TGF-ß/Smad signaling pathway plays a crucial role in patulin-induced pro-fibrotic changes in rat kidney via modulation of slug and snail expression.

Patulin (PAT) is a mycotoxin that contaminates a variety of food and foodstuffs. Earlier in vitro and in vivo findings have indicated that kidney is one of the target organs for PAT-induced toxicity. However, no study has evaluated the chronic effects of PAT exposure at environmentally relevant doses or elucidated the detailed mechanism(s) involved. Here, using in vitro and in vivo experimental approaches, we delineated the mechanism/s involved in pro-fibrotic changes in the kidney after low-dose chronic exposure to PAT. We found that non-toxic concentrations (50 nM and 100 nM) of PAT to normal rat kidney cells (NRK52E) caused a higher generation of reactive oxygen species (ROS) (mainly hydroxyl (•OH), peroxynitrite (ONOO-), and hypochlorite radical (ClO-). PAT exposure caused the activation of mitogen-activated protein kinases (MAPKs) and its downstream c-Jun/Fos signaling pathways. Moreover, our chromatin immunoprecipitation (ChIP) analysis suggested that c-Jun/Fos binds to the promoter region of Transforming growth factor beta (TGF-ß1) and possibly induces its expression. Results showed that PAT-induced TGF-ß1 further activates the TGF-ß1/smad signaling pathways. Higher activation of slug and snail transcription factors further modulates the regulation of pro-fibrotic molecules. Similarly, in vivo results showed that PAT exposure to rats through gavage at 25 and 100 µg/kg b. wt had higher levels of kidney injury/toxicity markers namely vascular endothelial growth factor (VEGF), kidney Injury Molecule-1 (Kim-1), tissue inhibitor of metalloproteinase-1 (Timp-1), and clusterin (CLU). Additionally, histopathological analysis indicated significant alterations in renal tubules and glomeruli along with collagen deposition in PAT-treated rat kidneys. Overall, our data provide evidence of the involvement of ROS mediated MAPKs and TGF-ß1/smad pathways in PAT-induced pro-fibrotic changes in the kidney via modulation of slug and snail expression.

Combination of Peroxisome Proliferator-Activated Receptor (PPAR) Alpha and Gamma Agonists Prevents Corneal Inflammation and Neovascularization in a Rat Alkali Burn Model.

Peroxisome proliferator-activated receptor alpha (PPARα) and gamma (PPARγ) agonists have anti-inflammatory and anti-neovascularization effects, but few reports have tested the combination of PPARα and PPARγ agonists. In this study, we investigated the therapeutic effects of ophthalmic solutions of agonists of PPARα, PPARγ, and the combination in a rat corneal alkali burn model. After alkali injury, an ophthalmic solution of 0.05% fenofibrate (PPARα group), 0.1% pioglitazone (PPARγ group), 0.05% fenofibrate + 0.1% pioglitazone (PPARα+γ group), or vehicle (vehicle group) was topically instilled onto the rat's cornea twice a day. After instillation, upregulation was seen of PPAR mRNA corresponding to each agonist group. Administration of agonists for PPARα, PPARγ, and PPARα+γ suppressed inflammatory cells, neovascularization, and fibrotic changes. In addition, the PPARγ agonist upregulated M2 macrophages, which contributed to wound healing, whereas the PPARα agonist suppressed immature blood vessels in the early phase. Administration of PPARα+γ agonists showed therapeutic effects in corneal wound healing, combining the characteristics of both PPARα and PPARγ agonists. The results indicate that the combination of PPARα and γ agonists may be a new therapeutic strategy.

Detection of fibrotic changes in the progression of liver diseases by label-free multiphoton imaging.

