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1.
Iran J Pathol ; 18(3): 270-278, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37942192

RESUMO

Background: To gain insight into the pathogenesis and clinical course of COVID-19 from a historical perspective, we reviewed paraclinical diagnostic tools of this disease and prioritized the patients with a more severe form of disease admitted to intensive care units (ICUs). The objective was to better predict the course and severity of the disease by collecting more paraclinical data, specifically by examining the relationship between hematological findings and cytological variation of blood neutrophils and monocytes. Methods: This retrospective study was conducted on 112 patients with confirmed COVID-19 admitted to Imam Hossein Hospital (Tehran, Iran) from August to September 2020. Peripheral blood smears of these patients were differentiated according to several cytological variations of neutrophils and monocytes, and the correlation to the severity of the disease was specified. Results: The mean percentages of degenerated monocytes, degenerated granulocytes, and spiky biky neutrophils were significantly different among critical and non-critical patients (P<0.05). Degenerated monocytes and granulocytes were higher in critical patients as opposed to spiky biky neutrophils, which were higher among non-critical ones. Comparing the peripheral blood smears of COVID-19 patients (regarding pulmonary involvement in chest computed tomography [CT] scans [subtle, mild, moderate, and severe groups]), the twisted form of neutrophils was significantly higher in the subtle group than in the mild and moderate groups (P=0.003). Conclusion: Different cytological morphologies of neutrophils and monocytes, including degenerated monocytes, degenerated granulocytes, and spiky biky and twisted neutrophils, could help to predict the course and severity of the disease.

2.
Ann Diagn Pathol ; 65: 152149, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37119647

RESUMO

INTRODUCTION: Surgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells. MATERIALS AND METHODS: A retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed. RESULTS: After excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs. All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains). Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs. CONCLUSION: Grade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.


Assuntos
Tumores Neuroectodérmicos Primitivos , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Humanos , Proliferação de Células , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Histonas , Antígeno Ki-67/metabolismo , Gradação de Tumores , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/patologia , Masculino , Feminino
3.
Ann Diagn Pathol ; 60: 151982, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35667232

RESUMO

INTRODUCTION: Barrett's esophagus (BE) is a premalignant condition that leads to susceptibility to developing adenocarcinoma. The most common endoscopic surveillance technique is forceps biopsy, which involves sampling the specimen every 1 to 2 cm along the length of the lesion. This technique has a low sensitivity and often leaves the majority of the esophageal mucosa untested. Recently, the use of wide-area transepithelial sampling with computer-assisted 3-dimensional analysis (WATS-3D) has received much attention. However, there is little known about this novel technique, and this research aims to add to our knowledge of WATS-3D by comparing it to traditional forceps biopsy. MATERIALS AND METHODS: A retrospective observational study was performed. All existing GI biopsy cases diagnosed with WATS-3D were identified from the institutional pathology databases of NYU Langone Hospital - Long Island from 2019 to 2021. Data collection included patients' age, sex, and dysplasia results. Existing pathology reports and CDx diagnostics were reviewed. All the existing slides of the biopsy cases were pulled out and reviewed. Dysplasia was classified as no dysplasia, indefinite for dysplasia, lowgrade dysplasia, and high-grade dysplasia. RESULTS: A total of 109 cases were included in this study. There are 59 cases diagnosed as BE with forceps biopsy, 72 cases by WATS-3D, and 77 cases by WATS-3D combined with forceps biopsy. The sensitivity of detecting BE was significantly increased by WATS-3D and further by WATS-3D combined with forceps biopsy. In 59 cases diagnosed as BE with forceps biopsy, 50 cases were classified as no dysplasia, 3 cases were indefinite for dysplasia, 5 cases were low-grade dysplasia, and 1 case was high-grade dysplasia. In 72 cases diagnosed as BE by WATS-3D, 64 cases were classified as no dysplasia, 7 cases were indefinite for dysplasia, 1 case was high-grade dysplasia, and no cases with low-grade dysplasia. In 77 cases diagnosed as BE by WATS-3D combined with forceps biopsy, 63 cases were classified as no dysplasia, 8 cases were indefinite for dysplasia, 5 cases with low-grade dysplasia, and 1 case was highgrade dysplasia. The maximal longitudinal extent of the esophageal mucosal changes strongly correlated with the severity of BE. CONCLUSION: Compared to traditional forceps biopsy, WATS-3D was more sensitive in finding intestinal metaplasia. However, WATS-3D could not clearly discriminate low-grade dysplasia from indefinite for dysplasia and tended to classify low-grade dysplasia as indefinite for dysplasia. The addition of WATS-3D to forceps biopsy resulted in an increase in diagnostic yield and thus an increase in the quality of patient care.


