Enrica Bianchi

Immunohistochemical Profile and VEGF, TGF-β and PGE2 in Human Pterygium and Normal Conjunctiva: Experimental Study and Review of the Literature

Human pterygium is made up of chronic proliferative fibro-vascular tissue growing on the ocular surface. This disease exhibits both degenerative and hyperplastic properties. Some fibroangiogenic factors have recently been shown to play a potential role in fibrovascular diseases via the angiogenesis process. The aim of this study is to evaluate VEGF, TGF-β and PGE2 expression in the epithelial, endothelial and stromal cells of human pterygium and normal conjunctiva in order to determine whether these factors participate in the development of pterygium. Ten specimens from patients with pterygium and two normal conjunctivas (cadavers) were analyzed by immunohistochemistry using specific antibodies against these growth factors. The technique used was ABC/HRP (Avidin complexed with biotinylated peroxidase). Immunoreactivity of VEGF was significantly increased in the epithelium, vascular endothelium and stromal cells in primary pterygium as compared with normal conjunctiva. A moderate expression of TGF-β in the pterygium was observed in the epithelial and stromal layers. On the contrary, immunolabeling of this growth factor in the human normal conjunctiva was weak. PGE2 was strongly expressed in the epithelium of patients with pterygium, as in control conjunctival tissues, and the immunolabeling was moderate in the stroma from the same patients. Our results suggest that these growth factors may contribute to the progression of primary pterygium by increasing angiogenesis, thus leading to the formation of new blood vessels from the pre-existing vasculature. We conclude that VEGF, TGF-β and PGE2 may be potential therapeutic targets in the treatment of this disease although proof of this evidence requires further studies.

Age and diabetes related changes of the retinal capillaries: An ultrastructural and immunohistochemical study

Normal human aging and diabetes are associated with a gradual decrease of cerebral flow in the brain with changes in vascular architecture. Thickening of the capillary basement membrane and microvascular fibrosis are evident in the central nervous system of elderly and diabetic patients. Current findings assign a primary role to endothelial dysfunction as a cause of basement membrane (BM) thickening, while retinal alterations are considered to be a secondary cause of either ischemia or exudation. The aim of this study was to reveal any initial retinal alterations and variations in the BM of retinal capillaries during diabetes and aging as compared to healthy controls. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in diabetic retina. Transmission electron microscopy (TEM) was performed on 46 enucleated human eyes with particular attention to alterations of the retinal capillary wall and Müller glial cells. Inflammatory cytokines expression in the retina was investigated by immunohistochemistry. Our electron microscopy findings demonstrated that thickening of the BM begins primarily at the level of the glial side of the retina during aging and diabetes. The Müller cells showed numerous cytoplasmic endosomes and highly electron-dense lysosomes which surrounded the retinal capillaries. Our study is the first to present morphological evidence that Müller cells start to deposit excessive BM material in retinal capillaries during aging and diabetes. Our results confirm the induction of pro-inflammatory cytokines TNF-α and IL-1β within the retina as a result of diabetes. These observations strongly suggest that inflammatory cytokines and changes in the metabolism of Müller glial cells rather than changes in of endothelial cells may play a primary role in the alteration of retinal capillaries BM during aging and diabetes.

Potential regulatory molecules in the human trabecular meshwork of patients with glaucoma: Immunohistochemical profile of a number of inflammatory cytokines

