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1.
Cureus ; 16(6): e62790, 2024 Jun.
Article in English | MEDLINE | ID: mdl-39036222

ABSTRACT

Patients with coronavirus disease 2019 (COVID-19) pneumonia are prone to intrapulmonary thrombosis owing to excessive inflammation and platelet activation. Myelodysplastic/myeloproliferative neoplasm (MDS/MPN) with ring sideroblasts and thrombocytosis (RS-T) is a rare disease in MDS/MPN overlap entities. Patients with MDS/MPN RS-T are known to be at a high risk of thrombosis, and platelet count control with drug therapy does not necessarily reduce this risk. Here, we report the autopsy case of an older male patient with MDS/MPN RS-T and severe COVID-19 pneumonia complicated by intrapulmonary thrombosis. His platelet count had been controlled in the normal range after treatment with hydroxyurea and 5-aza-2'-deoxycytidine. On admission day, he rapidly developed respiratory distress and tested positive on a polymerase chain reaction test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). After admission, he received supplemental oxygen and was administered remdesivir and dexamethasone; however, his respiratory and circulatory status did not improve. The patient died on day 4 of illness. Autopsy findings revealed massive thrombi within blood vessels and diffuse alveolar damage in both lungs, which were determined to be the cause of death. In patients with MDS/MPN RS-T combined with COVID-19 pneumonia, clinicians may need to pay close attention to the risk of pulmonary thrombosis.

2.
Acta Histochem Cytochem ; 57(2): 57-66, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38695038

ABSTRACT

Protein lactylation is a post-translational modification associated with glycolysis. Although recent evidence indicates that protein lactylation is involved in epigenetic gene regulation, its pathophysiological significance remains unclear, particularly in neoplasms. Herein, we investigated the potential involvement of protein lactylation in the molecular mechanisms underlying benign and malignant pancreatic epithelial tumors, as well as its role in the response of pancreatic cancer (PC) cells to gemcitabine. Increased lactylation was observed in the nuclei of intraductal papillary mucinous adenoma, non-invasive intraductal papillary mucinous carcinoma, and invasive carcinoma, in parallel to the upregulation of hypoxia-inducible factor-1α. This observation indicated that a hypoxia-associated increase in nuclear protein lactylation could be a biochemical hallmark in pancreatic epithelial tumors. The standard PC chemotherapy drug gemcitabine suppressed histone lactylation in vitro, suggesting that histone lactylation might be relevant to its mechanism of action. Taken together, our findings suggest that protein lactylation may be involved in the development of pancreatic epithelial tumors and could represent a potential therapeutic target for PC.

3.
Sci Rep ; 13(1): 21363, 2023 12 04.
Article in English | MEDLINE | ID: mdl-38049475

ABSTRACT

Rapid and precise intraoperative diagnosing systems are required for improving surgical outcomes and patient prognosis. Because of the poor quality and time-intensive process of the prevalent frozen section procedure, various intraoperative diagnostic imaging systems have been explored. Microscopy with ultraviolet surface excitation (MUSE) is an inexpensive, maintenance-free, and rapid imaging technique that yields images like thin-sectioned samples without sectioning. However, pathologists find it nearly impossible to assign diagnostic labels to MUSE images of unfixed specimens; thus, AI for intraoperative diagnosis cannot be trained in a supervised learning manner. In this study, we propose a deep-learning pipeline model for lymph node metastasis detection, in which CycleGAN translate MUSE images of unfixed lymph nodes to formalin-fixed paraffin-embedded (FFPE) sample, and diagnostic prediction is performed using deep convolutional neural network trained on FFPE sample images. Our pipeline yielded an average accuracy of 84.6% when using each of the three deep convolutional neural networks, which is a 18.3% increase over the classification-only model without CycleGAN. The modality translation to FFPE sample images using CycleGAN can be applied to various intraoperative diagnostic imaging systems and eliminate the difficulty for pathologists in labeling new modality images in clinical sites. We anticipate our pipeline to be a starting point for accurate rapid intraoperative diagnostic systems for new imaging modalities, leading to healthcare quality improvement.


