Association Between HMGB1 and Thrombogenesis in a Hyperlipaemia-induced Microminipig Model of Atherosclerosis

Downregulation of HMGB1 carried by macrophage-derived extracellular vesicles delays atherosclerotic plaque formation through Caspase-11-dependent macrophage pyroptosis

BACKGROUND

Macrophage-derived extracellular vesicle (macrophage-EV) is highly studied for its regulatory role in atherosclerosis (AS). Our current study tried to elucidate the possible role of macrophage-EV loaded with small interfering RNA against high-mobility group box 1 (siHMGB1) affecting atherosclerotic plaque formation.

METHODS

In silico analysis was performed to find critical factors in mouse atherosclerotic plaque formation. EVs secreted by RAW 264.7 cells were collected by ultracentrifugation and characterized, followed by the preparation of macrophage-EV-loaded siHMGB1 (macrophage-EV/siHMGB1). ApoE-/- mice were used to construct an AS mouse model by a high-fat diet, followed by injection of macrophage-EV/siHMGB1 to assess the in vivo effect of macrophage-EV/siHMGB1 on AS mice. RAW264.7 cells were subjected to ox-LDL, LPS or macrophage-EV/siHMGB1 for analyzing the in vitro effect of macrophage-EV/siHMGB1 on macrophage pyrophosis and inflammation.

RESULTS

In silico analysis found that HMGB1 was closely related to the development of AS. Macrophage-EV/siHMGB could inhibit the release of HMGB1 from macrophages to outside cells, and the reduced HMGB1 release could inhibit foam cell formation. Besides, macrophage-EV/siHMGB also inhibited the LPS-induced Caspase-11 activation, thus inhibiting macrophage pyroptosis and preventing atherosclerotic plaque formation.

CONCLUSION

Our results proved that macrophage-EV/siHMGB could inhibit foam cell formation and suppress macrophage pyroptosis, finally preventing atherosclerotic plaque formation in AS mice.

Risk factors analysis and the establishment of nomogram prediction model for PICC-related venous thrombosis in patients with lymphoma: a double-center cohort-based case-control study

Objective

The objective of this study is to examine the risk factors associated with the occurrence of PICC-Related Venous Thrombosis (PICC-RVTE) in individuals diagnosed with lymphoma, as well as to develop a predictive risk nomogram model.

Methods

A total of 215 patients with lymphoma treated at Yunnan Provincial Tumor Hospital from January 2017 to December 2020 were retrospectively evaluated as the training cohort; 90 patients with lymphoma treated at the Department of Oncology of the First People's Hospital of Anning, Affiliated to Kunming University of Science and Technology during the January 2021 to September 2023 were evaluated as the validation cohort. Independent influencing factors were analyzed by logistic regression, a nomogram was developed and validated, and the model was evaluated using internal and external data cohorts for validation.

Results

A total of 305 lymphoma patients were selected and 35 (11.48%) PICC-RVTE occurred, the median time was 13 days. The incidence within 1-2week was 65.71%. Multivariate analysis suggested that the activity amount, thrombosis history(within the last 12 months), ATIII, Total cholesterol and D-dimer levels were independently associated with PICC-RVTE, and a nomogram was constructed based on the multivariate analysis. ROC analysis indicated good discrimination in the training set (area under the curve [AUC] = 0.907, 95%CI:0.850-0.964) and the testing set (AUC = 0.896, 95%CI: 0.782-1.000) for the PICC-RVTE nomogram. The calibration curves showed good calibration abilities, and the decision curves indicated the clinical usefulness of the prediction nomograms.

Conclusions

Patients should be advised to undergo color Doppler ultrasound system testing within two week after the implantation of a PICC catheter to detect PICC-RVTE at an early stage. The validated nomogram can be used to predict the risk of catheter-related thrombosis (CRT) in patients with lymphoma who received at least one chemotherapy after PICC catheterization, no bleeding tendency, no recent history of anticoagulant exposure and no severe heart, lung, renal insufficiency. This model has the potential to assist clinicians in formulating individualized treatment strategies for each patient.

MicroRNA-98 inhibition accelerates the development of atherosclerosis via regulation of dysfunction of endothelial cell

BACKGROUND

Atherosclerosis has been recognized as a chronic inflammation initiated by dysfunction of endothelial cell that contributes to the increased morbidity and mortality of severe cardiovascular events. The reported important role of microRNA-98 (miR-98) in regulation of endothelial cell behaviors prompt us to hypothesize that miR-98 could be involved in the process of atherosclerosis.

METHODS AND RESULTS

The current research showed the miR-98 expression was gradually down-regulated in atherosclerotic mouse arteries isolated from ApoE ablation mice subjected to high fat diet. Additionally, a dramatically reduced miR-98 expression in endothelial cells administrated to oxidized low-density lipoprotein (Ox-LDL) but a slight down-regulated level was found in macrophages. Functionally, attenuated miR-98 expression promoted secretion of chemokines and adhesion molecules in human umbilical vein endothelial cells (HUVECs) induced by Ox-LDL, which subsequently increased infiltration and pro-inflammatory genes expression of macrophages, as well as the foam cell formation. Mechanistically, in vitro experiments indicated that the endothelial cell dysfunction regulated by miR-98 knockdown was partially contributed by upregulated expression of HMGB1. Furthermore, the animal experiment with ApoE-/- mice administrated with miR-98 inhibitor demonstrated that miR-98 silencing enhanced the atherosclerotic lesions in aorta and aortic sinus that were accompanied with increased adhesion molecules, chemokines, and pro-inflammatory markers expression.

