Colchicine Prevents Cardiac Rupture in Mice with Myocardial Infarction by Inhibiting P53-Dependent Apoptosis.

Shen L ，Huang S ，Fan H ，Zhai C ... -  《-》

Olmesartan prevents cardiac rupture in mice with myocardial infarction by modulating growth differentiation factor 15 and p53.

Cardiac rupture is a catastrophic complication that occurs after acute myocardial infarction (MI) and, at present, there are no effective pharmacological strategies for preventing this condition. Here we investigated the effect of the angiotensin II receptor blocker olmesartan (Olm) on post-infarct cardiac rupture and its underlying mechanisms of action. C57Bl/6 mice with MI were treated with Olm, aldosterone (Aldo) or vehicle. Cultured neonatal cardiomyocytes and fibroblasts were exposed to normoxia or anoxia and treated with angiotensin II (Ang II), RNH6270 (active ingredient of Olm) or Aldo. The mortality rate and incidence of cardiac rupture in MI mice during the first week in the Olm-treated group were significantly lower than in the vehicle-treated group. Olm or RNH6270 reduced myeloperoxidase staining in the infarcted myocardium, decreased apoptosis in cultured cardiomyocytes and fibroblasts, as assessed by Hoechst staining and TUNEL assay, attenuated the accumulation of p53 and phosphorylated p53 and cleaved caspase 3 induced by MI or Ang II, as assessed by Western blotting, and up-regulated growth differentiation factor-15 (GDF-15). In cultured cardiomyocytes and fibroblasts, treatment with Ang II, Aldo or anoxia significantly down-regulated the expression of GDF-15. Olm prevents cardiac rupture through inhibition of apoptosis and inflammation, which is attributable to the down-regulation of p53 activity and up-regulation of GDF-15. Our findings suggest that early administration of an AT1 receptor anatagonist to patients with acute MI is a potential preventive approach for cardiac rupture.

Chen B ，Lu D ，Fu Y ，Zhang J ，Huang X ，Cao S ，Xu D ，Bin J ，Kitakaze M ，Huang Q ，Liao Y ... -  《-》

Rapamycin prevents cyclophosphamide-induced ovarian follicular loss and potentially inhibits tumour proliferation in a breast cancer xenograft mouse model.