Subject(s)
Alprostadil , Neural Networks, Computer , Humans , Lymphatic Metastasis/diagnostic imaging , Microscopy, Fluorescence
4.
Intern Med ; 62(10): 1507-1512, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36198606

ABSTRACT

Primary pancreatic lymphoma is a rare pancreatic malignancy, reportedly accounting for only 0.2-0.7% of all primary pancreatic tumors. Primary pancreatic lymphoma is often difficult to distinguish from other diseases, such as acute pancreatitis. We herein report the autopsy of a patient with primary pancreatic lymphoma with imaging findings resembling those of severe acute pancreatitis, with a focus on the gross and histological features.


Subject(s)
Lymphoma , Pancreatic Neoplasms , Pancreatitis , Humans , Pancreatitis/diagnostic imaging , Autopsy , Acute Disease , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/diagnostic imaging , Lymphoma/diagnosis , Lymphoma/diagnostic imaging
5.
Biochem Biophys Res Commun ; 640: 192-201, 2023 01 15.
Article in English | MEDLINE | ID: mdl-36521425

ABSTRACT

Follicular neoplasms of the thyroid include follicular thyroid carcinoma (FTC) and follicular thyroid adenoma (FTA). However, the differences in cytological findings between FTC and FTA remain undetermined. Here, we aimed to evaluate the accumulation of lipid droplets (LDs) and the expression of adipophilin (perilipin 2/ADRP/ADFP), a known LD marker, in cultured FTC cells. We also immunohistochemically compared adipophilin expression in the FTC and FTA of resected human thyroid tissues. Cultured FTC (FTC-133 and RO82W-1) possessed increased populations of LDs compared to thyroid follicular epithelial (Nthy-ori 3-1) cells. In vitro treatment with phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling inhibitors (LY294002, MK2206, and rapamycin) in FTC-133 cells downregulated the PI3K/Akt/mTOR/sterol regulatory element-binding protein 1 (SREBP1) signaling pathway, resulting in a significant reduction in LD accumulation. SREBP1 is a master transcription factor that controls lipid metabolism. Fluorescence immunocytochemistry revealed adipophilin expression in the LDs of FTC-133 cells. Immunohistochemical analysis of surgically resected human thyroid tissues revealed significantly increased expression of adipophilin in FTC compared with FTA and adjacent non-tumorous thyroid epithelia. Taken together, LDs and adipophilin were abundant in cultured FTC; the evaluation of adipophilin expression can help distinguish FTC from FTA in surgical specimens.


Subject(s)
Adenocarcinoma, Follicular , Thyroid Neoplasms , Humans , Adenocarcinoma, Follicular/metabolism , Adenocarcinoma, Follicular/pathology , Lipid Droplets/metabolism , Perilipin-2 , Phosphatidylinositol 3-Kinase/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Thyroid Neoplasms/pathology , TOR Serine-Threonine Kinases/metabolism
6.
Proc Natl Acad Sci U S A ; 119(25): e2116027119, 2022 06 21.
Article in English | MEDLINE | ID: mdl-35704759

ABSTRACT

The epidermis is the outermost layer of the skin and the body's primary barrier to external pathogens; however, the early epidermal immune response remains to be mechanistically understood. We show that the chemokine CXCL14, produced by epidermal keratinocytes, exhibits robust circadian fluctuations and initiates innate immunity. Clearance of the skin pathogen Staphylococcus aureus in nocturnal mice was associated with CXCL14 expression, which was high during subjective daytime and low at night. In contrast, in marmosets, a diurnal primate, circadian CXCL14 expression was reversed. Rhythmically expressed CXCL14 binds to S. aureus DNA and induces inflammatory cytokine production by activating Toll-like receptor (TLR)9-dependent innate pathways in dendritic cells and macrophages underneath the epidermis. CXCL14 also promoted phagocytosis by macrophages in a TLR9-independent manner. These data indicate that circadian production of the epidermal chemokine CXCL14 rhythmically suppresses skin bacterial proliferation in mammals by activating the innate immune system.