Collagen fibers play an important role in the progression of liver diseases. The formation and progression of liver fibrosis is a dynamic pathological process accompanied by morphological changes in collagen fibers. In this study, we used multiphoton microscopy for label-free imaging of liver tissues, allowing direct detection of various components including collagen fibers, tumors, blood vessels, and lymphocytes. Then, we developed a deep learning classification model to automatically identify tumor regions, and the accuracy reaches 0.998. We introduced an automated image processing method to extract eight collagen morphological features from various stages of liver diseases. Statistical analysis showed significant differences between them, indicating the potential use of these quantitative features for monitoring fibrotic changes during the progression of liver diseases. Therefore, multiphoton imaging combined with automatic image processing method would hold a promising future in rapid and label-free diagnosis of liver diseases.

Endothelial activation and fibrotic changes are impeded by laminar flow-induced CHK1-SENP2 activity through mechanisms distinct from endothelial-to-mesenchymal cell transition.

Background: The deSUMOylase sentrin-specific isopeptidase 2 (SENP2) plays a crucial role in atheroprotection. However, the phosphorylation of SENP2 at T368 under disturbed flow (D-flow) conditions hinders its nuclear function and promotes endothelial cell (EC) activation. SUMOylation has been implicated in D-flow-induced endothelial-to-mesenchymal transition (endoMT), but the precise role of SENP2 in counteracting this process remains unclear. Method: We developed a phospho-specific SENP2 S344 antibody and generated knock-in (KI) mice with a phospho-site mutation of SENP2 S344A using CRISPR/Cas9 technology. We then investigated the effects of SENP2 S344 phosphorylation under two distinct flow patterns and during hypercholesteremia (HC)-mediated EC activation. Result: Our findings demonstrate that laminar flow (L-flow) induces phosphorylation of SENP2 at S344 through the activation of checkpoint kinase 1 (CHK1), leading to the inhibition of ERK5 and p53 SUMOylation and subsequent suppression of EC activation. We observed a significant increase in lipid-laden lesions in both the aortic arch (under D-flow) and descending aorta (under L-flow) of female hypercholesterolemic SENP2 S344A KI mice. In male hypercholesterolemic SENP2 S344A KI mice, larger lipid-laden lesions were only observed in the aortic arch area, suggesting a weaker HC-mediated atherogenesis in male mice compared to females. Ionizing radiation (IR) reduced CHK1 expression and SENP2 S344 phosphorylation, attenuating the pro-atherosclerotic effects observed in female SENP2 S344A KI mice after bone marrow transplantation (BMT), particularly in L-flow areas. The phospho-site mutation SENP2 S344A upregulates processes associated with EC activation, including inflammation, migration, and proliferation. Additionally, fibrotic changes and up-regulated expression of EC marker genes were observed. Apoptosis was augmented in ECs derived from the lungs of SENP2 S344A KI mice, primarily through the inhibition of ERK5-mediated expression of DNA damage-induced apoptosis suppressor (DDIAS). Summary: In this study, we have revealed a novel mechanism underlying the suppressive effects of L-flow on EC inflammation, migration, proliferation, apoptosis, and fibrotic changes through promoting CHK1-induced SENP2 S344 phosphorylation. The phospho-site mutation SENP2 S344A responds to L-flow through a distinct mechanism, which involves the upregulation of both mesenchymal and EC marker genes.

Arsenic exposure associated with lung interstitial changes in non-smoking individuals living near a petrochemical complex: A repeated cross-sectional study.

