Melatonin modulates inflammatory response and suppresses burn-induced apoptotic injury

Introduction: Melatonin, the principal secretory product of the pineal gland, has antioxidant functions as a potent antioxidant and free radical scavenger. Objectives of the present study were to investigate the effect of melatonin against inflammatory response, burn-induced oxidative damage and apoptotic changes of rat liver. Methods: Melatonin (10 mg /kg, i.p.) was applied immediately after 30% of total body surface area (TBSA) burns on male Wistar rats. The level of malondialdehyde (MDA) as a marker of an oxidative stress was quantified by thiobarbituric method. Hepatic TNFα and IL-10 as inflammatory markers were assayed by ELISA. Using light immunоchistochemistry the expression Ki67 proliferative marker was investigated. Results: Hepatic MDA and TNF-α levels increased significantly following burns without any change in IL-10 level. Intracellular vacuolization, hepatic cell degeneration and apoptosis occurred in rats after burns. The number of apoptotic cells was increased whereas no significant increase in Ki67 proliferative marker. Melatonin decreased the MDA and TNF-α content and increased the IL-10 level. It also limited the degenerative changes and formation of apoptotic cells in rat liver but did not increase expression of the marker of proliferation. In conclusion, our data show that melatonin relieves burn-induced hepatic damage associated with modulation of the proinflammatory/anti-inflammatory balance, mitigation of lipid peroxidation and hepatic apoptosis

Melatonin attenuates oxidative stress and modulates inflammatory response after experimental burn trauma

Introduction. Thermal injury activates an inflammatory response. Melatonin possesses anti-oxidant and anti-inflammatory properties. The objective of the present work was to study melatonin effects on the inflammatory response under conditions of oxidative stress during the early stage of thermal injury. Materials and methods. We used 24 white male rats of Wistar breed, randomly divided into three experimental groups. Group one was the control, group two was inflicted with burn trauma, and group three was inflicted with burn trauma, with melatonin application following the thermal injury. Melatonin was applied twice in doses of 10 g/kg b.m. immediately after the burn trauma and again at 12 hours. Plasma levels of tumor necrosis-factor-α (TNF-α), a pro-inflammatory mediator, and of interleukin-10 (Il-10), an anti-inflammatory mediator, were examined and their ratio was calculated. The levels of malondialdehyde (MDA), an oxidative stress marker, were also estimated. Results. Thermal trauma significantly increased plasma TNF-α levels (ð\u3c0.01) and TNF-α /IL-10 ratio but did not change IL-10 ones. Plasma MDA concentrations were significantly elevated as well (ð\u3c0.0001). Melatonin application significantly reduced TNF-α (ð\u3c0.05), increased IL-10 (ð\u3c0.05), down-regulated TNF-α/IL-10 ratio and changed MDA concentrations (ð\u3c0.01). In conclusion, our results show that local alteration induces oxidative stress and inflammatory response with TNF-α /IL-10 disbalance. Melatonin modulates this response and attenuates oxidative stress in experimental burn injury

Pathways of colorectal carcinogenesis

Колоректалният карцином (КРК) възниква в резултат на акумулиране на различни типове на увреждане на генома: нарушения в транскрипцията на гени и епигенетични нарушения. Сред генетичните нарушения най-голямо значение имат хромозомнатa (CIN) и микросателитна нестабилност (MSI). Мутациите в тумор-супресорните гени и протоонкогени: APC, TP53, SMAD2, SMAD4, DCC, KRAS, PIK3CA, и загубата на хетерозиготност (LOH) в хромозоми 1, 5, 8, 17 и 18 са най-честите причини за CIN. Инактивиращи мутации на гени, участващи в репарацията на ДНК - MMR (mismatch repair) - MLH1, MSH2, MSH6, обуславят възникването на мултиплени мутации и делеции. Епигенетичните нарушения са породени от хиперметилация на промоторните зони на множество гени, известни като CpG острови, и придобитият метилаторен фенотип заглушава множество гени, включително гените, участващи в репарацията на ДНК. Изясняването на геномните и епигеномни нарушения и ролята им в колоректалната карциногенеза е от съществено значение за изработване на ефективни стратегии за превенция и терапия на пациентите с КРК.Colorectal carcinoma (CRC) arises as a result of accumulation of different types of genome damages: transcription disorders of genes and epigenetic disorders. Among the genetic disorders, chromosomal instability (CIN) and microsatellite instability (MSI) are of major importance. Mutations in tumor suppressor genes and proto-oncogenes: APC, TP53, SMAD2, SMAD4, DCC, KRAS, PIK3CA and loss of heterozygosity (LOH) in chromosomes 1, 5, 8, 17 and 18 are the most common causes of CIN.Inactivation mutations of genes involved in DNA repair - MMR (mismatch repair) - MLH1, MSH2, MSH6, trigger the occurrence of multiple mutations and deletions. Epigenetic disorders are caused by genes promotor hypermethylation, known as CpG islands, and methylator phenotype silencing genes participating in DNA replication. The elucidation of genomic and epigenetic disorders and their role in colorectal cancerogenesis is essential for the development of effective prevention and therapy strategies for CRC patients