Subject(s)
Epidermis , Immunity, Innate , Skin Diseases, Bacterial , Animals , Chemokines, CXC/genetics , Chemokines, CXC/immunology , Circadian Clocks/immunology , Epidermis/immunology , Immunity, Innate/genetics , Immunity, Innate/immunology , Keratinocytes/immunology , Mammals , Mice , Skin Diseases, Bacterial/immunology , Skin Diseases, Bacterial/metabolism , Staphylococcal Infections/immunology , Staphylococcus aureus/immunology
7.
Sci Rep ; 9(1): 16912, 2019 11 15.
Article in English | MEDLINE | ID: mdl-31729459

ABSTRACT

Deep-UV (DUV) excitation fluorescence microscopy has potential to provide rapid diagnosis with simple technique comparing to conventional histopathology based on hematoxylin and eosin (H&E) staining. We established a fluorescent staining protocol for DUV excitation fluorescence imaging that has enabled clear discrimination of nucleoplasm, nucleolus, and cytoplasm. Fluorescence images of metastasis-positive/-negative lymph nodes of gastric cancer patients were used for patch-based training with a deep neural network (DNN) based on Inception-v3 architecture. The performance on small patches of the fluorescence images was comparable with that of H&E images. Gradient-weighted class activation mapping analysis revealed the areas where the trained model identified metastatic lesions in the images containing cancer cells. We extended the method to large-size image analysis enabling accurate detection of metastatic lesions. We discuss usefulness of DUV excitation fluorescence imaging with the aid of DNN analysis, which is promising for assisting pathologists in assessment of lymph node metastasis.


Subject(s)
Lymph Nodes/pathology , Lymphatic Metastasis/pathology , Microscopy, Fluorescence , Neural Networks, Computer , Algorithms , Biopsy , Fluorescent Antibody Technique , Humans , Image Interpretation, Computer-Assisted , Image Processing, Computer-Assisted , Immunohistochemistry , Machine Learning , Software
8.
Int J Surg Pathol ; 27(7): 713-721, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31203677

ABSTRACT

Background. The aim of this study was to assess the prognostic significance of residual cancer volume (RCV) in patients with esophageal squamous cell carcinoma (ESCC) who received esophagectomy after neoadjuvant chemotherapy. Methods. We measured RCV by using complete stepwise sections at 6- to 8-mm intervals obtained from 81 ESCC patients with clinical stages IB to III. RCV was defined as the summation of all products of residual cancer area and thickness, and its cutoff value was set by receiver operator characteristic curve analysis on 3-year disease-specific survival (DSS). The multivariate analyses were performed in comparison with histopathological factors including tumor regression grades according to the Japanese Classification of Esophageal Cancer (TRG-JPN) or reported by Becker et al (TRG-Becker). Results. The range of RCV was 0 to 49.3 cm3 (median = 1.4 cm3), and the cutoff value was set at 1.0 cm3 (sensitivity = 78%; specificity = 68%). In the Kaplan-Meier curve analysis with the log-rank test, RCV > 1.0 cm3 predicted poorer prognosis for relapse-free survival (RFS; 5-year RFS rate, 12% vs 47%; P < .001) and DSS (5-year DSS rate, 27% vs 61%; P < .001). The multivariate analyses by the Cox hazards model revealed that RCV > 1.0 cm3 was a factor predicting poor prognosis for RFS (P = .013; hazard ratios [HR] = 2.62) and DSS (P = .028; HR = 2.56) compared with histopathological factors including TRG-JPN; RFS (P = .014; HR = 3.03) and DSS (P = .045; HR = 2.71) compared with histopathological factors including TRG-Becker. Conclusions. The study suggested that determining RCV is a new method of predicting prognosis in ESCC patients after neoadjuvant chemotherapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Esophageal Mucosa/pathology , Esophageal Neoplasms/therapy , Esophageal Squamous Cell Carcinoma/therapy , Neoplasm Recurrence, Local/epidemiology , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Esophageal Mucosa/surgery , Esophageal Neoplasms/mortality , Esophageal Neoplasms/pathology , Esophageal Squamous Cell Carcinoma/mortality , Esophageal Squamous Cell Carcinoma/pathology , Esophagectomy , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Neoadjuvant Therapy/methods , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/prevention & control , Neoplasm Staging , Neoplasm, Residual , ROC Curve , Retrospective Studies , Survival Rate
9.
Int J Surg Pathol ; 25(8): 727-731, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28697692

