FMUL News
Dermatology Research Unit
In order to accompany the progress and development of the basic and clinical research in dermatology that has taken place over the last two decades on the international level it is fundamental to create dermatology research units in Portugal, preferably integrated within research centres of excellence.
Nowadays the study of cutaneous illnesses cannot be confined to conventional clinical departments. The scope of these studies lies within translational research units, which have been determining for the success of basic and clinical research programmes and of the practical application of their results in patients’ treatment and in the improving of their quality of life.
In dermatology, one of the paradigmatic illnesses is psoriasis. This dermatosis has an impact on dermatology, but also on internal medicine, rheumatology and cardiology, among other areas of medicine. The study of psoriasis requires interdisciplinary work leading to the integration of basic research and clinical research, needing an energetic collaboration among clinical dermatology teams and multidisciplinary academic departments.
The forming of a Dermatology Research Unit within the Institute of Molecular Medicine (IMM) appears in its initial stages in this context. The main aim of a Dermatology Research Unit is to promote and develop strategies of translational research, encouraging the formation of creative, multidisciplinary teams for the study of psoriasis in its aspects of basic research, clinical research and new therapeutic approaches directed towards the pathogenic paths identified in the pathogenesis of psoriasis.
The interactive environment of research in the existing University Dermatology Clinic, shown in the ongoing research projects, grants and joint supervision of students, strengthened by national and international collaborations with institutes from different scientific areas that allow the exchange of ideas and knowledge, is a determining factor for the creation of a research unit integrated in the IMM. The initial, and thus limited, group includes dermatologists and interns in the specialty of dermatovenereology with potential and interest in research, a biologist and a biochemist.
The group has collaborations with other institutes and research groups in the areas of biochemistry, of photobiology (INSERM – France; Hopital Saint-Louis …), of morphology and cellular biology (ITN/IST; CENBG, Bordeaux), of proteomics (Faculty of Sciences and Technology, UNL) and nanotoxicology (CMAM – Univ. Autónoma de Madrid; SPIRIT Network, http://www.spirit-ion.eu/Project.html ).
The research projects are centred on psoriasis, the aetiology of which is not known, and which is nowadays considered to be an immuno-inflammatory disease with systemic repercussion on the moderate and serious forms. The basic research aspects are dealt with (inflammation, oxidating stress, clastogenicity, proteomics) as well as the clinical research aspects (phototherapies, treatments with biological agents and with antioxidants).
In clinical research particular importance is granted to the way that inflammatory indicators, those of oxidative stress and the proteome are altered according to the phototherapies with the narrow band UVB methods, as well as with the biological agents and the new systemic therapeutic approaches that aim at the pathogenic mechanisms recently identified in psoriasis.
There is still no cure for psoriasis, but in general the current treatments are quite efficient in eliminating the signs and symptoms. However, the mechanisms through which these therapies are efficient, as well as the later side-effects, haven not been duly clarified yet.
1 – Oxidative stress/lesion
Cutaneous phototoxicity, provoked by the interaction of solar or artificial radiation with medicinal drugs, accumulated on exposed skin areas is a frequent health problem. On the other hand, some of these substances may be photogenotoxic and photo-immunotoxic, which suggests that they may contribute towards increased cutaneous carcinogenic risk. All of the essential biomolecules may be damaged as a result of reactions of photosensitivity induced by the absorbing of visible light and/or UVA radiation through photosensitising medication. Many of these reactions are photodynamic through leading to the activation of molecular oxygen through the forming of reactive species of oxygen. Staring from these presuppositions, it is natural for one to look for solutions for these harmful effects and to increase the benefit/risk ration of the medicinal drugs with photosensitising properties. One of the possible strategies is to look for antioxidant substances, aids capable of intercepting the reactive species of oxygen formed during reactions of photosensitivity and of increasing the cell’s natural antioxidant defences. We have chosen the flavonoid antioxidants in order to respond to this problem. Studies have been carried out on the molecular mechanisms of the flavonoid antioxidant action for optimization of oxidant and photo-oxidant stress control. The model-systems made up of plasma, LDL solutions and albumin are used in order to study the effect of natural and synthesis flavonoids in the consumption of endogenous antioxidants, in lipoperoxidation and in the oxidation of proteins, in order to select the most efficient compounds. The photoprotective effect of the natural and synthesis flavonoids in photosensitivity reactions induced by UVA radiation in the presence of phototoxic drugs is also studied in cultures of cutaneous keratinocytes and fibroblasts, assessing the cell viability after UVA irradiation, lipid cell peroxidation and photogenotoxicity.
2 – The Immuno-inflammatory Process
Over recent decades there has been a significant increase in studies in basic research, which have revealed molecular mechanisms, alterations in the functioning of the epidermis cells, the keratinocytes, and demonstrated the involvement of the immune system, in particular the cells that measure the innate/adaptative response, like the T lymphocytes and the dendritic cells. The T lymphocytes infiltrate the epidermis, where they remain due to the expression of molecules in the membrane of the keratinocytes that promote their adhering. These processes set off the production and segregation of signing molecules that in turn favour cell activation, creating a vicious cycle that perpetuates the inflammation. In psoriasis, the alterations are not only confined to cutaneous lesions, but also imply alterations in the blood circulation lymphocytes.