Whipple`s disease - clinical spectrum and diagnostic approach (with a contribution of eight cases)

PURPOSE: Whipple`s disease (WD) is a rare systemic infection caused by the bacterium Tropheryma whipplei. Since the clinical features of the disease are non-specific, diagnosis still remains a challenge. The aim of the study is to analyse the clinical presentation and diagnostic approach in patients with WD.MATERIAL AND METHODS: Eight patients, six females and two males at an average age of 59 years (range, 46-79 years) were diagnosed with WD from January, 2012 to May, 2013 in the Clinic of Hepatogastroenterology, St. Marina University Hospital of Varna. Laboratory tests, endoscopic, radiologic, ultrasound and histomorphological examinations were performed.RESULTS: The main symptoms are abdominal pain, chronic diarrhoea and meteorism. Only one female patient presents with clinical signs of malabsorbtion, such as weight loss, anasarca, ascites, pleural effusions and anaemia. There are no extraintestinal manifestations. Tests for Chlamydia trachomatis, tuberculosis and Clostridium difficile are negative. Stool examination does not show any parasitic or bacterial infection. Coeliac disease (CD) serological tests are negative, except in one female with co-existing gluten enteropathy since childhood onwards, where Crohn colitis is diagnosed, too. Endoscopy demonstrates mild to moderate atrophy of the intestinal mucosa. Histological examination establishes mild villous atrophy, lymphoplasmatic infiltration and lymph vessel dilation. All the biopsies show PAS-positive inclusions in the macrophages. Doxycycline therapy exerts a favourable effect on the clinical symptoms in all the patients.CONCLUSION: Whipple`s disease (WD) is a rare systemic disease that is commonly late or falsely diagnosed. The prognosis of non-treated patients is poor. The disease should be considered in any patients with prolonged gastrointestinal symptoms such as unexplained abdominal pain, diarrhoea and features of malabsorption syndrome. The appropriate antibiotic treatment achieves remission and improves the patient's quality of life.Keywords: Whipple disease, diagnosis, histology, malabsorption, treatmen

Diagnostic criteria and morphologic characteristics of bone marrow in Ph (-) classical type chronic myeloproliferative neoplasms according to the last revision of WHO 2016

Миелопролиферативните неоплазми (MPN) представляват хетерогенна група от хематологични моноклонални заболявания, характеризиращи се с първично нарушение на кръвотворните стволови клетки с последваща ексцесивна продукция на зрели клетки от еритроидния, гранулоцитния и мегакариоцитния ред. Честотата на MPN е сравнително ниска, средно на година заболяват около шест човека на 100 000 население. Засягат се предимно по-възрастни индивиди, като средната възраст на пациентите е между 65 и 70 години. Съгласно последната ревизия на СЗО на класификацията на тумори от хемопоетични и лимфни тъкани (2016) MPN се разделят на хронична миелогенна левкемия, носеща Philadelphia (Ph+) хромозома, която е резултат от транслокация t (9,22) с образуване на BCR-ABL1 фузионен ген, хронична неутрофилна левкемия, хронична еозинофилна левкемия от неспециален тип, миелопролиферативни неоплазми от некласифицируем тип и класически Ph(-) MPN: полицитемия вера, есенциална тромбоцитемия и първична миелофиброза в префибротичен / ранен стадий и фибротичен стадий. В последната ревизия на СЗО от 2016 г. са актуализирани някои от диагностичните критерии на Ph(-) MPN, a други са детайлизирани. Конкретизирани са случаите, при които се изисква костномозъчна биопсия.Myeloproliferative neoplasms (MPN) are a heterogeneous group of hematologic monoclonal diseases, characterized by a primary disorder of the pluripotent hematopoietic stem cell leading to overproduction of mature cells from erythroid, myeloid and megakaryocytic lineages. The incidence of MPN is relatively low, every sixth per 100 000 people gets ill annually. Affected patients are usually older individuals, with an average age between 65 and 70 years. According to the last revision of WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (2016), MPN are divided into chronic myeloid leukemia, carrying Philadelphia (Ph+) chromosome, which is a result from translocation t (9,22) with formation of BCR-ABL1 fusion gene, chronic neutrophilic leukemia, chronic eosinophilic leukemia not-otherwise specified, chronic myeloproliferative neoplasms unclassifiable, classical type Ph (-) MPN: polycythemia vera, essential trombocytemia, prefibrotic/early primary myelofibrosis, overt primary myelofibrosis. In the last revision of WHO (2016) some of the diagnostic criteria for MPN are revised and oth ers are slightly modified. There is a stress on the cases that require bone marrow biopsy