Assuntos
Esôfago de Barrett , Neoplasias Esofágicas , Esôfago de Barrett/diagnóstico , Esôfago de Barrett/patologia , Biópsia/métodos , Computadores , Endoscópios , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/patologia , Humanos , Hiperplasia
4.
Iran J Pathol ; 17(1): 37-47, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35096087

RESUMO

BACKGROUND & OBJECTIVE: Coronavirus disease 2019 (COVID-19) is progressively spreading, and many researchers have focused on the prognostic value of laboratory analyses. This study reviewed routine blood parameters, upper respiratory viral load, and chest imaging in recovered and expired COVID-19 patients and evaluated possible correlations. METHODS: In this retrograde study, 138 COVID-19 cases were enrolled. Chest tomography scores of patients, routine hematologic and biochemical parameters, and respiratory viral loads were measured. Furthermore, their correlation with severity of disease and the outcome was investigated during a week of admission. RESULTS: The mean age of participants was 58.6±16; 36.2% of whom were diagnosed as critical, 8.7% expired, and 46% showed less than 50% lung opacity. The expiring rate was only correlated to the severity of illness and viral load. During admission, hemoglobin concentration was decreased in critical patients (from 11.49±0.27 to 10.59±0.36, P=0.042) and also among CT-scan scoring groups (P=0.000), while neutrophils (P=0.04), WBC (P=0.03), and platelets (P=0.000) count were increased. In patients with more than 50% lung opacity, leukocyte counts were decreased, but neutrophil and platelets counts showed raise (all P<0.05), while other hematologic parameters did not change. CRP and LDH demonstrated no increase based on the severity of the illness, RT-PCR viral loads and/or outcome. However, both CRP and LDH were increased in patients with more than 50% lobal opacity (CRP: 69.3±9.9 to 1021.1±7.5 and LDH:589.5±93.2 to 1128.6±15.81, P<0.05). CONCLUSION: We found that hemoglobin, white blood cells, neutrophil, lymphocytes, and platelets count together with chest tomography score might be beneficial for expedition the diagnosis, assessmen the severity of the disease, and outcome in the hospitalized cases, while CRP and LDH might be considered as the consequence of lung involvement.

5.
Arch Iran Med ; 24(9): 678-683, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34816683

RESUMO

BACKGROUND: Uterine cervical malignancy is one of the commonly detected malignancies related to the human papillomavirus (HPV) and is increasing incidentally in developing countries. Therefore, the use of an efficient diagnostic method is required as an effectual step for cervical cancer prevention and treatment. The purpose of the study was to diagnose various types of HPV in the cervical cytology specimens in the South-East of Iran. METHODS: This cross-sectional study was performed on 1079 cervical fluid cytology specimens referred for two years, between 2018-2020. Polymerase chain reaction (PCR) and hybridization (INNO-LiPA HPV Genotyping EXTRA II assay) were used to determine HPV DNA and their genotypes, respectively. RESULTS: HPV was positive in 37.7% (407 of 1079) patients with a mean age of 34.62 ± 8.82. Among positive cases, 252 (62%) had only one HPV genotype and 155 (38.05%) had multiplex HPV genotypes, which included 94 (60.7%), 38 (24.6%), 18 (11.6%) and 5 (3.2%) cases with two, three, four and five or more genotypes, respectively. The samples with multiple strains revealed 31 HPV genotypes with the four most prevalent being HPV6 (14.7%), HPV16 (10.9%), HPV53 (9.6%) and HPV51 (5.9%). CONCLUSION: HPV infection is the main health challenge for women that requires improved health service programs and appropriate epidemic vaccination.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Adulto , Alphapapillomavirus/genética , Estudos Transversais , DNA Viral , Estudos Epidemiológicos , Feminino , Genótipo , Humanos , Irã (Geográfico)/epidemiologia , Papillomaviridae/genética , Infecções por Papillomavirus/epidemiologia , Neoplasias do Colo do Útero/epidemiologia
6.
Iran J Pathol ; 16(4): 348-353, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34567182

