Mitochondria-Targeted Sensor Array with Aggregation-Induced Emission Luminogens for Identification of Various Cells.

Accurate discrimination of cancerous cells is a good solution for early diagnosis of tumors. The mitochondrion plays an important role in cells. Herein, the five aggregation-induced emission luminogens (AIEgens) with various double positive charges are synthesized to image mitochondria. Tetraphenylethylene (TPE) molecules are modified by methoxy groups, conjugated donor-acceptor, and different positive charges to achieve multicolor emission. The five AIEgens form the PTx-Sa (positive mitochondria-target molecular sensor array) to perform cross-fluorescence response based on the mitochondria-targeted imaging to achieve the discrimination of various cells. Principal component analysis of the cross-response fluorescence data of PTx-Sa shows that 100% accurate identification of various cells, including cancer cells and normal cells, digestive tract cancer cells, gastric cancer cells, and mixed gastric cancer cells. By support vector machine to show the predictive ability of PTx-Sa to unknown cells by using blind samples. This is the first time to apply mitochondria-targeted sensor array to identification of various cells.

Combined tetraphenylethylene fluorogens with positive charge for imaging capsule-covered pathogens.

Capsule-covered pathogens can cause serious infectious diseases, and are highly pathogenic to humans. Herein, we developed four positively charged tetraphenylethylene derivatives (PC-TPEgens) that in certain combinations were applied to identify capsule-bearing pathogens using fluorescence imaging. The dual-charged probes were used to visualize the entire process of phagocytosis of pathogens into macrophages.

Mitochondria-Targeted Polydopamine Nanocomposite with AIE Photosensitizer for Image-Guided Photodynamic and Photothermal Tumor Ablation.

Photodynamic therapy (PDT) and photothermal therapy (PTT) are two kinds of treatment for tumors. Herein, a new aggregation-induced emission (AIE)gen (MeO-TPE-indo, MTi) is synthesized with a D-π-A conjugated structure. MTi, which has an electron donor and an acceptor on a tetraphenylethene (TPE) conjugated skeleton, can induce the effective generation of reactive oxygen species (ROS) for PDT. With the guide of the indolium group, MTi can target and image mitochondrion selectively. In order to get good dispersion in water and long-time retention in tumors, MTi is modified on the surface of polydopamine nanoparticles (PDA NPs) to form the nanocomposite (PDA-MeO-TPE-indo, PMTi) by π-π and hydrogen interactions. PMTi is a nanoscale composite for imaging-guided PDT and PTT in tumor treatment, which is constructed with AIEgens and PDA for the first time. The organic functional molecules are combined with nanomaterials for building a multifunctional diagnosis and treatment platform by utilizing the advantages of both sides.

Antioxidant catalase rescues against high fat diet-induced cardiac dysfunction via an IKKß-AMPK-dependent regulation of autophagy.

Autophagy, a conservative degradation process for long-lived and damaged proteins, participates in a variety of biological processes including obesity. However, the precise mechanism of action behind obesity-induced changes in autophagy still remains elusive. This study was designed to examine the role of the antioxidant catalase in high fat diet-induced changes in cardiac geometry and function as well as the underlying mechanism of action involved with a focus on autophagy. Wild-type (WT) and transgenic mice with cardiac overexpression of catalase were fed low or high fat diet for 20 weeks prior to assessment of myocardial geometry and function. High fat diet intake triggered obesity, hyperinsulinemia, and hypertriglyceridemia, the effects of which were unaffected by catalase transgene. Myocardial geometry and function were compromised with fat diet intake as manifested by cardiac hypertrophy, enlarged left ventricular end systolic and diastolic diameters, fractional shortening, cardiomyocyte contractile capacity and intracellular Ca²âº mishandling, the effects of which were ameliorated by catalase. High fat diet intake promoted reactive oxygen species production and suppressed autophagy in the heart, the effects of which were attenuated by catalase. High fat diet intake dampened phosphorylation of inhibitor kappa B kinase ß(IKKß), AMP-activated protein kinase (AMPK) and tuberous sclerosis 2 (TSC2) while promoting phosphorylation of mTOR, the effects of which were ablated by catalase. In vitro study revealed that palmitic acid compromised cardiomyocyte autophagy and contractile function in a manner reminiscent of fat diet intake, the effect of which was significantly alleviated by inhibition of IKKß, activation of AMPK and induction of autophagy. Taken together, our data revealed that the antioxidant catalase counteracts against high fat diet-induced cardiac geometric and functional anomalies possibly via an IKKß-AMPK-dependent restoration of myocardial autophagy. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.

