Cellular Edema Research Articles

Low-intensity open-field blast exposure effects on neurovascular unit ultrastructure in mice

Mild traumatic brain injury (mTBI) induced by low-intensity blast (LIB) is a serious health problem affecting military service members and veterans. Our previous reports using a single open-field LIB mouse model showed the absence of gross microscopic damage or necrosis in the brain, while transmission electron microscopy (TEM) identified ultrastructural abnormalities of myelin sheaths, mitochondria, and synapses. The neurovascular unit (NVU), an anatomical and functional system with multiple components, is vital for the regulation of cerebral blood flow and cellular interactions. In this study, we delineated ultrastructural abnormalities affecting the NVU in mice with LIB exposure quantitatively and qualitatively. Luminal constrictive irregularities were identified at 7 days post-injury (DPI) followed by dilation at 30 DPI along with degeneration of pericytes. Quantitative proteomic analysis identified significantly altered vasomotor-related proteins at 24 h post-injury. Endothelial cell, basement membrane and astrocyte end-foot swellings, as well as vacuole formations, occurred in LIB-exposed mice, indicating cellular edema. Structural abnormalities of tight junctions and astrocyte end-foot detachment from basement membranes were also noted. These ultrastructural findings demonstrate that LIB induces multiple-component NVU damage. Prevention of NVU damage may aid in identifying therapeutic targets to mitigate the effects of primary brain blast injury.

Effect of caffeine on hippocampal memory and levels of gene expression in social isolation stress.

Caffeine (Cf) antagonizes the adenosine receptors and has neuroprotective properties. The effect of Cf has been seen on stress-induced deficits of cognitive. In this study, we have investigated the effect of Cf on learning and memory functions induced by social isolation (SI) stress. In the present study, 21-day-old Wistar albino male rats (n = 28) were divided into four groups: the control (C), the SI, the Cf, and the social isolation + caffeine (SICf). Cf (0.3 g/L) was added to the drinking water of the experimental animals for 4weeks. The learning and memory functions were assessed using the Morris Water Maze Test (MWMT). Following, was performed histopathological evaluation and determined hippocampal gene expression levels by RT-qPCR. According to MWMT findings, the time spent in the quadrant where the platform removed was decreased in the SI group compared with the C (p < 0.05). Histological evaluation showed morphological changes in SI by irregular appearance, cellular edema, and dark pycnotic appearance of nuclei in some neurons. However, it was observed that the histological structure of most of the neurons in the SICf group was similar to the C and Cf groups. Hippocampal SNAP25 expression was decreased in the Cf and SICf groups than in the C group (p < 0.05). The GFAP expression was increased in the SICf group than in the C group (p < 0.05). NR2A increased in the SI and SICf groups compared with C and Cf groups (p < 0.05). NR2B expression decreased in the Cf group compared with C and SI groups (p < 0.05). SI impaired spatial memory and causes morphological changes in adolescent rats, but this effect of isolation was not seen in Cf-treated animals. The effects of SI on NR2A, Cf on NR2B, and SNAP25 are remarkable. Here, we propose that the impaired effect of SI on spatial memory may be mediated by NR2A, but further studies are needed to explain this effect.

Underlying mechnism of electroacupuncture for treating detrusor hyperreflexia after suprasacral spinal cord injury through the PACAP-cAMP signaling pathway: 基于PACAP-cAMP信号通路研究电针治疗骶上脊髓损伤后逼尿肌反射亢进型膀胱的效应机制

