Ultrastructural Findings and Possible Therapeutic Targets, at Micro and Nanoscales in Rectal Mucosa of Patients with HIV/AIDS |Chapter 2 | Medicine and Medical Research: New Perspectives Vol. 5

 

Background: Several studies have shown that human immunodeficiency virus (HIV) maintains residual replication in the lymph nodes of patients with undetectable viral load in peripheral blood despite highly active antiretroviral therapy (HAART). In other words, while the virus is eliminated in the peripheral blood by antiretroviral drugs, it continues to infect and replicate in new cells in the lymphoid tissue. This shows that the treatments used today against HIV do not achieve the total elimination of the virus in the body.

 

Other studies demonstrated that the concentrations of antiretrovirals at the lymph node level were lower compared to the concentrations in peripheral blood, not reaching optimal levels to stop viral replication. Additional investigations in intestinal mucosa showed that HIV RNA can be detected in the intestine of patients with successful HAART, suggesting that the intestinal mucosa is a cellular reservoir where HAART inhibits viral replication but does not eradicate the virus, therefore that it is necessary to carry out more in-depth studies in order to improve the understanding of the pathogenesis of HIV at the level of the intestinal mucosa. The above-captioned issues motivated the present investigation in search of micro- and nanoscale findings with a possible therapeutic approach.

 

Objective: The present study aimed to determine the ultrastructural findings on Rectal Mucosa (RM) of patients with HIV/AIDS and anorectal pathologies (ARP), at micrometric and nanometric scales.

 

Materials and Methods: 5 patients were evaluated, 18 - 55 years old, with ARP (HIV co-infection with HPV, n = 4, and HIV-negative patient with HPV infection) (control n = 1), who were referred to the Coloproctology Unit of the HUC, and subjected to rectoscopy and biopsy. RM samples were identified, placed in a sterile plastic bottle with 1 mL of 2% glutaraldehyde, and immediately transported for routine processing of fine cut (60 - 90 nm) to be evaluated via Transmission Electron Microscopy (TEM). They were fixed with Karnovsky solution with Millonig phosphate buffer (pH 7.4 and 320 mOsm) and post-fixed with OsO4 under the same conditions of pH and osmolarity.

 

Results: Ultrastructural findings, at 10-6 scale: 1) Intestinal mucosa: vacuoles of mucus of different sizes that seem to be fused. 2) Smooth muscle cells: loss of definition of contractile myofilaments mass. 3) Unmyelinated axons and terminals of Schwann cells (SC): Edema and loss of their plasma membranes in some areas of association with axon terminals as well as abundant collagen fibers associated with SC. Ultrastructural findings, at 10-9 scale: 1) Smooth muscle cells: folded wrapper cores and edema of mitochondria and rough endoplasmic reticulum cisterns (RER). 2) Myelinated axon terminals: Loss of synaptic vesicles. 3) Fibroblasts: One observes mitochondria and cisterns of RER with alterations. All these alterations can generate intestinal and anorectal dysfunction in these patients. The use of nanotechnology can be very useful for the therapeutic approach to HIV, offering unique advantages, such as improving the bioavailability, water solubility, stability, and targeting capacity of antiretroviral drugs, especially in those difficult sites for an effective therapeutic approach.

 

Conclusions: HIV causes changes in rectal and muscular mucosa despite HAART treatment with undetectable viral load. Nano-drugs could play an important role in drug delivery in sites where conventional ART has limited access, so as to achieve sufficient concentrations to execute optimal therapeutic responses and virus eradication in anatomical and intracellular sites.

 

Author (s) Details

Maria Antonieta Annunziato
Department of Internal Medicine, Medical Attention Center, General Checkups, Medical Exams and Consultations, Wheelchair Center, (BANDESIR), Caracas, Venezuela and Latin American Association of Clinical Nanomedicine (LATNAMCLI), Caracas, Venezuela.

