Aerobic Exercise Attenuates Pressure Overload-Induced Myocardial Remodeling and Myocardial Inflammation via Upregulating miR-574-3p in Mice.

BACKGROUND: Exercise training can promote cardiac rehabilitation, thereby reducing cardiovascular disease mortality and hospitalization rates. MicroRNAs (miRs) are closely related to heart disease, among which miR-574-3p plays an important role in myocardial remodeling, but its role in exercise-mediated cardioprotection is still unclear. METHODS: A mouse myocardial hypertrophy model was established by transverse aortic coarctation, and a 4-week swimming exercise training was performed 1 week after the operation. After swimming training, echocardiography was used to evaluate cardiac function in mice, and histopathologic staining was used to detect cardiac hypertrophy, myocardial fibrosis, and cardiac inflammation. Quantitative real-time polymerase chain reaction was used to detect the expression levels of miR-574-3p and cardiac hypertrophy markers. Western blotting detected the IL-6 (interleukin-6)/JAK/STAT inflammatory signaling pathway. RESULTS: Echocardiography and histochemical staining found that aerobic exercise significantly improved pressure overload-induced myocardial hypertrophy (n=6), myocardial interstitial fibrosis (n=6), and cardiac inflammation (n=6). Quantitative real-time polymerase chain reaction detection showed that aerobic exercise upregulated the expression level of miR-574-3p (n=6). After specific knockdown of miR-574-3p in mouse hearts with adeno-associated virus 9 using cardiac troponin T promoter, we found that the protective effect of exercise training on the heart was significantly reversed. Echocardiography and histopathologic staining showed that inhibiting the expression of miR-574-3p could partially block the effects of aerobic exercise on cardiac function (n=6), cardiomyocyte cross-sectional area (n=6), and myocardial fibrosis (n=6). Western blotting and immunohistochemical staining showed that the inhibitory effects of aerobic exercise on the IL-6/JAK/STAT pathway and cardiac inflammation were partially abolished after miR-574-3p knockdown. Furthermore, we also found that miR-574-3p exerts cardioprotective effects in cardiomyocytes by targeting IL-6 (n=3). CONCLUSIONS: Aerobic exercise protects cardiac hypertrophy and inflammation induced by pressure overload by upregulating miR-574-3p and inhibiting the IL-6/JAK/STAT pathway.

Loss of USP22 alleviates cardiac hypertrophy induced by pressure overload through HiF1-α-TAK1 signaling pathway.

Ubiquitin-specific protease 22 (USP22) is a member of the ubiquitin specific protease family (ubiquitin-specific protease, USPs), the largest subfamily of deubiquitinating enzymes, and plays an important role in the treatment of tumors. USP22 is also expressed in the heart. However, the role of USP22 in heart disease remains unclear. In this study, we found that USP22 was elevated in hypertrophic mouse hearts and in angiotensin II (Ang II)-induced cardiomyocytes. The inhibition of USP22 expression with adenovirus significantly rescued hypertrophic phenotype and cardiac dysfunction induced by pressure overloaded. Consistent with in vivo study, silencing by USP22 shRNA expression in vitro had similar results. Molecular analysis revealed that transforming growth factor-ß-activating protein 1 (TAK1)-(JNK1/2)/P38 signaling pathway and HIF-1α was activated in the Ang II-induced hypertrophic cardiomyocytes, whereas HIF-1α expression was decreased after the inhibition of USP22. Inhibition of HIF-1α expression reduces TAK1 expression. Co-immunoprecipitation and ubiquitination studies revealed the regulatory mechanism between USP22 and HIF1α.Under hypertrophic stress conditions, USP22 enhances the stability of HIF-1α through its deubiquitination activity, which further activates the TAK1-(JNK1/2)/P38 signaling pathway to lead to cardiac hypertrophy. Inhibition of HIF-1α expression further potentiates the in vivo pathological effects caused by USP22 deficiency. In summary, this study suggests that USP22, through HIF-1α-TAK1-(JNK1/2)/P38 signaling pathway, may be potential targets for inhibiting pathological cardiac hypertrophy induced by pressure overload.

Cardiac-Specific Overexpression of Caveolin-1 in Rats With Ischemic Cardiomyopathy Improves Arrhythmogenicity and Cardiac Remodelling.