Arsenic exposure is associated with airway inflammation and decreased lung function tests. Whether arsenic exposure associated with lung interstitial changes remains unknown. We conducted this population-based study in southern Taiwan during 2016 and 2018. Our study recruited individuals aged over 20 years, residing in the vicinity of a petrochemical complex and with no history of cigarette smoking. In both the 2016 and 2018 cross-sectional studies, we conducted chest low-dose computed tomography (LDCT) scans, as well as urinary arsenic and blood biochemistry analyses. Lung interstitial changes included lung fibrotic changes that were defined as the presence of curvilinear or linear densities, fine lines, or plate opacity in specific lobes; additionally, other interstitial changes were defined as the presence of ground-glass opacity (GGO) or bronchiectasis on the LDCT images. In both cross-sectional studies conducted in 2016 and 2018, participants with lung fibrotic changes exhibited a statistically significant increase in the mean urinary arsenic concentrations compared to those without fibrotic changes (geometric mean = 100.1 vs. 82.8 µg/g creatinine, p < 0.001 for cross-sectional study 2016, and geometric mean = 105.6 vs. 71.0 µg/g creatinine, p < 0.001 for cross-sectional study 2018). After controlling for age, gender, body mass index, platelet counts, hypertension, aspartate aminotransferase, cholesterol, HbA1c, and educational levels, we observed a significant positive association between a unit increase in log urinary arsenic concentrations and the risk of lung fibrotic changes in both cross-sectional study 2016 (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.04-1.90, p = 0.028) and cross-sectional study 2018 (OR = 3.03, 95% CI = 1.38-6.63, p = 0.006). Our study did not find a significant association between arsenic exposure and bronchiectasis or GGO. It is imperative for the government to take significant measures to reduce arsenic exposure levels among individuals living near petrochemical complexes.

Blood lead (Pb) is associated with lung fibrotic changes in non-smokers living in the vicinity of petrochemical complex: a population-based study.

Lead (Pb) is a toxic metal that has been extensively used in various industrial processes, and it persists in the environment, posing a continuous risk of exposure to humans. This study investigated blood lead levels in participants aged 20 years and older, who resided in Dalinpu for more than two years between 2016 to 2018, at Kaohsiung Municipal Siaogang Hospital. Graphite furnace atomic absorption spectrometry was used to analyze the blood samples for lead levels, and the LDCT (Low-Dose computed tomography) scans were interpreted by experienced radiologists. The blood lead levels were divided into quartiles, with Q1 representing levels of ≤1.10 µg/dL, Q2 representing levels of >1.11 and ≤1.60 µg/dL, Q3 representing levels of >1.61 and ≤2.30 µg/dL, and Q4 representing levels of >2.31 µg/dL. Individuals with lung fibrotic changes had significantly higher (mean ± SD) blood lead levels (1.88±1.27vs. 1.72±1.53 µg/dl, p< 0.001) than those with non-lung fibrotic changes. In multivariate analysis, we found that the highest quartile (Q4: >2.31 µg/dL) lead levels (OR: 1.36, 95% CI: 1.01-1.82; p= 0.043) and the higher quartile (Q3: >1.61 and ≤2.30 µg/dL) (OR: 1.33, 95% CI: 1.01-1.75; p= 0.041) was significantly associated with lung fibrotic changes compared with the lowest quartile (Q1: ≤1.10 µg/dL) (Cox and Snell R2, 6.1 %; Nagelkerke R2, 8.5 %). The dose-response trend was significant (Ptrend= 0.030). Blood lead exposure was significantly associated lung fibrotic change. To prevent lung toxicity, it is recommended to maintain blood lead levels lower than the current reference value.

Arsenic exposure was associated with lung fibrotic changes in individuals living near a petrochemical complex.

Individuals residing near petrochemical complexes have been found to have increasing the risk of respiratory distress and diseases. On visit 1 in 2016, all participants underwent urinary arsenic measurement and low-dose computed tomography (LDCT). The same participants had LDCT performed at visit 2 in 2018. Our study revealed that individuals with lung fibrotic changes had significantly higher levels of urinary arsenic compared to the non-lung fibrotic changes group. Moreover, we found that participants with urinary arsenic levels in the highest sextile (> 209.7 µg/g creatinine) had a significantly increased risk of lung fibrotic changes in both visit 1 (OR = 1.87; 95% CI= 1.16-3.02; P = 0.010) and visit 2 (OR = 1.74; 95% CI = 1.06-2.84; P = 0.028) compared to those in the lowest sextile (≤ 41.4 µg/g creatinine). We also observed a significantly increasing trend across urinary arsenic sextile in both visits (Ptrend = 0.015 in visit 1 and Ptrend = 0.026 in visit 2). Furthermore, participants with urinary arsenic levels in the highest sextile had a significantly increased risk of lung fibrotic positive to positive (OR = 2.18; 95% CI: 1.24, 3.82; P = 0.007) compared to the lowest sextile (reference category: lung fibrotic negative to negative). Our findings provide support for the hypothesis that arsenic exposure is significantly associated with an increased risk of lung fibrotic changes. It is advisable to reduce the levels of arsenic exposure for those residing near such petrochemical complexes.

