SGLT2 Inhibitor-pretreated Macrophage Transplantation Improves Adverse Ventricular Remodeling After Acute Myocardial Infarction.

ABSTRACT: Macrophages play an important role in the progression of acute myocardial infarction (AMI). Studies have shown that sodium-dependent glucose transporter 2 inhibitor (SGLT2i) after AMI could increase the proportion of M2 type/M1 macrophages and reduces adverse ventricular remodeling (AVR) post-AMI. This study aimed to investigate whether SGLT2i-pretreated macrophage transplantation could reduce AVR after AMI and the underlying mechanisms. C57BL/6 mice were used to establish an AMI model by ligating the coronary arteries. Dynamic observation of transplanted bone marrow-derived macrophages (BMDMs) was performed using an in vivo imaging system. Cardiac function was assessed using echocardiography. The fibrosis ratio was measured using Masson's trichrome staining. Cardiomyocyte (CM) apoptosis was measured using the TUNEL assay. Macrophage subtypes were measured using flow cytometry. We detected the expression of inflammatory factors in the myocardium and serum using enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction. The in vivo imaging system revealed that transplanted SGLT2i-pretreated BMDMs were present in the infarcted myocardium for 7 days. Flow cytometry revealed that SGLT2i-pretreated BMDMs promoted the conversion of native-derived macrophages to the M2 type. SGLT2i-pretreated BMDMs also reduced inflammatory factors (IL-6, TNFα, and IL-1ß) in the infarcted myocardium and serum. At 28 days post-AMI, SGLT2i-pretreated BMDMs increased cardiac function and vascular density, but reduced CM hypertrophy. SGLT2i-pretreated BMDMs could reduce CM apoptosis and fibrotic area ratio. In conclusion, transplanted SGLT2i-pretreated BMDMs were present in the infarcted myocardium for 7 days and improved AVR by reducing inflammation and modulating the conversion of native mice-derived macrophages to M2-type macrophages.

SGLT2 inhibitor dapagliflozin alleviates intramyocardial hemorrhage and adverse ventricular remodeling via suppressing hepcidin in myocardial ischemia-reperfusion injury.

Intramyocardial hemorrhage (IMH), a reperfusion therapy-associated complication, is the extravasation of red blood cells caused by severe microvascular injury. IMH is an independent predictor of adverse ventricular remodeling (AVR) after acute myocardial infarction (AMI). Hepcidin, a major regulator of iron uptake and systemic distribution, is a key factor affecting AVR. However, the role of cardiac hepcidin in the development of IMH has not been completely elucidated. This study aimed to explore if sodium-dependent glucose co-transporter 2 inhibitor (SGLT2i) exerts therapeutic effects on IMH and AVR by suppressing hepcidin and to elucidate the underlying mechanisms. SGLT2i alleviated IMH and AVR in the ischemia-reperfusion injury (IRI) mouse model. Additionally, SGLT2i downregulated the cardiac levels of hepcidin in IRI mice, suppressed M1-type macrophage polarization, and promoted M2-type macrophage polarization. The effects of hepcidin knockdown on macrophage polarization were similar to those of SGLT2i in RAW264.7 cells. SGLT2i treatment or hepcidin knockdown inhibited the expression of MMP9, an inducer of IMH and AVR, in RAW264.7 cells. Regulation of macrophage polarization and reduction of MMP9 expression by SGLT2i and hepcidin knockdown is achieved through activation of pSTAT3. In conclusion, this study demonstrated that SGLT2i alleviated IMH and AVR by regulating macrophage polarization. The potential mechanism through which SGLT2i exerted its therapeutic effect seems to involve the downregulation of MMP9 via the hepcidin-STAT3 pathway.

Validating the accuracy of a multifunctional smartwatch sphygmomanometer to monitor blood pressure.

