Silencing Matrix Metalloproteinases 9 and 2 Inhibits Human Retinal Microvascular Endothelial Cell Invasion and Migration

Design of ultra-wide-field scanning laser fundus imaging system with cascaded conicoid mirrors

We propose and design a multi-stage cascaded scanning laser ophthalmoscope (SLO) for ultra-wide field (UWF), which uses conicoid mirrors, constructed by conjugation of pupil plane. The vergence uniformity and the angular magnification of a cascaded conicoid mirrors (CCM) system are analyzed recursively and optimized preliminarily to achieve high quality imaging with UWF, and the optimal system with the model eye are obtained by simulation and optimization. Two-stage and three-stage cascaded systems are designed with this method, and the formulas of beam vergence and angular magnification are obtained by theoretical derivation. As compared to the two-stage CCM system, the proposed three-stage cascaded UWF SLO has superior performance in imaging quality. Its average RMS radius of spot diagram is calculated to be 26.372 µm, close to the diffractive limit resolution. The image resolution of human retina can be up to 30 µm with 135° FOV in theory. The three-stage cascaded SLO is more suitable for UWF fundus imaging. This study will be helpful for early screening and accurate diagnosis of various diseases in the peripheral retina.

Theaflavin alleviates oxidative injury and atherosclerosis progress via activating microRNA-24-mediated Nrf2/HO-1 signal

Theaflavin (TF) in black tea has been shown to have significant antioxidant and anti-inflammatory capacity; however, the effects and the underlying mechanism of TF on atherosclerosis (AS) remain unclear. Herein, we investigated the effects and the potential mechanism of TF on AS progression in vivo and in vitro. ApoE^-/- mice were administrated with high fat diet (HFD) or HFD + TF (5 or 10 mg, i.g.) for 12 weeks. The results indicated that TF administration effectively decreases the serum lipid levels and the production of MDA in HFD-fed mice. Meanwhile, TF promotes the activities of antioxidant enzymes (SOD, CAT, and GSH-Px) and inhibits the formation of atherosclerotic plaque and the process of histological alterations in the aorta. In vitro, TF pretreatment could protect against cholesterol-induced oxidative injuries in HUVEC cells, decreasing the level of ROS and MDA, maintaining the activities of antioxidant enzymes. Further study revealed that TF upregulates Nrf2/HO-1 signaling pathway in vascular endothelial cells. Moreover, TF increases the level of microRNA-24 (miR-24), and miR-24 inhibition markedly compromises TF-induced Nrf2 activation and protective effects. In conclusion, the present study indicated that theaflavins may achieve the anti-atherosclerotic effect via activating miR-24-mediated Nrf2/HO-1 signaling pathway.

Sensory neurons from dorsal root ganglia regulate endothelial cell function in extracellular matrix remodelling

BACKGROUND

Recent physiological and experimental data highlight the role of the sensory nervous system in bone repair, but its precise role on angiogenesis in a bone regeneration context is still unknown. Our previous work demonstrated that sensory neurons (SNs) induce the osteoblastic differentiation of mesenchymal stem cells, but the influence of SNs on endothelial cells (ECs) was not studied.

METHODS

Here, in order to study in vitro the interplay between SNs and ECs, we used microfluidic devices as an indirect co-culture model. Gene expression analysis of angiogenic markers, as well as measurements of metalloproteinases protein levels and enzymatic activity, were performed.

RESULTS

We were able to demonstrate that two sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), were involved in the transcriptional upregulation of angiogenic markers (vascular endothelial growth factor, angiopoietin 1, type 4 collagen, matrix metalloproteinase 2) in ECs. Co-cultures of ECs with SNs also increased the protein level and enzymatic activity of matrix metalloproteinases 2 and 9 (MMP2/MMP9) in ECs.

CONCLUSIONS

Our results suggest a role of sensory neurons, and more specifically of CGRP and SP, in the remodelling of endothelial cells extracellular matrix, thus supporting and enhancing the angiogenesis process. Video abstract.

Onconase Restores Cytotoxicity in Dabrafenib-Resistant A375 Human Melanoma Cells and Affects Cell Migration, Invasion and Colony Formation Capability

Melanoma is a lethal tumor because of its severe metastatic potential, and serine/threonine-protein kinase B-raf inhibitors (BRAFi) are used in patients harboring BRAF-mutation. Unfortunately, BRAFi induce resistance. Therefore, we tested the activity of onconase (ONC), a cytotoxic RNase variant, against BRAFi-resistant cells to re-establish the efficacy of the chemotherapy. To do so, an A375 dabrafenib-resistant (A375DR) melanoma cell subpopulation was selected and its behavior compared with that of parental (A375P) cells by crystal violet, 5-Bromo-2’-deoxyuridine incorporation, and cleaved poly(ADP-ribose) polymerase 1 (PARP1) western blot measurements. Then, nuclear p65 Nuclear Factor kappaB (NF-κB) and IκB kinases-α/β (IKK) phosphorylation levels were measured. Gelatin zymography was performed to evaluate metalloproteinase 2 (MMP2) activity. In addition, assays to measure migration, invasion and soft agar colony formation were performed to examine the tumor cell dissemination propensity. ONC affected the total viability and the proliferation rate of both A375P and A375DR cell subpopulations in a dose-dependent manner and also induced apoptotic cell death. Among its pleiotropic effects, ONC reduced nuclear p65 NF-κB amount and IKK phosphorylation level, as well as MMP2 activity in both cell subpopulations. ONC decreased cell colony formation, migration, and invasion capability. Notably, it induced apoptosis and inhibited colony formation and invasiveness more extensively in A375DR than in A375P cells. In conclusion, ONC successfully counteracts melanoma malignancy especially in BRAFi-resistant cells and could become a tool against melanoma recurrence.

