PI3K/mTOR mediate mitogen-dependent HDAC1 phosphorylation in breast cancer: a novel regulation of estrogen receptor expression

Histone deacetylase 1 (HDAC1) is an important epigenetic controller involved in transcriptional regulation through modification of chromatin structure. Genetic and epigenetic changes and deregulation of signal transduction pathways have been implicated in the development of breast cancer. Downregulation of estrogen receptor α (ERα) expression is one of the mechanisms behind the acquisition of endocrine resistance. Sustained and increased hormone and growth factor receptor signaling in breast cancer cells contribute to resistance to endocrine therapy. Both HDACs and the PI3K/mTOR signaling pathway are becoming promising targets in breast cancer, reversing also acquired hormone resistance. Here we show how mitogens, activating the PI3K/mTOR pathway, trigger the phosphorylation of HDAC1 in breast cancer cells, which is completely dependent on the activity of the p70 S6 kinase (S6K1). Our findings show that S6K1, overexpressed in many breast cancers, controls HDAC1-dependent transcriptional regulation of ERα levels upon mitogenic stimuli, controlling HDAC1 recruitment to the ERα promoter. Furthermore, cell treatment with both mTOR and HDACs inhibitors shows an additive effect in inhibiting breast cancer proliferation. This confirms the novel cross-talk between the HDAC1 and PI3K pathways with clinical implications towards the treatment of this malignant disease

Ribulose-1,5-bisphosphate regeneration in the Calvin-Benson-Bassham cycle: Focus on the last three enzymatic steps that allow the formation of Rubisco substrate

The Calvin-Benson-Bassham (CBB) cycle comprises the metabolic phase of photosynthesis and is responsible for carbon fixation and the production of sugar phosphates. The first step of the cycle involves the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) which catalyzes the incorporation of inorganic carbon into 3-phosphoglyceric acid (3PGA). The following steps include ten enzymes that catalyze the regeneration of ribulose-1,5-bisphosphate (RuBP), the substrate of Rubisco. While it is well established that Rubisco activity acts as a limiting step of the cycle, recent modeling studies and experimental evidence have shown that the efficiency of the pathway is also impacted by the regeneration of the Rubisco substrate itself. In this work, we review the current understanding of the structural and catalytic features of the photosynthetic enzymes that catalyze the last three steps of the regeneration phase, namely ribose-5-phosphate isomerase (RPI), ribulose-5-phosphate epimerase (RPE), and phosphoribulokinase (PRK). In addition, the redox- and metabolic-based regulatory mechanisms targeting the three enzymes are also discussed. Overall, this review highlights the importance of understudied steps in the CBB cycle and provides direction for future research aimed at improving plant productivity

Human dental pulp stem cells (hDPSCs): isolation, enrichment and comparative differentiation of two sub-populations

Human dental pulp represents a suitable alternative source of stem cells for the purpose of cell-based therapies in regenerative medicine, because it is relatively easy to obtain it, using low invasive procedures. This study characterized and compared two subpopulations of adult stem cells derived from human dental pulp (hDPSCs). Human DPSCs, formerly immune-selected for STRO-1 and c-Kit, were separated for negativity and positivity to CD34 expression respectively, and evaluated for cell proliferation, stemness maintenance, cell senescence and multipotency

Gastrointestinal Coronavirus disease 2019: epidemiology, clinical features, pathogenesis, prevention, and management

Introduction: The new Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the etiologic agent of coronavirus disease 2019. Some authors reported evidences that patients with SARS-CoV-2 infection could have a direct involvement of the gastrointestinal tract, and in symptomatic cases, gastrointestinal symptoms (diarrhea, nausea/vomiting, abdominal pain) could be very common. Area covered: In this article, we reviewed current published data of the gastrointestinal aspects involved in SARS-CoV-2 infection, including prevalence and incidence of specific symptoms, presumptive biological mechanism of GI infection, prognosis, clinical management and public health related concerns on the possible risk of oral-fecal transmission. Expert opinion: Different clues point to a direct virus infection and replication in mucosal cells of the gastrointestinal tract. In vitro studies showed that SARS-CoV-2 could enters into the gastrointestinal epithelial cells by the Angiotensin-Converting enzyme 2 membrane receptor. These findings, coupled with identification of viral RNA found in stools of patients, clearly suggest that a direct involvement of gastrointestinal tract is very likely. This can justify most of the gastrointestinal symptoms but also suggest a risk for an oral fecal route for transmission, additionally or alternatively to the main respiratory route

Spectral Photon-Counting Computed Tomography: Technical Principles and Applications in the Assessment of Cardiovascular Diseases

Spectral Photon-Counting Computed Tomography (SPCCT) represents a groundbreaking advancement in X-ray imaging technology. The core innovation of SPCCT lies in its photon-counting detectors, which can count the exact number of incoming x-ray photons and individually measure their energy. The first part of this review summarizes the key elements of SPCCT technology, such as energy binning, energy weighting, and material decomposition. Its energy-discriminating ability represents the key to the increase in the contrast between different tissues, the elimination of the electronic noise, and the correction of beam-hardening artifacts. Material decomposition provides valuable insights into specific elements’ composition, concentration, and distribution. The capability of SPCCT to operate in three or more energy regimes allows for the differentiation of several contrast agents, facilitating quantitative assessments of elements with specific energy thresholds within the diagnostic energy range. The second part of this review provides a brief overview of the applications of SPCCT in the assessment of various cardiovascular disease processes. SPCCT can support the study of myocardial blood perfusion and enable enhanced tissue characterization and the identification of contrast agents, in a manner that was previously unattainable