RESUMO

BACKGROUND & OBJECTIVE: Reproductive toxicity of cadmium (Cd) as an environmental toxicant has been proved in animals and humans. Exposure to Cd impairs testes organs and can reduce male fertility. The present study was designed to investigate the spectrum of histopathological changes in testicular tissue focusing on Sertoli cells in rats following Cd intoxication. METHODS: In the present experiment, acute testicular toxicity was induced by an intraperitoneal injection of 1.2 mg/kg CdCl2 to the animals in the test group, while the control group received normal saline. After 52 days, the animals were euthanized, and testicular tissue was stained by Hematoxylin and Eosin. In addition, immunohistochemical staining was performed on Sertoli cells for Wilms' Tumor, Melan-A, and CD99 to evaluate histopathological changes. RESULTS: Cd caused significant alterations in seminiferous tubules with varying effects on the patterns of spermatozoa production. These histopathological changes were significantly higher in the Cd group, compared to the control group. CONCLUSION: The Cd-induced stepwise spectrum changes included sloughing, disorganization, hypospermatogenesis, spermatic cell arrest, germ cell hypoplasia, Sertoli cell-only pattern, fibro-hyalinized seminiferous tubules, and calcification. Sertoli cells accumulated and created multinucleated giant cells in the seminiferous tubules during the atrophic process, which could be dependent upon Sertoli cells viability and function.

7.
Arch Iran Med ; 24(5): 419-426, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34196208

RESUMO

BACKGROUND: The pathogenesis of the COVID19 pandemic, that has killed one million nine hundred people and infected more the 90 million until end of 2020, has been studied by many researchers. Here, we try to explain its biological behavior based on our recent autopsy information and review of literature. METHODS: In this study, patients with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) result were considered eligible for enrollment. Histopathological examinations were done on 13 people who were hospitalized in Afzalipour hospital, Kerman, Iran. Clinical and laboratory data were reviewed. Tissue examination was done by light microscopy, immunohistochemistry and electron microscopy. RESULTS: The most frequent co-morbidity in the patients was cardiovascular disease. The common initial symptoms of COVID-19 infection were dyspnea and cough. In all cases, the number of white blood cells was higher than the normal range. Common histopathological findings were variable degrees of vasculitis as degenerative to necrotic changes of endothelium and trafficking of inflammatory cells in the vessel wall with fibrinoid necrosis. Tissue damage included interstitial acute inflammatory cells reaction with degenerative to necrotic changes of the parenchymal cells. CD34 and Factor VIII immunohistochemistry staining showed endothelial cell degeneration to necrosis at the vessel wall and infiltration by inflammatory cells. Electron microscopic features confirmed the degenerative damages in the endothelial cells. CONCLUSION: Our histopathological studies suggest that the main focus of the viral damage is the endothelial cells (endotheliopathica) in involved organs. Also, our findings suggest that degeneration of leukocytes occurs at the site of inflammation and release of cytokines (leukocytoclastica) resulting in a cytokine storm.


Assuntos
COVID-19/complicações , COVID-19/patologia , Células Endoteliais/patologia , Leucócitos/patologia , Adulto , Idoso , COVID-19/metabolismo , Estudos de Coortes , Citocinas/metabolismo , Feminino , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Pericardite/patologia , Pericardite/virologia , Dermatopatias/patologia , Dermatopatias/virologia
8.
Microb Pathog ; 152: 104654, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33253859

RESUMO

BACKGROUND: Cutaneous leishmaniasis (CL) is a neglected disease with important public health concerns in many parts of the world including Iran. OBJECTIVES: We aimed to explore the histological changes and immunohistochemical quantification of inflammatory cells and their role in the immunopathology of acute, chronic non-lupoid, and chronic lupoid skin lesions in anthroponotic CL (ACL). METHODS: In this study, skin biopsies of 53 patients with ACL were taken. Samples were studied by light microscopy and immunohistochemistry to quantify the immune and inflammatory cells. RESULTS: Of the 53 skin lesions, 38 were acute, nine chronic non-lupoid and six chronic lupoid. CD68+ macrophages were the most common cells. CD3+ T-lymphocytes were present as diffuse and focal dermal infiltrates and CD8+ cytotoxic T-lymphocytes were the dominant lymphocyte type, constituting more than 50% of the lymphocyte population. CD4+ T-lymphocytes in chronic non-lupoid (10.57 ± 2.37%) and chronic lupoid (14.40 ± 1.28%) lesions were more than those observed in the acute form (8.61 ± 1.31%), but the differences were not statistically significant. CD20+ B-lymphocytes constituted a small percentage of inflammatory cell infiltrates. CD1a + Langerhans cells showed progressively higher percentages from acute to chronic non-lupoid to chronic lupoid lesions. The differences were statistically significant (P < 0.05) between acute and chronic lupoid lesions. CD68+ macrophages were the most common cells and CD8+ T lymphocytes remained the predominant T-lymphocytes in acute, chronic non-lupoid, and chronic lupoid lesions, suggesting their central role in the pathogenesis and possible healing of CL. CONCLUSION: Focusing on the deep dermis, periadnexal and/or peripheral margins or even papillary tip of inflammatory sites of sandfly bites, we sometimes find granuloma inside lymphatic vessels (lymphangiectatic metastatic granuloma) or even infected macrophages with engulfed Leishman bodies faraway. Knowledge of the histopathological and immunohistochemical findings for various forms of ACL is essential in improving clinical and medical strategies and crucial for proper prophylactic and therapeutic plans.