The intention is to assess the effect of phototherapy, of the biological and antioxidant agents in patients with psoriasis through indicators of the inflammatory process and of the characterization of the cells of innate/adaptive immunity on skin level and indirectly on peripheral circulation. Particular attention will be paid to the activation of keratinocytes, T lymphocytes (CD4+, CD8+ and Tregs or Th17) and dentritic cells (CD11c+), to the production of cytocine TNF-a, of growth factors (e.g., TGFb1 and VEGF) and of interleukins (e.g., IL6, IL8, IL12, IL17, IL20, IL22, IL23). These indicators may contribute to assess the magnitude of the functional alteration of the T lymphocytes and Tregs, and of the activation of the keratinocytes and the dentritic cells, on psoriatic lesions.
3- The Proteome
The proteome, unlike the genome, is dynamic. The proteome of a cell may be altered as a response to extra- or intra-cellular stimuli. This aspect is very important in the evolution of the illness and in the evaluation of the effect of the therapies, as it allows identification of the proteins that are being expressed or the transcription of which is being inhibited. Thus the proteome may provide a molecular signature for the illness or the response to a determined therapeutic approach.
The serum and skin proteome (without lesion and with lesion) in patients with psoriasis, before and after PUVA, narrow band UVB and biotechnological agents may help identify the differential expression of proteins during the therapeutic treatment and identify proteomic profiles for patients responding or not responding to a determined therapeutic intervention. These proteomes, when compared to those in healthy individuals, may also help one to recognise which are the modified proteins or those in which the expression has been altered, and better understand the pathogenic paths of psoriasis.
The main technical support for the production of proteomes is two-dimensional electrophoresis, a technique capable of resolving thousands of proteins coming from a complex sample in one single gel. Comparison of the proteomic maps obtained for the different samples will allow a detecting of the biological response markers for the therapy. Their subsequent identification by mass spectrometry (peptide mass fingerprint) will provide crucial information for the understanding of the molecular mechanisms with therapeutic action on psoriasis.
The study of psoriasis by a multidisciplinary team in a research unit in the IMM, na institute or renown on the international level, is fundamental not only to help to understand psoriasis from the dermatological perspective, but it may create a network of collaborations with other existing units, making it possible to study this illness and other chronic immuno-inflammatory illnesses with mechanisms common to psoriasis.
Paulo Leal Filipe
Nowadays the study of cutaneous illnesses cannot be confined to conventional clinical departments. The scope of these studies lies within translational research units, which have been determining for the success of basic and clinical research programmes and of the practical application of their results in patients’ treatment and in the improving of their quality of life.
In dermatology, one of the paradigmatic illnesses is psoriasis. This dermatosis has an impact on dermatology, but also on internal medicine, rheumatology and cardiology, among other areas of medicine. The study of psoriasis requires interdisciplinary work leading to the integration of basic research and clinical research, needing an energetic collaboration among clinical dermatology teams and multidisciplinary academic departments.
The forming of a Dermatology Research Unit within the Institute of Molecular Medicine (IMM) appears in its initial stages in this context. The main aim of a Dermatology Research Unit is to promote and develop strategies of translational research, encouraging the formation of creative, multidisciplinary teams for the study of psoriasis in its aspects of basic research, clinical research and new therapeutic approaches directed towards the pathogenic paths identified in the pathogenesis of psoriasis.
The interactive environment of research in the existing University Dermatology Clinic, shown in the ongoing research projects, grants and joint supervision of students, strengthened by national and international collaborations with institutes from different scientific areas that allow the exchange of ideas and knowledge, is a determining factor for the creation of a research unit integrated in the IMM. The initial, and thus limited, group includes dermatologists and interns in the specialty of dermatovenereology with potential and interest in research, a biologist and a biochemist.
The group has collaborations with other institutes and research groups in the areas of biochemistry, of photobiology (INSERM – France; Hopital Saint-Louis …), of morphology and cellular biology (ITN/IST; CENBG, Bordeaux), of proteomics (Faculty of Sciences and Technology, UNL) and nanotoxicology (CMAM – Univ. Autónoma de Madrid; SPIRIT Network, http://www.spirit-ion.eu/Project.html ).
The research projects are centred on psoriasis, the aetiology of which is not known, and which is nowadays considered to be an immuno-inflammatory disease with systemic repercussion on the moderate and serious forms. The basic research aspects are dealt with (inflammation, oxidating stress, clastogenicity, proteomics) as well as the clinical research aspects (phototherapies, treatments with biological agents and with antioxidants).
In clinical research particular importance is granted to the way that inflammatory indicators, those of oxidative stress and the proteome are altered according to the phototherapies with the narrow band UVB methods, as well as with the biological agents and the new systemic therapeutic approaches that aim at the pathogenic mechanisms recently identified in psoriasis.