Low-dose Exogenous Ouabain Alleviates Cardiac Lipotoxicity Through Suppressing Expression of CD36.

CD36 is a key transporter involved in fatty acid (FA) uptake and contributes to the accumulation of FA in cardiomyocytes. The objective of this study was to investigate the role of ouabain, a glycoside regulator of Na(+)/K(+)-ATPase, in the regulation of CD36 expression and FA accumulation. FATP1 transgenic (Tg) mice with lipotoxic cardiomyopathy displayed significantly increased cardiac CD36 expression and free fatty acid accumulation. The data on enzyme-linked immunosorbent assay showed that endogenous ouabain was decreased in the serum of Tg mice versus wild-type mice. CD36 expression and free fatty acid accumulation in their primary cardiomyocytes were abated by treatment with 0.15-0.30 µM ouabain. CD36 expression was suppressed by 0.2 µM ouabain treatment, and the suppression was rescued by C-reactive protein. CD36 expression and free fatty acid accumulation in the heart were markedly reduced in Tg mice injected with 30 or 40 ng of ouabain (P < 0.01). Obvious fatty infiltration was found in noninjected Tg mice but not in the mice injected with 40 ng of ouabain. In conclusion, low-dose exogenous ouabain increased Na(+)/K(+)-ATPase activity, suppressed C-reactive protein-mediated CD36 expression, and alleviated murine cardiac lipotoxicity in vitro and in vivo.

Reduction of large-conductance Ca²(+) -activated K(+) channel with compensatory increase of nitric oxide in insulin resistant rats.

Cardiovascular disease prevalence and mortality are both increased by insulin resistance, hypertension, and atherosclerosis. The large-conductance Ca(2+)-activated K(+) channel (BK(Ca)) plays a pivotal role in the diastolic function of vascular smooth muscle cells. However, the role of this channel in insulin resistance remains unknown. Male Sprague-Dawley rats were randomly divided into an insulin resistant group and control group. We investigated the BK(Ca) current and subunit expression in myocytes from aortas and mesenteric arteries by Western blot, real-time PCR and the whole-cell patch-clamp methods. BK(Ca) current was decreased in smooth muscle cells in insulin resistant rats, compared with that in control group. Peak BK(Ca) current at + 60 mV was significantly decreased after iberiotoxin (IBTX) perfusion at 100 nmol/L (64.2 ± 4.7 versus 20.3 ± 3.5% in thoracic aortas and 65.6 ± 6.2 versus 29.3 ± 3.9% in mesenteric arteries, both p < 0.01). However, there was no significant difference in BK(Ca) alpha subunit between the two groups, both at the level of mRNA and protein. BK(Ca) beta 1 subunit expression in aortas and mesenteric arteries from the insulin resistant group was lower than in those from control group. The plasma level of nitric oxide was higher in the insulin resistant group than in the control group. Our results demonstrated that the BK(Ca) channel is decreased both in macrovessels and microvessels in insulin resistant rats. These impairments may be related to the down-regulation of ß1 subunit expression and compensatory increase in plasma nitric oxide levels.

[Corrigendum] Bradykinin receptors and EphB2/EphrinB2 pathway in response to high glucose­induced osteoblast dysfunction and hyperglycemia­induced bone deterioration in mice.

Subsequent to the publication of the above article, the authors have realized that the published version of Fig. 7 contained some incorrect data. Essentially, the images for Fig. 7B were selected incorrectly. The correct version of Fig. 7, as it should have been featured in the article, is shown opposite. The errors associated with this Figure did not have an impact on the overall meaning of the paper, or on the reported conclusions of this study. The authors regret that this figure was not corrected prior to the publication of this article, and apologize to the readership for the inconvenience caused. [the original article was published in International Journal of Molecular Medicine 37: 565­574, 2016; DOI: 10.3892/ijmm.2016.2457].

Ghrelin ameliorates atherosclerosis by inhibiting endoplasmic reticulum stress.

