Akt1 in endothelial cell and angiogenesis

Mechanisms of Tripterygium wilfordii Hook F on treating rheumatoid arthritis explored by network pharmacology analysis and molecular docking

Background

Rheumatoid arthritis (RA) is a chronic inflammatory and disabling disease that imposes significant economic and social costs. Tripterygium wilfordii Hook F (TwHF) has a long history of use in traditional Chinese medicine for treating joint disorders, and it has been shown to be cost-effective in treating RA, but its exact mechanism is unknown.

Objective

The goal of the network pharmacology analysis and molecular docking was to investigate the potential active compounds and associated anti-RA mechanisms of TwHF.

Methods

TCMSP and UniProt databases were searched for active compounds and related targets of TwHF. PharmGKB, DrugBank, OMIM, TTD, and the Human Gene Databases were used to identify RA-related targets. The intersected RA and TwHF targets were entered into the STRING database to create a protein-protein interaction network. R software was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Molecular docking technology was used to analyze the optimal effective components from TwHF for docking with the selected target gene.

Results

Following screening and duplicate removal, a total of 51 active compounds and 96 potential targets were chosen. The PPI network revealed that the target proteins are CXCL8, CXCL6, STAT3, STAT1, JUN, PPARG, TP53, IL14, MMP9, VEGFA, RELA, CASP3, PTGS2, IFNG, AKT1, FOS, ICAM1, and MAPK14. The results of the GO enrichment analysis focused primarily on the response to lipopolysaccharide, the response to molecules of bacterial origin, and the response to drugs. The KEGG results indicated that the mechanisms were closely related to lipid and atherosclerosis, chemical carcinogenesis-receptor activation, Kaposi sarcoma-associated, herpesvirus infection, hepatitis B, fluid shear stress and atherosclerosis, IL-17 signaling pathways, Th17-cell differentiation, and so on, all of which are involved in angiogenesis, immune cell chemotaxis, and inflammatory responses. Molecular docking results suggested that triptolide was the appropriate PTGS1, PTGS2, and TNF inhibitors.

Conclusion

Our findings provide an essential role and basis for further immune inflammatory studies into the molecular mechanisms of TwHF and PTGS1, PTGS2, and TNF inhibitor development in RA.

CD133-containing microvesicles promote colorectal cancer progression by inducing tumor angiogenesis

Angiogenesis is an indispensable mechanism in cancer progression, as cancer cells need to establish blood vessels to supply oxygen and nutrients. Extracellular vesicles (EVs) derived from cancer cells act as messengers in the tumor microenvironment and induce resistance to anti-angiogenic cancer treatment. EVs can be classified into two categories: exosomes and microvesicles (MVs). Although exosomes are involved in angiogenesis, the role of MVs in angiogenesis and cancer progression remains unclear. CD133 plays a key role in MV formation and oncoprotein trafficking. In this study, we investigated the role of CD133-containing MVs derived from colorectal cancer (CRC) in angiogenesis and cancer progression. CRC-derived MVs were incorporated into endothelial cells and increased the mesh area and tube length of endothelial cells. CD133-containing MVs also stimulate vessel sprouting in endothelial cell spheroids and mouse thoracic aortas. However, MVs derived from CD133-knockdown CRC cells exerted a limited effect on tube formation and vessel sprouting. CD133-containing MVs induced angiogenesis through p38 activation and angiogenesis induced by CD133-containing MVs was insensitive to the anti-vascular endothelial growth factor antibody bevacizumab. Survival analysis revealed that high expression level of CD133 correlated with poor prognosis in patients with metastatic CRC. These findings suggest that CD133-containing MVs act as key regulators of angiogenesis and are related to the prognosis of CRC patients.

Comparative transcriptomic analysis of circulating endothelial cells in sickle cell stroke

Ischemic stroke (IS) is one of the most impairing complications of sickle cell anemia (SCA), responsible for 20% of mortality in patients. Rheological alterations, adhesive properties of sickle reticulocytes, leukocyte adhesion, inflammation and endothelial dysfunction are related to the vasculopathy observed prior to ischemic events. The role of the vascular endothelium in this complex cascade of mechanisms is emphasized, as well as in the process of ischemia-induced repair and neovascularization. The aim of the present study was to perform a comparative transcriptomic analysis of endothelial colony-forming cells (ECFCs) from SCA patients with and without IS. Next, to gain further insights of the biological relevance of differentially expressed genes (DEGs), functional enrichment analysis, protein-protein interaction network (PPI) construction and in silico prediction of regulatory factors were performed. Among the 2469 DEGs, genes related to cell proliferation (AKT1, E2F1, CDCA5, EGFL7), migration (AKT1, HRAS), angiogenesis (AKT1, EGFL7) and defense response pathways (HRAS, IRF3, TGFB1), important endothelial cell molecular mechanisms in post ischemia repair were identified. Despite the severity of IS in SCA, widely accepted molecular targets are still lacking, especially related to stroke outcome. The comparative analysis of the gene expression profile of ECFCs from IS patients versus controls seems to indicate that there is a persistent angiogenic process even after a long time this complication has occurred. Thus, this is an original study which may lead to new insights into the molecular basis of SCA stroke and contribute to a better understanding of the role of endothelial cells in stroke recovery.

Prediction of the active compounds and mechanism of Biochanin A in the treatment of Legg-Calvé-Perthes disease based on network pharmacology and molecular docking

BACKGROUND

Legg-Calvé-Perthes disease is a special self-limited disease in pediatric orthopedics with a high disability rate and a long-term course, and there is still no clear and effective therapeutic drug in clinic. This study aimed to investigate the potential efficacy of biochanin A, a kind of oxygen-methylated isoflavone compound, in treating Perthes disease based on network pharmacology, molecular docking and in vitro experiments.

METHODS

IL-6 was used to stimulate human umbilical vein endothelial cells to construct endothelial cell dysfunction model. We demonstrated whether biochanin A could alleviate endothelial dysfunction through CCK8 assay, immunofluorescence. Targets of biochanin A from pharmMappeer, SWISS, and TargetNet databases were screened. Targets of endothelial dysfunction were obtained from Genecards and OMIM databases. Protein-protein interaction, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomics analyses were used to analyze the potential target and the key pathway of the anti-endothelial dysfunction activity of biochanin A. To validate the potential target-drug interactions, molecular docking and molecular dynamics simulations were performed and the result was proved by western blot.

RESULTS

It was found that biochanin A can promote the expression of ZO-1, reduce the expression of ICAM-1, which means improving endothelial dysfunction. A total of 585 targets of biochanin A from pharmMappeer, SWISS, and TargetNet databases were screened. A total of 10,832 targets of endothelial dysfunction were obtained from Genecards and OMIM databases. A total of 527 overlapping targets of endothelial dysfunction and biochanin A were obtained. AKT1, TNF-α, VCAM1, ICAM1, and NOS3 might be the key targets of the anti-endothelial dysfunction activity of biochanin A, and the key pathways might be PI3K-Akt and TNF signaling pathways. Molecular docking results indicated that the AKT1 and TNF-α had the highest affinity binding with biochanin A.

CONCLUSION

This study indicates that biochanin A can target AKT1 and TNF-α to alleviate endothelial dysfunction induced by IL-6 in Perthes disease, which provides a theoretical basis for the treatment of Perthes disease by using biochanin A.

Phosphoinositide 3-kinase as a therapeutic target in angiogenic disease

Phosphoinositide 3-kinases (PI3Ks) generate lipids that control multitudinous intracellular cell signaling events which participate in cell survival and proliferation. In addition, PI3K signaling also contributes to metabolism, immunity, angiogenesis and cardiovascular homeostasis, and many diseases. The diverse actions of PI3K stem from the existence of their various isoforms and a variety of protein effectors. Hence, PI3K isoform-specific inhibitors have already achieved a wonderful effect on treating cancer. Herein, we summarize the molecular mechanism of PI3K inhibitors in preventing the permeability of vessels and neovascularization. Additionally, we briefly illustrate how PI3K signaling modulates blood vessel growth and discuss the different roles that PI3K isoforms play in angiogenesis.

Mechanism of Artemisia annua L. in the treatment of acute myocardial infarction: network pharmacology, molecular docking and in vivo validation

This study was to evaluate the potential mechanism of action of Artemisia annua L. (A. annua) in the treatment of acute myocardial infarction (AMI) using network pharmacology, molecular docking and in vivo experiments. 22 active chemical compounds and 193 drug targets of A. annua were screened using the Traditional Chinese Medicine System Pharmacological (TCMSP) database. 3876 disease targets were also collected. Then 158 intersection targets between AMI and A. annua were obtained using R 4.2.0 software. String database was used to construct the protein-protein interaction (PPI) network and 6 core targets (MAPK1, TP53, HSP90AA1, RELA, AKT1, and MYC) were screened. Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed using the R package. GO enrichment results were mainly related to cell responses to chemical stress and cell membrane microregions. KEGG pathways were mainly involved in lipids, atherosclerosis and fluid shear stress. In addition, molecular docking between A. annua active compounds and core targets showed high binding activity. As for in vivo validation, A. annua extract showed significant effects on improving post-infarction ventricular function, delaying ventricular remodeling, and reducing myocardial fibrosis and apoptosis. This study has revealed the potential components and molecular mechanisms of A. annua in the treatment of AMI. Our work also showed that A. annua has great effect on reducing myocardial fibrosis and scar area after infarction.

