Giovanna Vermiglio

Immunohistochemical analysis of TGF-β1 and VEGF in gingival and periodontal tissues: A role of these biomarkers in the pathogenesis of scleroderma and periodontal disease

Periodontal disease is characterized by inflammation and bone loss. The balance between inflammatory mediators and their counter-regulatory molecules may be fundamental for determining the outcome of the immune pathology of periodontal disease. Transforming growth factor-β (TGF-β) and vascular endothelial growth factor (VEGF) represent a family of polypeptide proteins involved in the inflammation and regulation of immune responses, especially in rheumatic disease. The relationship between these growth factors and periodontitis has resulted in a new field of osteoimmunology and provides a context for better understanding the pathogenesis of periodontal disease. Therefore, the aim of this study was to compare the protein expression profile of these inflammatory mediators in 90 patients divided in three groups: healthy control, chronic periodontitis and in rheumatic disease, scleroderma. The findings presented here highlight that biomarkers, such as TGF-β1 and VEGF, play a key role in the evolution of the immune response, which in turn influences the outcome of disease establishment.

Membrane Transfer from Tumor Cells Overcomes Deficient Phagocytic Ability of Plasmacytoid Dendritic Cells for the Acquisition and Presentation of Tumor Antigens

The potential contribution of plasmacytoid dendritic cells (pDCs) in the presentation of tumor cell Ags remains unclear, and some controversies exist with regard to the ability of pDCs to phagocytose cell-derived particulate Ags and cross-present them to MHC class I–restricted T lymphocytes. In this study, we show that human pDCs, although inefficient in the internalization of cell membrane fragments by phagocytosis, can efficiently acquire membrane patches and associated molecules from cancer cells of different histotypes. The transfer of membrane patches to pDCs occurred in a very short time and required cell-to-cell contact. Membrane transfer also included intact HLA complexes, and the acquired Ags could be efficiently recognized on pDCs by tumor-specific CD8+ T cells. Remarkably, pDCs isolated from human colon cancer tissues displayed a strong surface expression of epithelial cell adhesion molecule, indicating that the exchange of exogenous Ags between pDCs and tumor cells also can occur in vivo. These data demonstrate that pDCs are well suited to acquire membrane patches from contiguous tumor cells by a cell-to-cell contact–dependent mechanism that closely resembles “trogocytosis.” This phenomenon may allow pDCs to proficiently present tumor cell–derived Ags, despite limited properties of endophagocytosis.

Sarcoglycans in the Normal and Pathological Breast Tissue of Humans: An Immunohistochemical and Molecular Study

The sarcoglycan complex, consisting of α-, β-, γ-, δ- and ε-sarcoglycans, is a multimember transmembrane system providing a mechanosignaling connection from the cytoskeleton to the extracellular matrix. Whereas the expression of α- and γ-sarcoglycan is restricted to striated muscle, other sarcoglycans are widely expressed. Although many studies have investigated sarcoglycans in all muscle types, insufficient data are available on the distribution of the sarcoglycan complex in nonmuscle tissue. On this basis, we used immunohistochemical and RT-PCR techniques to study preliminarily the sarcoglycans in normal glandular breast tissue (which has never been studied in the literature on these proteins) to verify the effective wider distribution of this complex. Moreover, to understand the role of sarcoglycans, we also tested samples obtained from patients affected by fibrocystic mastopathy and breast fibroadenoma. Our data showed, for the first time, that all sarcoglycans are always detectable in all normal samples both in epithelial and myoepithelial cells; in pathological breast tissue, all sarcoglycans appeared severely reduced. These data demonstrated that all sarcoglycans, not only β-, δ-, and ε-sarcoglycans, have a wider distribution, implying a new unknown role for these proteins. Moreover, in breast diseases, sarcoglycans containing cadherin domain homologs could provoke a loss of strong adhesion between epithelial cells, permitting and facilitating the degeneration of these benign breast tumors into malignant tumors. Consequently, sarcoglycans could play an important and intriguing role in many breast diseases and in particular in tumor progression from benign to malignant.