Follow-Up CT Patterns of Residual Lung Abnormalities in Severe COVID-19 Pneumonia Survivors: A Multicenter Retrospective Study.

Prior studies variably reported residual chest CT abnormalities after COVID-19. This study evaluates the CT patterns of residual abnormalities in severe COVID-19 pneumonia survivors. All consecutive COVID-19 survivors who received a CT scan 5-7 months after severe pneumonia in two Italian hospitals (Reggio Emilia and Parma) were enrolled. Individual CT findings were retrospectively collected and follow-up CT scans were categorized as: resolution, residual non-fibrotic abnormalities, or residual fibrotic abnormalities according to CT patterns classified following standard definitions and international guidelines. In 225/405 (55.6%) patients, follow-up CT scans were normal or barely normal, whereas in 152/405 (37.5%) and 18/405 (4.4%) patients, non-fibrotic and fibrotic abnormalities were respectively found, and 10/405 (2.5%) had post-ventilatory changes (cicatricial emphysema and bronchiectasis in the anterior regions of upper lobes). Among non-fibrotic changes, either barely visible (n = 110/152) or overt (n = 20/152) ground-glass opacities (GGO), resembling non-fibrotic nonspecific interstitial pneumonia (NSIP) with or without organizing pneumonia features, represented the most common findings. The most frequent fibrotic abnormalities were subpleural reticulation (15/18), traction bronchiectasis (16/18) and GGO (14/18), resembling a fibrotic NSIP pattern. When multiple timepoints were available until 12 months (n = 65), residual abnormalities extension decreased over time. NSIP, more frequently without fibrotic features, represents the most common CT appearance of post-severe COVID-19 pneumonia.

Lung Function, Radiological Findings and Biomarkers of Fibrogenesis in a Cohort of COVID-19 Patients Six Months After Hospital Discharge.

INTRODUCTION: Impairment in pulmonary function tests and radiological abnormalities are a major concern in COVID-19 survivors. Our aim is to evaluate functional respiratory parameters, changes in chest CT, and correlation with peripheral blood biomarkers involved in lung fibrosis at two and six months after SARS-CoV-2 pneumonia. METHODS: COVID-FIBROTIC (clinicaltrials.gov NCT04409275) is a multicenter prospective observational cohort study aimed to evaluate discharged patients. Pulmonary function tests, circulating serum biomarkers, chest radiography and chest CT were performed at outpatient visits. RESULTS: In total, 313, aged 61.12 ± 12.26 years, out of 481 included patients were available. The proportion of patients with DLCO < 80% was 54.6% and 47% at 60 and 180 days. Associated factors with diffusion impairment at 6 months were female sex (OR: 2.97, 95%CI 1.74-5.06, p = 0.001), age (OR: 1.03, 95% CI: 1.01-1.05, p = 0.005), and peak RALE score (OR: 1.22, 95% CI 1.06-1.40, p = 0.005). Patients with altered lung diffusion showed higher levels of MMP-7 (11.54 ± 8.96 vs 6.71 ± 4.25, p = 0.001), and periostin (1.11 ± 0.07 vs 0.84 ± 0.40, p = 0.001). 226 patients underwent CT scan, of whom 149 (66%) had radiological sequelae of COVID-19. In severe patients, 68.35% had ground glass opacities and 38.46% had parenchymal bands. Early fibrotic changes were associated with higher levels of MMP7 (13.20 ± 9.20 vs 7.92 ± 6.32, p = 0.001), MMP1 (10.40 ± 8.21 vs 6.97 ± 8.89, p = 0.023), and periostin (1.36 ± 0.93 vs 0.87 ± 0.39, p = 0.001). CONCLUSION: Almost half of patients with moderate or severe COVID-19 pneumonia had impaired pulmonary diffusion six months after discharge. Severe patients showed fibrotic lesions in CT scan and elevated serum biomarkers involved in pulmonary fibrosis.