ObjectiveTo elucidate the underlying mechanism and effect of electroacupuncture (EA) on the neurogenic bladder following suprasacral spinal cord injury (SSCI). A rat model of detrusor hyperreflexia after SSCI was established to examine the urodynamics, detrusor muscle tissue morphology, the protein and mRNA expression levels of pituitary adenylate cyclase activating peptide (PACAP) and its receptor PAC1R, and cyclic adenosine monophosphate (cAMP) content in the detrusor muscle with a focus on the PACAP-cAMP signaling pathway. MethodA total of 72 female SD rats were randomized into control group and sham operation group (n=12 per group) by using a random number table. The remaining 48 rats were established into the model of detrusor hyperreflexia after SSCI. After successful modeling, these rats were randomly assigned to model, EA, and EA + PACAP6-38 groups (n=12 per group). The unsuccessful modeled rats were used for exploratory observation. For the rats in EA group, “Ciliao (BL32)” “Zhongji (CV3)”, and “Sanyinjiao (SP6)” were needled and stimulated by EA. The PACAP receptor antagonist PACAP6-38 was administered intraperitoneally in the EA + PACAP6-38 group before EA, and EA was applied for seven consecutive days. After treatment, the urodynamics of the rats were analyzed, and hematoxylin and eosin staining was used to examine rat bladder detrusor tissue morphology. The expressions of PACAP-38 and PAC1R were detected by immunohistochemistry and Western blot. The mRNA expression levels of PACAP-38 and PAC1R were examined by RT-qPCR, while cAMP content was detected by ELISA. Results(1) Compared with sham operation group, it was exhibited disarray in the transitional epithelium cells of the bladder in the modeled rats. The intercellular space was significantly widened, accompanied by inflammatory cell infiltration and noticeable tissue edema. Both the bladder initial pressure and leak point pressure of the rats were higher (P < 0.01), whereas the maximum cystometric capacity and bladder compliance were lower (P < 0.01). The protein and mRNA expression levels of PACAP-38 and PAC1R in the detrusor muscle, together with the cAMP content, were lower (P < 0.05). (2) Compared with the model rats, the EA group showed reduced inflammatory response in the detrusor muscle tissue, with decreased monocyte infiltration and less severe tissue edema. The bladder smooth muscle cells exhibited increased integrity, and there was decreased cellular tissue edema, inflammatory cell infiltration, and fibroplasia. The bladder initial pressure and leak point pressure were lower (P < 0.05), while the maximum cystometric capacity and bladder compliance were higher (P < 0.01). The protein and mRNA expression levels of PACAP-38 and PAC1R in the detrusor muscle, along with the cAMP content, were higher (P < 0.05). (3) Compared to the EA group, the EA + PACAP6-38 group showed a less organized arrangement of muscle fibers in the detrusor muscle tissue, larger intercellular space, monocyte infiltration, and considerable tissue edema. The changes in bladder initial pressure and leak point pressure were not significant (P > 0.05), while the maximum cystometric capacity and bladder compliance were lower (P < 0.05). The changes in the protein and mRNA expressions of PACAP-38 within the detrusor muscle were not significant (P > 0.05), whereas the protein and mRNA expressions of PAC1R were reduced (P < 0.05), and the cAMP content within the detrusor muscle was lower (P < 0.05). ConclusionEA can ameliorate the uninhibited contractile condition of the detrusor muscle in the bladder following SSCI. By mediating the PACAP-cAMP signaling pathway, it reduces the pathological damage to the detrusor muscle, thereby improving bladder function.

Cation flux through SUR1-TRPM4 and NCX1 in astrocyte endfeet induces water influx through AQP4 and brain swelling after ischemic stroke.

Brain swelling causes morbidity and mortality in various brain injuries and diseases but lacks effective treatments. Brain swelling is linked to the influx of water into perivascular astrocytes through channels called aquaporins. Water accumulation in astrocytes increases their volume, which contributes to brain swelling. Using a mouse model of severe ischemic stroke, we identified a potentially targetable mechanism that promoted the cell surface localization of aquaporin 4 (AQP4) in perivascular astrocytic endfeet, which completely ensheathe the brain's capillaries. Cerebral ischemia increased the abundance of the heteromeric cation channel SUR1-TRPM4 and of the Na+/Ca2+ exchanger NCX1 in the endfeet of perivascular astrocytes. The influx of Na+ through SUR1-TRPM4 induced Ca2+ transport into cells through NCX1 operating in reverse mode, thus raising the intra-endfoot concentration of Ca2+. This increase in Ca2+ stimulated calmodulin-dependent translocation of AQP4 to the plasma membrane and water influx, which led to cellular edema and brain swelling. Pharmacological inhibition or astrocyte-specific deletion of SUR1-TRPM4 or NCX1 reduced brain swelling and improved neurological function in mice to a similar extent as an AQP4 inhibitor and was independent of infarct size. Thus, channels in astrocyte endfeet could be targeted to reduce postischemic brain swelling in stroke patients.

Hepatocytic ballooning in non-alcoholic steatohepatitis: Dilemmas and future directions.

Hepatocytic ballooning is a key histological feature in the diagnosis of non-alcoholic steatohepatitis (NASH) and is an essential component of the two most widely used histological scoring systems for diagnosing and staging non-alcoholic fatty liver disease (NAFLD) [namely, the NAFLD activity score (NAS), and the steatosis, activity and fibrosis (SAF) scoring system]. As a result of the increasing incidence of NASH globally, the diagnostic challenges of hepatocytic ballooning are unprecedented. Despite the clear pathological concept of hepatocytic ballooning, there are still challenges in assessing hepatocytic ballooning in 'real life' situations. Hepatocytic ballooning can be confused with cellular oedema and microvesicular steatosis. Significant inter-observer variability does exist in assessing the presence and severity of hepatocytic ballooning. In this review article, we describe the underlying mechanisms associated with hepatocytic ballooning. Specifically, we discuss the increased endoplasmic reticulum stress and the unfolded protein response, as well as the rearrangement of the intermediate filament cytoskeleton, the appearance of Mallory-Denk bodies and activation of the sonic Hedgehog pathway. We also discuss the use of artificial intelligence in the detection and interpretation of hepatocytic ballooning, which may provide new possibilities for future diagnosis and treatment.