BACKGROUND: Ischemic cardiomyopathy (ICM) is associated with electrical and structural remodelling, leading to arrhythmias. Caveolin-1 (Cav1) is a membrane protein involved in the pathogenesis of ischemic injury. Cav1 deficiency has been associated with arrhythmogenicity. The current study aimed to determine how Cav1 overexpression inhibits arrhythmias and cardiac remodelling in ICM. METHODS: ICM was modelled using left anterior descending (LAD) artery ligation for 4 weeks. Cardiac-specific Cav1 overexpression in ICM on arrhythmias, excitation-contraction coupling, and cardiac remodelling were investigated using the intramyocardial injection of an adeno-associated virus serotype 9 (AAV-9) system, carrying a specific sequence expressing Cav1 (AAVCav1) under the cardiac troponin T (cTnT) promoter. RESULTS: Cav1 overexpression decreased susceptibility to arrhythmias by upregulating gap junction connexin 43 (CX43) and reducing spontaneous irregular proarrhythmogenic Ca2+ waves in ventricular cardiomyocytes. It also alleviated ischemic injury-induced contractility weakness by improving Ca2+ cycling through normalizing Ca2+-handling protein levels and improving Ca2+ homeostasis. Masson stain and immunoblotting revealed that the deposition of excessive fibrosis was attenuated by Cav1 overexpression, inhibiting the transforming growth factor-ß (TGF-ß)/Smad2 signalling pathway. Coimmunoprecipitation assays demonstrated that the interaction between Cav1 and cSrc modulated CX43 expression and Ca2+-handling protein levels. CONCLUSIONS: Cardiac-specific overexpression of Cav1 attenuated ventricular arrhythmia, improved Ca2+ cycling, and attenuated cardiac remodelling. These effects were attributed to modulation of CX43, normalized Ca2+-handling protein levels, improved Ca2+ homeostasis, and attenuated cardiac fibrosis.

Metformin inhibits metastatic breast cancer progression and improves chemosensitivity by inducing vessel normalization via PDGF-B downregulation.

BACKGROUND: Vascular maturity and functionality are closely associated with tumor progression and chemosensitivity. The antidiabetic agent metformin has shown its ability to inhibit tumor angiogenesis in metastatic breast cancer models. However, it remains unclear if or how metformin remodels the abnormal vasculature of metastatic breast cancer, while inhibiting angiogenesis. METHODS: Metastatic breast cancer models were constructed to compare microvessel density (MVD), vascular maturity and function, lung metastasis and chemosensitivity in metformin-treated or untreated mice. Protein array assay and transcriptome sequencing were performed for genetic screening. Lentiviral shRNA-PDGF-B transfection was used for observing the contribution of PDGF-B knockdown to metformin's vascular effects. RESULTS: Metastatic breast cancers were characterized by an excessively angiogenic, immature and morphologically abnormal vasculature. Compared to control, metformin significantly reduced MVD, leakage and hypoxia, and increased vascular mural cells coverage and perfusion, namely, "vessel normalization". Metformin at human blood concentrations had no direct effect on the migration and proliferation of cancer cells. Based on that, reduced lung metastasis of the primary tumor and improved chemosensitization by metformin were assumed to be mediated via metformin's vascular effects. Further results of genetic screening and in vivo experiments showed that the downregulation of platelet-derived growth factor B (PDGF-B) greatly contributed to the metformin-induced vessel normalization. CONCLUSIONS: These findings provide pre-clinical evidences for the vascular mechanism of metformin-induced metastasis inhibition and the chemosensitization of metastatic breast cancers.

Interleukin 6-triggered ataxia-telangiectasia mutated kinase activation facilitates epithelial-to-mesenchymal transition in lung cancer by upregulating vimentin expression.

Matrix metalloproteinases (MMPs) and the epithelial-mesenchymal transition (EMT) contribute to metastasis. As shown in our previous studies, interleukin-6 (IL-6) induces ATM phosphorylation to increase MMP expression and metastasis in lung cancer. However, the exact roles of ATM activation in the IL-6-induced epithelial-mesenchymal transition and lung cancer metastasis are currently unclear. Here, ATM phosphorylation exerts its pro-metastatic effect via vimentin-mediated epithelial-mesenchymal transition, which was supported by the evidence described below. Firstly, IL-6 treatment increases vimentin expression via the ATM-NF-κB pathway. Second, ATM inactivation not only abolishes IL-6-induced increases in vimentin expression but also inhibits IL-6-induced nest formation in a xenograft lung metastasis model. Moreover, close positive correlations were observed between ATM phosphorylation and vimentin upregulation, IL-6 levels and metastasis in lung cancer specimens. Hence, ATM modulates vimentin expression to facilitate IL-6-induced epithelial-mesenchymal transition and metastasis in lung cancer, indicating that ATM and vimentin might be potential therapeutic targets for inflammation-associated lung cancer metastasis.