Glaucoma occurs when there are imbalances between the production and the drainage of the eye liquid. The vast majority of the aqueous humor leaves the eye through the trabecular meshwork (TM). The cause of hypertonicity may be due to an alteration in the thickness of the TM. In the majority of cases the molecular changes that determine primary open‑angle glaucoma (POAG) are unclear. However, it has been hypothesized that the significant increase in the extracellular matrix (ECM) of the fibrillary bands in the TM is associated with possible inflammatory conditions. In this study the tissue distribution of interleukin (IL)‑6, IL‑1β, transforming growth factor-β1 (TGF‑β1), vascular endothelial growth factor (VEGF) and tumor necrosis factor α (TNF‑α) was analyzed in TM samples from patients with POAG by immunohistochemistry. Seven specimens from patients with POAG and three control tissues were analyzed by immunohistochemistry using specific antibodies against these cytokines. Morphological changes in the TM, such as increased cell content, macrophages, fibrosis and accumulation of neutrophils, were observed by transmission electron microscopy. In human TM tissues, an evident immunoreactivity for IL‑6, IL‑1β and TNF‑α was observed in patients with POAG when compared with the control subjects, indicating that these cytokines may be correlated with disease activity. TM endothelial cells secrete a number of factors and cytokines that modulate the functions of the cells and the ECM of the conventional outflow pathway. In the TM in glaucoma, macrophages produce cytokines, including IL‑6, IL‑1β and TNF‑α, leading to an acute inflammatory response and recruitment of other immune cells, including T lymphocytes. In addition, TGF‑β1 regulates and induces the expression of IL‑6 in TM that indirectly induces angiogenesis by stimulating VEGF expression. The present results support previous evidence that suggests that growth factors and cytokines can induce ECM remodelling and alter cytoskeletal interactions in the TM.

Involvement of pro-inflammatory cytokines and growth factors in the pathogenesis of Dupuytren's contracture: a novel target for a possible future therapeutic strategy?

Dupuytrens contracture (DC) is a benign fibro-proliferative disease of the hand causing fibrotic nodules and fascial cords which determine debilitating contracture and deformities of fingers and hands. The present study was designed to characterize pro-inflammatory cytokines and growth factors involved in the pathogenesis, progression and recurrence of this disease, in order to find novel targets for alternative therapies and strategies in controlling DC. The expression of pro-inflammatory cytokines and of growth factors was detected by immunohistochemistry in fibrotic nodules and normal palmar fascia resected respectively from patients affected by DC and carpal tunnel syndrome (CTS; as negative controls). Reverse transcription (RT)-PCR analysis and immunofluorescence were performed to quantify the expression of transforming growth factor (TGF)-β1, interleukin (IL)-1β and vascular endothelial growth factor (VEGF) by primary cultures of myofibroblasts and fibroblasts isolated from Dupuytrens nodules. Histological analysis showed high cellularity and high proliferation rate in Dupuytrens tissue, together with the presence of myofibroblastic isotypes; immunohistochemical staining for macrophages was completely negative. In addition, a strong expression of TGF-β1, IL-1β and VEGF was evident in the extracellular matrix and in the cytoplasm of fibroblasts and myofibroblasts in Dupuytrens nodular tissues, as compared with control tissues. These results were confirmed by RT-PCR and by immunofluorescence in pathological and normal primary cell cultures. These preliminary observations suggest that TGF-β1, IL-1β and VEGF may be considered potential therapeutic targets in the treatment of Dupuytrens disease (DD).

Neurotrophins, their receptors and KI-67 in human GH-secreting pituitary adenomas: an immunohistochemical analysis.

Pituitary adenomas are a diverse group of tumors arising from the pituitary gland. Typically, they are small, slow-growing, hormonally inactive lesions that come to light as incidental findings on radiologic or postmortem examinations, although some small, slow-growing lesions with excessive hormonal activity may manifest with a clinical syndrome. The family of neurotrophins plays a key role in the development and maintenance of the pituitary endocrine cell function and in the regulation of hypothalamo-pituitary-adrenocortical axis activity. The objective of our experimental study is to investigate the localization of the neurotrophins, their relative receptors and to detect the expression level of Ki-67 to determine whether all these factors participate in the transformation and development of human pituitary adenomas. A very strong expression of Neurotrophin-3 (NT-3) and its receptor TrKC was observed in the extracellular matrix (ECM) and vessel endothelium, together with a clear/marked presence of Brain-derived neurotrophic factor (BDNF), and its receptor TrKB, thus confirming their direct involvement in the progression of pituitary adenomas. On the contrary, NGF (Nerve growth factor) and its receptor TrKA and p75NTR were weakly expressed in the epithelial gland cells and the ECM.

