Systematic in vivo candidate evaluation uncovers therapeutic targets for LMNA dilated cardiomyopathy and risk of Lamin A toxicity.

BACKGROUND: Dilated cardiomyopathy (DCM) is a severe, non-ischemic heart disease which ultimately results in heart failure (HF). Decades of research on DCM have revealed diverse aetiologies. Among them, familial DCM is the major form of DCM, with pathogenic variants in LMNA being the second most common form of autosomal dominant DCM. LMNA DCM is a multifactorial and complex disease with no specific treatment thus far. Many studies have demonstrated that perturbing candidates related to various dysregulated pathways ameliorate LMNA DCM. However, it is unknown whether these candidates could serve as potential therapeutic targets especially in long term efficacy. METHODS: We evaluated 14 potential candidates including Lmna gene products (Lamin A and Lamin C), key signaling pathways (Tgfß/Smad, mTor and Fgf/Mapk), calcium handling, proliferation regulators and modifiers of LINC complex function in a cardiac specific Lmna DCM model. Positive candidates for improved cardiac function were further assessed by survival analysis. Suppressive roles and mechanisms of these candidates in ameliorating Lmna DCM were dissected by comparing marker gene expression, Tgfß signaling pathway activation, fibrosis, inflammation, proliferation and DNA damage. Furthermore, transcriptome profiling compared the differences between Lamin A and Lamin C treatment. RESULTS: Cardiac function was restored by several positive candidates (Smad3, Yy1, Bmp7, Ctgf, aYAP1, Sun1, Lamin A, and Lamin C), which significantly correlated with suppression of HF/fibrosis marker expression and cardiac fibrosis in Lmna DCM. Lamin C or Sun1 shRNA administration achieved consistent, prolonged survival which highly correlated with reduced heart inflammation and DNA damage. Importantly, Lamin A treatment improved but could not reproduce long term survival, and Lamin A administration to healthy hearts itself induced DCM. Mechanistically, we identified this lapse as caused by a dose-dependent toxicity of Lamin A, which was independent from its maturation. CONCLUSIONS: In vivo candidate evaluation revealed that supplementation of Lamin C or knockdown of Sun1 significantly suppressed Lmna DCM and achieve prolonged survival. Conversely, Lamin A supplementation did not rescue long term survival and may impart detrimental cardiotoxicity risk. This study highlights a potential of advancing Lamin C and Sun1 as therapeutic targets for the treatment of LMNA DCM.

ß-elemene alleviates hyperglycemia-induced cardiac inflammation and remodeling by inhibiting the JAK/STAT3-NF-κB pathway.

BACKGROUND: Hyperglycemic induced cardiac hypertrophy and cardiac inflammation are important pathological processes in diabetic cardiomyopathy. ß-elemene (Ele) is a natural compound extracted from Curcuma Rhizoma and has anti-tumor effects. It also has therapeutic effects in some inflammatory diseases. However, the therapeutic effect of Ele on diabetic cardiomyopathy is not clear. The purpose of this study was to evaluate the effect of Ele on hyperglycemia-caused cardiac remodeling and heart failure. METHODS: C57BL/6 mice were intraperitoneally injected with streptozotocin to induce DCM, and Ele was administered intragastric after 8 weeks to investigate the effect of Ele. RNA sequencing of cardiac tissue was performed to investigate the mechanism. RESULTS: Ele markedly inhibited cardiac inflammation, fibrosis and hypertrophy in diabetic mice, as well as in high glucose-induced cardiomyocytes. RNA sequencing showed that cardioprotective effect of Ele involved the JAK/STAT3-NF-κB signaling pathway. Ele alleviated heart and cardiomyocyte inflammation in mice by blocking diabetes-induced JAK2 and STAT3 phosphorylation and NF-κB activation. CONCLUSIONS: The study found that Ele preserved the hearts of diabetic mice by inhibiting JAK/STAT3 and NF-κB mediated inflammatory responses, suggesting that Ele is an effective therapy for DCM.