Activation of the IL-6/JAK2/STAT3 pathway induces plasma cell mastitis in mice.

Plasma cell mastitis (PCM) is a chronic mastitis with limited treatment options and common recurrence. A histopathological hallmark of PCM is the infiltration of numerous plasma cells surrounding the mammary duct. Our previous study showed that the activity of the IL-6/STAT3 signaling pathway was elevated in patients with PCM. However, the etiology of PCM remains largely unclear. In this study, we sought to explore the effects of IL-6/JAK2/STAT3 signaling pathway in the pathogenesis of PCM. Histological analysis showed that the mammary glands of mice that received human breast tissue homogenates, followed by an injection of IL-6, exhibited features of PCM similar to human PCM. The IL-6/JAK2/STAT3 signaling activity was significantly elevated and Bcl-2 was highly expressed in CD138 + plasma cells in the mammary glands of mice with PCM. Furthermore, treatment with AG-490, an inhibitor of JAK family kinases, suppressed activation of the IL-6/JAK2/STAT3 signaling cascade, in turn resulting in a decreased number of plasma cells in the mammary gland and reversing the pathogenesis of PCM. Taken together, our study indicated that a PCM mouse model was successfully established through activation of the IL-6/JAK2/STAT3 pathway by injecting IL-6 into the mammary gland of mouse that had received homogenates of human breast tissue. Thus, the IL-6/JAK2/STAT3 signaling pathway plays a critical role in orchestrating the pathogenesis of PCM.

RTP801 is a critical factor in the neurodegeneration process of A53T α-synuclein in a mouse model of Parkinson's disease under chronic restraint stress.

BACKGROUND AND PURPOSE: Recently, the incidence of Parkinson's disease has shown a tendency to move to a younger population, linked to the constantly increasing stressors of modern society. However, this relationship remains obscure. Here, we have investigated the contribution of stress and the mechanisms underlying this change. EXPERIMENTAL APPROACH: Ten-month-old α-synuclein A53T mice, a model of Parkinson's disease (PD), were treated with chronic restraint stress (CRS) to simulate a PD-sensitive person with constant stress stimulation. PD-like behavioural tests and pathological changes were evaluated. Differentiated PC12-A53T cells were treated with corticosterone in vitro. We used Western blot, microRNA expression analysis, immunofluorescence staining, dual luciferase reporter assay and HPLC electrochemical detection to assess cellular and molecular networks after stress treatment. In vivo, stereotaxic injection of shRNA lentivirus was used to confirm our in vitro results. KEY RESULTS: The protein RTP801 is encoded by DNA-damage-inducible transcript 4, and it was specifically increased in dopaminergic neurons of the substantia nigra after CRS treatment. RTP801 was post-transcriptionally inhibited by the down-regulation of miR-7. Delayed turnover of RTP801, through the inhibition of proteasome degradation also contributed to its high content. Elevated RTP801 blocked autophagy, thus increasing accumulation of oligomeric α-synuclein and aggravating endoplasmic reticulum stress. RTP801 inhibition alleviated the symptoms of neurodegeneration during this process. CONCLUSIONS AND IMPLICATIONS: RTP801 is a promising target for the treatment of PD, especially for PD-sensitive patients who live under increased social pressure. Down-regulation of RTP801 could inhibit the current tendency to an earlier onset of PD.

Bioactive Coumarins from the Stems of Clausena emarginata.

Five new coumarins, clauemarmarins I - M (1 - 4), together with 10 known analogs (5 - 14), were isolated from the stems of Clausena emarginata. Compounds 8 - 13 were obtained from this plant for the first time. Their structures were established and elucidated by comprehensive analysis of spectroscopic data. The absolute configurations of 1 - 4 were further determined by their electronic circular dichroism spectroscopy. Compounds 5, 7, 12, and 14 exhibited inhibitory effects on LPS-induced NO production. Compounds 5 - 7 showed selective neuroprotective effects in Aß25 - 35 model at 10 µm.