The effects of ghrelin, a peptide hormone, on atherogenesis are mainly beneficial. This study aimed to investigate whether ghrelin ameliorates atherosclerosis (AS) by preventing endoplasmic reticulum stress (ERS). AS was induced by a high-fat diet in ApoE-/- mice. AS lesions in aortas were detected by Oil Red O staining, and the inner diameter and intima-media thickness (IMT) of the abdominal aorta were analyzed by ultrasonography. The protein expression of the ERS markers, 78-kDa glucose-regulated protein, C/EBP homologous protein, and active caspase-12, was detected by Western blot analysis. High-fat diet-fed ApoE-/- mice showed AS lesions and increased aortic IMT. Ghrelin ameliorated these findings. Moreover, the protein expression of ERS markers was upregulated in the AS aorta and downregulated by ghrelin treatment. The above beneficial effects of ghrelin on AS and ERS were blocked by the ERS inducer, tunicamycin. In rat aortic endothelial cells, oxidized low-density lipoprotein and tunicamycin triggered ERS, which could be inhibited by ghrelin pretreatment. These results suggest that ghrelin can ameliorate activation of ERS, which may be the beneficial effect of ghrelin on AS. Ghrelin may be a new target and strategy for prevention and therapy of AS.

Felodipine inhibits ox-LDL-induced reactive oxygen species production and inflammation in human umbilical vein endothelial cells.

Oxidative stress and inflammation are involved in the pathogenesis of atherosclerosis. Calcium channel blockers (CCBs) inhibit the development of atherosclerosis, although the underlying molecular basis has not been completely elucidated. The present study was designed to investigate the effects of felodipine, a CCB, on inflammation and oxidative stress in human umbilical vein endothelial cells (HUVECs) and to examine the underlying mechanisms of action. Oxidized low­density lipoprotein (ox­LDL) was used to induce an inflammatory response in HUVECs. The effects of felodipine were investigated by measuring the content of nitric oxide (NO) and reactive oxygen species (ROS), the mRNA and protein levels of intercellular adhesion molecule 1 (ICAM­1) and vascular cell adhesion protein 1 (VCAM­1), and the mRNA levels of endothelial NO synthase (eNOS) and inducible NO synthase (iNOS), in addition to the adhesion ability of U937 cells to HUVECs. ROS and NO levels were significantly increased in HUVECs following 24­h treatment with 25 mg/l ox­LDL (P<0.01). The increase in ROS was reversed by treatment with felodipine. In addition, NO levels were increased following treatment with 1 µmol/l felodipine (P<0.05). The mRNA expression of ICAM­1, VCAM­1, eNOS and iNOS was increased (P<0.05). Administration of 0.1 µM felodipine significantly decreased the expression of ICAM­1, VCAM­1, and iNOS (P<0.05). The number of U937 cells adhered to ox­LDL­treated HUVECs was significantly increased compared with control, which was reversed by felodipine (0.1 µM). In conclusion, felodipine was demonstrated to inhibit oxidative stress and inflammatory responses, suggesting that it may be used to treat atherosclerosis.

Bradykinin receptors and EphB2/EphrinB2 pathway in response to high glucose-induced osteoblast dysfunction and hyperglycemia-induced bone deterioration in mice.

This study was carried out in order to investigate bone dysfunction and the involvement of bradykinin receptors and the Eph/Ephrin signaling pathway in osteoblasts and in mice with diabetes-related osteoporosis in response to exposure to high glucose. Osteogenic transdifferentiation was inhibited when the osteoblasts were exposed to high glucose, and the expression levels of bone formation-related genes [Runx2 and alkaline phosphatase (ALP)] were decreased, while those of bone resorption-related genes [matrix metalloproteinase (MMP)9 and carbonic anhydrase II (CAII)] were increased. Moreover, the mRNA and protein expression levels of bradykinin receptor B1 (BK1R)/bradykinin receptor B2 (BK2R) and EphB2/EphrinB2 were significantly decreased in the osteoblasts following exposure to high glucose. Intriguingly, the interaction between BK2R and EphB2/EphrinB2 was confirmed, and BK2R loss-of-function significantly decreased the mRNA and protein expression levels of EphB2/EphrinB4. In vivo, hyperglycemia induced the disequilibrium of calcium homeostasis through the inhibition of bone formation and the acceleration of bone resorption, which was manifested by the reduction of trabecular bone mass of the primary and secondary spongiosa, as well as by the increase in the number of mature osteoclasts throughout the proximal tibial metaphysis in mice with diabetes-related osteoporosis. Furthermore, the mRNA and protein expression levels of BK1R/BK2R and EphB2/EphrinB2 in the tibias of the mice with diabetes-related osteoporosis were significantly decreased. These results demonstrate that bradykinin receptors and the EphB4/EphrinB2 pathway mediate the development of complications in mice with diabetes-related osteoporosis and suggest that the inactivation of bradykinin receptors and the EphB4/EphrinB2 pathway enhance the severity of complications in mice with diabetes-related osteoporosis.