 

Carlos Sardiñas
Coloproctology Unit, Caracas University Hospital (HUC), Caracas, Venezuela.

 

Hector J. Finol
Center for Electron Microscopy, Sciences Faculty, Central University of Venezuela, Caracas, Venezuela.

 

Ana Carvajal
Department of Infectious Diseases, University Hospital of Caracas (HUC), Caracas, Venezuela.

 

Antonio Roschman-González
Center for Electron Microscopy, Sciences Faculty, Central University of Venezuela, Caracas, Venezuela and School of Biology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela.

 

Yetsenia De Gouveia

School of Biology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela.

 

Estefanie García
School of Biology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela.

 

Liseth Garibaldi
Department of Electronic Microscopy, Venezuelan Institute of Scientific Research (IVIC), Miranda State, Venezuela.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/mmrnp/v5/1606

Evaluating the Role of the Tyrosine Phosphatase SHP-2 in Mediating Adrenomedullin Proangiogenic Activity in Solid Tumors | Chapter 2 | Achievements and Challenges of Medicine and Medical Science Vol. 4

Adrenomedullin (AM) is widely expressed in a variety of tumor types and was shown to be mitogenic for many human cancer cell lines in vitro whereas several in vivo studies have also highlighted its strong contribution to neoplastic angiogenesis. VE-cadherin is an essential adhesion molecule in endothelial adherens junctions, and the integrity of these complexes is thought to be regulated by VE-cadherin tyrosine phosphorylation. It was previously shown that AM blockade correlates with elevated levels of phosphorylated VE-cadherin (pVE-cadherinY731) in endothelial cells, associated with impaired barrier function and a persistent increase in vascular endothelial cell permeability. However, the mechanism underlying this effect is unknown. To reveal these mechanisms, techniques such as endothelial cell culture, Western blot analysis, immunoprecipitation, RNA interference, SHP-2 inhibitors, permeability assay, Matrigel plug assay in vitro and in vivo, and in vivo tumor xenograft growth were used in this study. For statistical analysis, non-parametric analysis Kruskal-Wallis followed by Bonferroni test was performed using XLSTAT Software throughout the whole manuscript. In this article, it is demonstrated that the AM-mediated dephosphorylation of pVE-cadherin^Y731 takes place through activation of the tyrosine phosphatase SHP-2, as judged by the rise of its active fraction phosphorylated at tyrosine 542 (pSHP-2^Y542) in HUVECs and glioblastoma-derived-endothelial cells. Both pre-incubation of HUVECs with SHP-2 inhibitors NSC-87877 and SHP099 and SHP-2 silencing hindered AM-induced dephosphorylation of pVE-cadherin^Y731 in a dose dependent-manner, showing the role of SHP-2 in the regulation of endothelial cell contacts. Furthermore, SHP-2 inhibition impaired AM-induced HUVECs differentiation into cord-like structures in vitro and impeded AM-induced neovascularization in in vivo Matrigel plugs bioassays. Subcutaneously transplanted U87-glioma tumor xenograft mice treated with AM- receptors-blocking antibodies showed a decrease in pSHP-2^Y542 associated with VE-cadherin in nascent tumor vasculature when compared to control IgG-treated xenografts.

Our findings show that AM acts on VE-cadherin dynamics through pSHP-2^Y542 to finally modulate cell-cell junctions in the angiogenesis process, thereby promoting a stable and functional tumor vasculature. This data, together with the reported observation that SHP-2 negative mutant ECs failed to organize themselves into a highly vascularized network in the yolk sac of mouse embryos (23), support the role of SHP-2 as an important player in the signaling transduced by AM to regulate pro-angiogenic and vascular stabilizing activities in endothelial cells.

 

Author (s) Details

 

Romain Sigaud
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Nadège Dussault
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Caroline Berenguer-Daize
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Christine Vellutini
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Zohra Benyahia
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Mylène Cayol
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Fabrice Parat
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France.

