Epigenetic Mechanisms Histone Deacetylase-Dependent Regulate the Glioblastoma Angiogenic Matrisome and Disrupt Endothelial Cell Behavior In Vitro

Glioblastoma (GBM) is the most aggressive brain tumor and different efforts have been employed in the search for new drugs and therapeutic protocols for GBM. Epitranscriptomics has shed light on new druggable Epigenetic therapies specifically designed to modulate GBM biology and behavior such as Histone Deacetylase inhibitors (iHDAC). Although the effects of iHDAC on GBM have been largely explored, there is a lack of information on the underlaying mechanisms HDAC-dependent that modulate the repertoire of GBM secreted molecules focusing on the set of Extracellular Matrix (ECM) associated proteins, the Matrisome, that may impact the surrounding tumor microenvironment. To acquire a better comprehension of the impacts of HDAC activity on the GBM Matrisome, we studied the alterations on the Matrisome-associated ECM regulators, Core Matrisome ECM glycoproteins, ECM-affiliated proteins and Proteoglycans upon HDAC inhibition in vitro as well as their relationship with glioma pathophysiological/clinical features and angiogenesis. For this, U87MG GBM cells were treated for with iHDAC or vehicle (control) and the whole secretome was processed by Mass Spectrometry NANOLC-MS/MS. In silico analyses revealed that proteins associated to the Angiogenic Matrisome (AngioMatrix), including Decorin, ADAM10, ADAM12 and ADAM15 were differentially regulated in iHDAC versus control secretome. Interestingly, genes coding for the Matrisome proteins differentially regulated were found mutated in patients and were correlated to glioma pathophysiological/clinical features. In vitro functional assays, using HBMEC endothelial cells exposed to the secretome of control or iHDAC treated GBM cells, coupled to 2D and 3D GBM cell culture system, showed impaired migratory capacity of endothelial cells and disrupted tubulogenesis in a Fibronectin and VEGF independent fashion. Collectively, our study provides understanding of epigenetic mechanisms HDAC-dependent to key Matrisomal proteins that may contribute to identify new druggable Epigenetic therapies or gliomagenesis biomarkers with relevant implications to improve therapeutic protocols for this malignancy.

Broad-spectrum antiviral activity of two structurally analogous CYP3A inhibitors against pathogenic human coronaviruses in vitro

Coronaviruses pose a permanent risk of outbreaks, with three highly pathogenic species and strains (SARS-CoV, MERS-CoV, SARS-CoV-2) having emerged in the last twenty years. Limited antiviral therapies are currently available and their efficacy in randomized clinical trials enrolling SARS-CoV-2 patients has not been consistent, highlighting the need for more potent treatments. We previously showed that cobicistat, a clinically approved inhibitor of Cytochrome P450-3A (CYP3A), has direct antiviral activity against early circulating SARS-CoV-2 strains in vitro and in Syrian hamsters. Cobicistat is a derivative of ritonavir, which is co-administered as pharmacoenhancer with the SARS-CoV-2 protease inhibitor nirmatrelvir, to inhibit its metabolization by CPY3A and preserve its antiviral efficacy. Here, we used automated image analysis for a screening and parallel comparison of the anti-coronavirus effects of cobicistat and ritonavir. Our data show that both drugs display antiviral activity at low micromolar concentrations against multiple SARS-CoV-2 variants in vitro, including epidemiologically relevant Omicron subvariants. Despite their close structural similarity, we found that cobicistat is more potent than ritonavir, as shown by significantly lower EC50 values in monotherapy and higher levels of viral suppression when used in combination with nirmatrelvir. Finally, we show that the antiviral activity of both cobicistat and ritonavir is maintained against other human coronaviruses, including HCoV-229E and the highly pathogenic MERS-CoV. Overall, our results demonstrate that cobicistat has more potent anti-coronavirus activity than ritonavir and suggest that dose adjustments could pave the way to the use of both drugs as broad-spectrum antivirals against highly pathogenic human coronaviruses.

Tissue-like environments shape functional interactions of HIV-1 with immature dendritic cells

Immature dendritic cells (iDCs) migrate in microenvironments with distinct cell and extracellular matrix densities in vivo and contribute to HIV-1 dissemination and mounting of antiviral immune responses. Here, we find that, compared to standard 2D suspension cultures, 3D collagen as tissue-like environment alters iDC properties and their response to HIV-1 infection. iDCs adopt an elongated morphology with increased deformability in 3D collagen at unaltered activation, differentiation, cytokine secretion, or responsiveness to LPS. While 3D collagen reduces HIV-1 particle uptake by iDCs, fusion efficiency is increased to elevate productive infection rates due to elevated cell surface exposure of the HIV-1-binding receptor DC-SIGN. In contrast, 3D collagen reduces HIV transfer to CD4 T cells from iDCs. iDC adaptations to 3D collagen include increased pro-inflammatory cytokine production and reduced antiviral gene expression in response to HIV-1 infection. Adhesion to a 2D collagen matrix is sufficient to increase iDC deformability, DC-SIGN exposure, and permissivity to HIV-1 infection. Thus, mechano-physical cues of 2D and 3D tissue-like collagen environments regulate iDC function and shape divergent roles during HIV-1 infection.