Interleukin 6 trigged ataxia-telangiectasia mutated activation facilitates lung cancer metastasis via MMP-3/MMP-13 up-regulation.

Our previous studies show that the phosphorylation of ataxia-telangiectasia mutated (ATM) induced by interleukin 6 (IL-6) treatment contributes to multidrug resistance formation in lung cancer cells, but the exact role of ATM activation in IL-6 increased metastasis is still elusive. In the present study, matrix metalloproteinase-3 (MMP-3) and MMP-13 were firstly demonstrated to be involved in IL-6 correlated cell migration. Secondly, IL-6 treatment not only increased MMP-3/MMP-13 expression but also augmented its activities. Thirdly, the inhibition of ATM phosphorylation efficiently abolished IL-6 up-regulating MMP-3/MMP-13 expression and increasing abilities of cell migration. Most importantly, the in vivo test showed that the inhibition of ATM abrogate the effect of IL-6 on lung cancer metastasis via MMP-3/MMP-13 down-regulation. Taken together, these findings demonstrate that IL-6 inducing ATM phosphorylation increases the expression of MMP-3/MMP-13, augments the abilities of cell migration, and promotes lung cancer metastasis, indicating that ATM is a potential target molecule to overcome IL-6 correlated lung cancer metastasis.

Gelatin nanoparticle-mediated intranasal delivery of substance P protects against 6-hydroxydopamine-induced apoptosis: an in vitro and in vivo study.

BACKGROUND: The aim of this study was to investigate the protective role of intranasally administered substance P-loaded gelatin nanoparticles (SP-GNPs) against 6-hydroxydopamine (6-OHDA)-induced apoptosis in vitro and in vivo, and to provide a new strategy for treating brain pathology, such as Parkinson's disease. METHODS: SP-GNPs were prepared by a water-in-water emulsion method, and their stability, encapsulating efficiency, and loading capacity were evaluated. PC-12 cells were used to examine the enhancement of growth and inhibition of apoptosis by SP-GNPs in vitro using MTT assays. In the in vivo study, hemiparkinsonian rats were created by intracerebroventricular injection of 6-OHDA. The rats then received intranasal SP-GNPs daily for 2 weeks. Functional improvement was assessed by quantifying rotational behavior, and the degree of apoptosis was assessed by immunohistochemical staining for caspase-3 in the substantia nigra region. RESULTS: PC-12 cells with 6-OHDA-induced disease treated with SP-GNPs showed higher cell viability than their untreated counterparts, and cell viability increased as the concentration of substance P (SP) increased, indicating that SP could enhance cell growth and inhibit the cell apoptosis induced by 6-OHDA. Rats with 6-OHDA-induced hemiparkinsonism treated with SP-GNPs made fewer rotations and showed less staining for caspase-3 than their counterparts not treated with SP, indicating that SP protects rats with 6-OHDA-induced hemiparkinsonism from apoptosis and therefore demonstrates their functional improvement. CONCLUSION: Intranasal delivery of SP-GNPs protects against 6-OHDA-induced apoptosis both in vitro and in vivo.

TIPE2 inhibits TNF-α-induced hepatocellular carcinoma cell metastasis via Erk1/2 downregulation and NF-κB activation.

Tumor necrosis factor-α-induced protein 8-like 2 (TNFAIP8L2, TIPE2), which belongs to the TNF-α-induced protein 8 family, is a negative regulator of immune homeostasis. Although pro-inflammatory cytokines such as TNF-α have been reported to be involved in liver carcinoma metastasis, the effect of TIPE2 on hepatocellular carcinoma metastasis remains unknown. We demonstrate that TNF-α clearly augments MMP-13/MMP-3 expression and promotes cell migration in HepG2 cells through activation of the Erk1/2-NF-κB pathways. Interestingly, in addition to human PBLs, macrophages and fibroblasts, liver cancer cells specifically express TNF-α following LPS treatment. Most importantly, TIPE2 overexpression efficiently abrogates the effects of LPS on TNF-α secretion and abolishes the effects of TNF-α on MMP-13/MMP-3 upregulation, cell migration and Erk1/2-NF-κB activation. Taken together, these findings demonstrate that TIPE2 was able to suppress TNF-α-induced hepatocellular carcinoma metastasis by inhibiting Erk1/2 and NF-κB activation, indicating that both TNF-α and TIPE2 might be potential targets for the treatment of HCC metastasis.