CONCLUSION

MicroRNA-98 knockdown promoted endothelial cell dysfunction to affect the inflammatory state of macrophage and the development of atherosclerosis, at least partially, through direct targeting HMGB1. Collected, these data suggested that miR-98 could be a novel drug target for atherogenesis management.

Glycyrrhizic Acid Inhibits High-Mobility Group Box-1 and Homocysteine-Induced Vascular Dysfunction

Hyperhomocysteinemia (HHcy) worsens cardiovascular outcomes by impairing vascular function and promoting chronic inflammation via release of danger-associated molecular patterns, such as high-mobility group box-1 (HMGB-1). Elevated levels of HMGB-1 have recently been reported in patients with HHcy. Therefore, targeting HMGB-1 may be a potential therapy to improve HHcy-induced cardiovascular pathologies. This study aimed to further elucidate HMGB-1's role during acute HHcy and HHcy-induced atherogenesis and to determine if inhibiting HMGB-1 with glycyrrhizic acid (Glyz) improved vascular function. Male New Zealand White rabbits (n = 25) were placed on either a standard control chow (CD; n = 15) or atherogenic diet (AD; n = 10) for 4 weeks. Rabbit serum and Krebs taken from organ bath studies were collected to quantify HMGB-1 levels. Isometric tension analysis was performed on abdominal aorta (AA) rings from CD and AD rabbits. Rings were incubated with homocysteine (Hcy) [3 mM] for 60 min to induce acute HHcy or rhHMGB-1 [100 nM]. Vascular function was assessed by relaxation to cumulative doses of acetylcholine. Markers of vascular dysfunction and inflammation were quantified in the endothelium, media, and adventitia of AA rings. HMGB-1 was significantly upregulated in serum (p < 0.0001) and Krebs (p < 0.0001) after Hcy exposure or an AD. Incubation with Hcy (p < 0.0001) or rhHMGB-1 (p < 0.0001) and an AD (p < 0.0001) significantly reduced relaxation to acetylcholine, which was markedly improved by Glyz. HMGB-1 expression was elevated (p < 0.0001) after Hcy exposure and AD (p < 0.0001) and was normalized after Glyz treatment. Moreover, markers of vascular function, cell stress and inflammation were also reduced after Glyz. These results demonstrate that HMGB-1 has a central role during HHcy-induced vascular dysfunction and inhibiting it with Glyz could be a potential treatment option for cardiovascular diseases.

LncRNA BANCR induced vascular smooth muscle cell proliferation by downregulating miR-34c methylation in atherosclerosis

Aberrant vascular smooth muscle cell (VSMCs) proliferation involves in the development of atherosclerosis. It reported that Long noncoding BRAF-activated noncoding RNA (BANCR) and miR-34c played opposite roles in the regulation of the proliferation of VSMCs, indicating that there might be a potential interaction between them. This study was to investigate the relationship between BANCR and miR-34c in atherosclerosis. Blood (5 ml) was obtained from 56 patients with atherosclerosis and 56 healthy volunteers after they were fasted overnight, and plasma was extracted from the blood. Human Aortic Smooth Muscle Cells (HASMCs) were used to perform in vitro cell experiments. RT-qPCR was performed to measure the expression of BANCR and miR-34c in plasma and HASMCs. Dual luciferase reporter assay detected the interaction between BANCR and miR-34c. CCK-8 assay was used to assess the effects of BANCR and miR-34c overexpression on the proliferation of HASMCs. Western blotting was used to assess the effects of BANCR and miR-34c overexpression on the protein expression of HMGB1, TNF-ɑ and Bcl-2. In this study, we found that BANCR was upregulated, while miR-34c was downregulated in atherosclerosis. Bioinformatics analysis showed that BANCR and miR-34c could directly interact with each other. Moreover, overexpression of BANCR could decrease the expression of miR-34c in HASMCs, but overexpression of miR-34c could not affect the expression of BANCR. Furthermore, overexpression of BACNR increased miR-34c methylation, and knockdown of endogenous BANCR decreased miR-34c methylation. In addition, overexpression of BANCR reduced the effects of miR-34c on HASMCs proliferation and reversed the effects of miR-34c on HMGB1, TNF-ɑ and Bcl-2 expression. BANCR overexpression could induce HASMCs proliferation by downregulating the miR-34c methylation. Therefore given BANCR upregulation in atherosclerosis, its expression may be considered as a novel and useful biomarker for atherosclerosis prevention and prognosis. However considering the possible effects of other underlying diseases on both BANCR expression and miR-34c in atherosclerosis, further investigation is suggested for future research.