To what extent and via what mechanism does the concomitant administration of rapamycin (a follicle activation pathway inhibitor and antitumour agent) and cyclophosphamide (a highly toxic ovarian anticancer agent) prevent cyclophosphamide-induced ovarian reserve loss and inhibit tumour proliferation in a breast cancer xenograft mouse model? Daily concomitant administration of rapamycin and a cyclic regimen of cyclophosphamide, which has sufficient antitumour effects as a single agent, suppressed cyclophosphamide-induced primordial follicle loss by inhibiting primordial follicle activation in a breast cancer xenograft mouse model, suggesting the potential of an additive inhibitory effect against tumour proliferation. Cyclophosphamide stimulates primordial follicles by activating the mammalian target of the rapamycin (mTOR) pathway, resulting in the accumulation of primary follicles, most of which undergo apoptosis. Rapamycin, an mTOR inhibitor, regulates primordial follicle activation and exhibits potential inhibitory effects against breast cancer cell proliferation. To assess ovarian follicular apoptosis, 3 weeks after administering breast cancer cells, 8-week-old mice were randomized into three treatment groups: control, cyclophosphamide, and cyclophosphamide + rapamycin (Cy + Rap) (n = 5 or 6 mice/group). Mice were treated with rapamycin or vehicle control for 1 week, followed by a single dose of cyclophosphamide or vehicle control. Subsequently, the ovaries were resected 24 h after cyclophosphamide administration (short-term treatment groups). To evaluate follicle abundance and the mTOR pathway in ovaries, as well as the antitumour effects and impact on the mTOR pathway in tumours, 8-week-old xenograft breast cancer transplanted mice were randomized into three treatment groups: vehicle control, Cy, and Cy + Rap (n = 6 or 7 mice/group). Rapamycin (5 mg/kg) or the vehicle was administered daily for 29 days. Cyclophosphamide (120 mg/kg) or the vehicle was administered thrice weekly (long-term treatment groups). The tumour diameter was measured weekly. Seven days after the last cyclophosphamide treatment, the ovaries were harvested, fixed, and sectioned (for follicle counting) or frozen (for further analysis). Similarly, the tumours were resected and fixed or frozen. Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) was performed to examine ovarian follicular apoptosis in the short-term treatment groups. All subsequent experiments were conducted in the long-term treatment groups. Tumour growth was evaluated using the tumour volume index. The tumour volume index indicates the relative volume, compared to the volume 3 weeks after tumour cell injection (at treatment initiation) set to 100%. Tumour cell proliferation was evaluated by Ki-67 immunostaining. Activation of the mTOR pathway in tumours was assessed using the protein extracts from tumours and analysed by western blotting. Haematoxylin and eosin staining of ovaries was used to perform differential follicle counts for primordial, primary, secondary, antral, and atretic follicles. Activation of the mTOR pathway in ovaries was assessed using protein extracts from whole ovaries and analysed by western blotting. Localization of mTOR pathway activation within ovaries was assessed by performing anti-phospho-S6 kinase (downstream of mTOR pathway) immunohistochemistry. Ovaries of the short-term treatment groups were resected 24 h after cyclophosphamide administration and subjected to TUNEL staining of apoptotic cells. No TUNEL-positive primordial follicles were detected in the control, Cy, and Cy + Rap groups. Conversely, many granulosa cells of growing follicles were TUNEL positive in the Cy group but negative in the control and Cy + Rap groups. All subsequent experimental results were obtained from the long-term treatment groups. The tumour volume index stabilized at a mean of 160-200% in the Cy group and 130% in the Cy + Rap group throughout the treatment period. In contrast, tumours in the vehicle control group grew continuously with a mean tumour volume index of 600%, significantly greater than that of the two treatment groups. Based on the western blot analysis of tumours, the mTOR pathway was activated in the vehicle control group and downregulated in the Cy + Rap group when compared with the control and Cy groups. Ki-67 immunostaining of tumours showed significant inhibition of cell proliferation in the Cy + Rap group when compared with that in the control and Cy groups. The ovarian follicle count revealed that the Cy group had significantly fewer primordial follicles (P < 0.001) than the control group, whereas the Cy + Rap group had significantly higher number of primordial follicles (P < 0.001, 2.5 times) than the Cy group. The ratio of primary to primordial follicles was twice as high in the Cy group than in the control group; however, no significant difference was observed between the control group and the Cy + Rap group. Western blot analysis of ovaries revealed that the mTOR pathway was activated by cyclophosphamide and inhibited by rapamycin. The phospho-S6 kinase (pS6K)-positive primordial follicle rate was 2.7 times higher in the Cy group than in the control group. However, this effect was suppressed to a level similar to the control group in the Cy + Rap group. None. The combinatorial treatment of breast cancer tumours with rapamycin and cyclophosphamide elicited inhibitory effects on cell proliferative potential compared to cyclophosphamide monotherapy. However, no statistically significant additive effect was observed on tumour volume. Thus, the beneficial antitumour effect afforded by rapamycin administration on breast cancer could not be definitively proven. Although rapamycin has ovarian-protective effects, it does not fully counteract the ovarian toxicity of cyclophosphamide. Nevertheless, rapamycin is advantageous as an ovarian protective agent as it can be used in combination with other ovarian protective agents, such as hormonal therapy. Hence, in combination with other agents, mTOR inhibitors may be sufficiently ovario-protective against high-dose and cyclic cyclophosphamide regimens. Compared with a cyclic cyclophosphamide regimen that replicates human clinical practice under breast cancer-bearing conditions, the combination with rapamycin mitigates the ovarian follicle loss of cyclophosphamide without interfering with the anticipated antitumour effects. Hence, rapamycin may represent a new non-invasive treatment option for cyclophosphamide-induced ovarian dysfunction in breast cancer patients. This work was not financially supported. The authors declare that they have no conflict of interest.

Tanaka Y ，Amano T ，Nakamura A ，Yoshino F ，Takebayashi A ，Takahashi A ，Yamanaka H ，Inatomi A ，Hanada T ，Yoneoka Y ，Tsuji S ，Murakami T ... -  《-》

Colchicine for the primary prevention of cardiovascular events.