Redrawing Urokinase Receptor (uPAR) Signaling with Cancer Driver Genes for Exploring Possible Anti-Cancer Targets and Drugs

During tumorigenesis, urokinase (uPA) and uPA receptor (uPAR) play essential roles in mediating pathological progression in many cancers. To understand the crosstalk between the uPA/uPAR signaling and cancer, as well as to decipher their cellular pathways, we proposed to use cancer driver genes to map out the uPAR signaling. In the study, an integrated pharmaceutical bioinformatics approach that combined modulator identification, driver gene ontology networking, protein targets prediction and networking, pathway analysis and uPAR modulator screening platform construction was employed to uncover druggable targets in uPAR signaling for developing a novel anti-cancer modality. Through these works, we found that uPAR signaling interacted with 10 of 21 KEGG cancer pathways, indicating the important role of uPAR in mediating intracellular cancerous signaling. Furthermore, we verified that receptor tyrosine kinases (RTKs) and ribosomal S6 kinases (RSKs) could serve as signal hubs to relay uPAR-mediated cellular functions on cancer hallmarks such as angiogenesis, proliferation, migration and metastasis. Moreover, we established an in silico virtual screening platform and a uPAR-driver gene pair rule for identifying potential uPAR modulators to combat cancer. Altogether, our results not only elucidated the complex networking between uPAR modulation and cancer but also provided a paved way for developing new chemical entities and/or re-positioning clinically used drugs against cancer.

In vitro siRNA-mediated GPX4 and AKT1 silencing in oxaliplatin resistance cancer cells induces ferroptosis and apoptosis

Oxaliplatin is a member of platinum-based chemotherapy drugs frequently used in colorectal cancer (CRC). However, resistance to oxaliplatin causes tumor progression and metastasis. Akt1 and Gpx4 are essential regulator genes of apoptosis and ferroptosis pathways. Inhibition of these genes might eradicate oxaliplatin resistance in resistant CRC cells. We compared two cell death strategies to reverse drug resistance in Caco-2 and HT-29 oxaliplatin-resistant cell lines. We used the AKT1-specific siRNA to induce apoptosis. Also, GPX4-specific siRNA and FIN56 were utilized to generate ferroptosis. The effect of these treatments was assessed by reactive oxygen species (ROS) formation, cell viability, and protein expression level assays. Besides, the expression of GPX4, CoQ10, and NRF2 was assessed in both cell lines after treatments. Correctly measuring the expression of these responsible genes and proteins confirms the occurrence of different types of cell death. In addition, the ability of Akt1/ GPX4 siRNA in resensitizing HT-29 and Caco-2 oxaliplatin resistance cells was evaluated. Our finding showed that the upregulation of GPX4/siRNA caused a reduction in GPX4 and CoQ10 expressions in both cell lines. However, the expression level of NRF2 showed the same level in our cell lines, so we observed a downregulation of NRF2 in resistant CRC cell lines. Cell viability assay indicated that induction of ferroptosis by GPX4/siRNA or FIN56 and apoptosis by Akt1/siRNA in resistant cell lines could reverse the oxaliplatin resistance. We concluded that downregulation of Akt1 or Gpx4 could increase the efficacy of oxaliplatin to overcome the resistance compared to FIN56.

Characterization of the Ang/Tie2 Signaling Pathway in the Diaphragm Muscle of DMD Mice

In Duchenne muscular dystrophy (DMD), angiogenesis appears to be attenuated. Local administration of angiopoietin 1 (Ang1) has been shown to reduce inflammation, ischemia, and fibrosis in DMD mice. Ang1 is a vital vascular stabilizing factor that activates the endothelial cell receptor Tie2, leading to downstream pro-survival PI3K/Akt pathway activation and eNOS phosphorylation. In this study, we aimed to characterize the Ang/Tie2 signaling pathway within the diaphragm muscle of mouse models of DMD. Utilizing ELISA, immunoblots, and RT-qPCR, we demonstrated that Ang1 was downregulated, while the antagonist angiopoietin 2 (Ang2) was upregulated, leading to a decreased Ang1/Ang2 ratio. This correlated with a reduction in the phosphorylated Tie2/total Tie2 ratio. Interestingly, no significant differences in Akt or eNOS phosphorylation were observed, although DMD murine models did have elevated total Akt protein concentrations. These observations suggest that Ang1/Tie2 signaling may be dysregulated in the diaphragm muscle of DMD and further investigations may lead to new therapeutic interventions for DMD.

Peptide Lv Promotes Trafficking and Membrane Insertion of KCa3.1 through the MEK1-ERK and PI3K-Akt Signaling Pathways

Peptide Lv is a small endogenous secretory peptide that is proangiogenic through hyperpolarizing vascular endothelial cells (ECs) by enhancing the current densities of KCa3.1 channels. However, it is unclear how peptide Lv enhances these currents. One way to enhance the current densities of ion channels is to promote its trafficking and insertion into the plasma membrane. We hypothesized that peptide Lv-elicited KCa3.1 augmentation occurs through activating the mitogen-activated protein kinase kinase 1 (MEK1)-extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt) signaling pathways, which are known to mediate ion channel trafficking and membrane insertion in neurons. To test this hypothesis, we employed patch-clamp electrophysiological recordings and cell-surface biotinylation assays on ECs treated with peptide Lv and pharmaceutical inhibitors of ERK and Akt. Blocking ERK or Akt activation diminished peptide Lv-elicited EC hyperpolarization and increase in KCa3.1 current densities. Blocking PI3K or Akt activation decreased the level of plasma membrane-bound, but not the total amount of KCa3.1 protein in ECs. Therefore, the peptide Lv-elicited EC hyperpolarization and KCa3.1 augmentation occurred in part through channel trafficking and insertion mediated by MEK1-ERK and PI3K-Akt activation. These results demonstrate the molecular mechanisms of how peptide Lv promotes EC-mediated angiogenesis.

Molecular insights into the behavior of the allosteric and ATP-competitive inhibitors in interaction with AKT1 protein: A molecular dynamics study

AKT1 is a family of serine/threonine kinases that play a key role in regulating cell growth, proliferation, metabolism, and survival. Two significant classes of AKT1 inhibitors (allosteric and ATP-competitive) are used in clinical development, and both of them could be effective in specific conditions. In this study, we investigated the effect of several different inhibitors on two conformations of the AKT1 by computational approach. We studied the effects of four inhibitors, including MK-2206, Miransertib, Herbacetin, and Shogaol, on the inactive conformation of AKT1 protein and the effects of four inhibitors, Capivasertib, AT7867, Quercetin, and Oridonin molecules on the active conformation of AKT1 protein. The results of simulations showed that each inhibitor creates a stable complex with AKT1 protein, although AKT1/Shogaol and AKT1/AT7867 complexes showed less stability than other complexes. Based on RMSF calculations, the fluctuation of residues in the mentioned complexes is higher than in other complexes. As compared to other complexes in either of its two conformations, MK-2206 has a stronger binding free energy affinity in the inactive conformation, -203.446 kJ/mol. MM-PBSA calculations showed that the van der Waals interactions contribute more than the electrostatic interactions to the binding energy of inhibitors to AKT1 protein.

Triciribine attenuates pathological neovascularization and vascular permeability in a mouse model of proliferative retinopathy

Proliferative retinopathies are the leading cause of irreversible blindness in all ages, and there is a critical need to identify novel therapies. We investigated the impact of triciribine (TCBN), a tricyclic nucleoside analog and a weak Akt inhibitor, on retinal neurovascular injury, vascular permeability, and inflammation in oxygen-induced retinopathy (OIR). Post-natal day 7 (P7) mouse pups were subjected to OIR, and treated (i.p.) with TCBN or vehicle from P14-P16 and compared with age-matched, normoxic, vehicle or TCBN-treated controls. P17 retinas were processed for flat mounts, immunostaining, Western blotting, and qRT-PCR studies. Fluorescein angiography, electroretinography, and spectral domain optical coherence tomography were performed on days P21, P26, and P30, respectively. TCBN treatment significantly reduced pathological neovascularization, vaso-obliteration, and inflammation marked by reduced TNFα, IL6, MCP-1, Iba1, and F4/80 (macrophage/microglia markers) expression compared to the vehicle-treated OIR mouse retinas. Pathological expression of VEGF (vascular endothelial growth factor), and claudin-5 compromised the blood-retinal barrier integrity in the OIR retinas correlating with increased vascular permeability and neovascular tuft formation, which were blunted by TCBN treatment. Of note, there were no changes in the retinal architecture or retinal cell function in response to TCBN in the normoxia or OIR mice. We conclude that TCBN protects against pathological neovascularization, restores blood-retinal barrier homeostasis, and reduces retinal inflammation without adversely affecting the retinal structure and neuronal function in a mouse model of OIR. Our data suggest that TCBN may provide a novel therapeutic option for proliferative retinopathy.

Ang II Controls the Expression of Mapkap1 by miR-375 and Affects the Function of Islet β Cells

BACKGROUND

The RAS system is involved in the regulation of islet function, but its regulation remains unclear.

OBJECTIVE

This study investigates the role of an islet-specific miR-375 in the effect of RAS system on islet β-cells.

METHODS

miR-375 mimics and inhibitors were transfected into insulin-secreting MIN6 cells in the presence or absence of RAS component.

RESULTS

Compared to control, in Ang II-treated MIN6 cells, miR-375 mimic transfection results in a decrement in cell viability and Akt-Ser levels (0.739±0.05 vs. 0.883±0.06 and 0.40±0.04 vs. 0.79±0.04, respectively), while the opposite occurred in miR-375 inhibitor-transfected cells (1.032±0.11 vs. 0.883±0.06 and 0.98±0.05 vs. 0.79±0.04, respectively, P<0.05). Mechanistically, transfection of miR- 375 mimics into Ang II-treated MIN6 cells significantly reduced the expression of Mapkap1 protein (0.97±0.15 vs. 0.63±0.06, P<0.05); while miR-375 inhibitor-transfected cells elevated Mapkap1 expression level (0.35±0.11 vs. 0.90±0.05, P<0.05), without changes in mRNA expression. Transfection of miR-375 specific inhibitors TSB-Mapkap1 could elevate Mapkap1 (1.62±0.02 vs. 0.68±0.01, P<0.05), while inhibition of Mapkap1 could significantly reduce the level of Akt-Ser473 phosphorylation (0.60±0.14 vs. 1.80±0.27, P<0.05).