Relationship between edema and intracranial pressure following intracerebral hemorrhage in rat

Elevated intracranial pressure (ICP) is a potentially fatal consequence of intracerebral hemorrhage (ICH). As the mass of the hematoma and regional edema builds, ICP rises and becomes increasingly variable acutely after stroke. High ICP may worsen cellular injury and edema by impairing local tissue perfusion, fueling a cycle that may ultimately cause fatality through ischemia and brain herniation. Time spent above an ICP of 20 mmHg often predicts a greater risk of death and disability following ICH. Compensatory mechanisms combat rising ICP. Classically, these include cerebrospinal fluid volume loss and cerebrovascular autoregulation, such as a reduction in the volume of venous blood. Additional mechanisms such as brain tissue compliance and skull volume compensation may also contribute. Compensatory compliance mechanisms are limited, and they vary by age and many other factors. Animal models of ICH are widely used to assess these variables and to gauge putative therapeutics. Most often those studies rely upon simple measures of edema, which may not accurately predict ICP data. Thus, we analyzed our past studies characterizing ICP, edema, and tissue compliance responses to striatal ICH in rat, including the collagenase (C-ICH) and whole blood models (WB-ICH). We found that both ICH models raised ICP, with greater effects in the C-ICH model, which may thus better reflect clinical findings of concern. Importantly, measures of edema, such as in the damaged hemisphere, on their own are not predictive of average or peak ICP response within either model, unless assessing across a very wide range of injury severities, or when including non-stroke animals. We caution against using edema data as a surrogate measure of mass effect and ICP following ICH.

Effect of ischemic preconditioning on skeletal tissue tolerance after warm venous ischemia

Free muscular flaps are commonly used in plastic surgery. The main reason of failure is thrombosis induced by a phenomenon called ischemia reperfusion. Preconditioning showed an interest to prevent ischemia reperfusion injury in transplantation surgery. The aim of the study is to evaluate the effect of ischemic preconditioning on skeletal tissue tolerance after warm venous ischemia. We realized an experimental study with latissimus dorsi flaps of 12 pigs, divided in 6 groups in function of their time of preconditioning and duration of warm venous ischemia. A morphologic analysis was performed measuring cell's diameter and interstitial tissue area and notifying the presence or absence of neutrophils, necrosis or intravascular thrombosis. To detect inflammation, necrosis or hypoxia, immunohistochemistry was effectuated using the follow primary antibodies, AIF, HIF1 alpha, caspase 3, SOD 1 and PKC epsilon. TUNEL assay showed apoptosis cells, were realized. One way Anova test was performed to compare the quantitative evolution over time of histological parameters and rate of apoptosis. Preconditioning of 40min or 1hour allowed to reduced ischemia reperfusion lesions: no cellular or interstitial oedema, reduction of neutrophils infiltrate and intravascular thrombus. TUNEL assay showed a higher rate of apoptosis nucleus for the control group E compared to preconditioning group C and D. Immunohistochemistry results were no relevant. We showed a diminution of lesions of ischemia reperfusion for experimental groups with preconditioning: diminution of interstitial oedema, of cellular oedema, diminution of neutrophils infiltrated and level of apoptosis cells. Preconditioning of 40minutes were as efficient as one hour.

Experimental Yellow Fever in Squirrel Monkey: Characterization of Liver In Situ Immune Response.

Non-human primates contribute to the spread of yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas, such as Brazil. This study aims to investigate virological, histopathological and immunohistochemical findings in livers of squirrel monkeys (Saimiri spp.) infected with the YFV. Viremia occurred 1-30 days post infection (dpi) and the virus showed a predilection for the middle zone (Z2). The livers were jaundiced with subcapsular and hemorrhagic multifocal petechiae. Apoptosis, lytic and coagulative necrosis, steatosis and cellular edema were also observed. The immune response was characterized by the expression of S100, CD11b, CD57, CD4 and CD20; endothelial markers; stress and cell death; pro and anti-inflammatory cytokines, as well as Treg (IL-35) and IL-17 throughout the experimental period. Lesions during the severe phase of the disease were associated with excessive production of apoptotic pro-inflammatory cytokines, such as IFN-γ and TNF-α, released by inflammatory response cells (CD4+ and CD8+ T lymphocytes) and associated with high expression of molecules of adhesion in the inflammatory foci observed in Z2. Immunostaining of the local endothelium in vascular cells and the bile duct was intense, suggesting a fundamental role in liver damage and in the pathogenesis of the disease.