IL-6/STAT3 signaling pathway is activated in plasma cell mastitis.

Plasma cell mastitis (PCM), a particular type of mastitis, mainly occurs in females at nonpregnant and nonlactating stages. The infiltration of abundant plasma cells and lymphocytes is the hallmark of the disease. The incidence rate of PCM increased gradually and its pathogenesis remained unclear. In this study, we investigated the expression of IL-6/STAT3 signaling pathway, which is vital not only for the differentiation of plasma cells but also for survival of plasma cells and T lymphocytes, in 30 PCM cases, 10 acute mastitis cases and 10 normal breast tissues by immunohistochemical analysis. IL-6 level was significantly higher in PCM patients than in acute mastitis patients or normal group. The positive rate of IL-6 and p-STAT3 staining in PCM samples was 93.3% (28/30) and 70% (21/30), respectively, and there was a significant positive association between IL-6 and p-STAT3 staining (r=0.408, P=0.025). In PCM group, the rate of nipple retraction was 40% (12/30). Significantly higher IL-6 expression was found in PCM patients with nipple retraction than in other PCM patients. However, no significant difference in IL-6 or p-STAT3 staining was detected between PCM patients experiencing recurrence and other PCM patients. In addition, Bcl-2 level was higher in PCM patients than in acute mastitis patients or normal group, but there was no difference in Bcl-2 immunostaining between PCM patients experiencing recurrence and other PCM patients. These indicate that IL-6/STAT3 signaling is activated in PCM and may play an important role in the pathogenesis of PCM.

Interleukin 6 augments lung cancer chemotherapeutic resistance via ataxia-telangiectasia mutated/NF-kappaB pathway activation.

Although it is known that ataxia-telangiectasia mutated (ATM) and interleukin 6 (IL-6) contribute to multiple drug resistance (MDR) in tumor chemotherapy, the exact role of ATM activation in MDR resulting from increased IL-6 expression is still unclear. In the present study, we demonstrate that the activation of the ATM-NF-kappaB pathway, resulting from increased IL-6 expression, plays a central role in augmented chemoresistance in lung cancer cell lines. This result was supported by the increased expressions of Bcl-2, Mcl-1, Bcl-xl, and the upregulation of MDR-associated protein ABCG2. The higher level of IL-6 reveals not only higher ATM/NF-kappaB activity but also increased expressions of ABCG2, Bcl-2, Mcl-1 and Bcl-xl. Most importantly, lung cancer cells themselves upregulated IL-6 secretion by activating the p38/NF-kappaB pathway through treatment with cisplatin and camptothecin. Taken together, these findings demonstrate that chemotherapeutic agents increase IL-6 expression, hence activating the ATM/NF-kappaB pathway, augmenting anti-apoptotic protein expression and contributing to MDR. This indicates that both IL-6 and ATM are potential targets for the treatment of chemotherapeutic resistance in lung cancer.

The natural outcome of melamine-induced bladder stones with bladder epithelial hyperplasia after the withdrawal of melamine in mice.

The natural outcome of melamine-induced bladder stones (cystoliths) with bladder epithelial hyperplasia (BEH) after melamine withdrawn is unclear. Using an ideal dual-model system, three experiments were conducted in BALB/c mice. Each experiment included a control, model 1 and model 2 groups. The mice were fed a regular diet in controls or a 9373 ppm melamine diet in models, and the first day was designated as dosing day 1. The melamine diet was then replaced by the regular diet in the model 2 groups, and the first day was designated as post-dosing day 1. On dosing days 12, 35 and 49, the incidence of cystoliths and diffusely active BEH was 8/8 in the mice of three model 1 groups. On post-dosing days 1, 4 and 8, in the mice of three model 2 groups, the incidence of cystoliths was 2/8, 0/8 and 1/8, respectively, and the progressive regression of BEH was observed. In conclusion, both the stones and BEH have the natural property of rapid development and rapid regression, and melamine withdrawn plays a key role in the stone dissolution-discharge necessary for BEH regression. BEH may be reversible after the discharge of the stones. The conventionally conservative therapy is thus reasonable.