Congenital asymptomatic diaphragmatic hernias in adults: a case series.

IntroductionCongenital diaphragmatic hernia is a major malformation occasionally found in newborns and babies. Congenital diaphragmatic hernia is defined by the presence of an orifice in the diaphragm, more often to the left and posterolateral, that permits the herniation of abdominal contents into the thorax. The aim of this case series is to provide information on the presentation, diagnosis and outcome of three patients with late-presenting congenital diaphragmatic hernias. The diagnosis of congenital diaphragmatic hernia is based on clinical investigation and is confirmed by plain X-ray films and computed tomography scans.Case presentationsIn the present report three cases of asymptomatic abdominal viscera herniation within the thorax are described. The first case concerns herniation of some loops of the large intestine into the left hemi-thorax in a 75-year-old Caucasian Italian woman. The second case concerns a rare type of herniation in the right side of the thorax of the right kidney with a part of the liver parenchyma in a 57-year-old Caucasian Italian woman. The third case concerns herniation of the stomach and bowel into the left side of the chest with compression of the left lung in a 32-year-old Caucasian Italian man. This type of hernia may appear later in life, because of concomitant respiratory or gastrointestinal disease, or it may be an incidental finding in asymptomatic adults, such as in the three cases featured here.ConclusionsPatients who present with late diaphragmatic hernias complain of a wide variety of symptoms, and diagnosis may be difficult. Additional investigation and research appear necessary to better explain the development and progression of this type of disease.

Ghrelin Inhibits Post-Operative Adhesions via Blockage of the TGF-β Signaling Pathway.

Post-operative adhesions are a critical problem in pelvic and abdominal surgery despite a multitude of studies dedicated to finding modalities to prevent their occurrence. Ghrelin administration promotes an anti-fibrotic response in a surgical mouse model of adhesion-induction, but the mechanisms mediating this effect have not been established. In the current study, the molecular mechanisms that underlie the anti-adhesion effect of ghrelin were investigated. Post-surgical adhesions were experimentally created in C57BL/6 wild-type mice via a combination of ischemic peritoneal buttons and cecal multiple abrasions. Ghrelin or saline intraperitoneal injections were given twice daily from two days before surgery to selected time points post-surgically to assess the phenotypic and molecular effects of treatment (1 day (n = 20), 4 days (n = 20) and 20 days (n = 40) after surgery). Endpoints included the scoring of adhesions and gene and protein expression analysis of pro-fibrogenic factors conducted on peritoneal ischemic tissue by quantitative PCR and Western blot. Ghrelin administration significantly reduced post-surgical adhesions and down-regulated pro-inflammatory gene and protein expression, including Tgfb3 and Tgfbr2. The up-regulation of inhibitory proteins Smad6 and Smad7 confirmed the ghrelin-induced blockage of TGF-β signaling. Ghrelin is a candidate therapeutic drug for post-operative adhesion prevention, inhibiting inflammatory responses via blockage of the TGF-β signaling pathway at the onset of surgery before the occurrence of the granulation-remodeling phase.

Immunohistochemical profile of cytokines and growth factors expressed in vestibular schwannoma and in normal vestibular nerve tissue

