Extracellular histones are a damage-associated molecular pattern (DAMP) involved in the pathogenesis of various diseases. The mechanisms of histone-mediated injury in certain organs have been ...extensively studied, but an understanding of the pathophysiological role of histone-mediated injury in multiple organ injury remains elusive. To elucidate this role, we systemically subjected C57BL/6 mice to various doses of histones and performed a chronological evaluation of the morphological and functional changes in the lungs, liver, and kidneys. Notably, histone administration ultimately led to death after a dose-dependent aggravation of multiple organ injury. In chronological studies, pulmonary and hepatic injuries occurred within 15 minutes, whereas renal injuries presented at a later phase, suggesting that susceptibility to extracellular histones varies among organs. Histones bound to pulmonary and hepatic endothelial cells immediately after administration, leading to endothelial damage, which could be ameliorated by pretreatment with heparin. Furthermore, release of another DAMP, high-mobility group protein box 1, followed the histone-induced tissue damage, and an antibody against the molecule ameliorated hepatic and renal failure in a late phase. These findings indicate that extracellular histones induce multiple organ injury in two progressive stages—direct injury to endothelial cells and the subsequent release of other DAMPs—and that combination therapies against extracellular histones and high-mobility group protein box 1 may be a promising strategy for treating multiple organ injury.
Sudden infant death syndrome (SIDS) remains a leading cause of infant death in high-income countries. Supporting models for categorization of sudden unexpected infant death into SIDS/non-SIDS could ...reduce mortality. Therefore, we aimed to develop such a tool utilizing forensic data, but the reduced number of SIDS cases renders this task inherently difficult. To overcome this, we constructed Bayesian network models according to diagnoses performed by expert pathologists and created conditional probability tables in a proof-of-concept study. In the diagnostic support model, the data of 64 sudden unexpected infant death cases was employed as the training dataset, and 16 known-risk factors, including age at death and co-sleeping, were added. In the validation study, which included 8 new cases, the models reproduced experts' diagnoses in 4 or 5 of the 6 SIDS cases. Next, to confirm the effectiveness of this approach for onset prediction, the data from 41 SIDS cases was employed. The model predicted that the risk of SIDS in 0- to 2-month-old infants exposed to passive smoking and co-sleeping is eightfold higher than that in the general infant population, which is comparable with previously published findings. The Bayesian approach could be a promising tool for constructing SIDS prevention models.
Aim
The mitochondria are highly plastic and dynamic organelles; mitochondrial dysfunction has been reported to play causative roles in diabetes, cardiovascular diseases, and nonalcoholic fatty liver ...disease (NAFLD). However, the relationship between mitochondrial fission and NAFLD pathogenesis remains unknown. We aimed to investigate whether alterations in mitochondrial fission could play a role in the progression of NAFLD.
Methods
Mice were fed a standard diet or choline‐deficient, L‐amino acid‐defined (CDAA) diet with vehicle or mitochondrial division inhibitor‐1.
Results
Substantial enhancement of mitochondrial fission in hepatocytes was triggered by 4 weeks of feeding and was associated with changes reflecting the early stage of human nonalcoholic steatohepatitis (NASH), steatotic change with liver inflammation, and hepatocyte ballooning. Excessive mitochondrial fission inhibition in hepatocytes and lipid metabolism dysregulation in adipose tissue attenuated liver inflammation and fibrogenesis but not steatosis and the systemic pathological changes in the early and chronic fibrotic NASH stages (4‐ and 12‐week CDAA feeding). These beneficial changes due to the suppression of mitochondrial fission against the liver and systemic injuries were associated with decreased autophagic responses and endoplasmic reticulum stress in hepatocytes. Injuries to other liver cells, such as endothelial cells, Kupffer cells, and hepatic stellate cells, were also attenuated by the inhibition of mitochondrial fission in hepatocytes.
Conclusions
Taken together, these findings suggest that excessive mitochondrial fission in hepatocytes could play a causative role in NAFLD progression by liver inflammation and fibrogenesis through altered cell cross‐talk. This study provides a potential therapeutic target for NAFLD.