Protection against Doxorubicin-Induced Cardiotoxicity by Ergothioneine.

Background: Anthracyclines such as doxorubicin remain a primary treatment for hematological malignancies and breast cancers. However, cardiotoxicity induced by anthracyclines, possibly leading to heart failure, severely limits their application. The pathological mechanisms of anthracycline-induced cardiac injury are believed to involve iron-overload-mediated formation of reactive oxygen species (ROS), mitochondrial dysfunction, and inflammation. The dietary thione, ergothioneine (ET), is avidly absorbed and accumulated in tissues, including the heart. Amongst other cytoprotective properties, ET was shown to scavenge ROS, decrease proinflammatory mediators, and chelate metal cations, including Fe2+, preventing them from partaking in redox activities, and may protect against mitochondrial damage and dysfunction. Plasma ET levels are also strongly correlated to a decreased risk of cardiovascular events in humans, suggesting a cardioprotective role. This evidence highlights ET's potential to counteract anthracycline cardiotoxicity. Methods and Findings: We investigated whether ET supplementation can protect against cardiac dysfunction in mice models of doxorubicin-induced cardiotoxicity and revealed that it had significant protective effects. Moreover, ET administration in a mouse breast cancer model did not exacerbate the growth of the tumor or interfere with the chemotherapeutic efficacy of doxorubicin. Conclusion: These results suggest that ET could be a viable co-therapy to alleviate the cardiotoxic effects of anthracyclines in the treatment of cancers.

Tabersonine attenuates obesity-induced renal injury via inhibiting NF-κB-mediated inflammation.

Obesity-induced metabolic disorders can cause chronic inflammation in the whole body, activating the nuclear factor kappa B (NF-κB) pathway and inducing apoptosis. Therefore, anti-inflammatory strategies may be effective in preventing obesity-related renal injury. Tabersonine (Tab) has been used pharmacologically to alleviate inflammation-related symptoms. This study evaluated the therapeutic effect of Tab on obesity-related renal injury and explored the pharmacological mechanism. Tab (20 mg/kg) relieved HFD-induced renal structural disorder and alleviated renal functional decline in mice, including improvement of renal tissue fibrosis, reducing renal cell apoptosis and inflammation in renal tissues. Mechanistically, we demonstrated that Tab inhibited the activation of NF-κB signaling pathway both in vivo and in vitro, thereby improving the renal tissue lesions in the mice with obesity-related renal injury. In both the obese mouse model and the mouse glomerular mesangial cell model, the natural compound Tab ameliorated HFD- and saturated fatty acid-induced renal cell injury by inhibiting the activation of NF-κB signaling pathway. Our data suggest that Tab may become a potential candidate for the prevention and treatment of obesity-related renal injury.

Yin Yang 1 Suppresses Dilated Cardiomyopathy and Cardiac Fibrosis Through Regulation of Bmp7 and Ctgf.

RATIONALE: Pathogenic variations in the lamin gene (LMNA) cause familial dilated cardiomyopathy (DCM). LMNA insufficiency caused by LMNA pathogenic variants is believed to be the basic mechanism underpinning LMNA-related DCM. OBJECTIVE: To assess whether silencing of cardiac Lmna causes DCM and investigate the role of Yin Yang 1 (Yy1) in suppressing Lmna DCM. METHODS AND RESULTS: We developed a Lmna DCM mouse model induced by cardiac-specific Lmna short hairpin RNA. Silencing of cardiac Lmna induced DCM with associated cardiac fibrosis and inflammation. We demonstrated that upregulation of Yy1 suppressed Lmna DCM and cardiac fibrosis by inducing Bmp7 expression and preventing upregulation of Ctgf. Knockdown of upregulated Bmp7 attenuated the suppressive effect of Yy1 on DCM and cardiac fibrosis. However, upregulation of Bmp7 alone was not sufficient to suppress DCM and cardiac fibrosis. Importantly, upregulation of Bmp7 together with Ctgf silencing significantly suppressed DCM and cardiac fibrosis. Mechanistically, upregulation of Yy1 regulated Bmp7 and Ctgf reporter activities and modulated Bmp7 and Ctgf gene expression in cardiomyocytes. Downregulation of Ctgf inhibited TGF-ß (transforming growth factor-ß)/Smad signaling in DCM hearts. Regulation of both Bmp7 and Ctgf further suppressed TGFß/Smad signaling. In addition, co-modulation of Bmp7 and Ctgf reduced CD3+ T cell numbers in DCM hearts. CONCLUSIONS: Our findings demonstrate that upregulation of Yy1 or co-modulation of Bmp7 and Ctgf offer novel therapeutic strategies for the treatment of DCM caused by LMNA insufficiency.