ABSTRACT

Intravascular selective growth of neoplastic B lymphocytes is a characteristic finding of intravascular large B-cell lymphoma (IVLBCL). However, because neoplastic B cells of IVLBCL grow merely in the lumina of capillaries or small vessels, primary IVLBCL of the great vessels is considered exceptional. To our knowledge, only 2 primary B-cell lymphomas in the lumina of the vena cava have been reported. However, there has been no report of primary B-cell lymphoma with intra-aortic growth. We describe a novel manifestation of primary Epstein-Barr virus-positive large B-cell lymphoma mainly affecting the lumina of the aorta and its major branches in a 76-year-old man. He had a long-term fever that was refractory to antibiotics and aortic mural thrombosis with visceral embolization. Because he had no detectable mass suggesting a malignancy, it was difficult to diagnose while he was alive. He died without anticancer treatment, and the confirmed diagnosis was made at autopsy.


Subject(s)
Aorta/pathology , Lymphoma, Large B-Cell, Diffuse/pathology , Vascular Neoplasms/pathology , Aged , Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human , Humans , Lymphoma, Large B-Cell, Diffuse/virology , Male , Thrombosis/etiology , Vascular Neoplasms/virology
10.
Nihon Shokakibyo Gakkai Zasshi ; 113(1): 86-93, 2016.
Article in Japanese | MEDLINE | ID: mdl-26743558

ABSTRACT

A 40-year-old man admitted to our hospital with diarrhea underwent abdominal computed tomography (CT) which showed multiple masses in the liver and pancreatic tail. Although there were no abnormal accumulations with fluorodeoxyglucose ((18)F) positron emission tomography (FDG-PET), (68)Ga-DOTATOC-PET/CT detected obvious abnormal accumulations for the both lobes of liver and pancreatic tail tumors. The serum gastrin was markedly high, and liver tumor biopsy demonstrated the presence of malignant cells with round nuclei that were positive for gastrin and somatostatin receptor. The patient was diagnosed with pancreatic tail gastrinoma with multiple liver metastases and treated with octreotide, everolimus, and a proton pump inhibitor which functionally controlled tumor growth. This case demonstrates (68)Ga-DOTATOC-PET/CT as a useful modality for the localization, qualitative diagnosis, and treatment of gastrinoma.


Subject(s)
Gastrinoma/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Pancreatic Neoplasms/diagnostic imaging , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Everolimus/administration & dosage , Gallium Radioisotopes , Gastrinoma/drug therapy , Humans , Liver Neoplasms/drug therapy , Liver Neoplasms/secondary , Male , Octreotide/administration & dosage , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Positron Emission Tomography Computed Tomography , Treatment Outcome
11.
Gastric Cancer ; 19(1): 192-7, 2016 Jan.
Article in English | MEDLINE | ID: mdl-25637176

ABSTRACT

BACKGROUND: Lymphatic involvement may sometimes be detected in differentiated-type intramucosal cancer resected endoscopically during routine examination, but its incidence and clinical significance remain unknown. METHODS: We examined 300 endoscopically resected lesions obtained from 238 patients diagnosed with differentiated-type intramucosal gastric cancer. All sections were subjected to D2-40 monoclonal-based immunohistochemistry. RESULTS: The incidence of lymphatic involvement in differentiated-type intramucosal cancer was 2.0% (6/300). An incidence of 1.8% (5/279) was determined in lesions that were ≤ 3 cm in size and 2.2% (6/276) in those without an ulcer or ulcer scar. Of the six lesions presenting lymphatic involvement, three were determined to be histologically mixed with a predominance of differentiated type, while the other three lesions were pure differentiated type. CONCLUSIONS: We determined that the incidence of lymphatic involvement in differentiated-type intramucosal cancer was 2.0%. To clarify the clinical significance of such lymphatic involvement, it is necessary to detect it with this incidence in mind and to gather and follow up the clinical courses of such cases.