There is still no cure for psoriasis, but in general the current treatments are quite efficient in eliminating the signs and symptoms. However, the mechanisms through which these therapies are efficient, as well as the later side-effects, haven not been duly clarified yet.
1 – Oxidative stress/lesion
Cutaneous phototoxicity, provoked by the interaction of solar or artificial radiation with medicinal drugs, accumulated on exposed skin areas is a frequent health problem. On the other hand, some of these substances may be photogenotoxic and photo-immunotoxic, which suggests that they may contribute towards increased cutaneous carcinogenic risk. All of the essential biomolecules may be damaged as a result of reactions of photosensitivity induced by the absorbing of visible light and/or UVA radiation through photosensitising medication. Many of these reactions are photodynamic through leading to the activation of molecular oxygen through the forming of reactive species of oxygen. Staring from these presuppositions, it is natural for one to look for solutions for these harmful effects and to increase the benefit/risk ration of the medicinal drugs with photosensitising properties. One of the possible strategies is to look for antioxidant substances, aids capable of intercepting the reactive species of oxygen formed during reactions of photosensitivity and of increasing the cell’s natural antioxidant defences. We have chosen the flavonoid antioxidants in order to respond to this problem. Studies have been carried out on the molecular mechanisms of the flavonoid antioxidant action for optimization of oxidant and photo-oxidant stress control. The model-systems made up of plasma, LDL solutions and albumin are used in order to study the effect of natural and synthesis flavonoids in the consumption of endogenous antioxidants, in lipoperoxidation and in the oxidation of proteins, in order to select the most efficient compounds. The photoprotective effect of the natural and synthesis flavonoids in photosensitivity reactions induced by UVA radiation in the presence of phototoxic drugs is also studied in cultures of cutaneous keratinocytes and fibroblasts, assessing the cell viability after UVA irradiation, lipid cell peroxidation and photogenotoxicity.
2 – The Immuno-inflammatory Process
Over recent decades there has been a significant increase in studies in basic research, which have revealed molecular mechanisms, alterations in the functioning of the epidermis cells, the keratinocytes, and demonstrated the involvement of the immune system, in particular the cells that measure the innate/adaptative response, like the T lymphocytes and the dendritic cells. The T lymphocytes infiltrate the epidermis, where they remain due to the expression of molecules in the membrane of the keratinocytes that promote their adhering. These processes set off the production and segregation of signing molecules that in turn favour cell activation, creating a vicious cycle that perpetuates the inflammation. In psoriasis, the alterations are not only confined to cutaneous lesions, but also imply alterations in the blood circulation lymphocytes.
The intention is to assess the effect of phototherapy, of the biological and antioxidant agents in patients with psoriasis through indicators of the inflammatory process and of the characterization of the cells of innate/adaptive immunity on skin level and indirectly on peripheral circulation. Particular attention will be paid to the activation of keratinocytes, T lymphocytes (CD4+, CD8+ and Tregs or Th17) and dentritic cells (CD11c+), to the production of cytocine TNF-a, of growth factors (e.g., TGFb1 and VEGF) and of interleukins (e.g., IL6, IL8, IL12, IL17, IL20, IL22, IL23). These indicators may contribute to assess the magnitude of the functional alteration of the T lymphocytes and Tregs, and of the activation of the keratinocytes and the dentritic cells, on psoriatic lesions.
3- The Proteome
The proteome, unlike the genome, is dynamic. The proteome of a cell may be altered as a response to extra- or intra-cellular stimuli. This aspect is very important in the evolution of the illness and in the evaluation of the effect of the therapies, as it allows identification of the proteins that are being expressed or the transcription of which is being inhibited. Thus the proteome may provide a molecular signature for the illness or the response to a determined therapeutic approach.
The serum and skin proteome (without lesion and with lesion) in patients with psoriasis, before and after PUVA, narrow band UVB and biotechnological agents may help identify the differential expression of proteins during the therapeutic treatment and identify proteomic profiles for patients responding or not responding to a determined therapeutic intervention. These proteomes, when compared to those in healthy individuals, may also help one to recognise which are the modified proteins or those in which the expression has been altered, and better understand the pathogenic paths of psoriasis.
The main technical support for the production of proteomes is two-dimensional electrophoresis, a technique capable of resolving thousands of proteins coming from a complex sample in one single gel. Comparison of the proteomic maps obtained for the different samples will allow a detecting of the biological response markers for the therapy. Their subsequent identification by mass spectrometry (peptide mass fingerprint) will provide crucial information for the understanding of the molecular mechanisms with therapeutic action on psoriasis.
The study of psoriasis by a multidisciplinary team in a research unit in the IMM, na institute or renown on the international level, is fundamental not only to help to understand psoriasis from the dermatological perspective, but it may create a network of collaborations with other existing units, making it possible to study this illness and other chronic immuno-inflammatory illnesses with mechanisms common to psoriasis.
Paulo Leal Filipe