Liposome encapsulated berberine treatment attenuates cardiac dysfunction after myocardial infarction.

Inflammation is a known mediator of adverse ventricular remodeling after myocardial infarction (MI) that may lead to reduction of ejection fraction and subsequent heart failure. Berberine is a isoquinoline quarternary alkaloid from plants that has been associated with anti-inflammatory, anti-oxidative, and cardioprotective properties. Its poor solubility in aqueous buffers and its short half-life in the circulation upon injection, however, have been hampering the extensive usage of this natural product. We hypothesized that encapsulation of berberine into long circulating liposomes could improve its therapeutic availability and efficacy by protecting cardiac function against MI in vivo. Berberine-loaded liposomes were prepared by ethanol injection and characterized. They contained 0.3mg/mL of the drug and were 0.11µm in diameter. Subsequently they were tested for IL-6 secretion inhibition in RAW 264.7 macrophages and for cardiac function protection against adverse remodeling after MI in C57BL/6J mice. In vitro, free berberine significantly inhibited IL-6 secretion (IC50=10.4µM), whereas encapsulated berberine did not as it was not released from the formulation in the time frame of the in vitro study. In vivo, berberine-loaded liposomes significantly preserved the cardiac ejection fraction at day 28 after MI by 64% as compared to control liposomes and free berberine. In conclusion, liposomal encapsulation enhanced the solubility of berberine in buffer and preserves ejection fraction after MI. This shows that delivery of berberine-loaded liposomes significantly improves its therapeutic availability and identifies berberine-loaded liposomes as potential treatment of adverse remodeling after MI.

Impact of crosslinking/riboflavin-UVA-photodynamic inactivation on viability, apoptosis and activation of human keratocytes in vitro.

Riboflavin-UVA photodynamic inactivation is a potential treatment alternative in therapy resistant infectious keratitis. The purpose of our study was to determine the impact of riboflavin-UVA photodynamic inactivation on viability, apoptosis and activation of human keratocytes in vitro. Primary human keratocytes were isolated from human corneal buttons and cultured in DMEM/Ham's F12 medium supplemented with 10% fetal calf serum. Keratocytes underwent UVA light illumination (375 nm) for 4.10 minutes (2 J/cm²) during exposure to different concentrations of riboflavin. Twenty-four hours after treatment, cell viability was evaluated photometrically, whereas apoptosis, CD34 and alpha-smooth muscle actin (α-SMA) expression were assessed using flow cytometry. We did not detect significant changes in cell viability, apoptosis, CD34 and α-SMA expression in groups only treated with riboflavin or UVA light. In the group treated with riboflavin-UVA-photodynamic inactivation, viability of keratocytes decreased significantly at 0.1% riboflavin (P<0.01) while the percentage of CD34 (P<0.01 for both 0.05% and 0.1% riboflavin) and alpha-SMA positive keratocytes (P<0.01 and P<0.05 for 0.05% and 0.1% riboflavin, respectively) increased significantly compared to the controls. There was no significant change in the percentage of apoptotic keratocytes compared to controls at any of the used riboflavin concentrations (P=0.09 and P=0.13). We concluded that riboflavin-UVA-photodynamic-inactivation decreases viability of myofibroblastic transformation and multipotent haematopoietic stem cell transformation; however, it does not have an impact on apoptosis of human keratocytes in vitro.