The Impact of Human Papilloma Viruses, Matrix Metallo-Proteinases and HIV Protease Inhibitors on the Onset and Progression of Uterine Cervix Epithelial Tumors: A Review of Preclinical and Clinical Studies

Infection of uterine cervix epithelial cells by the Human Papilloma Viruses (HPV) is associated with the development of dysplastic/hyperplastic lesions, termed cervical intraepithelial neoplasia (CIN). CIN lesions may regress, persist or progress to invasive cervical carcinoma (CC), a leading cause of death worldwide. CIN is particularly frequent and aggressive in women infected by both HPV and the Human Immunodeficiency Virus (HIV), as compared to the general female population. In these individuals, however, therapeutic regimens employing HIV protease inhibitors (HIV-PI) have reduced CIN incidence and/or clinical progression, shedding light on the mechanism(s) of its development. This article reviews published work concerning: (i) the role of HPV proteins (including HPV-E5, E6 and E7) and of matrix-metalloproteinases (MMPs) in CIN evolution into invasive CC; and (ii) the effect of HIV-PI on events leading to CIN progression such as basement membrane and extracellular matrix invasion by HPV-positive CIN cells and the formation of new blood vessels. Results from the reviewed literature indicate that CIN clinical progression can be monitored by evaluating the expression of MMPs and HPV proteins and they suggest the use of HIV-PI or their derivatives for the block of CIN evolution into CC in both HIV-infected and uninfected women.

Age-Related Macular Degeneration: New Paradigms for Treatment and Management of AMD

Age-related macular degeneration (AMD) is a well-characterized and extensively studied disease. It is currently considered the leading cause of visual disability among patients over 60 years. The hallmark of early AMD is the formation of drusen, pigmentary changes at the macula, and mild to moderate vision loss. There are two forms of AMD: the “dry” and the “wet” form that is less frequent but is responsible for 90% of acute blindness due to AMD. Risk factors have been associated with AMD progression, and they are taking relevance to understand how AMD develops: (1) advanced age and the exposition to environmental factors inducing high levels of oxidative stress damaging the macula and (2) this damage, which causes inflammation inducing a vicious cycle, altogether causing central vision loss. There is neither a cure nor treatment to prevent AMD. However, there are some treatments available for the wet form of AMD. This article will review some molecular and cellular mechanisms associated with the onset of AMD focusing on feasible treatments for each related factor in the development of this pathology such as vascular endothelial growth factor, oxidative stress, failure of the clearance of proteins and organelles, and glial cell dysfunction in AMD.

Nanoparticle-mediated arresten gene inhibits neointimal formation of vein grafts: an experimental research

BACKGROUND

Recently, we established a new rat model of venous arterialization by grafting the jugular vein into carotid arteries. In many respects, the morphological features of this murine vascular graft model resemble those of human venous bypass graft diseases. Using this model, we studied nanoparticles that mediated the arresten gene to inhibit the neointimal formation of vein grafts.

METHODS

Thirty healthy Wistar female rats were randomly divided into three groups. Rat models of grafting the jugular vein into carotid arteries were established. Before and after surgery, all rats were subjected to anticoagulant drugs; and these were subcutaneously injected through different reagents after surgery. Group A: subcutaneous injection of nanoparticles to mediate the arresten gene (0.2 mL); group B: subcutaneous injection of blank nanoparticles (0.2 mL); group C: subcutaneous injection of saline (0.2 mL). At two weeks after the operation, veins of the objective blood vessel were obtained. Pathological changes of local vascular tissues and the new intima hyperplasia of experimental vascular segments were observed. Immunohistochemistry was used to observe the expression of MMPs.

RESULTS

(I) After two weeks, pathological intimal hyperplasia reactions were more obvious in groups B and C than in group A (P<0.05). The difference between groups B and C was not statistically significant (P>0.05); (II) the expression of MMP-2 could be observed in different degrees among the three groups. The expression of MMP-2 markedly increased in groups B and C compared to group A (P<0.05), but the difference between these two groups was not statistically significant (P>0.05).

CONCLUSIONS

(I) Nanoparticle-mediated arresten genes can reduce intimal hyperplasia in grafts; (II) we have recently shown that this gene reduced intimal hyperplasia, and this reduction is related to the reduced expression of MMP-2. This shows that the arresten gene can inhibit the degradation of the extracellular matrix (ECM).