Subject(s)
Lymphatic Vessels/pathology , Stomach Neoplasms/pathology , Adenocarcinoma/epidemiology , Adenocarcinoma/pathology , Aged , Aged, 80 and over , Carcinoma, Signet Ring Cell/epidemiology , Carcinoma, Signet Ring Cell/pathology , Cell Differentiation , Endoscopy, Gastrointestinal , Female , Gastric Mucosa/pathology , Humans , Lymphatic Metastasis/pathology , Male , Middle Aged , Stomach Neoplasms/epidemiology
13.
Int J Cancer ; 132(12): 2755-66, 2013 Jun 15.
Article in English | MEDLINE | ID: mdl-23180648

ABSTRACT

Lymph node metastasis is a poor prognostic factor for patients with head and neck squamous cell carcinoma (HNSCC). However, its molecular mechanism has not yet been fully understood. In our study, we investigated the expression of CCR4 and its ligand CCL22 in the HNSCC tumor microenvironment and found that the CCR4/CCL22 axis was involved in lymph node metastasis of HNSCC. CCR4 was expressed in 20 of 31 (64.5%) human tongue cancer tissues, and its expression was significantly correlated with lymph node metastasis (p < 0.01) and lymphatic invasion (p < 0.05). CCR4 was expressed in three of five human HNSCC cell lines tested. CCR4(+) HNSCC cells, but not CCR4(-) cells, showed enhanced migration toward CCL22, indicating that functional CCR4 was expressed in HNSCC cell lines. CCL22 was also expressed in cancer cells (48.4% of tongue cancer tissues) or CD206(+) M2-like macrophages infiltrated in tumors and draining lymph nodes. CCL22 produced by cancer cells or CD206(high) M2-like macrophages increased the cell motility of CCR4(+) HNSCC cells in vitro in an autocrine or paracrine manner. In the mouse SCCVII in vivo model, CCR4(+) cancer cells, but not CCR4(-) cells, metastasized to lymph nodes which contained CCL22 producing M2-like macrophages. These results demonstrate that lymph node metastasis of CCR4(+) HNSCC is promoted by CCL22 in an autocrine or M2-like macrophage-dependent paracrine manner. Therefore, the CCR4/CCL22 axis may be an attractive target for the development of diagnostic and therapeutic strategies for patients with HNSCC.


Subject(s)
Carcinoma, Squamous Cell/immunology , Carcinoma, Squamous Cell/metabolism , Cell Communication , Chemokine CCL22/metabolism , Head and Neck Neoplasms/immunology , Head and Neck Neoplasms/metabolism , Macrophages/immunology , Macrophages/metabolism , Receptors, CCR4/metabolism , Aged , Aged, 80 and over , Animals , Autocrine Communication , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Cell Movement/genetics , Disease Models, Animal , Female , Gene Expression , Head and Neck Neoplasms/pathology , Humans , Lymph Nodes/metabolism , Lymph Nodes/pathology , Lymphatic Metastasis , Male , Mice , Middle Aged , Paracrine Communication , Squamous Cell Carcinoma of Head and Neck
15.
Hum Pathol ; 41(2): 208-13, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19801163

ABSTRACT

Chondroblastoma, which is histologically composed of mononuclear cell proliferation and lobules of immature cartilage, and chondromyxoid fibroma, which is composed of myxoid lobules with spindle or stellate cells and a cellular fibrous rim with spindle cells, are both rare tumors. Based on histogenetic investigation including immunohistochemistry, matrix biochemistry, and electron microscopy, chondroblastoma is thought to contain chondrogenic cells, whereas chondromyxoid fibroma is considered to contain myofibroblastic cells, as well as chondrogenic cells, and chondroid matrix. In this study, we performed immunohistochemical analysis for Sox9, which is an essential transcriptional factor for chondrogenesis, to examine the possible chondrogenic nature of chondroblastoma and chondromyxoid fibroma. Formalin-fixed, paraffin-embedded tissues obtained from 10 cases of chondroblastoma and 11 cases of chondromyxoid fibroma were immunostained with antibody to Sox9. In addition, immunohistochemical study for collagen type II, which is a major component of cartilaginous matrix, was performed. Sox9 was positive in 8 chondroblastomas and 10 chondromyxoid fibromas. Positive staining was observed in the nuclei of the tumor cells. The matrices of 7 chondroblastomas and of 8 chondromyxoid fibromas were immunopositive for collagen type II. The findings suggest the cartilaginous differentiation of chondroblastoma and chondromyxoid fibroma.