Apoptosis as a mechanism for burn-induced gastric mucosal injury

ABSTRACTIntroduction: Severe thermal burns disturb tissue homeostasis of many organs, but the exact mechanisms of gastric mucosa changes are not yet clear. Various cellular mechanisms, such as cell activation, mitochondrial dysfunction, free oxygen radicals and cytokine overproduction may be involved in this process.Aim: The aim of this study was to assess the levels of malondialdehyde (MDA), apoptotic proteins Bax and Bcl-2 in normal gastric mucosa and to test the hypothesis that oxidative stress activation induces apoptotic processes in the stomach after experimental thermal trauma.Materials and Methods: Under anesthesia, the shaved rats` dorsum was exposed to 90° C bath for 10 s to induce third-degree burn injury, involving 30% of the total body surface area. We determined the tissue level of MDA, a lipid peroxidation marker, by spectrophotometric method and the apoptosis of epithelial cells in gastric mucosa, which was immunohistochemically determined at the level of Bcl-2 and Bax in burn trauma.Results: The gastric MDA level was higher (p<0.01) in the burned group compared to the control group 24 hours after thermal injury. The gastric mucosa in the treated group showed congestion, degenerative changes in the surface epithelium, focal destruction of glandular epithelium with formation of acute erosions. Bax expressed moderately in epithelial cells, predominantly in the basal parts of the gastric glands, while in the control group protein content was localized in the same region, but it was weak. Bcl-2 protein in the control group revealed nuclear expression in surface epithelium, while in the basal layer of gastric mucosa the expression was moderate and mainly cytoplasmic. In the burned group, Bcl-2 expression was more diffuse, nuclear and cytoplasmic, but cytoplasmic expression was weak.Conclusion: Thermal skin trauma induces gastric mucosal injury through the activation of lipid peroxidation, increase of pro-apoptotic Bax protein expression and decrease of anti-apoptotic Bcl-2 protein expression in epithelial cells. We suggest that apoptosis is a possible mechanism for structural changes in the gastric mucosa

P53 Expression In Colorectal Epithelial Neoplasms And Its Relation To Clinical And Histopathological Features

Увод: Колоректалният карцином (КРК) е резултат от генетични и епигенетични нарушения. Ген p53, известен като пазител на генома, играе важна роля в апоптозата и инхибиране на ангиогенезата.Цел: Целта на настоящото изследване е да се проучи и сравни експресията на р53 в туморната тъкан на синхронни/метахронни аденоми и КРК във връзка с клинико-морфологичните показатели и да се оцени р53 като предиктивен маркер. Материали и методи: Материали от 18 синхронни/метахронни колоректални аденоми и 21 КРК са фиксирани в 10% неутрален формалин и са включени в парафин. Срези с дебелина 5μ са оцветени с хемалаун-еозин за оценка на хистологичните параметри. За имунохистохимичния анализ е използвано моноклоналното заешко р53 антитяло (Clone Y5). Използвана е петстепенна скала за оценка процента на позитивни ядра: липсва експресия - 0 (0 - 5%), 1 (6 - 25%), 2 (26 - 50%) и 3 (51 - 75%) и 4 (>75%).Резултати: Седем (38.89%) от доброкачествените неоплазми са позитивни за р53 и експресията на протеина е в права корелационна зависимост от размера, локализация в дясната половина на колона и вилозната компонента на аденома и в обратна зависимост от степента му на диференциация (р0.05). В нетуморната тъкан не се открива р53 позитивност.Заключение: Акумулирането на р53 е предиктор за малигнизация на колоректалните аденоми и за участие в аденом карциномната туморна прогресия.Introduction: Colorectal carcinoma (CRC) is the result of genetic and epigenetic disorders. The p53 gene, known as the guardian of the genome, plays an important role in apoptosis and inhibition of angiogenesis.Aim: The aim of our study is to investigate and compare the expression of p53 in the tumor tissue of synchronous/metachronous adenomas and CRC and its relation to clinical and histopathological features, and to evaluate p53 as a predictive marker.Materials and Methods: Materials from 18 synchronous/metachronous colorectal adenomas and 21 CRCs were fixed in formalin (10% neutral), followed by paraffin embedding of tissue. Tissue sections of 5 μ were stained with hematoxylin and eosin to evaluate histological parameters. For immunohistochemistry, the monoclonal rabbit p53 antibody (Clone Y5) was used. A five-step scale was used to evaluate the percentage of positive nuclear expression: 0 (0-5%), 1 (6-25%), 2 (26-50%) and 3 (51-75%) and 4 (>75%).Results: Seven (38.89%) of the benign neoplasms were positive for p53 and the expression of the protein was in correlation with size, localization in the right half of the colon and the villous component of the adenoma, and inversely dependent on its differentiation degree (p 0.05). The non-neoplastic colonic mucosa was negative in all cases.Conclusion: Accumulation of p53 is a predictor of malignancy in colorectal adenoma and plays part in adenoma-carcinoma tumor progression