Vestibular schwannomas, also known as acoustic neuromas, are benign tumors, which originate from myelin-forming Schwann cells. They develop in the vestibular branch of the eighth cranial nerve in the internal auditory canal or cerebellopontine angle. The clinical progression of the condition involves slow and progressive growth, eventually resulting in brainstem compression. The objective of the present study was to investigate the expression level and the localization of the pro-inflammatory cytokines, transforming growth factor-β1 (TGF-β1) interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), as well as the adhesion molecules, intracellular adhesion molecule-1 and vascular endothelial growth factor (VEGF), in order to determine whether these factors are involved in the transformation and development of human vestibular schwannoma. The present study investigated whether changes in inflammation are involved in tumor growth and if so, the mechanisms underlying this process. The results of the current study demonstrated that pro-inflammatory cytokines, including TGF-β1, IL-1β and IL-6 exhibited increased expression in human vestibular schwannoma tissue compared with normal vestibular nerve samples. TNF-α was weakly expressed in Schwann cells, confirming that a lower level of this cytokine is involved in the proliferation of Schwann cells. Neoplastic Schwann cells produce pro-inflammatory cytokines that may act in an autocrine manner, stimulating cellular proliferation. In addition, the increased expression of VEGF in vestibular schwannoma compared with that in normal vestibular nerve tissue, suggests that this factor may induce neoplastic growth via the promotion of angiogenesis. The present findings suggest that inflammation may promote angiogenesis and consequently contribute to tumor progression. In conclusion, the results of the present study indicated that VEGF and pro-inflammatory cytokines may be potential therapeutic targets in vestibular schwannoma. Further studies are necessary to confirm the involvement of these factors in the growth of neoplasms and to develop inhibitors of pro-inflammatory cytokines as a potential treatment option in the future.

Poly-ε-caprolactone composite scaffolds for bone repair

Synthetic biomaterials combined with cells and osteogenic factors represent a promising approach for the treatment of a number of orthopedic diseases, such as bone trauma and congenital malformations. To guarantee optimal biological properties, bone substitutes are prepared with a 3D structure and porosity grade functional to drive cell migration and proliferation, diffusion of factors, vascularization and cell waste expulsion. In this study, synthetic hydroxyapatite (HA) or rat bone extracellular matrix (BP) were examined in an effort to optimize the mechanical properties and osteogenic activity of poly-ε-caprolactone scaffolds prepared with alginate threads (PCL-AT). Using rabbit bone marrow-derived mesenchymal stem cells (rMSCs), the effects of PCL composite substrates on cell adhesion, growth and osteogenic differentiation were evaluated. Micro-CT analysis and scanning electron microscopy evidenced that porous PCL scaffolds containing HA or BP acquire a trabecular bone-like structure with interconnected pores homogenously distributed and are characterized by a pore diameter of approximately 10 µm (PCL-AT-BP) or ranging from 10 to 100 µm. Although the porosity grade of both PCL-AT-HA and PCL-AT-BP promoted optimal conditions for the cell growth of rMSCs at the early phase, the presence of BP was crucial to prolong the cell viability at the late phase. Moreover, a precocious expression of Runx2 (at 7 days) was observed in PCL-AT-BP in combination with osteogenic soluble factors suggesting that BP controls better than HA the osteogenic maturation process in bone substitutes.

Growth factors, their receptor expression and markers for proliferation of endothelial and neoplastic cells in human osteosarcoma.

Osteosarcoma is the most common primary malignant tumour of the bone. Although new therapies continue to be reported, osteosarcoma-related morbidity and mortality remain high. Modern medicine has greatly increased knowledge of the physiopathology of this neoplasm. Novel targets for drug development may be identified through an understanding of the normal molecular processes that are deeply modified in pathological conditions. The aim of the present study is to investigate, by immunohistochemistry, the localisation of different growth factors and of the proliferative marker Ki-67 in order to determine whether these factors are involved in the transformation of osteogenic cells and in the development of human osteosarcoma. We observed a general positivity for NGF — TrKA — NT3 — TrKC — VEGF in the cytoplasm of neoplastic cells and a strong expression for NT4 in the nuclear compartment. TGF-p was strongly expressed in the extracellular matrix and vascular endothelium. BDNF and TrKB showed a strong immunolabeling in the extracellular matrix. Ki-67/MIB-1 was moderately expressed in the nucleus of neoplastic cells. We believe that these growth factors may be considered potential therapeutic targets in the treatment of osteosarcoma, although proof of this hypothesis requires further investigation.