CONCLUSION

The effects of Ang II on mouse islet β cells were mediated by miR-375 through miR- 375/Mapkap 1 axis. This targeted regulation may occur by affecting Akt phosphorylation of β cells. These results may provide new ideas and a scientific basis for further development of miRNA-targeted islet protection measures.

Low-Frequency Repetitive Transcranial Magnetic Stimulation in the Early Subacute Phase of Stroke Enhances Angiogenic Mechanisms in Rats

Objective To characterize the repetitive transcranial magnetic stimulation (rTMS) induced changes in angiogenic mechanisms across different brain regions.Methods Seventy-nine adult male Sprague-Dawley rats were subjected to a middle cerebral artery occlusion (day 0) and then treated with 1-Hz, 20-Hz, or sham stimulation of their lesioned hemispheres for 2 weeks. The stimulation intensity was set to 100% of the motor threshold. The neurological function was assessed on days 3, 10, and 17. The infarct volume and angiogenesis were measured by histology, immunohistochemistry, Western blot, and real-time polymerase chain reaction (PCR) assays. Brain tissue was harvested from the ischemic core (IC), ischemic border zone (BZ), and contralateral homologous cortex (CH).Results Optical density of angiopoietin1 and synaptophysin in the IC was significantly greater in the low-frequency group than in the sham group (p=0.03 and p=0.03, respectively). The 1-Hz rTMS significantly increased the level of Akt phosphorylation in the BZ (p<0.05 vs. 20 Hz). Endothelial nitric oxide synthase phosphorylation was increased in the IC (p<0.05 vs. 20 Hz), BZ (p<0.05 vs. 20 Hz), and CH (p<0.05 vs. 20 Hz and p<0.05 vs. sham). Real-time PCR demonstrated that low-frequency stimulation significantly increased the transcriptional activity of the TIE2 gene in the IC (p<0.05).Conclusion Low-frequency rTMS of the ipsilesional hemisphere in the early subacute phase of stroke promotes the expression of angiogenic factors and related genes in the brain, particularly in the injured area.

Expression of AKT1 Related with Clinicopathological Parameters in Clear Cell Renal Cell Carcinoma

Pathways such as VEGF, EGF and mTOR are known to be one of the major mechanisms of tumorigenesis including kidney cancer. To identify potential signaling pathway proteins, we performed differential/correlation analyses of mTOR-associated genes from three public datasets. AKT1 protein, one of the PI3K/AKT/mTOR pathways, turned out to be the potential by showing a consistent discrepancy between ccRCC-associated conditions as well as strong correlation with other mTOR-associated genes across the datasets. Then, we analyzed how AKT1 alteration affects clear cell renal cell carcinoma. The pathology of 58 kidney cancer patients was constructed to analyze the relationship between the expression level of AKT1 through immunohistochemical staining and their clinicopathological data. Gender, age and TNM stage did not show significant results. AKT1 is a known oncogene. However, in this study, high expression of AKT1 showed a slight correlation with lower WHO/ISUP grade, longer recurrence-free and progression-free survival rates.

Endothelial cell-specific loss of eNOS differentially affects endothelial function

The endothelium maintains and regulates vascular homeostasis mainly by balancing interplay between vasorelaxation and vasoconstriction via regulating Nitric Oxide (NO) availability. Endothelial nitric oxide synthase (eNOS) is one of three NOS isoforms that catalyses the synthesis of NO to regulate endothelial function. However, eNOS’s role in the regulation of endothelial function, such as cell proliferation and migration remain unclear. To gain a better understanding, we genetically knocked down eNOS in cultured endothelial cells using sieNOS and evaluated cell proliferation, migration and also tube forming potential in vitro. To our surprise, loss of eNOS significantly induced endothelial cell proliferation, which was associated with significant downregulation of both cell cycle inhibitor p21 and cell proliferation antigen Ki-67. Knockdown of eNOS induced cell migration but inhibited formation of tube-like structures in vitro. Mechanistically, loss of eNOS was associated with activation of MAPK/ERK and inhibition of PI3-K/AKT signaling pathway. On the contrary, pharmacologic inhibition of eNOS by inhibitors L-NAME or L-NMMA, inhibited cell proliferation. Genetic and pharmacologic inhibition of eNOS, both promoted endothelial cell migration but inhibited tube-forming potential. Our findings confirm that eNOS regulate endothelial function by inversely controlling endothelial cell proliferation and migration, and by directly regulating its tube-forming potential. Differential results obtained following pharmacologic versus genetic inhibition of eNOS indicates a more complex mechanism behind eNOS regulation and activity in endothelial cells, warranting further investigation.

Automated in vivo compound screening with zebrafish and the discovery and validation of PD 81,723 as a novel angiogenesis inhibitor

Angiogenesis is a critical process in tumor progression. Inhibition of angiogenesis by blocking VEGF signaling can impair existing tumor vessels and halt tumor progression. However, the benefits are transient, and most patients who initially respond to these therapies develop resistance. Accordingly, there is a need for new anti-angiogenesis therapeutics to delay the processes of resistance or eliminate the resistive effects entirely. This manuscript presents the results of a screen of the National Institutes of Health Clinical Collections Libraries I & II (NIHCCLI&II) for novel angiogenesis inhibitors. The 727 compounds of the NIHCCLI&II library were screened with a high-throughput drug discovery platform (HTP) developed previously with angiogenesis-specific protocols utilizing zebrafish. The screen resulted in 14 hit compounds that were subsequently narrowed down to one, with PD 81,723 chosen as the lead compound. PD 81,723 was validated as an inhibitor of angiogenesis in vivo in zebrafish and in vitro in human umbilical vein endothelial cells (HUVECs). Zebrafish exposed to PD 81,723 exhibited several signs of a diminished endothelial network due to the inhibition of angiogenesis. Immunochemical analysis did not reveal any significant apoptotic or mitotic activity in the zebrafish. Assays with cultured HUVECs elucidated the ability of PD 81,723 to inhibit capillary tube formation, migration, and proliferation of endothelial cells. In addition, PD 81,723 did not induce apoptosis while significantly down regulating p21, AKT, VEGFR-2, p-VEGFR-2, eNOS, and p-eNOS, with no notable change in endogenous VEGF-A in cultured HUVECs.

Akt1-dependent expression of angiopoietin 1 and 2 in vascular smooth muscle cells leads to vascular stabilization

Retinal angiogenesis was delayed in VSMC-specific Akt1-deficient mice (Akt1^∆SMC) but not in Akt2^∆SMC mice. The proliferation of ECs, recruitment of pericytes, and coverage of VSMCs to the endothelium were defective in Akt1^∆SMC. The silencing of Akt1 in VSMCs led to the downregulation of angiopoietin 1 (Ang1) and the upregulation of Ang2. The activation of Notch3 in VSMCs was significantly reduced in the retinas of Akt1^∆SMC mice. Silencing Akt1 suppressed the activation of Notch3. Moreover, the silencing of Notch3 downregulated Ang1, whereas the overexpression of Notch3 intracellular domain (NICD3) enhanced Ang1 expression. The nuclear localization and transcriptional activity of yes-associated protein (YAP) were affected by the expression level of Akt1. Silencing YAP downregulated Ang2 expression, whereas overexpression of YAP showed the opposite results. Ang1 antibody and Ang2 suppressed endothelial sprouting of wild-type aortic tissues, whereas the Ang2 antibody and Ang1 facilitated the endothelial sprouting of aortic tissues from Akt1^∆SMC mice. Finally, severe hemorrhage was observed in Akt1^∆SMC mice, which was further facilitated under streptozotocin (STZ)-induced diabetic conditions. Therefore, the Akt1-Notch3/YAP-Ang1/2 signaling cascade in VSMCs might play an essential role in the paracrine regulation of endothelial function.

Doxorubicin-induced hepatic toxicity in rats: Mechanistic protective role of Omega-3 fatty acids through Nrf2/HO-1 activation and PI3K/Akt/GSK-3β axis modulation

Doxorubicin (DOX), a common antibiotic used to treat a variety of tumors, has several substantial adverse effects that limit its clinical use. As a result, finding effective protective agents to combat DOX-induced organ damage is a necessity. The current study was set to delineate the hepatoprotective role of omega‐3 fatty acids (ω-3FA) against DOX-mediated acute liver damage in rats and the underlined mechanism of GSK-3β inhibition. Five groups of rats were orally received either saline (groups 1 & 2) or ω-3FA (25, 50 and 100 mg/kg/day; groups 3, 4 & 5, respectively) for 28 consecutive days. Single DOX intraperitoneal injection (20 mg/kg) was used to induce hepatic toxicity in all groups except group 1 (negative control). Blood samples and liver tissues were collected 48-hr after injection. Our results revealed that pre-administration of ω-3FA (25, 50 and 100 mg/kg) to DOX-induced hepatic injured rats showed a significant reduction in serum hepatic injury biomarkers (ALT, AST, total and direct bilirubin) as well as hepatic contents of MDA, GSH, Nrf2 and HO-1. Additionally, hepatic PI3K, pAkt and GSK-3β have been restored significantly in a dose-dependent manner. Furthermore, all the hepatic histopathological features have been retained upon ω-3FA treatment together with the immunostaining intensity of tumor necrosis factor-α and caspase-3. These results suggest that ω-3FA have shown a marked activation of the Nrf2/HO-1 signaling pathway and modulation of the PI3K/pAkt/GSK-3β axis against DOX-induced hepatotoxicity.