PS-C02-10: IMPACT OF SARCOPENIA AND ATRIAL FIBRILLATION ON THE INCIDENCE OF HEART FAILURE IN ELDERLY PATIENTS

Objective: Sarcopenia is an age-dependent skeletal muscle disorder that is associated with multiple adverse outcomes including cardiovascular events. Sarcopenia can influence the outcomes of patients with heart failure, myocardial infarctions, and atrial fibrillation (AF). This study aimed to clarify the clinical significance of sarcopenia in the incidence of heart failure in elderly individuals. Design and method: A total of 118 elderly participants with cardiovascular risk factors (mean age 76.7 years old) were included in the study. The body composition including the skeletal muscle mass index (SMI), body fat percentage, ratio of extracellular water to the total body water (ECW/TBW), and phase angle were measured using a multifrequency bioelectrical impedance analysis (BIA). Sarcopenia was defined according to the criteria of the Asian Working Group, which involves a low grip strength or slow gait speed and low SMI. Heart failure (HF) was defined according to the Framingham criteria. Statistical associations between those BIA-related parameters and the incidence of HF were evaluated by multiple logistic regression analysis. The threshold for a statistical significance was set at p &lt; 0.05. Result: Sarcopenia was observed in 33 subjects (28.0%) and AF was observed in 29 (25.4%) of 118 participants. The ECW/TBW, which reflected cellular edema, was higher in patients with HF than in those without whereas the body fat percentage and phase angle did not differ between the patients with and without HF. Although AF was associated with the incidence of HF and sarcopenia was not associated with it, concomitant sarcopenia and AF, was associated with the incidence of HF than sarcopenia or AF alone. A multiple logistic regression analysis showed that AF accompanied with sarcopenia and ECW/TBW were significantly and positively associated with the incidence of HF independently of the age, gender, and other cardiovascular risk factors. Conclusion: In the present study, AF complicated with sarcopenia and cellular edema increased the incidence of HF in elderly individuals with cardiovascular risk factors. The obtained results suggested that the management of sarcopenia and cellular edema is a critical problem for the prevention of HF in elderly patients with AF.

“Fishcide” effect of the fungicide difenoconazole in freshwater fish (Labeo rohita): A multi-endpoint approach

Difenoconazole is widely used to protect crops, fruits, and vegetables. However, this fungicide can enter aquatic environments and cause harmful effects to non-target organisms and induce little-known biological disorders. Thus, aiming to expand our knowledge about the ecotoxicity of difenoconazole on freshwater ichthyofauna, we aimed to determine the median lethal concentration (LC50) of difenoconazole and evaluate its possible impacts from different toxicity biomarkers, using freshwater fish Labeo rohita as a model system. Using the probit analysis method, the 96 h LC50 value of difenoconazole in the fish was calculated as 4.5 mg L−1. Posteriorly, fish were exposed to two sublethal concentrations (0.45 mg L−1 1/10th and 0.9 mg L−1 1/5th LC50 value) for 21 days. A significant reduction of superoxide dismutase (SOD) and catalase (CAT) activity was noted in the gill, liver, and kidneys of fish compared to the control groups. The level of glutathione-S-transferase (GST) and lipid peroxidation (LPO) activity was higher in all vital tissues of difenoconazole-treated fish. Histological alterations in the gill include epithelial lifting, lamellar fusion, hypertrophy, and epithelial necrosis. At the same time, the liver showed pyknotic nucleus, vacuolation, cellular edema and tubular necrosis, shrinkage of glomeruli, vacuolation, and pyknotic nuclei in the kidney. DNA damage was increased significantly with tail formation based on the concentration and time-dependent manner. Therefore, our study confirms that the exposure of L. rohita to difenoconazole induces negative biological consequences and sheds light on the danger of this fungicide for freshwater fish species. We believe that studies like ours can support actions and strategies for the remediation/mitigation of aquatic pollution by difenoconazole and for the conservation of freshwater ichthyofauna.

A Comprehensive Review of Pediatric Acute Encephalopathy.