Subject(s)
Bone Neoplasms/metabolism , Bone and Bones/metabolism , Cartilage/metabolism , Chondroblastoma/metabolism , Fibroma/metabolism , SOX9 Transcription Factor/metabolism , Adolescent , Adult , Child , Collagen Type II/metabolism , Female , Humans , Immunohistochemistry , Male , Middle Aged
16.
Acta Neuropathol ; 115(6): 663-74, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18369646

ABSTRACT

The molecular signaling pathway linked to hypertrophy of the anti-gravity/postural soleus muscle after mechanical overloading has not been identified. Using reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunohistochemical analyses, we investigated whether the amounts of myocyte enhancer factor (MEF)2C, MEF2D, and myogenin change in the mechanically overloaded soleus muscle after treatment with the calcineurin inhibitor cyclosporine A (CsA). Adult male ICR mice were subjected to a surgical ablation of the gastrocnemius muscle and treated with either CsA (25 mg/kg) or vehicle, once daily. They were killed at 2, 4, 7, 10, and 14 days post-injury. Mechanical overloading resulted in a significant increase in the wet weight and the cross-sectional area of slow and fast fibers of the soleus muscle in placebo-treated mice but not CsA-treated mice. RT-PCR analysis did not show a marked difference in MEF2C and MEF2D mRNA levels in the overloaded soleus muscle in placebo- or CsA-administered mice. After 2 days of mechanical overloading, we observed co-localization of MEF2C and myogenin in several mononuclear cells under both conditions. These MEF2C-positive mononuclear cells also possessed immunoreactivity for c-Met, a satellite cell marker. At 4 days, mechanical overloading induced marked expression of MEF2C but not MEF2D in the subsarcolemmal region in a group of myotubes and/or myofibers. Such a MEF2C-positive region emerged less often in the hypertrophied soleus muscle subjected to the treatment with CsA. At 7 days, we observed many mononuclear cells possessing both MEF2C and myogenin protein in mice treated with CsA, but not the placebo. Our results demonstrated that CsA treatment modulates the amount and cellular localization of MEF2C protein. The modulation of MEF2C by CsA treatment may inhibit the hypertrophic process in the soleus muscle after mechanical overloading.


Subject(s)
Cyclosporine/pharmacology , Enzyme Inhibitors/pharmacology , Muscle Fibers, Skeletal/pathology , Muscle, Skeletal/drug effects , Myogenic Regulatory Factors/metabolism , Weight-Bearing/physiology , Analysis of Variance , Animals , Gene Expression Regulation/drug effects , Hypertrophy/prevention & control , Indoles , MEF2 Transcription Factors , Male , Mice , Mice, Inbred ICR , Muscle Fibers, Skeletal/drug effects , Muscle, Skeletal/pathology , Myogenic Regulatory Factors/genetics
17.
Biochim Biophys Acta ; 1760(6): 980-7, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16595164

ABSTRACT

Presenilin-1 and nicastrin, two components of gamma-secretase associated with Alzheimer's disease plaques, are present in the synapses of the brain and in various peripheral organs, including skeletal muscle. In the present study, we examined the expression pattern of presenilin-1 and nicastrin in normal and denervated hindlimb muscles of the rat. Using immunohistochemical approaches, we found that presenilin-1 and AChRalpha was co-localized at the neuromuscular junction in the normal skeletal muscles of rats. The immunoreactivities of both presenilin-1 and nicastrin were also observed at the sarcolemma of muscle fibers. We discovered that presenilin-1 mRNA and its protein are upregulated after denervation of the soleus and tibialis anterior muscles. Furthermore, clear co-localization between presenilin-1 and DAPI, but not nicastrin, was noted in several myonuclei in the denervated muscles. We recognized a few fibers possessing both ubiquitin and presenilin-1 protein in the cytosol. The amount of presenilin-1 in the nucleus and membrane fraction was more abundantly expressed in the denervated muscle fibers. In contrast, no significant difference in the nicastrin protein level was observed between normal and denervated muscle fibers. These data suggest that enhanced presenilin-1 protein may play a role in the degeneration and regeneration of skeletal muscle.