Discovering Tuberosin and Villosol as Potent and Selective Inhibitors of AKT1 for Therapeutic Targeting of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a major cause of death in developing countries because of high tobacco consumption. RAC-alpha serine-threonine kinase (AKT1) is considered as an attractive drug target because its prolonged activation and overexpression are associated with cancer progression and metastasis. In addition, several AKT1 inhibitors are being developed to control OSCC and other associated forms of cancers. We performed a screening of the IMPPAT (Indian Medicinal Plants, Phytochemistry and Therapeutics) database to discover promising AKT1 inhibitors which pass through various important filters such as ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, physicochemical properties, PAINS (pan-assay interference compounds) filters, PASS (prediction of activity spectra for substances) analysis, and specific interactions with AKT1. Molecules bearing admirable binding affinity and specificity towards AKT1 were selected for further analysis. Initially, we identified 30 natural compounds bearing appreciable affinity and specific interaction with AKT1. Finally, tuberosin and villosol were selected as potent and selective AKT1 inhibitors. To obtain deeper insights into binding mechanism and selectivity, we performed an all-atom molecular dynamics (MD) simulation and principal component analysis (PCA). We observed that both tuberosin and villosol strongly bind to AKT1, and their complexes were stable throughout the simulation trajectories. Our in-depth structure analysis suggested that tuberosin and villosol could be further exploited in the therapeutic targeting of OSCC and other cancers after further clinical validations.

Transcriptomic analysis of papillary thyroid cancer focused on immune-subtyping, oncogenic fusion, and recurrence

Objectives

Thyroid cancer is the most common endocrine tumor, with rapidly increasing incidence worldwide. However, its transcriptomic characteristics associated with immunological signatures, driver fusions, and recurrence markers remain unclear. We aimed to investigate the transcriptomic characteristics of advanced papillary thyroid cancer.

Methods

This study included 282 papillary thyroid cancer tumor samples and 155 normal samples from Chungnam National University Hospital and Seoul National University Hospital. Transcriptomic quantification was determined by high-throughput RNA sequencing. We investigated the associations of clinical parameters and molecular signatures using RNA sequencing. We validated predictive biomarkers using the Cancer Genome Atlas database.

Results

Through a comparison of differentially expressed genes, gene sets, and pathways in papillary thyroid cancer compared to normal tumor-adjacent tissue, we found increased immune signaling associated with cytokines or T cells and decreased thyroid hormone synthetic pathways. In addition, patients with recurrence presented increased CD8+ T-cell and Th1-cell signatures. Interestingly, we found differentially overexpressed genes related to immune-escape signaling such as CTLA4, IDO1, LAG3, and PDCD1 in advanced papillary thyroid cancer with a low thyroid differentiation score. Fusion analysis showed that the PI3K and mitogen-activated protein kinase (MAPK) signaling pathways were regulated differently according to the RET fusion partner genes (CCDC6 or NCOA4). Finally, we identified HOXD9 as a novel molecular biomarker that predicts the recurrence of thyroid cancer in addition to known risk factors (tumor size, lymph node metastasis, and extrathyroidal extension).

Conclusion

We identified a high association with immune-escape signaling in the immune-hot group with aggressive clinical characteristics among Korean thyroid cancer patients. Moreover, RET fusion differentially regulated PI3K and MAPK signaling depending on the partner gene of RET, and HOXD9 was found to be a recurrence marker for advanced papillary thyroid cancer.

Thymosin beta-4 improves endothelial function and reparative potency of diabetic endothelial cells differentiated from patient induced pluripotent stem cells

Background

Prior studies show that signature phenotypes of diabetic human induced pluripotent stem cells derived endothelial cells (dia-hiPSC-ECs) are disrupted glycine homeostasis, increased senescence, impaired mitochondrial function and angiogenic potential as compared with healthy hiPSC-ECs. In the current study, we aimed to assess the role of thymosin β-4 (Tb-4) on endothelial function using dia-hiPSC-ECs as disease model of endothelial dysfunction.

Methods and results

Using dia-hiPSC-ECs as models of endothelial dysfunction, we determined the effect of Tb-4 on cell proliferation, senescence, cyto-protection, protein expression of intercellular adhesion molecule-1 (ICAM-1), secretion of endothelin-1 and MMP-1, mitochondrial membrane potential, and cyto-protection in vitro and angiogenic potential for treatment of ischemic limb disease in a mouse model of type 2 diabetes mellitus (T2DM) in vivo. We found that 600 ng/mL Tb4 significantly up-regulated AKT activity and Bcl-XL protein expression, enhanced dia-hiPSC-EC viability and proliferation, limited senescence, reduced endothelin-1 and MMP-1 secretion, and improved reparative potency of dia-hiPSC-ECs for treatment of ischemic limb disease in mice with T2DM. However, Tb4 had no effect on improving mitochondrial membrane potential and glycine homeostasis and reducing intercellular adhesion molecule-1 protein expression in dia-hiPSC-ECs.

Conclusions

Tb-4 improves endothelial dysfunction through enhancing hiPSC-EC viability, reducing senescence and endothelin-1 production, and improves angiogenic potency in diabetes.

AKT Isoforms in the Immune Response in Cancer

AKT is a protein kinase that exists in three isoforms: AKT1, AKT2, and AKT3. Though similar in structure, these isoforms display different effects. AKT is activated downstream of PI3K, and together, this signaling pathway helps regulate cellular processes including cell growth, proliferation, metabolism, survival, and apoptosis. Disruption in these pathways has been associated with disorders including cardiovascular diseases, developmental disorders, inflammatory responses, autoimmune diseases, neurologic disorders, type 2 diabetes, and several cancers. In cancer, deregulation in the PI3K/AKT pathway can be manifested as tumorigenesis, pathological angiogenesis, and metastasis. Increased activity has been correlated with tumor progression and resistance to cancer treatments. Recent studies have suggested that inhibition of the PI3K/AKT pathway plays a significant role in the development, expansion, and proliferation of cells of the immune system. Additionally, AKT has been found to play an important role in differentiating regulatory T cells, activating B cells, and augmenting tumor immunosurveillance. This emphasizes AKT as a potential target for inhibition in cancer therapy. This chapter reviews AKT structure and regulation, its different isoforms, its role in immune cells, and its modulation in oncotherapy.

Extracellular Vesicles Mediate Communication between Endothelial and Vascular Smooth Muscle Cells

The recruitment of pericytes and vascular smooth muscle cells (SMCs) that enwrap endothelial cells (ECs) is a crucial process for vascular maturation and stabilization. Communication between these two cell types is crucial during vascular development and in maintaining vessel homeostasis. Extracellular vesicles (EVs) have emerged as a new communication tool involving the exchange of microRNAs between cells. In the present study, we searched for microRNAs that could be transferred via EVs from ECs to SMCs and vice versa. Thanks to a microRNA profiling experiment, we found that two microRNAs are more exported in each cell type in coculture experiments: while miR-539 is more secreted by ECs, miR-582 is more present in EVs from SMCs. Functional assays revealed that both microRNAs can modulate both cell-type phenotypes. We further identified miR-539 and miR-582 targets, in agreement with their respective cell functions. The results obtained in vivo in the neovascularization model suggest that miR-539 and miR-582 might cooperate to trigger the process of blood vessel coverage by smooth muscle cells in a mature plexus. Taken together, these results are the first to highlight the role of miR-539 and miR-582 in angiogenesis and communication between ECs and SMCs.

Novel Pathways for Targeting Tumor Angiogenesis in Metastatic Breast Cancer

Breast cancer is the most common cancer affecting women and is the second leading cause of cancer related death worldwide. Angiogenesis, the process of new blood vessel development from pre-existing vasculature, has been implicated in the growth, progression, and metastasis of cancer. Tumor angiogenesis has been explored as a key therapeutic target for decades, as the blockade of this process holds the potential to reduce the oxygen and nutrient supplies that are required for tumor growth. However, many existing anti-angiogenic approaches, such as those targeting Vascular Endothelial Growth Factor, Notch, and Angiopoietin signaling, have been associated with severe side-effects, limited survival advantage, and enhanced cancer regrowth rates. To address these setbacks, alternative pathways involved in the regulation of tumor angiogenesis are being explored, including those involving Bone Morphogenetic Protein-9 signaling, the Sonic Hedgehog pathway, Cyclooxygenase-2, p38-mitogen-activated protein kinase, and Chemokine Ligand 18. This review article will introduce the concept of tumor angiogenesis in the context of breast cancer, followed by an overview of current anti-angiogenic therapies, associated resistance mechanisms and novel therapeutic targets.