Acute encephalopathy typically affects previously healthy children and often results in death or severe neurological sequelae. Acute encephalopathy is a group of multiple syndromes characterized by various clinical symptoms, such as loss of consciousness, motor and sensory impairments, and status convulsions. However, there is not only localized encephalopathy but also progression from localized to secondary extensive encephalopathy and to encephalopathy, resulting in a heterogeneous clinical picture. Acute encephalopathy diagnosis has advanced over the years as a result of various causes such as infections, epilepsy, cerebrovascular disorders, electrolyte abnormalities, and medication use, and new types of acute encephalopathies have been identified. In recent years, various tools, including neuroradiological diagnosis, have been developed as methods for analyzing heterogeneous acute encephalopathy. Encephalopathy caused by genetic abnormalities such as CPT2 and SCN1A is also being studied. Researchers were able not only to classify acute encephalopathy from image diagnosis to typology by adjusting the diffusion-weighted imaging/ADC value in magnetic resonance imaging diffusion-weighted images but also fully comprehend the pathogenesis of vascular and cellular edema. Acute encephalopathy is known as a very devastating disease both medically and socially because there are many cases where lifesaving is sometimes difficult. The overall picture of childhood acute encephalopathy is becoming clearer with the emergence of the new acute encephalopathies. Treatment methods such as steroid pulse therapy, immunotherapy, brain hypothermia, and temperature control therapy have also advanced. Acute encephalopathy in children is the result of our predecessor’s zealous pursuit of knowledge. It is reasonable to say that it is a field that has advanced dramatically over the years. We would like to provide a comprehensive review of a pediatric acute encephalopathy, highlighting advancements in diagnosis and treatment based on changing disease classification scenarios from the most recent clinical data.

AQP4-A25Q Point Mutation in Mice Depolymerizes Orthogonal Arrays of Particles and Decreases Polarized Expression of AQP4 Protein in Astrocytic Endfeet at the Blood-Brain Barrier.

Aquaporin-4 (AQP4) is characterized by the formation of orthogonal arrays of particles (OAPs) comprising its M1 and M23 isoforms in the plasma membrane. However, the biological importance of OAP formation is obscure. Here, we developed an OAP depolymerization male mouse model by transgenic knock-in of an AQP4-A25Q mutation. Analyses of the mutant brain tissue using blue native polyacrylamide gel electrophoresis, super-resolution imaging, and immunogold electron microscopy revealed remarkably reduced OAP structures and glial endfeet localization of the AQP4-A25Q mutant protein without effects on its overall mRNA and protein expression. AQP4A25Q/A25Q mice showed better survival and neurologic deficit scores when cerebral edema was induced by water intoxication or middle cerebral artery occlusion/reperfusion. The brain water content and swelling of pericapillary astrocytic endfeet processes in AQP4A25Q/A25Q mice were significantly reduced, functionally supporting decreased AQP4 protein expression at the blood-brain barrier. The infarct volume and neuronal damage were also reduced in AQP4A25Q/A25Q mice in the middle cerebral artery occlusion/reperfusion model. Astrocyte activation in the brain was alleviated in AQP4A25Q/A25Q mice, which may be associated with decreased cell swelling. We conclude that the OAP structure of AQP4 plays a key role in its polarized expression in astrocytic endfeet processes at the blood-brain barrier. Therefore, our study provided new insights into intervention of cerebral cellular edema caused by stroke and traumatic brain injury through regulating AQP4 OAP formation.SIGNIFICANCE STATEMENT Aquaporin-4 (AQP4) is characterized by orthogonal arrays of particles (OAPs) comprising the M1 and M23 isoforms in the membrane. Here, an OAP depolymerization male mouse model induced by AQP4-A25Q mutation was first established, and the functions of OAP depolymerization in cerebral edema have been studied. The results revealed that AQP4 lost its OAP structure without affecting AQP4 mRNA and protein levels in AQP4-A25Q mice. AQP4-A25Q mutation mice has neuroprotective effects on cerebral edema induced by water intoxication and middle cerebral artery occlusion/reperfusion through relieving the activation of astrocytes and suppressed microglia-mediated neuroinflammation. We concluded that the OAP structure of AQP4 plays a key role in its polarized expression in astrocytic endfeet processes at the blood-brain barrier. Therefore, our study provided new insights into intervention of cerebral cellular edema caused by stroke and traumatic brain injury through regulating AQP4 OAP formation.

Dysnatremia and risk of bloodstream infection in dialysis patients

Emerging data suggest that sodium disarrays including hyponatremia are potential risk factors for infection ensuing from impairments in host immunity, which may be exacerbated by coexisting conditions (i.e. mucosal membrane and cellular edema leading to breakdown of microbial barrier function). While dysnatremia and infection-related mortality are common in dialysis patients, little is known about the association between serum sodium levels and the risk of bloodstream infection in this population. Among 823 dialysis patients from the national Biospecimen Registry Grant Program who underwent serum sodium testing over the period January 2008-December 2014, we examined the relationship between baseline serum sodium levels and subsequent rate of bloodstream infection. Bloodstream infection events were directly ascertained using laboratory blood culture data. Associations between serum sodium level and the incidence of bloodstream infection were estimated using expanded case mix-adjusted Poisson regression models. In the overall cohort, ∼10% of all patients experienced one or more bloodstream infection events during the follow-up period. Patients with both lower sodium levels <134mEq/l and higher sodium levels ≥140mEq/l had higher incident rate ratios (IRRs) of bloodstream infection in expanded case mix analyses (reference 136-<138mEq/l), with adjusted IRRs of 2.30 [95% confidence interval (CI) 1.19-4.44], 0.77 (95% CI 0.32-1.84), 1.39 (95% CI 0.78-2.47), 1.88 (95% CI 1.08-3.28) and 1.96 (95% CI 1.08-3.55) for sodium levels <134, 134-<136, 138-<140, 140-<142 and ≥142Eq/l, respectively. Both lower and higher baseline serum sodium levels were associated with a higher rate of subsequent bloodstream infections in dialysis patients. Further studies are needed to determine whether correction of dysnatremia ameliorates infection risk in this population.