Subject(s)
Membrane Glycoproteins/metabolism , Membrane Proteins/metabolism , Muscle, Skeletal/innervation , Muscle, Skeletal/metabolism , Amyloid Precursor Protein Secretases , Animals , Cell Membrane/metabolism , Cell Nucleus/metabolism , Male , Membrane Glycoproteins/genetics , Membrane Glycoproteins/immunology , Membrane Proteins/genetics , Membrane Proteins/immunology , Muscle Denervation , Muscle, Skeletal/cytology , Presenilin-1 , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction
18.
Acta Neuropathol ; 110(3): 269-80, 2005 Sep.
Article in English | MEDLINE | ID: mdl-15986223

ABSTRACT

The molecular signaling pathway linked to muscle regeneration has not yet been identified. Previously, we demonstrated that mice treated with cyclosporin A (CsA), a calcineurin inhibitor, failed to regenerate normally after muscle damage. Using reverse transcription (RT)-PCR, Western blot and immunohistochemical analysis, we investigated whether the amounts of nuclear factor of activated T cells (NFAT), myocyte-enhancer factor 2 (MEF2), the MyoD family, Id-1, and Smad3 change in the regenerating muscle after CsA treatment. Adult male ICR mice were subjected to a bupivacaine injection into the tibialis anterior muscle, and were treated with either CsA (25 mg/kg) or vehicle once daily. They were killed at 1, 2, 4, 6, 9 and 14 days post injury. RT-PCR analysis did not show a significant difference in MEF2s, MyoD and myogenin mRNA levels in the regenerating muscle in either placebo- and CsA-administered mice. In contrast, a significant increase in MRF4 mRNA was seen in CsA-administered mice compared to the placebo-treated mice at 4 and 9 days post surgery. In CsA-treated mice, the level of Id1 mRNA was elevated at day 9 relative to the placebo-treated mice. After 6 days, the CsA-treated mice possessed more abundant proliferating cell nuclear antigen (PCNA) and cyclin D1 protein in many satellite cells and/or myoblast-like cells in the regenerating muscle. The amount of myostatin, TGF-beta2 and Smad3 mRNA and proteins was increased more markedly in the mice treated with CsA. After 9 days, many satellite cells and/or myoblasts showed apparent co-localization of both MyoD and Smad3 in CsA-, but not in placebo-, treated mice. Our results demonstrated that CsA treatment upregulates Id1 and Smad3 expression and delays skeletal muscle regeneration in vivo.


Subject(s)
Cyclosporine/pharmacology , Inhibitor of Differentiation Protein 1/genetics , Muscle, Skeletal/drug effects , Regeneration/drug effects , Smad3 Protein/genetics , Up-Regulation/drug effects , Animals , Cell Proliferation/drug effects , Cyclin D , Cyclins/metabolism , Enzyme Inhibitors/pharmacology , Growth Inhibitors/pharmacology , MEF2 Transcription Factors , Male , Mice , Mice, Inbred ICR , Muscle, Skeletal/cytology , Muscle, Skeletal/metabolism , MyoD Protein/metabolism , Myoblasts/drug effects , Myoblasts/metabolism , Myogenic Regulatory Factors/genetics , Myogenic Regulatory Factors/metabolism , Myostatin , NFATC Transcription Factors/metabolism , Proliferating Cell Nuclear Antigen/metabolism , RNA, Messenger/drug effects , RNA, Messenger/metabolism , Regeneration/physiology , Satellite Cells, Skeletal Muscle/drug effects , Satellite Cells, Skeletal Muscle/metabolism , Signal Transduction/drug effects , Signal Transduction/physiology , Transforming Growth Factor beta/pharmacology
19.
Acta Neuropathol ; 108(3): 241-9, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15221330