Overexpression of dimethylarginine dimethylaminohydrolase 1 protects from angiotensin II-induced cardiac hypertrophy and vascular remodeling

Cardiovascular complications are the leading cause of death, and elevated levels of asymmetric dimethyarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, are implicated in their pathophysiology. We investigated the role of dimethylarginine dimethylaminohydrolase 1 (DDAH1), an enzyme hydrolyzing ADMA, in prevention of cardiovascular remodeling during hypertension. We hypothesized that the animals overexpressing DDAH1 will be protected from angiotensin II (ANG II)-induced end organ damage. Angiotensin II (ANG II) was infused in two doses: 0.75 and 1.5 mg/kg/day in DDAH1 transgenic mice (DDAH1 TG) and wild-type (WT) littermates for 2 or 4 wk. Echocardiography was performed in the first and fourth weeks of the infusion, systolic blood pressure (SBP) was measured weekly, and cardiac hypertrophy and vascular remodeling was assessed by histology. Increase in SBP after 1 wk of ANG II infusion was not different between the groups, whereas TG mice had lower SBP at later time points. TG mice were protected from cardiovascular remodeling after 2 wk of ANG II infusion in the high dose and after 4 wk in the moderate dose. TG mice had higher left ventricular lumen-to-wall ratio, lower cardiomyocyte cross-sectional area, and less interstitial fibrosis compared with WT controls. In aorta, TG mice had less adventitial fibrosis, lower medial thickness with preserved elastin content, lower counts of inflammatory cells, lower levels of active matrix metalloproteinase-2, and showed better endothelium-dependent relaxation. We demonstrated that overexpression of DDAH1 protects from ANG II-induced cardiovascular remodeling and progression of hypertension by preserving endothelial function and limiting inflammation.NEW & NOTEWORTHY We showed that overexpression of dimethylarginine dimethylaminohydrolase 1 (DDAH1) protects from angiotensin II-induced cardiovascular damage, progression of hypertension, and adverse vascular remodeling in vivo. This protective effect is associated with decreased levels of asymmetric dimethylarginine, preservation of endothelial function, inhibition of cardiovascular inflammation, and lower activity of matrix metalloproteinase-2. Our findings are highly clinically relevant, because they suggest that upregulation of DDAH1 might be a promising therapeutic approach against angiotensin II-induced end organ damage.

Osteoprotegerin regulates vascular function through syndecan-1 and NADPH oxidase-derived reactive oxygen species

Osteogenic factors, such as osteoprotegerin (OPG), are protective against vascular calcification. However, OPG is also positively associated with cardiovascular damage, particularly in pulmonary hypertension, possibly through processes beyond effects on calcification. In the present study, we focused on calcification-independent vascular effects of OPG through activation of syndecan-1 and NADPH oxidases (Noxs) 1 and 4. Isolated resistance arteries from Wistar-Kyoto (WKY) rats, exposed to exogenous OPG, studied by myography exhibited endothelial and smooth muscle dysfunction. OPG decreased nitric oxide (NO) production, eNOS activation and increased reactive oxygen species (ROS) production in endothelial cells. In VSMCs, OPG increased ROS production, H2O2/peroxynitrite levels and activation of Rho kinase and myosin light chain. OPG vascular and redox effects were also inhibited by the syndecan-1 inhibitor synstatin (SSNT). Additionally, heparinase and chondroitinase abolished OPG effects on VSMCs-ROS production, confirming syndecan-1 as OPG molecular partner and suggesting that OPG binds to heparan/chondroitin sulphate chains of syndecan-1. OPG-induced ROS production was abrogated by NoxA1ds (Nox1 inhibitor) and GKT137831 (dual Nox1/Nox4 inhibitor). Tempol (SOD mimetic) inhibited vascular dysfunction induced by OPG. In addition, we studied arteries from Nox1 and Nox4 knockout (KO) mice. Nox1 and Nox4 KO abrogated OPG-induced vascular dysfunction. Vascular dysfunction elicited by OPG is mediated by a complex signalling cascade involving syndecan-1, Nox1 and Nox4. Our data identify novel molecular mechanisms beyond calcification for OPG, which may underlie vascular injurious effects of osteogenic factors in conditions such as hypertension and/or diabetes.

Non-HLA antibodies targeting angiotensin II type 1 receptors and endothelin-1 type A receptors impair endothelial repair via a β2-arrestin link to the mTOR pathway

Functional non-HLA antibodies (antibodies to non-human leukocyte antigens) targeting the G protein-coupled receptors angiotensin II type 1 receptor (AT1R) and endothelin-1 type A receptor (ETAR) are implicated in the pathogenesis of transplant vasculopathy. While ERK signaling (a regulator of cell growth) may represent a general cellular response to agonist stimulation, the molecular link between receptor stimulation and development of vascular obliteration has not been fully established. Here we hypothesize involvement of the versatile adaptor proteins, β-arrestins, and the major regulator of cell growth, PI3K/mTOR signaling, in impaired endothelial repair. To test this, human microvascular endothelial cells were treated with AT1R/ETAR antibodies isolated from patients with kidney transplant vasculopathy. These antibodies activated both mTOR complexes via AT1R and ETAR in a PI3K-dependent and ERK-independent manner. The mTOR inhibitor, rapamycin, completely abolished activation of mTORC1 and mTORC2 after long-term treatment with receptor antibodies. Imaging studies revealed that β2- but not β1-arrestin was recruited to ETAR in response to ET1 and patient antibodies but not with antibodies isolated from healthy individuals. Silencing of β2-arrestin by siRNA transfection significantly reduced ERK1/2 and mTORC2 activation. Non-HLA antibodies impaired endothelial repair by AT1R- and ETAR-induced mTORC2 signaling. Thus, we provide evidence that functional AT1R/ETAR antibodies induce ERK1/2 and mTOR signaling involving β2-arrestin in human microvascular endothelium. Hence, our data may provide a translational rational for mTOR inhibitors in combination with receptor blockers in patients with non-HLA receptor recognizing antibodies.

Lipopolysaccharides Enhance Epithelial Hyperplasia and Tubular Adenoma in Intestine-Specific Expression of krasV12 in Transgenic Zebrafish

Intestinal carcinogenesis is a multistep process that begins with epithelial hyperplasia, followed by a transition to an adenoma and then to a carcinoma. Many etiological factors, including KRAS mutations and inflammation, have been implicated in oncogenesis. However, the potential synergistic effects between KRAS mutations and inflammation as well as the potential mechanisms by which they promote intestinal carcinogenesis remain unclear. Thus, the objective of this study was to investigate the synergistic effects of kras^V12, lipopolysaccharides (LPS), and/or dextran sulfate sodium (DSS) on inflammation, tumor progression, and intestinal disorders using transgenic adults and larvae of zebrafish. Histopathology and pathological staining were used to examine the intestines of kras^V12 transgenic zebrafish treated with LPS and/or DSS. LPS and/or DSS treatment enhanced intestinal inflammation in kras^V12 transgenic larvae with concomitant increases in the number of neutrophils and macrophages in the intestines. The expression of kras^V12, combined with LPS treatment, also enhanced epithelial hyperplasia and tubular adenoma, demonstrated by histopathological examinations and by increases in cell apoptosis, cell proliferation, and downstream signaling of phosphorylated AKT serine/threonine kinase 1 (AKT), extracellular-signal-regulated kinase (ERK), and histone. We also found that kras^V12 expression, combined with LPS treatment, significantly enhanced changes in intestinal morphology, specifically (1) decreases in goblet cell number, goblet cell size, villi height, and intervilli space, as well as (2) increases in villi width and smooth muscle thickness. Moreover, kras^V12 transgenic larvae cotreated with DSS and LPS exhibited exacerbated intestinal inflammation. Cotreatment with DSS and LPS in kras^V12-expressing transgenic adult zebrafish also enhanced epithelial hyperplasia and tubular adenoma, compared with wild-type fish that received the same cotreatment. In conclusion, our data suggest that kras^V12 expression, combined with LPS and/or DSS treatment, can enhance intestinal tumor progression by activating the phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathway and may provide a valuable in vivo platform to investigate tumor initiation and antitumor drugs for gastrointestinal cancers.

Network Pharmacological Study and Molecular Docking Analysis of Qiweitangping in Treating Diabetic Coronary Heart Disease

Background

Coronary heart disease (CHD) is one of the most important complications of diabetes mellitus, having a high disability fatality rate. Qiweitangping is a Chinese medicine to control diabetes (type 1 and type 2 diabetes) and complications, having been used in clinic for more than 20 years, with the expected therapeutic effect. In a previous clinical study, the total effective rate of the drug for the treatment of type 2 diabetes reached 92.7%. However, the mechanism of the treatment process is unclear. Therefore, this research was conducted to explore the mechanism of treating diabetic coronary heart disease with the assistance of bioinformatics methods.

Methods

The TCMSP database was used to collect the effective chemical constituents of Qiweitangping and the target genes of the chemical constituents, and the related genes of diabetic CHD were obtained from the GeneCard database. Furthermore, the intersection was found between the target gene of the drug and the related gene of the disease to obtain the candidate genes; the STRING database and DAVID database were used to perform protein interaction analysis and KEGG enrichment analysis on the candidate genes. Also, molecular docking was used for auxiliary verification. Finally, a “drug component-gene target-pathway” network was constructed by using Cytoscape software.

Results

Sixty-two effective chemical components including naringin, diosgenin, formogenin, isorolin, and isocryptanshinone, fifty-nine candidate target genes (such as AKT1, CASP3, and VEGF-A), and thirty-nine related pathways in Qiweitangping were obtained. In addition, two pairs (CASP-naringenin and STAT3-cryptotanshinone) of molecular docking results showed good affinity (<−5.00 kcal/mol).

Conclusion

The results of the study indicate that Qiweitangping treats diabetic CHD with multiple chemical components. Its mechanism of action may be related to the HIF-1 signaling pathway, PI3K-Akt signaling pathway, and ErbB signaling pathway. STAT3 and CASP genes have been verified by molecular docking to have a relatively good combination with Qiweitangping. This study is the theoretical basis for further experimental study on the treatment mechanism of diabetic CHD with Qiweitangping.