Assuntos
Leishmaniose Cutânea , Estudos de Casos e Controles , Granuloma , Humanos , Irã (Geográfico) , Células de Langerhans , Leishmaniose Cutânea/diagnóstico
9.
Hum Pathol ; 109: 59-68, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33307078

RESUMO

Although coronavirus disease 2019 (COVID-19) is transmitted via respiratory droplets, there are multiple gastrointestinal and hepatic manifestations of the disease, including abnormal liver-associated enzymes. However, there are not many published articles on the pathological findings in the liver of patients with COVID-19. We collected the clinical data from 17 autopsy cases of patients with COVID-19 including age, sex, Body mass index (BMI), liver function test (alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP), direct bilirubin, and total bilirubin), D-dimer, and anticoagulation treatment. We examined histopathologic findings in postmortem hepatic tissue, immunohistochemical (IHC) staining with antibody against COVID-19 spike protein, CD68 and CD61, and electron microscopy. We counted the number of megakaryocytes in liver sections from these COVID-19-positive cases. Abnormal liver-associated enzymes were observed in 12 of 17 cases of COVID-19 infection. With the exception of three cases that had not been tested for D-dimer, all 14 patients' D-dimer levels were increased, including the cases that received varied doses of anticoagulation treatment. Microscopically, the major findings were widespread platelet-fibrin microthrombi, steatosis, histiocytic hyperplasia in the portal tract, mild lobular inflammation, ischemic-type hepatic necrosis, and zone 3 hemorrhage. Rare megakaryocytes were found in sinusoids. COVID-19 IHC demonstrates positive staining of the histiocytes in the portal tract. Under electron microscopy, histiocyte proliferation is present in the portal tract containing lipid droplets, lysosomes, dilated ribosomal endoplasmic reticulum, microvesicular bodies, and coronavirus. The characteristic findings in the liver of patients with COVID-19 include numerous amounts of platelet-fibrin microthrombi, as well as various degrees of steatosis and histiocytic hyperplasia in the portal tract. Possible mechanisms are also discussed.


Assuntos
COVID-19/complicações , Fígado/virologia , SARS-CoV-2/patogenicidade , Trombose/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Autopsia/métodos , COVID-19/virologia , Fígado Gorduroso/patologia , Fígado Gorduroso/virologia , Feminino , Humanos , Fígado/patologia , Hepatopatias/patologia , Masculino , Pessoa de Meia-Idade , Trombose/virologia
10.
Arch Iran Med ; 21(5): 185-190, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29738261

RESUMO

BACKGROUND: Gene expression profiling of breast cancer has demonstrated the importance of stromal response in determining the prognosis of invasive breast cancer. The host response to breast cancer is of increasing interest to pathologists and may be a future focus for novel pharmacological treatments. METHODS: This study describes the pattern of distribution of stromal myofibroblasts using immunostains for CD10 and smooth muscle actin (SMA) in 50 primary breast cancers and their matched nodal metastases (68.6% nodes positive and 31.4% nodes negative). The stroma within the tumor (intratumoral) and at the advancing tumor edge (peri-tumoral) was studied in both primary and nodal sites. A simple quantitative scoring system was employed for both immunostains. The correlation between expression of these markers by stromal cells and standard pathological prognostic factors of stage, grade, hormone receptor and Her-2 status was analysed. RESULTS: SMA-positive stromal cells were more abundant in peri-tumoral stroma compared with intratumoral stroma in both primary and metastatic lesions. SMA expression in the lymph node metastases showed a significant correlation with tumor stage. SMA expression in peri-tumoral stroma correlated with Her-2 status. CONCLUSION: The results of this study suggest that myofibroblasts, particularly those expressing SMA, might potentiate the progression of the carcinomatous process especially in nodal metastases. Thus these cells may be a potential therapeutic target.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Miofibroblastos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/metabolismo , Mama/irrigação sanguínea , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Feminino , Humanos , Metástase Linfática/patologia , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/metabolismo , Adulto Jovem
11.
Iran J Kidney Dis ; 11(5): 360-366, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29038391