Atherosclerotic cardiovascular diseases (ACVDs), a condition characterised by lipid accumulation in arterial walls, which is often exacerbated by chronic inflammation disorders, is the major cause of mortality and morbidity worldwide. Colchicine, with its first medicinal use in ancient Egypt, is an inexpensive drug with anti-inflammatory properties. However, its role in primary prevention of ACVDs in the general population remains unknown. To assess the clinical benefits and harms of colchicine as primary prevention of cardiovascular outcomes in the general population. We searched the Cochrane Heart Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, Web of Science, and LILACS. We searched ClinicalTrials.gov and WHO ICTRP for ongoing and unpublished studies. We also scanned the reference lists of relevant included studies, reviews, meta-analyses, and health technology reports to identify additional studies. There were no limitations on language, date of publication, or study setting. The search results were updated on 31 May 2023. Randomised controlled trials (RCTs) in any setting, recruiting adults without pre-existing cardiovascular disease. We included trials that compared colchicine versus placebo, non-steroidal anti-inflammatory drugs, corticosteroids, immunomodulating drugs, or usual care. Our primary outcomes were all-cause mortality, non-fatal myocardial infarction, stroke, and adverse events. Two or more review authors independently selected studies, extracted data, and performed risk of bias and GRADE assessments. We identified 15 RCTs (1721 participants randomised; 1412 participants analysed) with follow-up periods ranging from 4 to 728 weeks. The intervention was oral colchicine compared with placebo, immunomodulating drugs, or usual care or no treatment. Due to biases and imprecision, the evidence was very uncertain for all outcomes. All trials but one had a high risk of bias. Five out of seven meta-analyses included fewer than six trials (71.4%). The objectives of the review were to assess cardiovascular outcomes in the general population, but many of the included trials focused on liver disease. Colchicine compared to placebo Colchicine may reduce all-cause mortality compared to placebo in primary prevention, but the evidence is very uncertain (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.51 to 0.91; 6 studies, 463 participants; very low-certainty evidence; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 6 to 67). Colchicine may result in little to no difference in non-fatal myocardial infarction, but the evidence is very uncertain (RR 0.87, 95% CI 0.41 to 1.82; 1 study, 100 participants; very low-certainty evidence). Colchicine may not reduce the incidence of stroke, but the evidence is very uncertain (RR 2.43, 95% CI 0.67 to 8.86; 1 study, 100 participants; very low-certainty evidence). Regarding adverse events, colchicine may increase the incidence of diarrhoea (RR 3.99, 95% CI 1.44 to 11.06; 8 studies, 605 participants; very low-certainty evidence; number needed to treat for an additional harmful outcome (NNTH) 10, 95% CI 6 to 17), and may have little to no effect on neurological outcomes such as seizure or mental confusion (RR 0.72, 95% CI 0.31 to 1.66; 2 studies, 155 participants; very low-certainty evidence), but the evidence is very uncertain. The effect of colchicine on cardiovascular mortality is also very uncertain (RR 1.27, 95% CI 0.03 to 62.43; 2 studies, 160 participants; very low-certainty evidence). Colchicine may not reduce post-cardiac procedure atrial fibrillation, but the evidence is very uncertain (RR 0.74, 95% CI 0.25 to 2.19; 1 study, 100 participants). We found no trials reporting on pericardial effusion, peripheral artery disease, heart failure, or unstable angina. Colchicine compared to methotrexate (immunomodulating drug) Colchicine may result in little to no difference in all-cause mortality compared to methotrexate, but the evidence is very uncertain (RR 0.42, 95% CI 0.12 to 1.51; 1 study, 85 participants; very low-certainty evidence). We found no trials reporting other cardiovascular outcomes or adverse events for this comparison. Colchicine compared to usual care or no treatment The evidence is very uncertain about the effect of colchicine compared with usual care on all-cause mortality in primary prevention (RR 1.07, 95% CI 0.90 to 1.27; 2 studies, 729 participants; very low-certainty evidence). Regarding adverse events, colchicine may increase the incidence of diarrhoea compared to usual care, but the evidence is very uncertain (RR 3.32, 95% CI 1.56 to 7.03; 2 studies, 729 participants; very low-certainty evidence; NNTH 18, 95% CI 12 to 42). No trials reported other cardiovascular outcomes for this comparison. This Cochrane review evaluated the clinical benefits and harms of using colchicine for the primary prevention of cardiovascular events in the general population. Comparisons were made against placebo, immunomodulating medications, or usual care or no treatment. However, the certainty of the evidence for the predefined outcomes was very low, highlighting the pressing need for high-quality, rigorous studies to ascertain colchicine's clinical impact definitively. We identified numerous biases and inaccuracies in the included studies, limiting their generalisability and precluding a conclusive determination of colchicine's efficacy in preventing cardiovascular events. The existing evidence regarding colchicine's potential cardiovascular benefits or harms for primary prevention is inconclusive owing to the limitations inherent in the current studies. More robust clinical trials are needed to bridge this evidence gap effectively.