ABSTRACT

Laminin alpha2 (merosin)-deficient congenital muscular dystrophy (CMD) patients show progressive muscle fiber necrosis and ineffective muscle regeneration. This is probably due to decreased formation of multi nucleated myotubes resulting from a myoblast fusion defect. When receiving a mechanical signal from muscle membranes, a cascade of RhoA, focal adhesion kinase (FAK), and serum response factor (SRF) positively regulates myogenesis and muscle hypertrophy associated with functional overload. In contrast, myostatin, a potent negative regulator of skeletal muscle hypertrophy, appears to be up-regulated in the muscles of mdx mice, an animal model for Duchenne muscular dystrophy. Using Western blot and immunohistochemical analyses, we investigated the levels of RhoA, FAK, SRF, and myostatin in the skeletal muscles of dy mice. The amount of RhoA protein was increased in the hindlimb muscles of dy mice aged 12 weeks. At 12 weeks, FAK immunoreactivity was observed in the myonuclei and/or satellite cells of normal mice, but not of dy mice. SRF protein levels decreased markedly in the gastrocnemius and rectus femoris muscles of dy mice at 2 and 12 weeks. Several muscle fibers in normal mice possessed uniform SRF immunoreactivity in the cytoplasm. An SRF immunostaining pattern in muscle was not detected in dy mice. Western blot and the densitometric analysis showed a decreased amount of myocyte enhancer factor 2C (MEF2C) in hindlimb muscles of dy mice. Although slight myostatin immunoreactivity was observed in the nuclei of some normal mice, marked myostatin immunoreactivity was observed in the cytoplasm of mature dy mice myonuclei and/or satellite cells. A low expression of FAK, SRF and MEF2C in muscles of dy mice may inhibit postnatal muscle hypertrophy by fusing satellite cells with existing fibers. Enhancing myostatin protein would result in further atrophy and degeneration of muscle fiber in dy mice.


Subject(s)
Muscle, Skeletal/metabolism , Muscular Dystrophy, Animal/metabolism , Myogenic Regulatory Factors/metabolism , Protein-Tyrosine Kinases/metabolism , Serum Response Factor/metabolism , rhoA GTP-Binding Protein/metabolism , Animals , Blotting, Western , Disease Models, Animal , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Hindlimb/physiology , Immunohistochemistry , Integrin beta Chains , MEF2 Transcription Factors , Mice , Muscle, Skeletal/chemistry , Muscle, Skeletal/pathology , Myostatin , Signal Transduction/physiology , Transforming Growth Factor beta/metabolism
20.
Histochem Cell Biol ; 119(2): 149-60, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12610734

ABSTRACT

Molecular signaling pathways linking the hypertrophy after mechanical overloading in vivo have not been identified. Using western blot analysis, immunoprecipitation, and immunohistochemistry, we investigated the effect of the mechanical overloading state on RhoA, serum response factor (SRF), and MyoD in the rat plantaris muscle. Adult male rats (10 weeks of age) were used in this experiment. Compensatory enlargement of the plantaris muscle was induced in one leg of each rat by surgical removal of the ipsilateral soleus and gastrocnemius muscles. In the normal plantaris muscle of rats, slight expression of RhoA and SRF was observed in the quiescent satellite cells possessing CD34 and c-Met. Western blotting using the homogenate of whole muscle clearly showed that mechanical overloading of the plantaris muscle significantly increased the amount of RhoA during 3-6 days postsurgery. Threonine phosphorylation of SRF occurred at 2-4 h after mechanical overloading. The most marked increase in SRF protein was observed in the hypertrophied muscle at 6 days postsurgery. At 2 days postoperation, SRF immunoreactivity was not detected in the proliferating satellite cells possessing bromodeoxyuridine and in the infiltrating macrophages expressing ED1 in the overloaded muscle by surgical removal. The SRF protein was colocalized with RhoA, FAK, and myogenin but not Myf-5 in many mononuclear cells at 6 days of functional overload. At this time, MyoD immunoreactivity was detected in the cytoplasm of mononuclear cells (possibly satellite cell-derived myoblasts) possessing SRF protein at the nucleus. These results suggest that the signaling pathway through RhoA-FAK-SRF is important to the differentiation of satellite cells by interacting MyoD and myogenin in the hypertrophied muscle of rats.


Subject(s)
Adaptation, Physiological , Muscle, Skeletal/metabolism , Serum Response Factor/metabolism , Weight-Bearing/physiology , Animals , Blotting, Western , Disease Models, Animal , Hypertrophy , Immunoblotting , Immunohistochemistry , Male , Muscle, Skeletal/pathology , MyoD Protein/metabolism , Rats , Satellite Cells, Skeletal Muscle/metabolism , Satellite Cells, Skeletal Muscle/pathology , Stress, Mechanical , rhoA GTP-Binding Protein/metabolism
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