Tetrandrine promotes angiogenesis via transcriptional regulation of VEGF-A

Tetrandrine promotes the survival of the random skin flap via the PI3K/AKT signaling pathway

Flaps are mainly used for wound repair. However, postoperative ischemic necrosis of the distal flap is a major problem, which needs to be addressed urgently. We evaluated whether tetrandrine, a compound found in traditional Chinese medicine, can prolong the survival rate of random skin flaps. Thirty-six rats were randomly divided into control, low-dose tetrandrine (25 mg/kg/day), and high-dose tetrandrine (60 mg/kg/day) groups. On postoperative Day 7, the flap survival and average survival area were determined. After the rats were sacrificed, the levels of angiogenesis, apoptosis, and inflammation in the flap tissue were detected with immunology and molecular biology analyses. Tetrandrine increased vascular endothelial growth factor and Bcl-2 expression, in turn promoting angiogenesis and anti-apoptotic processes, respectively. Additionally, tetrandrine decreased the expression of Bax, which is associated with the induction of apoptosis, and also decreased inflammation in the flap tissue. Tetrandrine improved the survival rate of random flaps by promoting angiogenesis, inhibiting apoptosis, and reducing inflammation in the flap tissue through the modulation of the PI3K/AKT signaling pathway.

A 14-bp deletion in bovine EPAS1 gene is associated with carcass traits

EPAS1 (Endothelial PAS Domain Protein 1) gene is well-known for its function in plateau hypoxia adaptability. It encodes HIF-2α, which involved in the induction of genes regulated by oxygen and then affects multiple physiological processes such as angiogenesis and energy metabolism. All of these indicate it may affect the development of animals. In this study, a 14-bp deletion in EPAS1 gene was uncovered in Shandong black cattle population (n = 502). Two genotypes (II and ID) were found and the frequency of the homozygous II genotype is higher than the heterozygous ID genotype. This population is consisted with HWE (p > 0.05). And more importantly, the 14-bp deletion was associated with outside flat (p = 0.003), brisket (p = 0.001), and knuckle (p = 0.032). These findings suggested that the 14-bp deletion is significantly associated with carcass traits, which could be served as a molecular marker applied to cow breeding.

Tetrandrine synergizes with MAPK inhibitors in treating KRAS-mutant pancreatic ductal adenocarcinoma via collaboratively modulating the TRAIL-death receptor axis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal malignancies lacking effective therapies. KRAS mutations that occur in over 90% of PDAC are major oncogenic drivers of PDAC. The MAPK signaling pathway plays a central role in KRAS-driven oncogenic signaling. However, pharmacological inhibitors of the MAPK pathway are poorly responded in KRAS-mutant PDAC, raising a compelling need to understand the mechanism behind and to seek new therapeutic solutions. Herein, we perform a screen utilizing a library composed of 800 naturally-derived bioactive compounds to identify natural products that are able to sensitize KRAS-mutant PDAC cells to the MAPK inhibition. We discover that tetrandrine, a natural bisbenzylisoquinoline alkaloid, shows a synergistic effect with MAPK inhibitors in PDAC cells and xenograft models. Mechanistically, pharmacological inhibition of the MAPK pathway exhibits a double-edged impact on the TRAIL-death receptor axis, transcriptionally upregulating TRAIL yet downregulating its agonistic receptors DR4 and DR5, which may explain the limited therapeutic outcomes of MAPK inhibitors in KRAS-mutant PDAC. Of great interest, tetrandrine stabilizes DR4/DR5 protein via impairing ubiquitination-mediated protein degradation, thereby allowing a synergy with MAPK inhibition in inducing apoptosis in KRAS-mutant PDAC. Our findings identify a new combinatorial approach for treating KRAS-mutant PDAC and highlight the role of TRAIL-DR4/DR5 axis in dictating the therapeutic outcome in KRAS-mutant PDAC.

Research Progress on Neuroprotective Effects of Isoquinoline Alkaloids

Neuronal injury and apoptosis are important causes of the occurrence and development of many neurodegenerative diseases, such as cerebral ischemia, Alzheimer's disease, and Parkinson's disease. Although the detailed mechanism of some diseases is unknown, the loss of neurons in the brain is still the main pathological feature. By exerting the neuroprotective effects of drugs, it is of great significance to alleviate the symptoms and improve the prognosis of these diseases. Isoquinoline alkaloids are important active ingredients in many traditional Chinese medicines. These substances have a wide range of pharmacological effects and significant activity. Although some studies have suggested that isoquinoline alkaloids may have pharmacological activities for treating neurodegenerative diseases, there is currently a lack of a comprehensive summary regarding their mechanisms and characteristics in neuroprotection. This paper provides a comprehensive review of the active components found in isoquinoline alkaloids that have neuroprotective effects. It thoroughly explains the various mechanisms behind the neuroprotective effects of isoquinoline alkaloids and summarizes their common characteristics. This information can serve as a reference for further research on the neuroprotective effects of isoquinoline alkaloids.