Martí-Carvajal AJ ，Gemmato-Valecillos MA ，Monge Martín D ，De Sanctis JB ，Martí-Amarista CE ，Hidalgo R ，Alegría-Barrero E ，Riera Lizardo RJ ，Correa-Pérez A ... -  《Cochrane Database of Systematic Reviews》

Lipoxin A(4) improves cardiac remodeling and function in diabetes-associated cardiac dysfunction.

Diabetic heart disease may eventually lead to heart failure, a leading cause of mortality in diabetic individuals. The lack of effective treatments for diabetes-induced heart failure may result from a failure to address the underlying pathological processes, including chronic, low-grade inflammation. Previous studies have reported that lipoxin A4 (LXA4), known to promote resolution of inflammation, attenuates diabetes-induced atherosclerosis, but its impact on diabetic hearts has not been sought. Thus, we aimed to determine whether LXA4 therapeutic treatment attenuates diabetes-induced cardiac pathology. Six-week-old male apolipoprotein E-deficient (ApoE-/-) mice were followed for 16 weeks after injection of streptozotocin (STZ, 55 mg/kg/day, i.p. for 5 days) to induce type-1 diabetes (T1DM). Treatment with LXA4 (5 μg/kg, i.p.) or vehicle (0.02% ethanol, i.p.) was administered twice weekly for the final 6 weeks. One week before endpoint, echocardiography was performed within a subset of mice from each group. At the end of the study, mice were euthanized with sodium pentobarbital (100 mg/kg i.p.) and hearts were collected for ex vivo analysis, including histological assessment, gene expression profiling by real-time PCR and protein level measurement by western blot. As expected diabetic mice showed a significant elevation in plasma glycated hemoglobin (HbA1c) and glucose levels, along with reduced body weight. Vehicle-treated diabetic mice exhibited increased cardiac inflammation, macrophage content, and an elevated ratio of M1-like to M2-like macrophage markers. In addition, myocardial fibrosis, cardiomyocytes apoptosis and hypertrophy (at the genetic level) were evident, with echocardiography revealing early signs of left ventricular (LV) diastolic dysfunction. Treatment with LXA4 ameliorated diabetes-induced cardiac inflammation, pro-inflammatory macrophage polarization and cardiac remodeling (especially myocardial fibrosis and cardiomyocytes apoptosis), with ultimate improvement in cardiac function. Of note, this improvement was independent of glucose control. These findings demonstrated that LXA4 treatment attenuated the extent of cardiac inflammation in diabetic hearts, resulting in limited cardiac remodeling and improved LV diastolic function. This supports further exploration of LXA4-based therapy for the management of diabetic heart disease. The recent development of stable LXA4 mimetics holds potential as a novel strategy to treat cardiac dysfunction in diabetes, paving the way for innovative and more effective therapeutic strategies.

Fu T ，Mohan M ，Bose M ，Brennan EP ，Kiriazis H ，Deo M ，Nowell CJ ，Godson C ，Cooper ME ，Zhao P ，Kemp-Harper BK ，Woodman OL ，Ritchie RH ，Kantharidis P ，Qin CX ... -  《Cardiovascular Diabetology》