 

Kamel Mabrouk
Aix Marseille University, CNRS, Institut de Chimie Radicalaire (ICR), Unité Mixte de Recherche (UMR) 7273 Chimie Radicalaire Organique et Polymères de Spécialité (CROPS), Marseille, France.

 

Ramiro Va zquez
Preclinical Department, Early Drug Development Group (E2DG), Boulogne-Billancourt, France and Center for Genomic Science of Istituto Italiano di Tecnologia, Center for Genomic Science, European School of Molecular Medicine (IIT@SEMM), Fondazione Istituto Italiano di Tecnologia (IIT), Milan, Italy.

 

Maria E. Riveiro
Preclinical Department, Early Drug Development Group (E2DG), Boulogne-Billancourt, France.

 

Philippe Metellus
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France and Centre Hospitalier Clairval, De´ partement de Neurochirurgie, Marseille, France.

 

L’Houcine Ouafik
Aix Marseille University, Centre National de la Recherche Scientifique (CNRS), Institut de Neurophysiopathologie (INP), Inst Neurophysiopathol, Marseille, France and Assistance Publique Hôpitaux de Marseille (APHM), Centre Hospitalo Universitaire (CHU) Nord, Service d’OncoBiologie, Marseille, France.

 

Please see the book here:- https://doi.org/10.9734/bpi/acmms/v4/2836  

Protecting the Endothelial Cells, Reducing the Mortality of COVID-19 | Chapter 21 | Diagnostic and Treatment Advances in COVID-19 and SARS-CoV-2

As the current pandemic of SARS-CoV-2, physicians and hepatologists should be aware of the potential detrimental effects of this infection on the short-term outcome of such a fragile patient population. Especially, extra attention should be paid to the protection of endothelial cells, and actively respond to the acute inflammatory due to the endothelial cell injury. This would make a positive effect on the treatment of cirrhosis patients with SARS-CoV-2 infection and reduce the mortality of COVID-19.

Author(s) Details:

Jianshe Yang,
Third Affiliated Hospital of the Chinese University of Hong Kong, Shenzhen, China.

Please see the link here: https://stm.bookpi.org/DTACSC/article/view/9573

Potential Value of Circulating Endothelial Cells for the Diagnosis and Treatment of COVID-19 | Chapter 2 | Diagnostic and Treatment Advances in COVID-19 and SARS-CoV-2

 The ongoing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has been a formidable global challenge. As yet, there are very few drugs to treat this infection and no vaccine is currently available. It has gradually become apparant that coronavirus disease 2019 (COVID-19) is not a simple disease involving a single organ; rather, many vital organs and systems are affected. The endothelium is one target of SARS-CoV-2. Damaged endothelial cells, which break away from organs and enter the bloodstream to form circulating endothelial cells, were recently reported as putative biomarkers for COVID-19. Modulation of the expression level of sphingosine-1 phosphate via sphingosine kinase activation can control endothelial cell proliferation and apoptosis. As such, it may be possible to obtain a sensitive and specific diagnosis of the severity of COVID-19 by assessing the absolute number and the viable/apoptotic ratio of circulating endothelial cells. Furthermore, a focus on the endothelium could help to develop a strategy for COVID-19 treatment from the perspective of endothelial protection and repair.

Author(s) Details:

Xuchang Zhang,
Third Affiliated Hospital, The Chinese University of Hong Kong, Shenzhen, China and Department of Oncology, Longgang District People’s Hospital, Shenzhen, China.

Man Jiang,
Third Affiliated Hospital, The Chinese University of Hong Kong, Shenzhen, China and Department of Oncology, Longgang District People’s Hospital, Shenzhen, China.

Jianshe Yang,
Third Affiliated Hospital, The Chinese University of Hong Kong, Shenzhen, China and Shanghai Tenth People’s Hospital, Tongji University, Shanghai, China.

Please see the link here: https://stm.bookpi.org/DTACSC/article/view/9552