HPV DNA Associates With Breast Cancer Malignancy and It Is Transferred to Breast Cancer Stromal Cells by Extracellular Vesicles

A causal link between Human Papillomavirus (HPV) and breast cancer (BC) remains controversial. In spite of this, the observation that HPV DNA is over-represented in the Triple Negative (TN) BC has been reported. Here we remark the high prevalence of HPV DNA (44.4%) in aggressive BC subtypes (TN and HER2+) in a population of 273 Italian women and we convey the presence of HPV DNA in the epithelial and stromal compartments by in situ hybridization. As previously reported, we also found that serum derived-extracellular vesicles (EVs) from BC affected patients contain HPV DNA. Interestingly, in one TNBC patient, the same HPV DNA type was detected in the serum-derived EVs, cervical and BC tissue samples. Then, we report that HPV DNA can be transferred by EVs to recipient BC stromal cells that show an activated phenotype (e.g., CD44, IL6 expression) and an enhanced capability to sustain mammospheres (MS) formation. These data suggest that HPV DNA vehiculated by EVs is a potential trigger for BC niche aggressiveness.

The chaperone dynein LL1 mediates cytoplasmic transport of empty and mature hepatitis B virus capsids

BACKGROUND & AIMS

Hepatitis B virus (HBV) has a DNA genome but replicates within the nucleus by reverse transcription of an RNA pregenome, which is converted to DNA in cytoplasmic capsids. Capsids in this compartment are correlated with inflammation and epitopes of the capsid protein core (Cp) are a major target for T cell-mediated immune responses. We investigated the mechanism of cytoplasmic capsid transport, which is important for infection but also for cytosolic capsid removal.

METHODS

We used virion-derived capsids containing mature rcDNA (matC) and empty capsids (empC). RNA-containing capsids (rnaC) were used as a control. The investigations comprised pull-down assays for identification of cellular interaction partners, immune fluorescence microscopy for their colocalization and electron microscopy after microinjection to determine their biological significance.

RESULTS

matC and empC underwent active transport through the cytoplasm towards the nucleus, while rnaC was poorly transported. We identified the dynein light chain LL1 as a functional interaction partner linking capsids to the dynein motor complex and showed that there is no compensatory transport pathway. Using capsid and dynein LL1 mutants we characterized the required domains on the capsid and LL1.

CONCLUSIONS

This is the first investigation on the detailed molecular mechanism of how matC pass the cytoplasm upon infection and how empC can be actively removed from the cytoplasm into the nucleus. Considering that hepatocytes with cytoplasmic capsids are better recognized by the T cells, we hypothesize that targeting capsid DynLL1-interaction will not only block HBV infection but also stimulate elimination of infected cells.

LAY SUMMARY

In this study, we identified the molecular details of HBV translocation through the cytoplasm. Our evidence offers a new drug target which could not only inhibit infection but also stimulate immune clearance of HBV infected cells.

Importin β Can Bind Hepatitis B Virus Core Protein and Empty Core-Like Particles and Induce Structural Changes

Hepatitis B virus (HBV) capsids are found in many forms: immature single-stranded RNA-filled cores, single-stranded DNA-filled replication intermediates, mature cores with relaxed circular double-stranded DNA, and empty capsids. A capsid, the protein shell of the core, is a complex of 240 copies of core protein. Mature cores are transported to the nucleus by a complex that includes both importin α and importin β (Impα and Impβ), which bind to the core protein's C-terminal domains (CTDs). Here we have investigated the interactions of HBV core protein with importins in vitro. Strikingly, empty capsids and free core protein can bind Impβ without Impα. Cryo-EM image reconstructions show that the CTDs, which are located inside the capsid, can extrude through the capsid to be bound by Impβ. Impβ density localized on the capsid exterior near the quasi-sixfold vertices, suggested a maximum of 30 Impβ per capsid. However, examination of complexes using single molecule charge-detection mass spectrometry indicate that some complexes include over 90 Impβ molecules. Cryo-EM of capsids incubated with excess Impβ shows a population of damaged particles and a population of "dark" particles with internal density, suggesting that Impβ is effectively swallowed by the capsids, which implies that the capsids transiently open and close and can be destabilized by Impβ. Though the in vitro complexes with great excess of Impβ are not biological, these results have implications for trafficking of empty capsids and free core protein; activities that affect the basis of chronic HBV infection.

[Evaluation of hearing by studying acoustic distortion products in noise-induced hearing loss]

In this work, the Authors want to verify the possibility of an objective method of cochlear function evaluation in subjects affected by chronic acoustic trauma, through the study of the acoustic distortion products. Undertaking 46 subjects, the researchers have demonstrated a direct correlation between the tonal acoustic threshold and that of the distortion products. This method was able to show the useful indications of an objective evaluation of acoustic capacity in non collaborating subject. Because of the large variability of intensity of the distortion products and their absence when the acoustic threshold is more than 50-60 dB HL, they by themselves, don't permit exact evaluation of the tonal threshold for a given frequency.