Transforming Growth Factor Beta 1 and Vascular Endothelial Growth Factor Levels in the Pathogenesis of Periodontal Disease

Periodontal disease is characterized by inflammation and bone loss. The balance between inflammatory mediators and their counter-regulatory molecules may be fundamental for determining the outcome of immune pathology of periodontal disease. Cytokines play crucial roles in the maintenance of tissue homeostasis, a process which requires a delicate balance between anabolic and catabolic activities. In particular, two families of growth factors-such as transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF) are thought to play important roles in modulating the proliferation and/or migration of structural cells involved in inflammation and regulation of immune responses. The aim of this work was to analyze gingival samples and periodontal tissue specimens collected from thirty-eight patients with chronic periodontal disease and from forty healthy individuals, in order to detect the expression and distribution of TGF-β1 and VEGF between the two groups. TGF-β1 and VEGF expression levels were detected using immunohistochemical analysis and computer-assisted morphometric analysis. The findings presented here suggest that biomarker such as TGF-β1 and VEGF have an important regulating role in the orchestration of the immune response, which in turn influence the outcome of disease establishment and evolution.

Expression of muscle-specific integrins in masseter muscle fibers during malocclusion disease

Integrins are heterodimeric cell surface membrane proteins linking the extracellular matrix to actin. α7B integrin is detected in proliferating and adult myofibers, whereas α7A plays a role in regenerating muscle fibers with a minor function in mature muscle fibers. The expression levels of β1A appear to be very low, whereas β1D appears to be the predominant integrin form in mature muscle. Considering the important features of masseter muscle we have studied integrin expression in masseter muscle specimens of surgical patients with posterior right crossbite and comparing them to left side masseter muscle specimens. Our results showed that the expression of integrins was significantly lower in the crossbite side muscle. Furthermore, the most important finding is that β1A is clearly detectable in adult masseter muscle. This behavior could be due to the particular composition of masseter, since it contains hybrid fibers showing the capacity to modify the contractile properties to optimize the energy efficiency or the action of the muscle during contraction. Moreover, masseter is characterized by a high turnover of muscle fibers producing a regeneration process. This may indicate a longer time to heal, justifying the loss of β1D and the consequential increase of β1A. Thus, our data provide the first suggestion that integrins in masseter muscle play a key role regulating the functional activity of muscle and allowing the optimization of contractile forces.

From periodontal mechanoreceptors to chewing motor control: A systematic review

PURPOSE This critical review summarizes the current knowledge of the structural and functional characteristics of periodontal mechanoreceptors, and understands their role in the signal pathways and functional motor control. METHOD A systematic review of the literature was conducted. Original articles were searched through Pubmed, Cochrane Central database and Embase until january 2016. RESULT 1466 articles were identified through database searching and screened by reviewing the abstracts. 160 full-text were assessed for eligibility, and after 109 exclusion, 51 articles were included in the review process. Studies selected by the review process were mainly divided in studies on animal and studies on humans. Morphological, histological, molecular and electrophysiological studies investigating the periodontal mechanoreceptors in animals and in humans were included, evaluated and described. CONCLUSION Our knowledge of the periodontal mechanoreceptors, let us conclude that they are very refined neural receptors, deeply involved in the activation and coordination of the masticatory muscles during function. Strictly linked to the rigid structure of the teeth, they determine all the functional physiological and pathological processes of the stomatognathic system. The knowledge of their complex features is fundamental for all dental professionists. Further investigations are of utmost importance for guiding the technological advances in the respect of the neural control in the dental field.

Effect of bisphosphonates on the mandibular bone and gingival epithelium of rats without tooth extraction

Osteonecrosis of the jaw (ONJ) is an adverse effect of bisphosphonate treatment that has become the subject of increasing investigations, in particular due to its poorly understood pathogenesis. Several experimental studies on animal models have been conducted; however, the majority of these replicate human ONJ following tooth extraction, and describe alterations in the bone and gingival epithelium when necrosis is manifested. The aim of the present study was to analyze the rat mandibular bone and gingival epithelium during 45 days of zoledronate treatment (which is a bisphosphonate agent), without tooth extraction. Intraperitoneal injections of zoledronate acid (0.1 mg/kg) were performed three times a week in normal male Wistar rats (n=20), while a control group of rats (n=20) was treated with saline solution for 45 days. After 7, 15, 30 and 45 days of drug treatment, all rats were sacrificed and hematoxilin and eosin staining, immunofluorescence and scanning electron microscopy analyses were performed. The results of the analyses after 7 and 15 days of treatment were similar in the treatment and control group. After 30 and 45 days of treatment, structural alterations were observed in the bone. No structural alterations to the gingival epithelium were observed. Based on these results, it was hypothesized that low doses of zoledronate act directly on the bone tissues to induce morphological alterations from bone to necrotic tissue following surgical procedures, although no cytotoxic effects were detected in the gingival epithelium.