The pathogenesis of renal impairment in chronic liver diseases (CLDs) has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early ...phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy), autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the pathophysiological mechanisms of sublethal tubular cell injury.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Few proteomic studies have examined human cardiac tissue following acute lethal infarction. Here, we applied a novel proteomic approach to formalin‐fixed, paraffin‐embedded human tissue ...and aimed to reveal the molecular changes in the very early phase of acute myocardial infarction.
Methods and Results
Heart tissue samples were collected from 5 patients who died within 7 hours of myocardial infarction and from 5 age‐ and sex‐matched control cases. Infarcted and control myocardia were histopathologically diagnosed and captured using laser microdissection. Proteins were extracted using an originally established method and analyzed using liquid chromatography–tandem mass spectrometry. The label‐free quantification demonstrated that the levels of 21 proteins differed significantly between patients and controls. In addition to known biomarkers, the sarcoplasmic protein sorbin and SH3 domain‐containing protein 2 (SORBS2) was greatly reduced in infarcted myocardia. Immunohistochemical analysis of cardiac tissues confirmed the decrease, and Western blot analysis showed a significant increase in serum sorbin and SH3 domain‐containing protein 2 in acute myocardial infarction patients (n=10) compared with control cases (n=11).
Conclusions
Our advanced comprehensive analysis using patient tissues and serums indicated that sarcoplasmic sorbin and SH3 domain‐containing protein 2 is released from damaged cardiac tissue into the bloodstream upon lethal acute myocardial infarction. The proteomic strategy presented here is based on precise microscopic findings and is quite useful for candidate biomarker discovery using human tissue samples stored in depositories.
Fulminant type 1 diabetes, established in 2000, is defined as a novel subtype of diabetes mellitus that results from remarkably acute and almost complete destruction of pancreatic beta cells at the ...disease onset. In this study, we aimed to clarify the pathogenesis of fulminant type 1 diabetes with special reference to insulitis and viral infection. We examined pancreatic autopsy samples from three patients who had died soon after the onset of disease and analyzed these by immunohistochemistry and in situ-hybridization. The results were that both beta and alpha cell areas were significantly decreased in comparison with those of normal controls. Mean beta cell area of the patients just after the onset was only 0.00256 % while that of normal control was 1.745 %. Macrophages and T cells-but no natural killer cells-had infiltrated the islets and the exocrine pancreas. Although both of them had massively infiltrated, macrophages dominated islet infiltration and were detected in 92.6 % of the patients' islets. Toll-like receptor (TLR) 3, a sensor of viral components, was detected in 84.7± 7.0 % of T cells and 62.7± 32.3 % of macrophages (mean± SD) in all three patients. TLR7 and TLR9 were also detected in the pancreas of all three patients. Enterovirus RNA was detected in beta-cell positive islets in one of the three patients by in situ-hybridization. In conclusion, our results suggest that macrophage-dominated insulitis rather than T cell autoimmunity contributes to beta cell destruction in fulminant type 1 diabetes.
ABSTRACTTriphenyltetrazolium chloride (TTC) is one of the most conventional stains to detect infarcted area of the heart in animal experiments. However, its availability and limitations have not been ...thoroughly discussed in the forensic field. Here, authors stained human hearts with TTC soon after the harvest. Photographs of the samples were analyzed using image analysis software, which evaluated the occupying ratio of the stained area on the surface of each slice. The results showed that the stainability of TTC declines with the length of the postmortem interval (PMI). Specimens reacted well to TTC within 1.5 days after death and then decreased the stainability logarithmically with PMI (y = − 0.294 In (x) + 1.0441; x = PMI, y = TTC-stained area / total myocardial area, R = 0.5673). Samples with old myocardial infarction produced clear TTC contrast; normal tissue is vivid red, and fibrotic myocardium is white discoloration. In acute myocardial infarction cases where death occurred within 9 hours after the attack, however, the detection of infarcted area was very difficult even when PMI was less than 1.5 days. In summary, the TTC method may be useful within 1.5 days after death, but short suffering period before death disturbs its staining efficiency.
