Leucine zipper protein 1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling.

INTRODUCTION: Cardiac hypertrophy is an important contributor of heart failure, and the mechanisms remain unclear. Leucine zipper protein 1 (LUZP1) is essential for the development and function of cardiovascular system; however, its role in cardiac hypertrophy is elusive. OBJECTIVES: This study aims to investigate the molecular basis of LUZP1 in cardiac hypertrophy and to provide a rational therapeutic approach. METHODS: Cardiac-specific Luzp1 knockout (cKO) and transgenic mice were established, and transverse aortic constriction (TAC) was used to induce pressure overload-induced cardiac hypertrophy. The possible molecular basis of LUZP1 in regulating cardiac hypertrophy was determined by transcriptome analysis. Neonatal rat cardiomyocytes were cultured to elucidate the role and mechanism of LUZP1 in vitro. RESULTS: LUZP1 expression was progressively increased in hypertrophic hearts after TAC surgery. Gain- and loss-of-function methods revealed that cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated pressure overload-elicited hypertrophic growth and cardiac dysfunction in vivo and in vitro. Mechanistically, the transcriptome data identified Stat3 pathway as a key downstream target of LUZP1 in regulating pathological cardiac hypertrophy. Cardiac-specific Stat3 deletion abolished the pro-hypertrophic role in LUZP1 cKO mice after TAC surgery. Further findings suggested that LUZP1 elevated the expression of Src homology region 2 domain-containing phosphatase 1 (SHP1) to inactivate Stat3 pathway, and SHP1 silence blocked the anti-hypertrophic effects of LUZP1 in vivo and in vitro. CONCLUSION: We demonstrate that LUZP1 attenuates pressure overload-induced cardiac hypertrophy through inhibiting Stat3 signaling, and targeting LUZP1 may develop novel approaches to treat pathological cardiac hypertrophy.

Lipoprotein(a) and Benefit of PCSK9 Inhibition in Emergency Complex Higher-risk and Indicated Patients.

OBJECTIVE: There is a large population of patients classified as complex higher-risk and indicated patients (CHIPs) in China with a poor prognosis. The treatment of these patients is complex and challenging, especially when acute cardiac events occur, such as acute coronary syndrome (ACS) or heart failure. Pharmacotherapy and some mechanical circulatory support (MCS) therapeutic devices can provide stable hemodynamic support for CHIPs-percutaneous coronary intervention (PCI). LDL-C is an important pathogenic factor in atherosclerosis, and the target of blood lipid control. Recent studies have revealed that lipoprotein(a) [Lp(a)], which is formed when a covalent bond between apolipoprotein(a) and apolipoprotein B-100 is made, produces an LDL-like particle. This particle is an independent risk factor for the development of atherosclerosis, and is closely correlated to stent thrombosis and restenosis. Furthermore, this requires active intervention. PCSK9 inhibitors have been used in lipid-lowering treatment, and preventing atherosclerosis. The present study explores the efficacy of PCSK9 inhibitors in CHIPs-ACS, and the association between the change in Lp(a) and survival after 2 years of follow-up. METHODS: The present real-world, prospective control study enrolled 321 CHIPs-ACS who underwent emergency PCI from August 2019 to November 2020, and these patients were followed up for 2 years. These patients were divided into two groups: PCSK9 group (n=161) given the combined PCSK9 inhibitor (140 mg of evolocumab every 2 weeks) and statins-based therapy, and SOC group (n=160) treated with statin-based lipid-lowering therapy alone. Then, the change in lipid index was measured, and the cardiovascular (CV) event recurrence rate was evaluated after one month and 2 years. Afterwards, the contribution of serum lipid parameters, especially the Lp(a) alteration, in patients with earlier initiation of the PCSK9 inhibitor to the CV outcome was analyzed. RESULTS: The LDL-C level was significantly reduced in both groups: 52.3% in the PCSK9 group and 32.3% (P<0.001) in the SOC group. It is noteworthy that the Lp(a) level decreased by 13.2% in the PCSK9 group, but increased by 30.3% in the SOC group (P<0.001). Furthermore, the number of CV events was not significantly different between the PCSK9 and SOC groups after the 2-year follow-up period. In the PCSK9 group, the Lp(a) reduction was associated with the baseline Lp(a) levels of the patients (r2 =-0.315, P<0.001). Moreover, the decrease in Lp(a) contributed to the decline in CV events in patients who received ACS CHIPs-PCI, and the decrease in Lp(a) level was independent of the LDL-C level reduction. CONCLUSION: The early initiation of PCSK9 inhibitors can significantly reduce the LDL-C and Lp(a) levels in ACS CHIPs-PCI. However, further studies are needed to confirm whether PCSK9 inhibitors can reduce the incidence of CV disease in CHIPs.

[Exhaustion of CD8+T Lymphocytes Plays a Critical Role in the Pathogenesis of Secondary Hemophagocytic Lymphohistiocytosis].

OBJECTIVE: To investigate the changes in function of CD8+ T cell subsets, and explore its significance in pathogenesis of secondary hemophagocytic lymphohistiocytosis (sHLH). METHODS: Flow cytometry was used to detect the expressions of PD-1, TIM-3, and LAG-3, which were the markers of exhausted CD8+ T cell, as well as the secretion levels of interferon γ (IFN-γ) and expression of ΔCD107a after the stimulation; the numbers of effector-memory CD8+ T cells, regulatory T cells and double negative T cells were also detected. RESULTS: The expressions of inhibitory receptors (PD-1, TIM3 and LAG-3) on CD8+ T cells of sHLH patients were 40.73±22.64, 15.97±14.45 and 0.73 (0-37.41), respectively, which were significantly higher than those of the control group (P<0.001). In contrast, the expression of ΔCD107a (4.49±2.71 vs 6.07±2.14, P=0.035) and secretion level of IFN-γ (37.30±24.46 vs 55.17±22.23, P=0.034) were significantly lower. The number of effector-memory CD8+ T cells in sHLH patients was also lower as compared with that in control group (14.35±10.37 vs 22.92±11.12, P=0.016). But there was no significant difference in the number of regulatory T cell and double negative T cell. In addition, the expressions of PD-1, TIM3 and LAG-3 in active stage of sHLH were 38.09±21.87, 14.35±13.70 and 0.82 (0-13.22), respectively, which were significant higher than those in remission stage [24.27±17.23 (P=0.03), 8.64±5.60 (P=0.014) and 0.13 (0-3.69)]. CONCLUSION: The exhausted CD8+ T lymphocytes may play a critical role in the development of sHLH.

Scaled-up production and application of co-processed excipient mannitol-HPMC in traditional Chinese medicine / 中国中药杂志

Spray drying technology was used to produce co-processed excipients mannitol- hydroxypropyl methylcellulose (HPMC), and study the scaled-up production. The consistency of powder and tablet properties before and after scale-up of co-processed excipients was compared, and their applicability in traditional Chinese medicine (TCM) powder's direct compression was tested on five TCM extracts such as gardenia extract and Radix Paeoniae Alba extract. It was shown that after scaled-up production, the key properties of co-processed excipients had little changes (such as compactability, disintegrating time, and lubrication sensitivity) or improvement (such as flowability and yield). As compared to commercially available spray-dried mannitol, co-processed excipients achieved better compactability and higher drug loading for direction compression of TCM powder. In conclusion, the mannitol-HPMC co-processed excipient, with excellent physicomechanical properties, is promising to be explored as a new excipient for direct powder compression.