Morphofunctional compensation of masseter muscles in unilateral posterior crossbite patients

Unilateral posterior crossbite is a widespread, asymmetric malocclusion characterized by an inverse relationship of the upper and lower buccal dental cusps, in the molar and premolar regions, on one side only of the dental arch. Patients with unilateral posterior crossbite exhibit an altered chewing cycles and the crossbite side masseter results to be less active with respect to the contralateral one. Few studies about morphological features of masticatory muscle in malocclusion disorders exist and most of these have been performed on animal models. The aim of the present study was to evaluate morphological and protein expression characteristics of masseter muscles in patients affected by unilateral posterior crossbite, by histological and immunofluorescence techniques. We have used antibody against PAX-7, marker of satellite cells, and against α-, β-, γ-, δ-, ε- and ζ-sarcoglycans which are transmembrane glycoproteins involved in sarcolemma stabilization. By statistical analysis we have evaluated differences in amount of myonucley between contralateral and ipsilateral side. Results have shown: i) altered fibers morphology and atrophy of ipsilateral muscle if compared to the contralateral one; ii) higher number of myonuclei and PAX-7 positive cells in contralateral side than ipsilateral one; iii) higher pattern of fluorescence for all tested sarcoglycans in contralateral side than ipsilateral one. Results show that in unilateral posterior crossbite hypertrophic response of contralateral masseter and atrophic events in ipsilateral masseter take place; by that, in unilateral posterior crossbite malocclusion masticatory muscles modify their morphology depending on the function. That could be relevant in understanding and healing of malocclusion disorders; in fact, the altered balance about structure and function between ipsilateral and contralateral muscles could, long-term, lead and/ or worsen skeletal asymmetries.

Sarcoglycan complex in masseter and sternocleidomastoid muscles of baboons: an immunohistochemical study

The sarcoglycan complex consists of a group of single-pass transmembrane glycoproteins that are essential to maintain the integrity of muscle membranes. Any mutation in each sarcoglycan gene causes a series of recessive autosomal dystrophin-positive muscular dystrophies. Negative fibres for sarcoglycans have never been found in healthy humans and animals. In this study, we have investigated whether the social ranking has an influence on the expression of sarcoglycans in the skeletal muscles of healthy baboons. Biopsies of masseter and sternocleidomastoid muscles were processed for confocal immunohistochemical detection of sarcoglycans. Our findings showed that baboons from different social rankings exhibited different sarcoglycan expression profiles. While in dominant baboons almost all muscles were stained for sarcoglycans, only 55% of muscle fibres showed a significant staining. This different expression pattern is likely to be due to the living conditions of these primates. Sarcoglycans which play a key role in muscle activity by controlling contractile forces may influence the phenotype of muscle fibres, thus determining an adaptation to functional conditions. We hypothesize that this intraspecies variation reflects an epigenetic modification of the muscular protein network that allows baboons to adapt progressively to a different social status.

The cerebellum-periaqueductal gray connectivity: a constrained spherical deconvolution tractography study

The periaqueductal gray (PAG) is a relevant neuronal station situated in the midbrain, which play a pivotal role in triggering behavioral responses to stressful stimuli, such as pain or threat. Current knowledge concerning PAG functions is based on several tract-tracing studies conducted on animals, which unveiled PAG connectivity to both cortical and subcortical areas [1]. Considering that descending projections to spinal cord reach the dorsal horn and connections to motor related cortical areas have never been described yet, the neural structure which best fits PAG modulation of motor behavior is the cerebellum. Direct connections between PAG and cerebellar cortex were firstly described in cats and neurophysiological studies conducted on animals, suggesting either direct or undirect PAG influence to cerebellar activity. In the last decades, the rise of diffusion weighted imaging and tractography have made possible to reliably reconstruct white matter pathways in the human brain. To the best of our knowledge, few tractography studies explored PAG connectivity in humans and the evidences concerning direct or undirect connections with the cerebellar cortex are still sparse. Aimed at investigating PAG connectivity with particular focus on PAG-cerebellum connections, we used high quality diffusion weighted imaging data of thirty healthy subjects from the Human Connectome Project. Fiber tracts have been reconstructed using Spherical Informed Filtering of Tractograms, a novel algorithm improving streamline reconstruction and selection [2]. Connectivity analysis revealed that the PAG is mainly connected with subcortical structures, such as the thalamus and the cerebellum. Taken together our results show a direct interplay between the PAG and the cerebellum, thus suggesting the cerebellum as a likely candidate to modulate complex features of motor behavior in stressful conditions, such as adaptation after social defeat and computing strategies to avoid threatening situations.