Abstract Background The bile canaliculus is the smallest and first biliary channel and is formed by two or three adjacent hepatocytes. Previous studies of chronic cholangiopathies such as primary ...sclerosing cholangitis have focused on the bile ductules. However, little is known about the pathological alterations in bile canaliculi in the early phase of cholangiopathies. Aim To characterize the bile canalicular morphology in the early phase of sclerosing cholangitis we used 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced mouse model of sclerosing cholangitis. Methods Mice were fed a diet with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (0.1%). Serum biochemical, histological, immunohistochemical, and electron microscopic analyses were performed 1, 2, 4, and 7 days after feeding. Results All experimental groups showed significantly increased serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels. From day 1, bile canalicular abnormalities such as dilatation and meandering and loss of microvilli were observed. After bile canalicular abnormalities had appeared, substantial infiltration of inflammatory cells was observed amongst the necrotic cells and periductal region. After these inflammatory changes, cholangiocytes proliferated in the portal area and formed ductular reactions. Finally, periductal fibrosis appeared. Conclusion This study provides novel evidence of the occurrence of bile canalicular abnormalities during the early phase of sclerosing cholangitis.
Liver sinusoidal endothelial cells (LSECs) are involved in the transport of nutrients, lipids, and lipoproteins, and LSEC injury occurs in various liver diseases including nonalcoholic fatty liver ...disease (NAFLD). However, the association between LSEC injury and NAFLD progression remains elusive. Accordingly, in this study, we aimed to elucidate the precise role of LSEC in the pathophysiology of NAFLD using two different mouse models, namely the choline-deficient, L-amino acid-defined and high-fat diet models. Administration of these diets resulted in liver metabolic dysregulation mimicking human NAFLD, such as steatosis, ballooning, lobular inflammation, and fibrosis, as well as central obesity, insulin resistance, and hyperlipidemia. LSEC injury appeared during the simple steatosis phase, and preceded the appearance of activated Kupffer cells and hepatic stellate cells (HSCs). These results indicate that LSEC injury may have a ‘gatekeeper' role in the progression from simple steatosis to the early nonalcoholic steatohepatitis (NASH) stage, and LSEC injury may be necessary for the activation of Kupffer cells and HSCs, which in turn results in the development and perpetuation of chronic liver injuries. Taken together, our data provide new insights into the role of LSEC injury in NAFLD/NASH pathogenesis.
Little is known about the relationship between splenic arteriolar hyaline and cause of death. The purpose of this retrospective study was to evaluate the clinicopathological significance of splenic ...arteriolar hyaline in autopsy cases and estimate the applicability of hyaline for diagnosing the cause and rapidity of death.
Archival data and histological slides from 82 cases were reviewed retrospectively. One section of each spleen was evaluated microscopically. The tinctorial pattern of splenic arteriolar hyaline was examined with Heidenhain's Azan trichrome stain, and the relationships between this pattern and age, cause of death, and rapidity of death were investigated.
Fifty-four cases demonstrated hyaline change, with 3 different tinctorial patterns: red, blue, and a combination of red and blue. The 3 patterns coexisted in various proportions in each tissue section. Frequency of the blue pattern increased with age (P < 0.01) and was unrelated to cause of death. By contrast, the red pattern was unrelated to age and appeared with different frequency according to cause of death. The red pattern appeared with significantly higher frequency in the circulatory disease group and the drowning and asphyxia group (both P < 0.01). Moreover, the presence of the red pattern had high specificity for the detection of rapidly fatal cases. The combination of the 2 colors was excluded from clinicopathological analyses due to its admixed nature.
Estimation of splenic arteriolar hyaline with Heidenhain's Azan trichrome stain is useful for assessment of the cause and rapidity of death.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1132441651796836.
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