Viability, apoptosis, proliferation, activation, and cytokine secretion of human keratoconus keratocytes after cross-linking.

PURPOSE: The purpose of this study was to determine the impact of cross-linking (CXL) on viability, apoptosis, proliferation, activation, and cytokine secretion of human keratoconus (KC) keratocytes, in vitro. METHODS: Primary KC keratocytes were cultured in DMEM/Ham's F12 medium supplemented with 10% FCS and underwent UVA illumination (370 nm, 2 J/cm(2)) during exposure to 0.1% riboflavin and 20% Dextran in PBS. Twenty-four hours after CXL, viability was assessed using Alamar blue assay; apoptosis using APO-DIRECT Kit; proliferation using ELISA-BrdU kit; and CD34 and alpha-smooth muscle actin (α-SMA) expression using flow cytometry. Five and 24 hours after CXL, FGFb, HGF, TGFß1, VEGF, KGF, IL-1ß, IL-6, and IL-8 secretion was measured using enzyme-linked-immunoabsorbent assay (ELISA). RESULTS: Following CXL, cell viability and proliferation decreased (P < 0.05; P = 0.009), the percentage of apoptotic keratocytes increased (P < 0.05) significantly, and CD34 and α-SMA expression remained unchanged (P > 0.06). Five hours after CXL, FGFb secretion increased significantly (P = 0.037); however no other cytokine secretion differed significantly from controls after 5 or 24 hours (P > 0.12). CONCLUSIONS: Cross-linking decreases viability, triggers apoptosis, and inhibits proliferation, without an impact on multipotent hematopoietic stem cell transformation and myofibroblastic transformation of KC keratocytes. CXL triggers FGFb secretion of KC keratocytes transiently (5 hours), normalizing after 24 hours.

[Studies on chemical constituents from leaves of Uraria lacei].

OBJECTIVE: To study the chemical constituents from leaves of Uraria lacei. METHOD: Chemical constituents were isolated by silica gel column and Sephadex LH-20, and identified by physiochemical and spectral analyses and by comparison with the standard compounds. RESULT: Eleven compounds were isolated and identified as naringenin-7-0-beta-D-glucopyranside (1), (2S)-5, 7-dimethoxy-4'-hydroxyflavan (2), dalbergioidin (3), 5, 7-dihydroxy-2'-methoxy-3', 4'-methylenedioxyisoflavanone (4), apigenin (5), 5, 7-dihydroxy-2', 4'-dimethoxyisoflavanone (6), 5, 7, 2', 4'-tetrahydroxyisoflavone (7), emodin (8), saliylic acid (9), daucosterol (10), and tetracosane (11). CONCLUSION: All compounds were isolated from this plant for the first time.

[Studies on the chemical constituents of the stems of Piper betle].

OBJECTIVE: To study the chemical constituents from the stems of Piper betle. METHODS: Various chromatographic techniques were used to isolate and purify the constituents. The structures of these compounds were elucidated on the basis of spectral analysis. RESULTS: Nine compounds were isolated from the petroleum ester and ethyl acetate soluble fractions of the 70% acetone extract and their structures were identified as 6beta-hydroxystigmast-4-en-3-one (1), beta-sitosterol (2), stigmasterol (3), oleanolic acid (4), 23-hydroxyursan-12-en-28-oic acid (5), beta-sitosterol-3-O-beta-D-glucoside-6'-O-palmitate (6), beta-daucosterol (7), (2S) -4'-hydroxy- 2,3-dihydroflavonone-7-O-beta-D-glucoside (8) and alpha-ethyl glucoside (9). CONCLUSION: Among these compounds, 1, 3 -9 are isolated from this plant for the first time.