressure. Their
highly sensitive range covers a narrow part of tolerable pressure
range of the human skin and has a weak response to the injurious high
pressures. Herein, inspired by a bioluminescent jellyfish, we develop
an electronic skin with dual-mode response characteristics, which
is able to quantify and map the static and dynamic pressures by combining
electrical and optical responses. The electronic skin shows notable
changes in capacitance in the low-pressure regime and can emit bright
luminescence in the high-pressure regime, which, respectively, imitates
the functions of the mechanoreceptors and nociceptors in the biological
skin, enabling it to sense gentle tactile and injurious pressure with
sensitivities up to 0.66 and 0.044 kPa<sup>–1</sup>, respectively.
The complementary highly sensitive sensing ranges of the electronic
skin realize a reliable perception to different levels of pressure,
and its mechanically robust and stretchable properties may find a
wide range of applications in intelligent robots
The information of experimental design.
<p>The euthanized rats in the yellow box were used to explore the expression levels of NLRP3 inflammasome in different stages of DCM. The sacrificed rats in the green box were used in the rest of experiments in vivo. IPGTT: intraperitoneal glucose tolerance test; IPITT: intraperitoneal insulin tolerance test; HF: high fat diet; Ctrl: control rats; DM: diabetes rats; DM+NLRP3-miRNA: diabetes rats received lentiviral NLRP3-miRNA; DM+vehicle: diabetes rats received empty lentiviral vector.</p
NF-kB and TXNIP induced NLRP3 inflammasome activation.
<p>Relative mRNA expression of NF-kB (A) and protein levels of NLRP3, pro-caspase-1, activated caspase-1, pro-IL-1β and mature IL-1β (B-G) in H9c2 cardiomyocytes with treatment. Relative mRNA expression of TXNIP (H) and protein levels of TXNIP, NLRP3, pro-caspase-1, activated caspase-1, pro-IL-1β and mature IL-1β (I-O) in H9c2 cardiomyocytes. Data were presented as means±SEM, from 3 independent experiments. *p<0.05, **p<0.01 vs. Ctrl; <sup>§§</sup>p<0.01 vs. HG+vehicle.</p
NLRP3 gene silencing alleviated myocardial cell death, ultrastructral disorder and fibrosis in diabetic group.
<p>Heart size (A1) and cross sections of hearts at the papillary muscle level (A2); scale bar: 5 mm. (B) Quantitative data for heart weight to body weight ratio. TUNEL staining of myocardium (D, scale bar: 20 µm) and quantitative analysis of TUNEL positive cells (C) in each group. (E) Transmission electron microscopy of rat hearts; normal myofibrils (M); normal mitochondria (MT); normal Z-lines (Z); disorganized myofibrils (black asterisk); swollen mitochondria (white asterisk); accumulated lipid (white arrow); excessive glycogen lysis (black arrow); scale bar: 1 µm. (F) Cardiac fibrosis in rats; (F1) Masson staining; fibrotic areas stained green and normal cardiac myocytes stained red; bright field (F2) and dark field (F3) with Sirius red staining; collagen was stained dark red in bright field; collagen I was stained red and collagen III green in dark field; scale bar: 50 µm. (G) Quantitative analysis of the fibrotic area to total area ratio. (H–K) Western blot analysis of collagen I and III. Data were presented as means±SEM, n = 4–6. **p<0.01 vs. Ctrl; <sup>§§</sup>p<0.01 vs. DM+vehicle.</p
NLRP3 gene silencing improved cardiac dysfunction in diabetes rats.
<p>(A) The cardiac function of rats in different groups shown by echocardiography. Representative images of 2D echocardiograms (A1), M-mode echocardiograms (A2), pulse-wave Doppler echocardiograms of mitral inflow (A3), tissue Doppler echocardiograms (A4). (B–F) Evaluation of LVEDd, LVEF, FS, E/A and E′/A′. Data were presented as means±SEM, n = 6. **p<0.01 vs. Ctrl; <sup>§</sup>p<0.05, <sup>§§</sup>p<0.01 vs. DM+vehicle. LV: left ventricle; IVS: interventricular septum; LVEDd: left ventricular end-diastolic dimension; LVEF: left ventricular ejection fraction; FS: fractional shortening; E/A: peak E to peak A ratio; E′/A′: early (E′) to late (A′) diastolic velocity ratio.</p
NLRP3 gene silencing suppressed activated caspase-1, inflammatory cytokines, and pyroptosis in high glucose-treated H9c2 cells.
<p>Relative mRNA expression of NLRP3 (A) and protein levels of NLRP3, pro-caspase-1, activated caspase-1, pro-IL-1β and mature IL-1β (B–G) in H9c2 cardiomyocytes with treatment. (H–K) The protein levels of IL-1β, IL-18, TNF-α and IL-6 in the cultured supernatants of H9c2 cardiomyocytes. (L) TUNEL staining of H9c2 cells, positive cell indicated by black arrow; scale bar: 20 µm. (M) Quantitative analysis of TUNEL positive cell in each group. (O) EthD-III (red) staining; scale bar: 50 µm. (N) Quantitative analysis of EthD-III positive cell. Data were presented as means±SEM, from 3 independent experiments. *p<0.05, **p<0.01 vs. Ctrl; <sup>§</sup>p<0.05, <sup>§§</sup>p<0.01 vs. HG+vehicle.</p
NLRP3 inflammasome was activated in myocardium after 4 weeks of diabetes.
<p>(A) The relative mRNA expression of NLRP3 (A1), ASC (A2), caspase-1(A3) and IL-1β (A4). (B and C) The protein levels of NLRP3 (C1), ASC (C2), pro-caspase-1 (C3), activated caspase-1(C4), pro-IL-1β (C5) and mature IL-1β (C6). Data were presented as means±SEM, n = 3. *p<0.05, **p<0.01 vs. Ctrl at 20 w; <sup>#</sup>p<0.05, <sup>##</sup>p<0.01 vs. DM at 0 w. Ctrl: control rats sacrificed at 20 weeks after diabetes rats received STZ injection; DM: diabetes rats; w: weeks; Pro-Casp-1: pro-caspase-1; Casp-1 p20: activated caspase-1; IL-1β p17: mature IL-1β.</p