The FGF/FGFR system in the physiopathology of the prostate gland.

Fibroblast growth factors (FGFs) are a family of proteins possessing paracrine, autocrine, or endocrine functions in a variety of biological processes, including embryonic development, angiogenesis, tissue homeostasis, wound repair, and cancer. Canonical FGFs bind and activate tyrosine kinase FGF receptors (FGFRs), triggering intracellular signaling cascades that mediate their biological activity. Experimental evidence indicates that FGFs play a complex role in the physiopathology of the prostate gland that ranges from essential functions during embryonic development to modulation of neoplastic transformation. The use of ligand- and receptor-deleted mouse models has highlighted the requirement for FGF signaling in the normal development of the prostate gland. In adult prostate, the maintenance of a functional FGF/FGFR signaling axis is critical for organ homeostasis and function, as its disruption leads to prostate hyperplasia and may contribute to cancer progression and metastatic dissemination. Dissection of the molecular landscape modulated by the FGF family will facilitate ongoing translational efforts directed toward prostate cancer therapy.

Combining RNAscope, Immunohistochemistry (IHC) and Digital Image Analysis to Assess Podoplanin (PDPN) Protein and PDPN_mRNA Expression on Formalin-Fixed Paraffin-Embedded Normal Human Placenta Tissues.

The expression and function of podoplanin (PDPN) in the normal human placenta has been debated in placental evaluation. This study emphasizes the importance of a multimodal approach of PDPN expression in normal human placentas. A complete examination is performed using immunohistochemistry, RNAscope and automated Digital Image examination (DIA) interpretation. QuPath DIA-based analysis automatically generated the stromal and histological scores of PDPN expression for immunohistochemistry and RNAscope stains. The umbilical cord's isolated fibroblasts and luminal structures expressed PDPN protein and PDPN_mRNA. RNAscope detected PDPN_mRNA upregulation in syncytial placental knots trophoblastic cells, but immunohistochemistry did not certify this at the protein level. The study found a significant correlation between the IHC and RNAscope H-Score (p = 0.033) and Allred Score (p = 0.05). A successful multimodal strategy for PDPN assessment in human placentas confirmed PDPN expression heterogeneity in the full-term human normal placenta and umbilical cord at the protein and mRNA level. In placental syncytial knots trophoblastic cells, PDPN showed mRNA overexpression, suggesting a potential role in placenta maturation.

Aqueous humor as eye lymph: A crossroad between venous and lymphatic system.

Aqueous humor (AQH) is a transparent fluid with characteristics similar to those of the interstitial fluid, which fills the eyeball posterior and anterior chambers and circulates in them from the sites of production to those of drainage. The AQH volume and pressure homeostasis is essential for the trophism of the ocular avascular tissues and their normal structure and function. Different AQH outflow pathways exist, including a main pathway, quite well defined anatomically and referred to as the conventional pathway, and some accessory pathways, more recently described and still not fully morphofunctionally understood, generically referred to as unconventional pathways. The conventional pathway is based on the existence of a series of conduits starting with the trabecular meshwork and Schlemm's Canal and continuing with a system of intrascleral and episcleral venules, which are tributaries to veins of the anterior segment of the eyeball. The unconventional pathways are mainly represented by the uveoscleral pathway, in which AQH flows through clefts, interstitial conduits located in the ciliary body and sclera, and then merges into the aforementioned intrascleral and episcleral venules. A further unconventional pathway, the lymphatic pathway, has been supported by the demonstration of lymphatic microvessels in the limbal sclera and, possibly, in the uvea (ciliary body, choroid) as well as by the ocular glymphatic channels, present in the neural retina and optic nerve. It follows that AQH may be drained from the eyeball through blood vessels (TM-SC pathway, US pathway) or lymphatic vessels (lymphatic pathway), and the different pathways may integrate or compensate for each other, optimizing the AQH drainage. The present review aims to define the state-of-the-art concerning the structural organization and the functional anatomy of all the AQH outflow pathways. Particular attention is paid to examining the regulatory mechanisms active in each of them. The new data on the anatomy and physiology of AQH outflow pathways is the key to understanding the pathophysiology of AQH outflow disorders and could open the way for novel approaches to their treatment.

Lysosomal diacylglycerol pyrophosphate phosphatase is not essential in Trypanosoma brucei.