COVID-19 Case Fatality Ratio of Latino America Countries with Temperate Climate Partially Follows European and Oceania Trends According to Seasonal Change

The objective of our study is, therefore, to verify whether the trend of the pandemic regarding the lethality of the virus is similar in Argentina and Chile to that which emerged in the temperate countries of Europe and Oceania. The CFRs were derived from the John Hopkins University database. To check the trend of the Case Fatality Ratio and Argentina, Chile we calculated this index on the same dates in which it was calculated for comparison in European countries and in Australia and New Zealand: i.e., May 6th and from May 6th to the September 21st. We continued comparing the other countries of the southern hemisphere, recalculating the CFR as of 11th November. For comparing a period of year homogeneous, late spring, we calculate the change if CFR from 20th March to 15th April in the North Hemisphere. Our study's results seem to confirm in Latin America a possible influence of the climate and the changing of the seasons in the lethality of the virus. For the same exceptions, it is evident that the study shows that this factor is not the only one nor probably the most important. The obvious exception concerns Argentina, which does not show any summer improvement of the CFR, unfortunately; for this, nation-specific data are not available to verify if the trend is homogeneous in the different climates that the vast territory presents. Other very important factors come into play, among which the diffusivity of the virus also seems to play a role

The Role of a Panel of Pro-Fibrogenic miRs in Fibrotic Lung Disorders

Rationale: Pulmonary idiopathic fibrosis (IPF), Cryptogenetic organizing pneumonia (COP) and bronchiolitis obliterans syndrome (BOS) are rare pulmonary disorders, linked by the presence of fibrotic lesions. In our previous work (Di Carlo, 2016) on BOS we computationally identified a panel of candidate miRNAs and demonstrated by in situ hybridization analysis (ISH) and qRT-PCR, a dysregulation of two highly ranked miRNAs, miR-21 and miR-34a;ISH confirmed abnormal miR-21 and miR-34a expression in BOS lesions; other miRNAs where indicated as potential candidates in BOS by computational analysis. Aim We extended our previous work by analyzing the expression of miR-21, miR-34a and three other highly ranked miRNAs (miR-145, miR-146b-5p and miR-381) in BOS and other lung diseases associated with fibroblast activation/proliferation and collagen deposition. Identifying a specific profile of dysregulated miRNAs could provide useful diagnostic markers and potential therapeutic target. Methods :We evaluated miRNAs expression profile by ISH and RT-PCR quantification in a series of formalin-fixed and paraffin-embedded lung samples obtained from patients with IPF (n. 8), OP (n. 8), BOS (n. 12) and normal lung from organ donors. Results In BOS, COP and IPF/UIP miR-21 and miR-145 were expressed in fibroblasts of BO lesions, OP plugs and in fibroblast foci respectively, and in reactive alveolar epithelia; miR-146b expression correlated to the amount of inflammatory cell infiltrates and epithelial activation in all cases, while a weak expression was evident in OP and IPF/UIP lesions. miR-34a overexpression was associated with the activation of alveolar epithelia and to a lesser extent with fibroblast lesions in OP. miR-381 showed a weak expression in all diseases, and was localized especially in inflammatory cells. ISH data have been confirmed by qRTPCR analysis obtained on same samples. Conclusions: miR-21, miR-145 and miR-146b are over-expressed in fibroblasts in all the cases analyzed, but their expression is not disease-specific, although some differences are observed in different diseases. This finding underlies their role in non-specific fibrotic lung processes.ISH complements the results of qPCR, allows the precise cellular localization of miR expression, and improves correlations with cell-specific pathway

Dual Source Photon-Counting Computed Tomography-Part II: Clinical Overview of Neurovascular Applications

Photon-counting detector (PCD) is a novel computed tomography detector technology (photon-counting computed tomography-PCCT) that presents many advantages in the neurovascular field, such as increased spatial resolution, reduced radiation exposure, and optimization of the use of contrast agents and material decomposition. In this overview of the existing literature on PCCT, we describe the physical principles, the advantages and the disadvantages of conventional energy integrating detectors and PCDs, and finally, we discuss the applications of the PCD, focusing specifically on its implementation in the neurovascular field

Dual-Source Photon-Counting Computed Tomography-Part I: Clinical Overview of Cardiac CT and Coronary CT Angiography Applications

The photon-counting detector (PCD) is a new computed tomography detector technology (photon-counting computed tomography, PCCT) that provides substantial benefits for cardiac and coronary artery imaging. Compared with conventional CT, PCCT has multi-energy capability, increased spatial resolution and soft tissue contrast with near-null electronic noise, reduced radiation exposure, and optimization of the use of contrast agents. This new technology promises to overcome several limitations of traditional cardiac and coronary CT angiography (CCT/CCTA) including reduction in blooming artifacts in heavy calcified coronary plaques or beam-hardening artifacts in patients with coronary stents, and a more precise assessment of the degree of stenosis and plaque characteristic thanks to its better spatial resolution. Another potential application of PCCT is the use of a double-contrast agent to characterize myocardial tissue. In this current overview of the existing PCCT literature, we describe the strengths, limitations, recent applications, and promising developments of employing PCCT technology in CCT