A scenario for the origin of life: Volume regulation by bacteriorhodopsin required extremely voltage sensitive Na-channels and very selective K-channels.

The osmotic activity produced by internal, non-permeable, anionic nucleic acids and metabolites causes a persistent and life-threatening cell swelling, or cellular edema, produced by the Gibbs-Donnan effect. This evolutionary-critical osmotic challenge must have been resolved by LUCA or its ancestors, but we lack a cell-physiology look into the biophysical constraints to the solutions. Like mycoplasma, early cells conceivably preserved their volume with Cl- , Na+ , and K+ -channels, Na+ /H+ -exchangers, and a light-dependent bacteriorhodopsin-like H+ -pump. Here, I simulated protocells having these ionic-permeabilities and inhabiting an oceanic pond before the Great-Oxygenation-Event. Protocells showed better volume control and stable resting potentials at lower external pH and higher temperatures, favoring a certain type of extremophile life. Prevention of Na+ -influx at night, with low bacteriorhodopsin activity, required deep shutdown of highly voltage-sensitive Na+ -channels and extremely selective K+ -channels, two conserved features essential for modern neuronal encoding. The Gibbs-Donnan effect universality implies that extraterrestrial cells, if they exist, may reveal similar volume-controlling mechanisms.

Osteocalcin reduces fat accumulation and inflammatory reaction by inhibiting ROS-JNK signal pathway in chicken embryonic hepatocytes

Osteocalcin (OCN) has a function in preventing fatty liver hemorrhagic syndrome (FLHS) in poultry. The aim of this study was to investigate the effects of OCN on fat emulsion stimulated chicken embryonic hepatocytes and related signaling pathways. The primary chicken embryonic hepatocytes were isolated from the incubated 15-day (E15) pathogen free eggs and cultured with dulbecco's modified eagle medium (DMEM). After the hepatocyte density reached 80%, the cells were divided into 5 groups: control group (CONT), fat emulsion group (FE, 10% FE, v/v), FE with ucOCN at 1 ng/mL (FE-LOCN), 3 ng/mL (FE-MOCN), and 9 ng/mL (FE-HOCN). In addition, 2 mM N-Acetyl-L-cysteine (NAC) a reactive oxygen species (ROS) scavenger, and 5 μM SP600125, a Jun N-terminal kinase (JNK) inhibitor, were added separately in to the DMEM with 10% FE to test effects of FE on the function of ROS-JNK signal pathway. The number of hepatocytes, cell ultra-microstructure, viability, and apoptosis were detected after 48 h treatment, and the protein expressions and enzyme concentrations were detected after 72 h treatment. The results showed that, compared to the control group, FE increased the triglyceride (TG) concentration and lipid droplets (LDs) in chicken embryonic hepatocytes (P < 0.05), and induced hepatocytic edema with obviously mitochondrial swelling, membrane damage, and cristae rupture. FE also decreased ATP concentration, increased ROS concentrations and mitochondrial DNA (mtDNA) copy number, promoted inflammatory interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-α) concentrations and hepatocytic apoptosis rate, and raised phospho-c-Jun N-terminal kinase (p-JNK) protein expressions. Compared to the FE group, ucOCN significantly increased hepatocyte viability, reduced hepatocytic TG concentrations and LDs numbers, and alleviated hepatocytic edema and mitochondrial swelling. Furthermore, ucOCN significantly decreased ROS concentrations, increased ATP concentrations, reduced IL-1, IL-6, TNF-α concentrations and hepatocytic apoptosis rate, and inhibited p-JNK protein expressions (P < 0.05). NAC had the similar functions of ucOCN reduced the ROS concentration and inhibited the TNF-α protein expression and p-JNK/JNK ration. Similarly, SP600125 reduced p-JNK/JNK protein expression, IL-1, IL-6, TNF-α, and TG concentrations without effects on ROS concentration and hepatocytic apoptosis. These results suggest that ucOCN alleviates FE-induced mitochondrial damage, cellular edema, and apoptosis of hepatocytes. These results reveal that the functions of ucOCN in reducing fat accumulation and inflammatory reaction in chicken embryonic hepatocytes are mostly via inhibiting the ROS-JNK signal pathway.