Role of epigenetic m6 A RNA methylation in vascular development: mettl3 regulates vascular development through PHLPP2/mTOR-AKT signaling

N⁶ -methyladenosine (m6A) methylation is the most prevalent RNA modification, and it emerges as an important regulatory mechanism of gene expression involved in many cellular and biological processes. However, the role of m⁶ A methylation in vascular development is not clear. The m⁶ A RNA methylation is regulated by dynamic interplay among methyltransferases, binding proteins, and demethylases. Mettl3 is a member of the mettl3-mettl14 methyltransferase complex, referred to as writers that catalyze m6A RNA methylation. Here, we used CRISPR-Cas9 genome editing to develop two lines of knockout (KO) zebrafish for mettl3. Heterozygous mettl3^+/- KO embryos show defective vascular development, which is directly visible in fli-EGFP and flk-EGFP zebrafish. Alkaline phosphatase staining and whole mount in situ hybridization with cdh5, and flk markers demonstrated defective development of intersegmental vessels (ISVs), subintestinal vessels (SIVs), interconnecting vessels (ICVs) and dorsal longitudinal anastomotic vessels (DLAV) in both heterozygous mettl3^+/- and homozygous mettl3^-/- KO zebrafish embryos. Similar phenotypes were observed in zebrafish embryos with morpholino knockdown (KD) of mettl3; however, the vascular defects were rescued fully by overexpression of constitutively active AKT1. KD of METTL3 in human endothelial cells inhibited cell proliferation, migration, and capillary tube formation. Mechanistically, mettl3 KO and KD significantly reduced the levels of m⁶ A RNA methylation, and AKT phosphorylation (S473) by an increase in the expression of phosphatase enzyme PHLPP2 and reduction in the phosphorylation of mTOR (S2481), a member of the phosphatidylinositol 3-kinase-related kinase family of protein kinases. These data suggest that m⁶ A RNA methylation regulates vascular development via PHLPP2/mTOR-AKT signaling.

Protective Effect of GM1 Attenuates Hippocampus and Cortex Apoptosis After Ketamine Exposure in Neonatal Rat via PI3K/AKT/GSK3β Pathway

Ketamine is a widely used analgesic and anesthetic in obstetrics and pediatrics. Ketamine is known to promote neuronal death and cognitive dysfunction in the brains of humans and animals during development. Monosialotetrahexosyl ganglioside (GM1), a promoter of brain development, exerts neuroprotective effects in many neurological disease models. Here, we investigated the neuroprotective effect of GM1 and its potential underlying mechanism against ketamine-induced apoptosis of rats. Seven-day-old Sprague Dawley (SD) rats were randomly divided into the following four groups: (1) group C (control group: normal saline was injected intraperitoneally); (2) group K (ketamine); (3) group GM1 (GM1 was given before normal saline injection); and (4) GM1+K group (received GM1 30 min before continuous exposure to ketamine). Each group contained 15 rats, received six doses of ketamine (20 mg/kg), and was injected with saline every 90 min. The Morris water maze (MWM) test, the number of cortical and hippocampal cells, apoptosis, and AKT/GSK3β pathway were analyzed. To determine whether GM1 exerted its effect via the PI3K/AKT/GSK3β pathway, PC12 cells were incubated with LY294002, a PI3K inhibitor. We found that GM1 protected against ketamine-induced apoptosis in the hippocampus and cortex by reducing the expression of Bcl-2 and Caspase-3, and by increasing the expression of Bax. GM1 treatment increased the expression of p-AKT and p-GSK3β. However, the anti-apoptotic effect of GM1 was eliminated after inhibiting the phosphorylation of AKT. We showed that GM1 lessens ketamine-induced apoptosis in the hippocampus and cortex of young rats by regulating the PI3K/AKT/GSK3β pathway. Taken together, GM1 may be a potential preventive treatment for the neurotoxicity caused by continuous exposure to ketamine.

Bone morphogenetic protein-7 inhibits endothelial-to-mesenchymal transition in primary human umbilical vein endothelial cells and mouse model of systemic sclerosis via Akt/mTOR/p70S6K pathway

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune inflammatory and vascular disorder that causes tissue fibrosis of the skin and internal organs. Endothelial-to-mesenchymal transition (EndoMT) has been considered an important mechanism in the pathogenesis of vascular remodeling in SSc. Recent studies suggested that bone morphogenic protein 7 (BMP-7) has anti-fibrotic effects in several fibrotic diseases.

OBJECTIVES

To investigate the mechanism of BMP-7 in inhibiting TGF-β-induced EndoMT in systemic sclerosis (SSc).

METHODS

Skin tissues of both healthy controls and SSc patients were detected the distribution of BMP-7. TGF-β was applied to induce the EndoMT model of human umbilical vein endothelial cells (HUVECs), and bleomycin was used to established the SSc mouse model. After treatment of BMP-7, the protein levels of endothelial specific markers, mesenchymal cell products, transcription factors and Akt signal pathway were examined by western blotting, immunofluorescence or immunohistochemistry both in vivo and in vitro.

RESULTS

The expression of BMP-7 was decreased in the basal layer of epidermis and dermis of SSc patients. EndoMT in TGF-β-treated HUVECs and skins of SSc mouse model were markedly attenuated after treatment with rh-BMP-7. Moreover, Akt/mTOR/p70S6K phosphorylation was involved in EndoMT and BMP-7 suppressed TGF-β- or bleomycin-induced theses phosphorylation in HUVECs or SSc mouse model.

CONCLUSION

BMP-7 reduced the production of TGF-β-induced EndoMT in HUVECs and SSc mouse model through Akt/mTOR/p70S6K signaling pathway. These findings suggested that BMP-7 could be employed as a promising antifibrotic therapy for SSc.

Gene Expression Profile of Vascular Endothelial Growth Factors (VEGFs) and Platelet-derived Growth Factors (PDGFs) in the Normal Cornea

BACKGROUND/AIM

Angiogenic growth factors expression is not known in the normal cornea. The aim was to study corneal gene expression profile of VEGF and PDGF pathways influencing the avascular state of cornea.

MATERIALS AND METHODS

cDNA synthesis was performed from mRNA extracted from five fresh pig corneas followed by cDNA synthesis and analysis of VEGF and PDGF pathways by TaqMan Array gene expression profile.

RESULTS

Normal pig cornea lacks VEGFR2 and VEGFR3 gene expression. MK2 and AKT1 genes were significantly overexpressed (p=0.000684, p=0.050995, respectively). Six PDGF pathway genes were overexpressed: TIAM1 (p=0.047), PIK3CA (p=0.00005), IKBKG (p=0.000006), PAK4 (p=0.034), RAC1 (p=0.000006 and PTGS2, p=0.00375). PDGF A was up-regulated, but not with a statistical significance (p=0.79911), while PDGFRα was down-regulated and PDGFRβ was not expressed.

CONCLUSION

Normal cornea avascularity is given by growth factor receptors down-regulation. Rapid corneal neovascularisation is induced by activation of the main angiogenic growth factors that induce angiogenic cascade and vessel recruitment.

MZT2A promotes NSCLC viability and invasion by increasing Akt phosphorylation via the MOZART2 domain

Mitotic spindle organizing protein 2A (MZT2A) is localized at the centrosome and regulates microtubule nucleation activity in cells. This study assessed the role of MZT2A in non-small-cell lung cancer (NSCLC). Differential MZT2A expression was bioinformatically assessed using TCGA database, the GEPIA database, and Kaplan-Meier survival data to determine the association between MZT2A expression and NSCLC prognosis. Furthermore, NSCLC tissue specimens were evaluated by immunohistochemistry. MZT2A was overexpressed or knocked down in NSCLC cells using cDNA and siRNA, respectively. The cells were subjected to various assays and treated with the selective Akt inhibitor LY294002 or co-transfected with galectin-3-binding protein (LGALS3BP) siRNA. MZT2A mRNA and protein levels were upregulated in NSCLC lesions and MTZ2A expression was associated with poor NSCLC prognosis. MZT2A protein was also highly expressed in NSCLC cells compared with the expression in normal bronchial cells. MZT2A expression promoted NSCLC cell viability and invasion, whereas MTZ2A siRNA had the opposite effect on NSCLC cells in vitro. At the protein level, MZT2A induced Akt phosphorylation, promoting NSCLC proliferation and invasion (but the selective Akt inhibitor blocked these effects) through upregulation of LGALS3BP via the MTZ2A MOZART2 domain, whereas LGALS3BP siRNA suppressed MTZ2A activity in NSCLC cells. The limited in vivo experiments confirmed the in vitro data. In conclusion, MZT2A exhibits oncogenic activity by activating LGALS3BP and Akt in NSCLC. Future studies will assess MTZ2A as a biomarker to predict NSCLC prognosis or as a target in the control of NSCLC progression.

Xenocoumacin 2 reduces protein biosynthesis and inhibits inflammatory and angiogenesis-related processes in endothelial cells

Xenocoumacin (Xcn) 1 and 2 are the major antibiotics produced by the insect-pathogenic bacterium Xenorhabdus nematophila. Although the antimicrobial activity of Xcns has been explored, research regarding their action on mammalian cells is lacking. We aimed to investigate the action of Xcns in the context of inflammation and angiogenesis. We found that Xcns do not impair the viability of primary endothelial cells (ECs). Particularly Xcn2, but not Xcn1, inhibited the pro-inflammatory activation of ECs: Xcn2 diminished the interaction between ECs and leukocytes by downregulating cell adhesion molecule expression and blocked critical steps of the NF-κB activation pathway including the nuclear translocation of NF-κB p65 as well as the activation of inhibitor of κBα (IκBα) and IκB kinase β (IKKβ). Furthermore, the synthesis of pro-inflammatory mediators and enzymes, nitric oxide (NO) production and prostaglandin E₂ (PGE₂), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2), was evaluated in leukocytes. The results showed that Xcns reduced viability, NO release, and iNOS expression in activated macrophages. Beyond these anti-inflammatory properties, Xcn2 effectively hindered pro-angiogenic processes in HUVECs, such as proliferation, undirected and chemotactic migration, sprouting, and network formation. Most importantly, we revealed that Xcn2 inhibits de novo protein synthesis in ECs. Consequently, protein levels of receptors that mediate the inflammatory and angiogenic signaling processes and that have a short half-live are reduced by Xcn2 treatment, thus explaining the observed pharmacological activities. Overall, our research highlights that Xcn2 exhibits significant pharmacological in vitro activity regarding inflammation and angiogenesis, which is worth to be further investigated preclinically.