RESUMO

INTRODUCTION: Embryogenesis of the kidney glomeruli, especially its vascular component, has not been well documented. Glomeruli capillary tuft is surrounded and enveloped by visceral epithelial cells, which is a unique portal system that connects afferent with efferent arteriole without interaction with venular circulation. We hypothesized that the portal system embryologically has developed by extension of the intima of afferent arteriole into the stroma of glomerulus. We also hypothesized that juxtaglomeruli apparatus was developed from remnants of smooth muscle cells of the media of afferent arteriole at the anastomosing site with the Bowman capsule entrance. MATERIALS AND METHODS: We studied 5 human fetal kidneys by hematoxylin-eosin, periodic acid-Schiff, and immunoperoxidase staining techniques. RESULTS: Hematoxylin-eosin staining of fetal kidney showed presence of erythrocytes in early vesicle form of glomeruli that was confirmed by immunohistochemical staining with CD31, smooth muscle actin, and CD34 markers. These stains showed extension of extraglomerular arterioles to the glomeruli. Periodic acid-Schiff staining showed also the continuity of the basement membrane in extraglomeruli and internal glomerular vascular tufts. CONCLUSIONS: This study shows that there is a relationship between the metanephric blast cells and major vessel critical for angiogenesis. When afferent arteriole come in contact with the immature glomeruli, its intima migrates into the glomerular tuft to form intraglomerular capillary system, while its smooth muscle remains at the entrance orifice and develops juxtaglomerular apparatus cells.


Assuntos
Biomarcadores/sangue , Desenvolvimento Embrionário , Sistema Justaglomerular/irrigação sanguínea , Sistema Justaglomerular/embriologia , Arteríolas , Desenvolvimento Fetal , Humanos , Imuno-Histoquímica
12.
J Neurochem ; 133(5): 684-99, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25761412

RESUMO

Morphological changes in mitochondria have been primarily attributed to fission and fusion, while the more pliable transformations of mitochondria (remodeling, rounding, or stretching) have been largely overlooked. In this study, we quantify the contributions of fission and remodeling to changes in mitochondrial morphology induced by the Ca(2+) ionophore 4Br-A23187 and the metabolic toxin rotenone. We also examine the role of reactive oxygen species (ROS) in the regulation of mitochondrial remodeling. In agreement with our previous studies, mitochondrial remodeling, not fission, is the primary contributor to Ca(2+) -mediated changes in mitochondrial morphology induced by 4Br-A23187 in rat cortical astrocytes. Treatment with rotenone produced similar results. In both paradigms, remodeling was selectively blocked by antioxidants whereas fission was not, suggesting a ROS-mediated mechanism for mitochondrial remodeling. In support of this hypothesis, inhibition of endogenous ROS by overnight incubation in antioxidants resulted in elongated reticular networks of mitochondria. Examination of inner and outer mitochondrial membranes revealed that they largely acted in concert during the remodeling process. While mitochondrial morphology is traditionally ascribed to a net output of fission and fusion processes, in this study we provide evidence that the acute pliability of mitochondria can be a dominant factor in determining their morphology. More importantly, our results suggest that the remodeling process is independently regulated through a ROS-signaling mechanism. Mitochondrial morphology is traditionally ascribed to a balance of fission and fusion processes. We have shown that mitochondria can undergo more pliable transformations; remodeling, rounding, or stretching. We demonstrate that remodeling, not fission, is the primary contributor to calcium mediated changes in mitochondrial morphology in primary astrocytes. Others have shown fission is mediated by calcineurin. Our results suggest the remodeling process distinct from fission and is independently regulated through a ROS-signaling mechanism (CsA: Cyclosporine A; NAC: N-acetyl-l-cysteine; GSH: Reduced-L-Glutathione).


Assuntos
Astrócitos/efeitos dos fármacos , Cálcio/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Espécies Reativas de Oxigênio/metabolismo , Rotenona/farmacologia , Desacopladores/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Cultura Primária de Células , Ratos , Estaurosporina/farmacologia , Transfecção
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