Mg2+-independent phosphatidic acid phosphatase (PAP2), diacylglycerol pyrophosphate phosphatase 1 (Dpp1) is a membrane-associated enzyme in Saccharomyces cerevisiae. The enzyme is responsible for inducing the breakdown of ß-phosphate from diacylglycerol pyrophosphate (DGPP) into phosphatidate (PA) and then removes the phosphate from PA to give diacylglycerol (DAG). In this study through RNAi suppression, we have demonstrated that Trypanosoma brucei diacylglycerol pyrophosphate phosphatase 1 (TbDpp1) procyclic form production is not required for parasite survival in culture. The steady-state levels of triacylglycerol (TAG), the number of lipid droplets, and the PA content are all maintained constant through the inducible down-regulation of TbDpp1. Furthermore, the localization of C-terminally tagged variants of TbDpp1 in the lysosome was demonstrated by immunofluorescence microscopy.

Evolution toward beta common chain receptor usage links the matrix proteins of HIV-1 and its ancestors to human erythropoietin.

The HIV-1 matrix protein p17 (p17) is a pleiotropic molecule impacting on different cell types. Its interaction with many cellular proteins underlines the importance of the viral protein as a major determinant of human specific adaptation. We previously showed the proangiogenic capability of p17. Here, by integrating functional analysis and receptor binding, we identify a functional epitope that displays molecular mimicry with human erythropoietin (EPO) and promotes angiogenesis through common beta chain receptor (ßCR) activation. The functional EPO-like epitope was found to be present in the matrix protein of HIV-1 ancestors SIV originated in chimpanzees (SIVcpz) and gorillas (SIVgor) but not in that of HIV-2 and its ancestor SIVsmm from sooty mangabeys. According to biological data, evolution of the EPO-like epitope showed a clear differentiation between HIV-1/SIVcpz-gor and HIV-2/SIVsmm branches, thus highlighting this epitope on p17 as a divergent signature discriminating HIV-1 and HIV-2 ancestors. P17 is known to enhance HIV-1 replication. Similarly to other ßCR ligands, p17 is capable of attracting and activating HIV-1 target cells and promoting a proinflammatory microenvironment. Thus, it is tempting to speculate that acquisition of an epitope on the matrix proteins of HIV-1 ancestors capable of triggering ßCR may have represented a critical step to enhance viral aggressiveness and early human-to-human SIVcpz/gor dissemination. The hypothesis that the p17/ßCR interaction and ßCR abnormal stimulation may also play a role in sustaining chronic activation and inflammation, thus marking the difference between HIV-1 and HIV-2 in term of pathogenicity, needs further investigation.

Hematopoiesis and Mast Cell Development.

Hematopoietic stem cells (HSCs) are defined based on their capacity to replenish themselves (self-renewal) and give rise to all mature hematopoietic cell types (multi-lineage differentiation) over their lifetime. HSCs are mainly distributed in the bone marrow during adult life, harboring HSC populations and a hierarchy of different kinds of cells contributing to the "niche" that supports HSC regulation, myelopoiesis, and lymphopoiesis. In addition, HSC-like progenitors, innate immune cell precursors such as macrophages, mast cells, natural killer cells, innate lymphoid cells, and megakaryocytes and erythrocyte progenitor cells are connected by a series of complex ontogenic relationships. The first source of mast cells is the extraembryonic yolk sac, on embryonic day 7. Mast cell progenitors circulate and enter peripheral tissues where they complete their differentiation. Embryonic mast cell populations are gradually replaced by definitive stem cell-derived progenitor cells. Thereafter, mast cells originate from the bone marrow, developing from the hematopoietic stem cells via multipotent progenitors, common myeloid progenitors, and granulocyte/monocyte progenitors. In this review article, we summarize the knowledge on mast cell sources, particularly focusing on the complex and multifaceted mechanisms intervening between the hematopoietic process and the development of mast cells.

MUC1 Expression Affects the Immunoflogosis in Renal Cell Carcinoma Microenvironment through Complement System Activation and Immune Infiltrate Modulation.

Mucin1 (MUC1), a glycoprotein associated with an aggressive cancer phenotype and chemoresistance, is aberrantly overexpressed in a subset of clear cell renal cell carcinoma (ccRCC). Recent studies suggest that MUC1 plays a role in modulating cancer cell metabolism, but its role in regulating immunoflogosis in the tumor microenvironment remains poorly understood. In a previous study, we showed that pentraxin-3 (PTX3) can affect the immunoflogosis in the ccRCC microenvironment by activating the classical pathway of the complement system (C1q) and releasing proangiogenic factors (C3a, C5a). In this scenario, we evaluated the PTX3 expression and analyzed the potential role of complement system activation on tumor site and immune microenvironment modulation, stratifying samples in tumors with high (MUC1H) versus tumors with low MUC1 expression (MUC1L). We found that PTX3 tissue expression was significantly higher in MUC1H ccRCC. In addition, C1q deposition and the expressions of CD59, C3aR, and C5aR were extensively present in MUC1H ccRCC tissue samples and colocalized with PTX3. Finally, MUC1 expression was associated with an increased number of infiltrating mast cells, M2-macrophage, and IDO1+ cells, and a reduced number of CD8+ T cells. Taken together, our results suggest that expression of MUC1 can modulate the immunoflogosis in the ccRCC microenvironment by activating the classical pathway of the complement system and regulating the immune infiltrate, promoting an immune-silent microenvironment.