Diagnosing nasal hyperreactivity with positional rhinomanometry

Positional rhinomanometry is a physiologic method for estimating nasal resistance, which is variable, difficult to predict, and linked to vasomotor activity of the functional system culminating in the turbinate valves. Thirty subjects suffering from allergic rhinitis, 25 patients affected by aspecific rhinitis, and 40 healthy controls underwent positional rhinomanometry. Test positions included the seated (baseline), supine, and recumbent (homolateral and contralateral to the nasal fossa under examination). In patients with perennial allergic rhinitis and in those with aspecific rhinitis, positional rhinomanometry elicited two pathologic responses: either an average percentage rise of more than 80% in nasal resistance in the supine and homolateral and contralateral recumbent positions compared with basal values, or a paradoxical fall in the supine and homolateral recumbent positions.

Laryngeal microsurgery under general anesthesia using small-bore endotracheal tubes: blood gas analysis

This study reports variations observed under general anesthesia through small-bore endotracheal tubes in PO2, PCO2, HCO3, percentage saturation of O2, and pH levels in 39 patients who underwent laryngeal microsurgery lasting from 10 to 100 minutes. The tendency to an increase in PCO2 levels reached statistical significance only at the 100th minute but did not constitute a risk for patients as values remained within the limits of "permitted hypercapnia." PO2, percentage saturation of oxygen, and HCO3 levels did not vary significantly. pH values tended to fall (respiratory acidosis) in correlation to the increase in PCO2. Small-bore endotracheal tubes can safely be used for laryngeal microsurgery when operating times are not longer than 100 minutes.

[Positional rhinomanometry in hypertrophic vasomotor chronic rhinitis: considerations before and after functional surgery of turbinates]

The Authors report their experience regarding Positional Active Rhinomanometry performed before and after surgery in hypertrophic-vasomotor chronic rhinitis. Twenty-five patients suffering of hypertrophy of the turbinates and/or nasal vasomotor disorders were examined pre-operatively and 3, 6 and 12 months after inferior submucosal turbinoplasty. Tests were performed in the seated, supina, homolateral and contralateral positions with regard to the fossa in question. Values were compared with those of forty normal subjects. Pre-operative examinations showed a large number of paradoxical responses and very high increase in nasal resistance. Postoperative values were quite similar to those of normal subjects, a demonstration of the efficacy of surgical treatment of turbinates hyper-reactivity.

[Positional rhinomanometry in specific nasal hyperreactivity]

Following up the results obtained in a previous work testing Positional Rhinomanometry in normal subjects, the authors performed this test in subjects affected with specific nasal hyperreactivity. The aim was to offer an objective evaluation of decubitus-caused variations in air flow resistance through the nasal cavities. Thirty subjects suffering from allergic rhinitis (18 from seasonal and 12 perennial allergic rhinitis) underwent Anterior Active Rhinomanometry during the intercritical period of the disease. Tests were performed in the seated, supine positions homolateral and contralateral to the fossa in question. The positional tests show a marked difference between normality and specific hyperreactivity as a consequence of paradoxical responses. Moreover it can indicate the greater increase in nasal resistance, expression of a clear disreactivity of the cavernous tissue stimulated by variations in posture and found mostly in the perennial allergic rhinitis subjects.

[Postural rhinomanometry in normal subjects]

Measurement of decubitus-caused variations in air flow resistance through the nasal cavities indicates the vascular reactivity of turbinate cavernous tissue and makes it possible to evaluate the variable component in nasal resistance; a component usually suppressed by previous pharmacological vasoconstriction. The aim of the present work has been to indicate normative values regarding variations in nasal resistance in different types of decubitus. The latter will be referenced for future studies regarding nasal vasomotor pathologies (specific or aspecific hyperreactivity). Eighty nasal cavities from normal subjects were examined by means of Anterior Active Rhinomanometry in the following positions: seated, supine, homolateral and contralateral to the fossa in question. As absolute values are highly variable even in normal subjects, the resistance variations in decubitus were expressed in percentage of basal value (seated position). In every decubitus there is an average increase in resistance due to the increased venous pressure in the cephalic area although the greatest statistical significance and lowest scattering of values is found in the supine position with 20 degrees head-trunk angle. Mean values and standard deviations are given and will be referenced for further studies on rhinopathology.

Auditory brainstem responses in noise-induced permanent hearing loss

Fifty-four patients (108 ears) with presumed noise-induced hearing loss, were subjected to tonal and speech audiometry, impedance tests and measurements of auditory brainstem responses (ABR), in order to check for possible retrocochlear involvement. ABR data indicated that latency values of waves I, III and V, as well as III-I, V-III and V-I intervals fell within the normal range in all cases (M +/- 2 SD), even for fast repetition rates (51 stim/s). Poor waveform resolution of early components, particularly of wave I, was found in 12 ears (11.1%) and a total absence of evoked potentials not always related to the hearing loss, occurred in 5 ears (4.6%).