Efficacy of topical and systemic transplantation of mesenchymal stem cells in a rat model of diabetic ischemic wounds

BACKGROUND

Mesenchymal stem cells (MSCs) exert positive effects in chronic wounds. However, critical parameters, such as the most effective administration routes, remain unclear. Accordingly, the purpose of this study was to compare the effects of topical and systemic transplantation MSCs on diabetic ischemic wound healing and explored the underlying mechanisms.

METHOD

A diabetic ischemic wound model was created on the dorsal foot of type 2 diabetes mellitus (T2DM) rat. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were administered via two routes: topical injection and intravenous (IV) infusion. Wound healing outcomes and blood glucose level were assessed dynamically. Meanwhile, blood flow recovery was evaluated in ischemic gastrocnemius muscles. The homing and transdifferentiation of mKate2-labeled BM-MSCs were assessed by fluorescence imaging and immunohistochemistry (IHC) analysis.

RESULT

Both topical and systemic treatments had a positive effect on the diabetic ischemic wound showing a significant reduction in wound area at day 14. Histological results showed an increase in the length of epithelial edges, collagen content, microvessel density in the wound bed, and a higher expression of vascular endothelial growth factor (VEGF). Meanwhile, systemic administration can ameliorate hyperglycemia and improve the blood perfusion of the ischemic hindlimb. BM-MSCs administered systemically were found distributed in wounded tissue and transdifferentiated into endothelial cells. Furthermore, BM-MSCs stimulated angiogenesis at wound sites by downregulating phosphatase and tensin homolog (PTEN) and activation of AKT signaling pathway.

CONCLUSIONS

The results demonstrated that both transplantation delivery method (topical and systemic) of BM-MSCs accelerated wound healing remarkably under pathological conditions. Nevertheless, systemic administration has the potential to ameliorate hyperglycemia and repair the damaged tissue.

Endothelial deletion of PKCδ prevents VEGF inhibition and restores blood flow reperfusion in diabetic ischemic limb

AIMS

Peripheral artery disease is a complication of diabetes leading to critical hindlimb ischemia. Diabetes-induced inhibition of VEGF actions is associated with the activation of protein kinase Cδ (PKCδ). We aim to specifically investigate the role of PKCδ in endothelial cell (EC) function and VEGF signaling.

METHODS

Nondiabetic and diabetic mice, with (ec-Prkcd-/-) or without (ec-Prkcdf/f) endothelial deletion of PKCδ, underwent femoral artery ligation. Blood flow reperfusion was assessed up to 4 weeks post-surgery. Capillary density, EC apoptosis and VEGF signaling were evaluated in the ischemic muscle. Src homology region 2 domain-containing phosphatase-1 (SHP-1) phosphatase activity was assessed in vitro using primary ECs.

RESULTS

Ischemic muscle of diabetic ec-Prkcdf/f mice exhibited reduced blood flow reperfusion and capillary density while apoptosis increased as compared to nondiabetic ec-Prkcdf/f mice. In contrast, blood flow reperfusion and capillary density were significantly improved in diabetic ec-Prkcd-/- mice. VEGF signaling pathway was restored in diabetic ec-Prkcd-/- mice. The deletion of PKCδ in ECs prevented diabetes-induced VEGF unresponsiveness through a reduction of SHP-1 phosphatase activity.

CONCLUSIONS

Our data provide new highlights in mechanisms by which PKCδ activation in EC contributed to poor collateral vessel formation, thus, offering novel therapeutic targets to improve angiogenesis in the diabetic limb.

Donor-specific phenotypic variation in hiPSC cardiomyocyte-derived exosomes impacts endothelial cell function

Exosomes are an important mechanism of cell-cell interaction in the cardiovascular system, both in maintaining homeostasis and in stress response. Interindividual differences that alter content in exosomes may play a role in cardiovascular disease pathology. To study the effect of interindividual cardiomyocyte (CM) variation, we characterized exosomal content in phenotypically diverse human induced pluripotent stem cell-derived CMs (hiPSC-CMs). Cell lines were generated from six participants in the HyperGEN cohort: three with left ventricular hypertrophy (LVH) and three with normal left ventricular mass (LVM). Sequence analysis of the intracellular and exosomal RNA populations showed distinct expression pattern differences between hiPSC-CM lines derived from individuals with LVH and those with normal LVM. Functional analysis of hiPSC-endothelial cells (hiPSC-ECs) treated with exosomes from both hiPSC-CM groups showed significant variation in response, including differences in tube formation, migration, and proliferation. Overall, treatment of hiPSC-ECs with exosomes resulted in significant expression changes associated with angiogenesis and endothelial cell vasculogenesis. However, the hiPSC-ECs treated with exosomes from the LVH-affected donors exhibited significantly increased proliferation but decreased tube formation and migration, suggesting angiogenic dysregulation.NEW & NOTEWORTHY The intracellular RNA and the miRNA content in exosomes are significantly different in hiPSC-CMs derived from LVH-affected individuals compared with those from unaffected individuals. Treatment of endothelial cells with these exosomes functionally affects cellular phenotypes in a donor-specific manner. These findings provide novel insight into underlying mechanisms of hypertrophic cell signaling between different cell types. With a growing interest in stem cells and exosomes for cardiovascular therapeutic use, this also provides information important for regenerative medicine.

Pravastatin Promotes Endothelial Colony-Forming Cell Function, Angiogenic Signaling and Protein Expression In Vitro

Endothelial dysfunction is a primary feature of several cardiovascular diseases. Endothelial colony-forming cells (ECFCs) represent a highly proliferative subtype of endothelial progenitor cells (EPCs), which are involved in neovascularization and vascular repair. Statins are known to improve the outcome of cardiovascular diseases via pleiotropic effects. We hypothesized that treatment with the 3-hydroxy-3-methyl-glutaryl–coenzyme A (HMG-CoA) reductase inhibitor pravastatin increases ECFCs’ functional capacities and regulates the expression of proteins which modulate endothelial health in a favourable manner. Umbilical cord blood derived ECFCs were incubated with different concentrations of pravastatin with or without mevalonate, a key intermediate in cholesterol synthesis. Functional capacities such as migration, proliferation and tube formation were addressed in corresponding in vitro assays. mRNA and protein levels or phosphorylation of protein kinase B (AKT), endothelial nitric oxide synthase (eNOS), heme oxygenase-1 (HO-1), vascular endothelial growth factor A (VEGF-A), placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and endoglin (Eng) were analyzed by real time PCR or immunoblot, respectively. Proliferation, migration and tube formation of ECFCs were enhanced after pravastatin treatment, and AKT- and eNOS-phosphorylation were augmented. Further, expression levels of HO-1, VEGF-A and PlGF were increased, whereas expression levels of sFlt-1 and Eng were decreased. Pravastatin induced effects were reversible by the addition of mevalonate. Pravastatin induces beneficial effects on ECFC function, angiogenic signaling and protein expression. These effects may contribute to understand the pleiotropic function of statins as well as to provide a promising option to improve ECFCs’ condition in cell therapy in order to ameliorate endothelial dysfunction.

Cell-cell junctions: structure and regulation in physiology and pathology

Epithelial and endothelial cell-cell contacts are established and maintained by several intercellular junctional complexes. These structurally and biochemically differentiated regions on the plasma membrane primarily include tight junctions (TJs), and anchoring junctions. While the adherens junctions (AJs) provide essential adhesive and mechanical properties, TJs hold the cells together and form a near leak-proof intercellular seal by the fusion of adjacent cell membranes. AJs and TJs play essential roles in vascular permeability. Considering their involvement in several key cellular functions such as barrier formation, proliferation, migration, survival, and differentiation, further research is warranted on the composition and signaling pathways regulating cell-cell junctions to develop novel therapeutics for diseases such as organ injuries. The current review article presents our current state of knowledge on various cell-cell junctions, their molecular composition, and mechanisms regulating their expression and function in endothelial and epithelial cells.

Autodisplay of human PIP5K1α lipid kinase on Escherichia coli and inhibitor testing

The human phosphatidylinositol 4-phosphate 5-kinase type I α (hPIP5K1α) plays a major role in the PI3K/AKT/mTOR signaling pathway. As it has been shown before that hPIP5K1α is involved in the development of different types of cancer in particular prostate cancer, inhibitors of the enzyme might be a new option for the treatment of this disease. Here we report on the expression of hPIP5K1α on the surface of E. coli using Autodisplay. Autodisplay is defined as the surface display of a recombinant protein on a gramnegative bacterium by the autotransporter secretion pathway. After verification of surface expression, enzyme activity of whole cells displaying hPIP5K1α was determined by a capillary electrophoresis based assay. When using cells at an OD₅₇₈ of 2.5, the artificial substrate phosphatidylinositol4-phosphate (PI(4)P) fluorescein was converted by a rate of 10.7 ± 0.2 fmol/min. Using this substrate inhibition of three pyranobenzoquinone type compounds was tested. The most active compound was 4-(2-amino-3-cyano-6-hydroxy-5,8-dioxo-7-undecyl-5,8-dihydro-4H-chromen-4-yl) benzoic acid with an IC₅₀ value of 8.6 μM. Because until now, all attempts to purify hPIP5K1α failed, we suggest the use of whole cells of E. coli displaying the enzyme as a convenient tool for inhibitor identification.