Vessel co-option and angiotropic extravascular migratory metastasis: a continuum of tumour growth and spread?

Two fields of cancer research have emerged dealing with the biology of tumour cells localised to the abluminal vascular surface: vessel co-option (VCo), a non-angiogenic mode of tumour growth and angiotropic extravascular migratory metastasis (EVMM), a non-hematogenous mode of tumour migration and metastasis. VCo is a mechanism by which tumour cells gain access to a blood supply by spreading along existing blood vessels in order to grow locally. Angiotropic EVMM involves "pericytic mimicry" (PM), which is characterised by tumour cells continuously migrating in the place of pericytes distantly along abluminal vascular surfaces. When cancer cells are engaged in PM and EVMM, they migrate along blood vessels beyond the advancing front of the tumour to secondary sites with the formation of regional and distant metastases. In the present perspective, the authors review the current scientific literature, emphasising the analogies between embryogenesis and cancer progression, the re-activation of embryonic signals by "cancer stem cells", and the important role of laminins and epithelial-mesenchymal-transition. This perspective maintains that VCo and angiotropic EVMM constitute complementary processes and represent a continuum of cancer progression from the primary tumour to metastases and of tumour growth to EVMM, analogous to the embryonic development program.

COVID-19 Vasculopathy: Mounting Evidence for an Indirect Mechanism of Endothelial Injury.

Patients with coronavirus disease 2019 (COVID-19) who are critically ill develop vascular complications characterized by thrombosis of small, medium, and large vessels. Dysfunction of the vascular endothelium due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated in the pathogenesis of the COVID-19 vasculopathy. Although initial reports suggested that endothelial injury was caused directly by the virus, recent studies indicate that endothelial cells do not express angiotensin-converting enzyme 2, the receptor that SARS-CoV-2 uses to gain entry into cells, or express it at low levels and are resistant to the infection. These new findings, together with the observation that COVID-19 triggers a cytokine storm capable of injuring the endothelium and disrupting its antithrombogenic properties, favor an indirect mechanism of endothelial injury mediated locally by an augmented inflammatory reaction to infected nonendothelial cells, such as the bronchial and alveolar epithelium, and systemically by the excessive immune response to infection. Herein we review the vascular pathology of COVID-19 and critically discuss the potential mechanisms of endothelial injury in this disease.

Thrombopoietin Promotes Angiogenesis and Disease Progression in Patients with Multiple Myeloma.

Multiple myeloma (MM) progression closely depends on bone marrow (BM) angiogenesis. Several factors sustain angiogenesis, including cytokines, growth factors, and cell-to-cell interactions. Herein, BM thrombopoietin (TPO) was shown to support angiogenesis and disease progression in MM. Patients with MM at different progression phases had higher levels of BM and circulating TPO than monoclonal gammopathy of undetermined significance/smoldering MM patients, suggesting that TPO correlates with disease progression and prognosis. Endothelial cells from patients with monoclonal gammopathy of undetermined significance (MGECs) and endothelial cells from MM (MMECs) expressed TPO receptor, and the TPO treatment triggered their angiogenic capabilities in vitro. Indeed, TPO-treated MGECs and MMECs showed enhanced angiogenesis on Matrigel and spontaneous cell migration and chemotaxis by acting as a chemotactic agent. TPO also had an angiogenic activity in vivo in the chorioallantoic membrane assay system. Finally, TPO treatment increased the release of active matrix metalloproteinase (MMP)-9 and MMP-2 in MGECs and of MMP-2 in MMECs and affected the balance between angiogenic/antiangiogenic factors in the MM BM. Our results support the angiogenic activity of TPO, and suggest that it may have a critical role in promoting the angiogenic switch during MM progression. Accordingly, TPO may be envisaged as a new angiogenic and prognostic factor in patients with MM.

Perivascular and endomysial macrophages expressing VEGF and CXCL12 promote angiogenesis in anti-HMGCR immune-mediated necrotizing myopathy.