Role of the apoptosis-inducing factor in physiological conditions and in malignant neoplasms

Apoptosis is a process of programmed cell death that functions in conditions of complex interactions with a number of other processes in the organism. It is an invariable companion in physiological life events such as growth, development, and aging. There is more and more evidence that disorders in the processes of its implementation and control are the basis of a number of pathological conditions such as autoimmune, neurodegenerative, and malignant diseases. Apoptosis is induced through a classical or alternative signaling pathway and proteins called caspases that play an essential role in cell death are being activated. Recently, a caspase-independent pathway of cell death was discovered, which is executed with the participation of mitochondria-localized apoptosis-inducing factor (AIF). During apoptosis, the protein is released into the cell cytoplasm, it undergoes conformational changes, is translocated to the nucleus with the help of macrophage migration inhibitory factor (MIF), and, as a result, cellular DNA fragmentation occurs. On the other hand, AIF takes part in the processes of oxidative phosphorylation, captures free oxygen radicals and prevents apoptosis induced by them. In a number of malignant tumors, tumor cells have acquired the ability to suppress or avoid apoptosis, which facilitates their survival and metastasis. In-depth study of the mechanisms by which neoplastic cells manage to avoid and manipulate programmed cell death is valuable and extremely important information needed to discover new approaches and drugs for therapeutic impact and overcoming treatment resistance in different types of tumors

Necroptosis—molecular mechanisms and role in tumor growth

Necroptosis is a necrotic form of programmed cell death with potent immunogenicity that is involved in complex interactions with other types of cell death such as autophagy and apoptosis. There is growing evidence that necroptosis is involved in the regulation of various normal physiological processes, especially during the development of organisms. In addition, deregulated signaling pathways involved in the control of necroptosis are thought to underlie many human diseases, such as viral or bacterial infections, ischemic-reperfusion injury, neurodegenerative diseases, or malignancies. Among the key molecules participating in the necroptotic process are the RIPK1 and RIPK3 proteins, forming the necrosome, and the pseudokinase MLKL, which is its main effector. RIPK1 is constitutively present in both the nucleus and cytoplasm, while RIPK3 and MLKL perform continuous shuttling transport between these cell structures. Experimental pharmacological blocking of the transport mechanism leads to the impossibility of necrosome formation and thus prevention of cell death is achieved.Suppression of cell death is a hallmark of malignant tumors. While the mechanism by which tumor cells avoid apoptosis has been well studied, information on how necroptosis is controlled by oncogenic signals in cancer cells is scarce. Many types of malignant cells have defense mechanisms against necroptotic processes by developing systems that can suppress the components involved in necroptosis. Pharmaceutical influence on the formation of the necrosome would make it possible to inhibit carcinogenesis by potentiating necroptosis and neutralizing the antinecroptotic mechanisms that a number of malignant tumors have evolutionarily acquired. In-depth study of this process can both reveal markers of important prognostic value in oncology and can identify cellular proteins as molecular targets in personalized medicine

Tetraspanin 151 and its role in carcinogenesis

CD151, a member of the tetraspanin protein family, is a transmembrane protein involved in a number of physiological processes such as maintaining cell integrity, intercellular transport, wound healing, and more. It is not the main participant in these functions, but rather acts as a mediator molecule, interacting with other tetraspanins, integrins, adhesion receptors, signaling receptors and matrix metalloproteases. It is commonly expressed in endothelial cells and platelets, and its overexpression is associated with processes of progression and metastasis in neoplastic diseases. CD151, associated with laminin and laminin-binding integrins, is involved in the regulation of carcinogenesis. CD151 has been shown to play a significant role in the de novo carcinogenesis and progression of squamous cell carcinoma of the skin, influencing transcription factors related to the processes of cell proliferation and apoptosis. There are reports in the scientific literature of the association of impaired regulation of various tetraspanins with malignancies in humans. A number of authors have also reported that CD151 overexpression has been associated with a poor prognosis in cancers of the lung, colon, esophagus, pancreas and endometrium.In prostate cancer, overall survival rates were found to be significantly higher with low CD151 expression than with high expression. This tendency is particularly pronounced in highly and moderately differentiated tumors.Significant heterogeneity of CD151 expression in different tumor tissues was observed. The intensity of staining is noticeably lower in well-differentiated squamous cell carcinoma of the oral cavity. The expression gradient of CD151 is particularly noticeable at the front of tumor growth.Large-scale prospective and retrospective studies on various types of malignant tumors have established CD151 as a prognostic marker for tumor therapy with minimal side effects on normal cells