Pharmacological mechanism of natural drugs and their active ingredients in the treatment of arrhythmia via calcium channel regulation

Arrhythmia is characterized by abnormal heartbeat rhythms and frequencies caused by heart pacing and conduction dysfunction. Arrhythmia is the leading cause of death in patients with cardiovascular disease, with high morbidity and mortality rates, posing a serious risk to human health. Natural drugs and their active ingredients, such as matrine(MAT), tetrandrine(TET), dehydroevodiamine, tanshinone IIA, and ginsenosides, have been widely used for the treatment of atrial fibrillation, ventricular ectopic beats, sick sinus syndrome, and other arrhythmia-like diseases owing to their unique advantages. This review summarizes the mechanism of action of natural drugs and their active ingredients in the treatment of arrhythmia via the regulation of Ca²⁺, such as alkaloids, quinones, saponins, terpenoids, flavonoids, polyphenols, and lignan compounds, to provide ideas for the innovative development of natural drugs with potential antiarrhythmic efficacy.

Functional recovery of myocardial infarction by specific EBP-PR1P peptides bridging injectable cardiac extracellular matrix and vascular endothelial growth factor

Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor and plays an important role in therapy of myocardial infarction (MI). Currently, how to retain regional concentration and decrease rapid diffusion is critical for its clinical application of VEGF. In recent years, the application of targeting peptides has been developed rapidly and provides new strategies for the sustained release of VEGF. In present study, a bi-functional EBP-PR1P peptide was designed and bridged VEGF to injectable cardiac extracellular matrix (c-ECM). Through EBP-PR1P peptides, VEGF could specifically bind with c-ECM to realize the sustained release, without impacting the bioactivity of VEGF. Then VEGF/EBP-PR1P/c-ECM scaffolds were constructed and administrated into rats with MI. The results showed VEGF/EBP-PR1P/c-ECM could promote angiogenesis, protect cardiomyocytes survival against apoptosis, and improve the recovery of cardiac function. In addition, the mechanism of EBP-PR1P/VEGF was also investigated which canonical downstream of VEGF-Akt signaling pathway was activated. These results showed specific VEGF/EBP-PR1P/c-ECM scaffolds served as promising delivery system for VEGF that facilitated the functional recovery of MI.

[JAG1 promotes migration, invasion, and adhesion of triple-negative breast cancer cells by promoting angiogenesis]

OBJECTIVE

To investigate the effect of JAG1 on the malignant phenotype of triple-negative breast cancer (TNBC) and its role in angiogenesis in breast cancer microenvironment.

METHODS

The expressions of Notch molecules were detected in human TNBC 231 and 231B cells using RT-qPCR. Five female nude mice were inoculated with 231 cells and another 5 with 231B cells into the mammary fat pads, and 4-6 weeks later, the tumors were collected for immunohistochemical and immunofluorescence tests. 231 cells and 231B cells were treated with recombinant JAG (rJAG) protein and DAPT, respectively, and changes in their malignant phenotypes were assessed using CCK-8 assay, Hoechst 33258 staining, wound healing assay, Transwell chamber assay and endothelial cell adhesion assay. Western blotting was used to detect the changes in the expressions of proteins related with the malignant phenotypes of 231 and 231B cells. The effects of conditioned medium (CM) derived from untreated 231 and 231 B cells, rJAG1-treated 231 cells and DAPT-treated 231B cells on proliferation and tube formation ability of cultured human umbilical vein endothelial cells (HUVECs) were evaluated using CCK-8 assay and tube-forming assay.

RESULTS

The expression of JAG1 was higher in 231B cells than in 231 cells (P < 0.05). Tumor 231B showed higher expression of VEGFA and CD31. Compared with 231-Blank group, the migration, invasion and adhesion of 231 cells in 231-rJAG1 were significantly enhanced (P < 0.05). Protein levels of Twist1 and Snail increased (P < 0.01), anti-apoptotic protein Bcl-2 increased (P < 0.05), while DAPT inhibited the related phenomena and indicators of 231B. The 231-rJAG1-CM increased the cell number and tubule number of HUVEC (P < 0.05).

CONCLUSION

JAG1 may affect the malignant phenotype of TNBC and promote angiogenesis in the tumor microenvironment.

Baohuoside I Inhibits Tumor Angiogenesis in Multiple Myeloma via the Peroxisome Proliferator-Activated Receptor γ/Vascular Endothelial Growth Factor Signaling Pathway

Angiogenesis plays an important role in the development of multiple myeloma (MM). Baohuoside I (BI) is a core flavonoid monomer with anticancer property. However, the mechanism of BI on MM-stimulated angiogenesis has not been revealed. In this study, we demonstrated that BI inhibits MM-induced angiogenesis in vitro and angiogenesis in a xenograft mouse model in vivo. We further showed that peroxisome proliferator–activated receptor γ (PPARγ) transcriptional activity was mediated by a direct physical association between BI and PPARγ. Meanwhile, inhibition of PPARγ using lentivirus transfection of shRNA in human myeloma cell lines showed that the facilitation of PPARγ blocked angiogenesis and PPARγ repressed vascular endothelial growth factor (VEGF) transcription. Furthermore, BI treatment decreased VEGF expression, whereas VEGF expression remained unchanged after PPARγ knockdown when exposed to BI. Overall, our study is the first to reveal that BI inhibits MM angiogenesis by the PPARγ–VEGF signaling axis.