OBJECTIVES: To study the phenotype of macrophage infiltrates and their role in angiogenesis in different idiopathic inflammatory myopathies (IIMs). METHODS: The density and distribution of the subpopulations of macrophages subsets (M1, inducible nitric oxide+, CD11c+; M2, arginase-1+), endomysial capillaries (CD31+, FLK1+), degenerating (C5b-9+) and regenerating (NCAM+) myofibres were investigated by immunohistochemistry in human muscle samples of diagnostic biopsies from a large cohort of untreated patients (n: 81) suffering from anti-3-hydroxy-3-methylglutaryl coenzyme A reductase (anti-HMGCR)+ immune mediated necrotizing myopathy (IMNM), anti-signal recognition particle (anti-SRP)+ IMNM, seronegative IMNM, DM, PM, PM with mitochondrial pathology, sporadic IBM, scleromyositis, and anti-synthetase syndrome. The samples were compared with mitochondrial myopathy and control muscle samples. RESULTS: Compared with the other IIMs and controls, endomysial capillary density (CD) was higher in anti-HMGCR+ IMNM, where M1 and M2 macrophages, detected by confocal microscopy, infiltrated perivascular endomysium and expressed angiogenic molecules such as VEGF-A and CXCL12. These angiogenic macrophages were preferentially associated with CD31+ FLK1+ microvessels in anti-HMGCR+ IMNM. The VEGF-A+ M2 macrophage density was significantly correlated with CD (rS: 0.98; P: 0.0004). Western blot analyses revealed increased expression levels of VEGF-A, FLK1, HIF-1α and CXCL12 in anti-HMGCR+ IMNM. CD and expression levels of these angiogenic molecules were not increased in anti-SRP+ and seronegative IMNM, offering additional, useful information for differential diagnosis among these IIM subtypes. CONCLUSION: Our findings suggest that in IIMs, infiltrating macrophages and microvascular cells interactions play a pivotal role in coordinating myogenesis and angiogenesis. This reciprocal crosstalk seems to distinguish anti-HMGCR associated IMNM.

Two new applications in the study of angiogenesis the CAM assay: Acellular scaffolds and organoids.

The chick embryo chorioallantoic membrane (CAM) is a rich vascularized extraembryonic membrane that is commonly used as an in vivo experimental model to study molecules with angiogenic and anti-angiogenic activity, tumor growth and metastasis. Among other applications of the CAM assay, more recently this assay has been used for the study of acellular scaffolds and of organoids, and of their angiogenic capacity. The aim of this review article is to summarize the literature data concerning these two new applications of the CAM assay and to underline the advantages of this assay.

The Underestimated Role of Mast Cells in the Pathogenesis of Rhinopathies.

Mast cells (MCs) are involved in several biological processes, such as defense against pathogens, immunomodulation, tissue repair after injury, and angiogenesis. MCs have been shown to change from protective immune cells to potent pro-inflammatory cells, influencing the progression of many pathological conditions, including autoimmune diseases and cancers. The role of MCs in the pathogenesis of rhinopathies has often been underestimated, since previous studies have focused their attention on eosinophils and neutrophils, while MCs were considered involved exclusively in allergic rhinitis. However, recent nasal cytology findings have shown the involvement of MCs in several rhinopathies, such as NARMA, NARESMA, and CRSwNP. These recent evidences highlight the crucial role that MCs play in orchestrating the inflammation of the nasal mucosa, through complex biological mechanisms, not yet fully understood. In this context, a better understanding of these mechanisms is fundamental for practicing Precision Medicine, which requires careful population selection and stratification into subgroups based on the phenotype/endotype of the patients, in order to guarantee the patient a tailored therapy. Based on this background, further studies are needed to understand the pathophysiological mechanisms involving MCs and, consequently, to develop targeted therapies aimed to obtain a selective inhibition of tissue remodeling and preventing MC-mediated immune suppression.

The CAM assay in the study of the metastatic process.

Among the in vivo experimental models, the chick embryo chorioallantoic membrane (CAM) has been routinely used to implant several malignant cell lines or tumor tissues to study their angiogenic and metastatic capability. Since the chick embryo is naturally immunodeficient, the CAM can support the engraftment of tumor cells, and their growth therein can faithfully recapitulate most of the characteristics of the carcinogenic process including: growth, invasion, angiogenesis and colonization of distant tissues. This review article is focused on the discussion of the more recent literature data concerning the use of the CAM to investigate the metastatic process.