BACKGROUND: Hypertension is the most modifiable factor associated with cardiovascular events and complications. The conventional blood pressure (BP) meter method is simple but is limited in terms of real-time monitoring abnormal BP. Therefore, the development of a multifunction smartwatch (HUAWEI WATCH D) sphygmomanometer could significantly improve integrated BP monitoring. METHODS: We enrolled 361 subjects from Chinese PLA General Hospital, Beijing, China to validate the accuracy of the smartwatch versatile sphygmomanometer using ISO 81060-2:2018. Resting and ambulatory BP accuracy of the smartwatch were compared with gold standard clinical sphygmomanometers using ISO 81060-2:2018 guidelines, the accuracy of 24 h systolic blood pressure (SBP) circadian rhythm monitoring, and diurnal high SBP alert for this smartwatch were assessed using a confusion matrix approach. Additionally, we analyzed online users of different ages for compliance. RESULTS: Eighty-five subjects underwent resting BP measurements; the mean resting BP differences between two devices were -0.683 ± 6.203 mmHg (SBP) (P = 0.723) and 1.628 ± 5.028 mmHg (diastolic blood pressure, DBP) (P = 0.183). In 35 subjects' ambulatory BP measurements, the mean differences of ambulatory BP were -1.943 ± 5.475 mmHg (SBP) (P = 0.923) and 3.195 ± 5.862 mmHg (DBP) (P = 0.065). All data complied with ISO 81060-2:2018 guidelines (mean ≤ ±5 mmHg and standard deviation ≤ ±8 mmHg) with no significant differences. Positive predictive values (PPV) of resting SBP and DBP were 0.635 and 0.671, respectively. The PPV of ambulatory SBP and DBP were 0.686. Also, 24 h SBP circadian rhythm monitoring was performed in 107 subjects: accuracy = 0.850, specificity = 0.864, precision/PPV = 0.833, sensitivity = 0.833, and F1-measure (F1) = 0.833. The accuracy, specificity, precision, sensitivity, and F1 values in 85 subjects undergoing diurnal high SBP alerting were 0.858, 0.876, 0.706, 0.809, and 0.754, respectively. CONCLUSIONS: When compared with the gold standard clinical sphygmomanometer, smartwatch results were consistent and accurate. Online user feedback showed that elderly individuals cared more about BP monitoring accuracy, with better compliance.

Oxymatrine pretreatment protects H9c2 cardiomyocytes from hypoxia/reoxygenation injury by modulating the PI3K/Akt pathway.

Ischemia-reperfusion (I/R) plays an important role in myocardial damage, which has been widely recognized as a key procedure in the cardiovascular disease. A hypoxia/reoxygenation (H/R) model was established using H9c2 cardiomyocytes to investigate the possible positive effect of oxymatrine (OMT), an alkaloid originating from the traditional Chinese herb Sophora flavescens Aiton, on cardiomyocytes exposed to H/R injury and the underlying molecular mechanisms. Cell viability was measured using the MTT assay, lactate dehydrogenase release measurements and hematoxylin and eosin staining. Oxidative stress was detected by measuring cellular malondialdehyde (MDA) content, as well as superoxide dismutase (SOD) and catalase (CAT) activities. Apoptosis was detected using TUNEL staining and flow cytometric analysis, and the underlying mechanism was investigated using reverse transcription-quantitative PCR and western blot analyses. The results revealed that OMT increased the viability of H9c2 cardiomyocytes exposed to H/R. The OMT pretreatment decreased the production of MDA by reactive oxygen species and increased the activities of SOD and CAT. Furthermore, the OMT pretreatment reduced the expression of Bax and caspase-3, while inducing Bcl-2 expression. In addition, the protective effect of OMT was shown to be associated with the PI3K/Akt signaling pathway, and the PI3K inhibitor LY294002 attenuated the effects of OMT on the H9c2 cardiomyocytes exposed to H/R. These findings indicate that OMT could be a potential therapeutic candidate for the treatment of myocardial ischemia/reperfusion injury.