Hemodynamic changes and neuronal damage detected by 9.4 T MRI in rats with chronic cerebral ischemia and cognitive impairment

IntroductionThe bilateral common carotid artery occlusion (BCCAO) rat model is an ideal animal model for simulating the pathology of chronic brain hypoperfusion in humans. However, dynamic changes in neuronal activity, cellular edema, and neuronal structural integrity in vivo after BCCAO have rarely been reported. The purpose of this study is to use a 9.4 T MRI to explore the pathophysiological mechanisms of vascular dementia.Materials and MethodsTwelve Sprague–Dawley (SD) rats were randomly divided into two groups: the sham group and the model group (n = 6 for each group). Rats were subjected to MRI using T2*WI, diffusion tensor imaging (DTI), and DWI sequences by MRI at the following six time points: presurgery and 6 h, 3 days, 7 days, 21 days, and 28 days postsurgery. Then, the T2*, fractional anisotropy (FA), and average apparent diffusion coefficient (ADC) values were measured in the bilateral cortices and hippocampi. After MRI scanning, all rats in both groups were subjected to the Y‐maze test, novel object recognition test, and open‐field test to assess their learning, memory, cognition, and locomotor activity.ResultsThe T2*, FA, and ADC values in the cerebral cortex and hippocampus decreased sharply at 6 h after BCCAO in the model group compared with those of the sham group. By Day 28, the T2* and ADC values gradually increased to close to those in the sham group, but the FA values changed little, and the rats in the model group had worse learning, memory, and cognition and less locomotor activity than the rats in the sham group.ConclusionsThe BCCAO is an ideal rat model for studying the pathophysiological mechanisms of vascular dementia.

Osmosensing by cytoplasmic biomolecular condensates of antiviral MxA GTPase

Cellular and tissue‐level edema is a common feature of acute viral infections, including covid‐19. However, there is little understanding of the effects of tissue edema on antiviral effector mechanisms. In as much as defects in IFN‐α function (such as due to presence of autoantibodies) are now implicated in enhanced severity of covid‐19 disease, we investigated how hypoosmolarity and cellular edema might affect the antiviral activity of IFN‐α‐induced human MxA GTPase, a major antiviral effector against several RNA and DNA viruses. We had previously discovered that cytoplasmic human MxA existed in the cytoplasm in phase‐separated membraneless biomolecular condensates with a gel‐like internal consistency. The vesicular stomatitis virus (VSV) nucleocapsid (N) protein associated with such MxA condensates in cells exhibiting an antiviral phenotype. Unexpectedly, MxA condensates displayed rapid and reversible osmosensing properties. Condensates of both IFN‐α‐induced endogenous MxA and of exogenous GFP‐MxA expressed in human A549 lung and Huh7 hepatoma cells rapidly disassembled within 1‐2 min when cells were exposed to hypotonic buffer (approx. 50 mOsm), and rapidly reassembled into new structures within 1‐2 min of shifting of cells to isotonic culture medium (approx. 330 mOsm). GFP‐MxA condensates in cells continuously exposed to culture medium in the range one‐fourth, one‐third or one‐half isotonicity first rapidly disassembled within 1‐2 min, and then, in most cells. spontaneously reassembled 7‐15 min later into new structures. The data are consistent with cytoplasmic “crowding” as the mechanism driving MxA condensate formation. In terms of antiviral function, one 5 min cycle of disassembly and reassembly of GFP‐MxA condensates at 1 or 2 hr after VSV infection did not affect MxA antiviral activity. Additionally, continuous exposure of GFP‐MxA expressing A549 lung cells to culture medium at one‐fourth or one‐third tonicity (thus triggering a cycle of disassembly and slower spontaneous reassembly in the continued presence of hypotonic culture medium) together with a VSV challenge, left antiviral activity largely unaffected. Such cultures showed an increase in number of cells with VSV N colocalized with the reassembled GFP‐MxA condensates. The data reveal a novel property of MxA biomolecular condensates ‐ rapid and reversible osmosensing. Importantly, antiviral activity was largely unaffected by tonicity‐driven disassembly/reassembly mimicking conditions of cellular and tissue‐level edema.

Boswellic Acids, Pentacyclic Triterpenes, Attenuate Oxidative Stress, and Bladder Tissue Damage in Cyclophosphamide-Induced Cystitis.