The effect of pentadecapeptide BPC 157 on hippocampal ischemia/reperfusion injuries in rats

BACKGROUND AND PURPOSE

We focused on the, yet undescribed, therapy effect of the stable gastric pentadecapeptide BPC 157 in hippocampal ischemia/reperfusion injuries, after bilateral clamping of the common carotid arteries in rats. The background is the proven therapy effect of BPC 157 in ischemia/reperfusion injuries in different tissues. Furthermore, there is the subsequent oxidative stress counteraction, particularly when given during reperfusion. The recovering effect it has on occluded vessels, results with activation of the alternative pathways, bypassing the occlusion in deep vein thrombosis. Finally, the BPC 157 therapy benefits with its proposed role as a novel mediator of Roberts' cytoprotection and bidirectional effects in the gut-brain axis.

MATERIALS AND METHODS

Male Wistar rats underwent bilateral clamping of the common carotid arteries for a 20-min period. At 30 s thereafter, we applied medication (BPC 157 10 µg/kg; or saline) as a 1 ml bath directly to the operated area, that is, trigonum caroticum. We documented, in reperfusion, the resolution of the neuronal damages sustained in the brain, resolution of the damages reflected in memory, locomotion, and coordination disturbances, with the presentation of the particular genes expression in hippocampal tissues.

RESULTS

In the operated rats, at 24 and 72 hr of the reperfusion, the therapy counteracted both early and delayed neural hippocampal damage, achieving full functional recovery (Morris water maze test, inclined beam-walking test, lateral push test). mRNA expression studies at 1 and 24 hr, provided strongly elevated (Egr1, Akt1, Kras, Src, Foxo, Srf, Vegfr2, Nos3, and Nos1) and decreased (Nos2, Nfkb) gene expression (Mapk1 not activated), as a way how BPC 157 may act.

CONCLUSION

Together, these findings suggest that these beneficial BPC 157 effects may provide a novel therapeutic solution for stroke.

Cellular Based Strategies for Microvascular Engineering

Vascularization is a major hurdle in complex tissue and organ engineering. Tissues greater than 200 μm in diameter cannot rely on simple diffusion to obtain nutrients and remove waste. Therefore, an integrated vascular network is required for clinical translation of engineered tissues. Microvessels have been described as <150 μm in diameter, but clinically they are defined as <1 mm. With new advances in super microsurgery, vessels less than 1 mm can be anastomosed to the recipient circulation. However, this technical advancement still relies on the creation of a stable engineered microcirculation that is amenable to surgical manipulation and is readily perfusable. Microvascular engineering lays on the crossroads of microfabrication, microfluidics, and tissue engineering strategies that utilize various cellular constituents. Early research focused on vascularization by co-culture and cellular interactions, with the addition of angiogenic growth factors to promote vascular growth. Since then, multiple strategies have been utilized taking advantage of innovations in additive manufacturing, biomaterials, and cell biology. However, the anatomy and dynamics of native blood vessels has not been consistently replicated. Inconsistent results can be partially attributed to cell sourcing which remains an enigma for microvascular engineering. Variations of endothelial cells, endothelial progenitor cells, and stem cells have all been used for microvascular network fabrication along with various mural cells. As each source offers advantages and disadvantages, there continues to be a lack of consensus. Furthermore, discord may be attributed to incomplete understanding about cell isolation and characterization without considering the microvascular architecture of the desired tissue/organ.

The Risk of Arterial Thrombosis in Patients With Chronic Myeloid Leukemia Treated With Second and Third Generation BCR-ABL Tyrosine Kinase Inhibitors May Be Explained by Their Impact on Endothelial Cells: An In-Vitro Study

BCR-ABL tyrosine kinase inhibitors (TKIs) revolutionized the treatment of chronic myeloid leukemia, inducing deep molecular responses, largely improving patient survival and rendering treatment-free remission possible. However, three of the five BCR-ABL TKIs, dasatinib, nilotinib, and ponatinib, increase the risk of developing arterial thrombosis. Prior investigations reported that nilotinib and ponatinib affect the endothelium, but the mechanisms by which they exert their toxic effects are still unclear. The impact of dasatinib and bosutinib on endothelial cells has been poorly investigated. Here, we aimed to provide an in vitro homogenous evaluation of the effects of BCR-ABL TKIs on the endothelium, with a special focus on the type of cell death to elucidate the mechanisms responsible for the potential cytotoxic effects of BCR-ABL TKIs nilotinib and ponatinib on endothelial cells. We tested the five BCR-ABL TKIs at three concentrations on human umbilical venous endothelial cells (HUVECs). This study highlights the endothelial toxicity of ponatinib and provides insights about the mechanisms by which it affects endothelial cell viability. Ponatinib induced apoptosis and necrosis of HUVECs after 72 h. Dasatinib affected endothelial cells in vitro by inhibiting their proliferation and decreased wound closure as soon as 24 h of treatment and even at infra-therapeutic dose (0.005 µM). Comparatively, imatinib, nilotinib, and bosutinib had little impact on endothelial cells at therapeutic concentrations. They did not induce apoptosis nor necrosis, even after 72 h of treatment but they inhibited HUVEC proliferation. Overall, this study reports various effects of BCR-ABL TKIs on endothelial cells and suggests that ponatinib and dasatinib induce arterial thrombosis through endothelial dysfunction.

KLF15-Wnt-Dependent Cardiac Reprogramming Up-Regulates SHISA3 in the Mammalian Heart

BACKGROUND

The combination of cardiomyocyte (CM) and vascular cell (VC) fetal reprogramming upon stress culminates in end-stage heart failure (HF) by mechanisms that are not fully understood. Previous studies suggest KLF15 as a key regulator of CM hypertrophy.

OBJECTIVES

This study aimed to characterize the impact of KLF15-dependent cardiac transcriptional networks leading to HF progression, amenable to therapeutic intervention in the adult heart.

METHODS

Transcriptomic bioinformatics, phenotyping of Klf15 knockout mice, Wnt-signaling-modulated hearts, and pressure overload and myocardial ischemia models were applied. Human KLF15 knockout embryonic stem cells and engineered human myocardium, and human samples were used to validate the relevance of the identified mechanisms.

RESULTS

The authors identified a sequential, postnatal transcriptional repression mediated by KLF15 of pathways implicated in pathological tissue remodeling, including distinct Wnt-pathways that control CM fetal reprogramming and VC remodeling. The authors further uncovered a vascular program induced by a cellular crosstalk initiated by CM, characterized by a reduction of KLF15 and a concomitant activation of Wnt-dependent transcriptional signaling. Within this program, a so-far uncharacterized cardiac player, SHISA3, primarily expressed in VCs in fetal hearts and pathological remodeling was identified. Importantly, the KLF15 and Wnt codependent SHISA3 regulation was demonstrated to be conserved in mouse and human models.

CONCLUSIONS

The authors unraveled a network interplay defined by KLF15-Wnt dynamics controlling CM and VC homeostasis in the postnatal heart and demonstrated its potential as a cardiac-specific therapeutic target in HF. Within this network, they identified SHISA3 as a novel, evolutionarily conserved VC marker involved in pathological remodeling in HF.

Inhibition of protein kinase C beta phosphorylation activates nuclear factor-kappa B and improves postischemic recovery in type 1 diabetes

IMPACT STATEMENT

Diabetes worsens the outcomes of peripheral arterial disease (PAD) likely in part through inducing chronic inflammation. However, in PAD, recovery requires the nuclear factor-kappa B (NF-κB) activation, a known contributor to inflammation. Our study shows that individually, both ischemia and high glucose activate the canonical and non-canonical arms of the NF-κB pathways. We show for the first time that prolonged high glucose specifically impairs ischemia-induced activation of the canonical NF-κB pathway through activation of protein kinase C beta (PKCβ). Accordingly, inhibition of PKCβ restores the ischemia-induced NF-κB activity both in vitroin endothelial cells and in vivoin hind limbs of type 1 diabetic mice and improves perfusion recovery after experimental PAD. Thus, this study provides a mechanistic insight into how diabetes contributes to poor outcomes in PAD and a potential translational approach to improve PAD outcomes.

Fatty acid extracts facilitate cutaneous wound healing through activating AKT, ERK, and TGF-β/Smad3 signaling and promoting angiogenesis

Fatty acids (FAs) are potential therapeutic agents for cutaneous wound healing; however, the mechanisms underlying this effect have not been clearly defined. In this study, we extracted and characterized FAs from dried Lucilia sericata larvae and investigated the molecular basis by which FAs promote cutaneous wound healing. We first confirmed that FA sodium salts (FASSs) stimulated proliferation, migration, and tube formation of cultured human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. We then showed that FASSs promoted endothelial-to-mesenchymal transition (EndMT), which plays an important role in stabilizing the neovasculature during angiogenesis. Mechanistically, FASSs up-regulated the expression of angiogenesis-related growth factors, platelet-derived growth factor (PDGF), transforming growth factor-β1 (TGF-β1), and vascular endothelial growth factor A (VEGFA), and activated angiogenesis-related signaling pathways, AKT, ERK, and TGF-β/Smad3. In a rat acute cutaneous-wound model, FAs promoted wound healing. Following treatment, we further found that expression of anti-apoptosis-related factors (c-Myc and Bcl-2) was up-regulated and expression of apoptosis-related factors (p53 and Bad) was down-regulated. Our findings suggest that FAs can promote cutaneous wound healing by inducing angiogenesis, partly by activating AKT, ERK, and TGF-β/Smad3 signaling.