The role of vascular niche and endothelial cells in organogenesis and regeneration.

The term vascular niche indicate the physical and biochemical microenvironment around blood vessel where endothelial cells, pericytes, and smooth muscle cells organize themselves to form blood vessels and release molecules involved in the recruitment of hematopoietic stem cells, endothelial progenitor cells and mesenchymal stem cells. The vascular niche creates a permissive environment that enables different cell types to realize their developmental or regenerative programs. In this context, the proximity between the endothelium and the new-forming cellular components of organs suggests an essential role of endothelial cells in the organs maturation. Dynamic interactions between specific organ endothelial cells and different cellular conponents are crucial for different organ morphogenesis and function. Conversely, organs provide cues shaping vascular network structure.

Chorioallantoic membrane vascularization. A meta-analysis.

The CAM is a widely used experimental assay to study angiogenesis, wound healing, tumor growth and metastatic process. In this study, we have analyzed and compared the existent literature data concerning the growth of the CAM. Moreover, we have analyzed the data concerning the development of the vascular system and the expression of the most important pro-angiogenic and anti-angiogenic factors. The availability of these data and their comparative evaluation allow to better analyze the experimental data concerning the testing of different pro-angiogenic and anti-angiogenic molecules, as well as biomaterials in the CAM assay. Moreover, the dynamic of the angiogenic response to different tumor cell lines and or tumor bioptic specimens, may be also better evaluated and estimated.

Nutraceuticals and their role in tumor angiogenesis.

Angiogenesis plays a pivotal role in cancer initiation, maintenance, and progression. Diet may inhibit, retard or reverse these processes affecting angiogenesis (angioprevention). Nutraceuticals, such as omega-3 fatty acids, amino acids, proteins, vitamins, minerals, fibers, and phenolic compounds, improve health benefits as they are a source of bioactive compounds that, among other effects, can regulate angiogenesis. The literature concerning the pro-angiogenic and/or anti-angiogenic nutraceuticals and the possible activated pathways in cancer and other non-neoplastic diseases by in vivo and in vitro experiments are reviewed.

The studies of Rita Levi-Montalcini on the effects of tumor transplantation on the chorioallantoic membrane.

In 1986, Rita Levi-Montalcini and Stanley Cohen were awarded with the Nobel Prize for Physiology and Medicine for the discovery of the nerve growth factor. Among the experimental models used by Levi-Montalcini in the first part of her studies it was the chick embryo chorioallantoic membrane, currently used in the study of tumor growth and angiogenesis. Levi-Montalcini grafted fragments of mouse sarcomas on to the chorioallantoic membranes of 4- to 6-day chick embryos and demonstrated that the tumors infiltrated the host blood vessels. Moreover, the ganglia showed hypertrophy, nerve fibers reaching to the implanted tumors. Levi-Montalcini hypothesized that the effects could have been mediated by a soluble factor, which was later identified as the nerve growth factor.

Standardized statement for the ethical use of human cadaveric tissues in anatomy research papers: Recommendations from Anatomical Journal Editors-in-Chief.

Human cadaveric donors are essential for research in the anatomical sciences. However, many research papers in the anatomical sciences often omit a statement regarding the ethical use of the donor cadavers or, as no current standardized versions exist, use language that is extremely varied. To rectify this issue, 22 editors-in-chief of anatomical journals, representing 17 different countries, developed standardized and simplified language that can be used by authors of studies that use human cadaveric tissues. The goal of these editor recommendations is to standardize the writing approach by which the ethical use of cadaveric donors is acknowledged in anatomical studies that use donor human cadavers. Such sections in anatomical papers will help elevate our discipline and promote standardized language use in others non anatomy journals and also other media outlets that use cadaveric tissues.

Molecular Mechanisms Linking Inflammation to Autoimmunity in Sjögren's Syndrome: Identification of New Targets.

Sjögren's syndrome (SS) is a systemic autoimmune rheumatic disorder characterized by the lymphocytic infiltration of exocrine glands and the production of autoantibodies to self-antigens. The involvement of the exocrine glands drives the pathognomonic manifestations of dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) that define sicca syndrome. To date, the molecular mechanisms mediating pathological salivary gland dysfunction in SS remain to be elucidated, despite extensive studies investigating the underlying cause of this disease, hampering the development of novel therapeutic strategies. Many researchers have identified a multifactorial pathogenesis of SS, including environmental, genetic, neuroendocrine, and immune factors. In this review, we explore the latest developments in understanding the molecular mechanisms involved in the pathogenesis of SS, which have attracted increasing interest in recent years.