Boswellic acids, derived from the Boswellia serrata plant, have been demonstrated to have anti-inflammatory properties in experimental animal models. The present study was aimed to evaluate the uro-protective effect of boswellic acids in rats with cyclophosphamide-induced cystitis. Interstitial cystitis was induced by cyclophosphamide (CYP). In order to analyze the reduction of the urothelial damage, the bladder weight, the nociception response, and the Evans blue dye extravasation from the bladder were evaluated. To investigate the involvement of lipid peroxidation and enzymatic antioxidants CAT, SOD, and GPX and MPO and NO were evaluated. IL-6 and TNF-α were measured by the ELISA immunoassay technique. The results showed that pretreatment with boswellic acids significantly reduced urothelial damage which was accompanied by a decrease in the activity of MDA, CPO, and NO levels and prevention of the depletion of CAT, SOD, and GPX. The levels of IL-6 and TNF-α were dramatically reduced by boswellic acids. Histopathological findings revealed a considerable reduction in cellular infiltration, edema, epithelial denudation, and bleeding. Our findings showed that boswellic acids, by their antioxidant and anti-inflammatory properties, negate the detrimental effects of cyclophosphamide on the bladder, suggesting boswellic acids as promising therapeutic alternatives for cystitis.

TNF-α induces AQP4 overexpression in astrocytes through the NF-κB pathway causing cellular edema and apoptosis

Aquaporin 4 (AQP4) is highly expressed on astrocytes and is critical for controlling brain water transport in neurological diseases. Tumor necrosis factor (TNF)-α is a common cytokine found in disease microenvironment. The aim of the present study was to determine whether TNF-α can regulate the expression of AQP4 in astrocytes. Primary astrocyte cultures were treated with different concentrations of TNF-α and the cell viability was assessed through cell counting kit-8 (CCK-8) assay and AQP4 expression was detected by qPCR, Western blots, and immunofluorescence assays. The activation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) pathway was detected by Western blot. Further, dual-luciferase reporting system and chromatin immunoprecipitation (ChIP) were used to detect the transcriptional regulation of AQP4 by p65. These experiments demonstrated that treatment with TNF-α can lead to astrocyte edema and an increase in AQP4 expression. Following TNF-α treatment, the expression levels of P-IKKα/β-IκBα and P-p65 increased significantly over time. The results of the dual-luciferase reporter system and ChIP assays revealed that p65 protein and AQP4 promoter had a robust binding effect after TNF-α treatment, and the NF-κB pathway inhibitor, BAY 11-7082 could inhibit these effects of TNF-α. The expression level of AQP4 was significantly decreased upon p65 interference, while the astrocyte viability was significantly increased compared with that in the TNF-α only group. In conclusion, TNF-α activated NF-κB pathway, which promoted the binding of p65 to the AQP4 gene promoter region, and enhanced AQP4 expression, ultimately reducing astrocyte viability and causing cell edema.

No-reflow phenomenon and reperfusion injury. Mechanisms and treatment

Currently, one of the key methods of treating a patient with ST-elevation myocardial infarction is to restore blood flow to the infarct-related artery as quickly, completely and steadily as possible. However, in some cases, it is not possible to achieve adequate myocardial reperfusion, despite the restoration of coronary blood flow. This phenomenon was named no-reflow. Due to the lack of a unified approach to the diagnosis of no-reflow, its occurrence varies widely – from 2 to 44 %. Failure to achieve adequate myocardial perfusion leads to a higher mortality rate – from 7.4 to 30.3 %, as well as to more aggressive remodeling of the myocardium. For a long time, distal embolization in percutaneous coronary intervention was considered one of the leading mechanisms. However, the routine use of protective devices did not show a pronounced effect on the outcome and prognosis, although it is justified in certain clinical situations. Ischemic injury directly plays a significant role due to overload of cardiomyocytes with calcium, cellular edema, necrosis and apoptosis, which is significantly aggravated by myocardial reperfusion and forms obstruction at the level of the microcirculatory bed. More data is being accumulated about immune-mediated injury through activation of cellular immunity, intense inflammation and thrombosis in situ. Despite the success in the animal experiment, the clinical use of certain groups of drugs showed an ambiguous results. According to the latest recommendations European Society of Cardiology / European Association for Cardio-Thoracic Surgery (ESC / EACTS) 2018, GPIIb / IIIa platelet receptor inhibitors are recommended in the case of no-reflow. Besides this, according to the literature nicorandil and sodium nitroprusside, as well as IL-1β antagonists, seem to be promising. As a non-drug therapy, selective intracoronary hypothermia also has shown its effectiveness and safety in a pilot study. To date, it is clear that the no-reflow phenomenon is a manifestation of a complex cascade of reactions, including ischemic, reperfusion and immune-related injury, as well as distal embolization. Considering its significant contribution to the frequency of adverse outcomes and late complications, it seems necessary to introduce unified approaches to the diagnosis, prevention and treatment of no-reflow, which requires high-quality clinical studies.