INTRODUCCIÓN: El deterioro de la función pulmonar en las pruebas correspondientes y las alteraciones radiológicas son las preocupaciones principales en los supervivientes de la COVID-19. Nuestro objetivo fue evaluar los parámetros de la función respiratoria, los cambios en la TC de tórax y la correlación con los biomarcadores en sangre periférica involucrados en la fibrosis pulmonar a los 2 y a los 6 meses tras la neumonía por SARS-CoV-2. MÉTODOS: El ensayo COVID-FIBROTIC (clinicaltrials.gov NCT04409275) es un estudio de cohortes multicéntrico, prospectivo y observacional cuyo objetivo fue evaluar los pacientes dados de alta. Se realizaron pruebas de función pulmonar, detección de biomarcadores en plasma circulante y radiografía y TC de tórax durante las visitas ambulatorias. RESULTADOS: En total 313 pacientes, de 61,12 ± 12,26 años, de los 481 incluidos estuvieron disponibles.La proporción de pacientes con DLCO < 80% fue del 54,6 y del 47% a los 60 y 180 días.Los factores que se asociaron a la alteración de la difusión a los 6 meses fueron el sexo femenino (OR: 2,97; IC del 95%: 1,74-5,06; p = 0,001), la edad (OR: 1,03; IC del 95%: 1,01-1,05; p = 0,005) y la puntuación RALE más alta (OR: 1,22; IC del 95%: 1,06-1,40; p = 0,005). Los pacientes con alteración de la difusión pulmonar mostraron niveles más altos de MMP-7 (11,54 ± 8,96 frente a 6,71 ± 4,25; p = 0,001) y periostina (1,11 ± 0.07 frente a 0,84 ± 0,40; p = 0,001). Se le realizó una TC a 226 pacientes de los cuales 149 (66%) presentaban secuelas radiológicas de la COVID-19. En los pacientes graves, el 68,35% mostraban opacidades en vidrio esmerilado y el 38,46%, bandas parenquimatosas. Los cambios fibróticos tempranos se asociaron a niveles más altos de MMP7 (13,20 ± 9,20 frente a 7,92 ± 6,32; p = 0,001), MMP1 (10,40 ± 8,21 frente a 6,97 ± 8,89; p = 0,023), y periostina (1,36 ± 0,93 frente a 0,87 ± 0,39; p = 0,001). CONCLUSIÓN: Casi la mitad de los pacientes con neumonía moderada o grave por COVID-19 presentaba alteración de la difusión pulmonar 6 meses después del alta. Los pacientes graves mostraban lesiones fibróticas en laTC y un aumento de los biomarcadores séricos relacionados con la fibrosis pulmonar.

Predictors of Mortality in Progressive Fibrosing Interstitial Lung Diseases.

Background: Progressive fibrosing interstitial lung disease (PF-ILD) and idiopathic pulmonary fibrosis (IPF) share similar progression phenotype but with different pathophysiological mechanism. The purpose of this study was to assess clinical characteristics and outcomes of patients with PF-ILD in a single-center cohort. Methods: Patients with PF-ILD treated in Shanghai Pulmonary Hospital from Jan. 2013 to Dec. 2014 were retrospectively analyzed. Baseline characteristics and clinical outcomes were collected for survival analysis to identifying clinical predictors of mortality. Results: Among 608 patients with ILD, 132 patients met the diagnostic criteria for PF-ILD. In this single-center cohort, there were 51 (38.6%) cases with connective tissue disease-associated interstitial lung disease (CTD-ILD) and 45 (34.1%) with unclassifiable ILDs. During follow-up, 83 patients (62.9%) either died (N = 79, 59.8%) or underwent lung transplantations (N = 4, 3.0%) with a median duration follow-up time of 53.7 months. Kaplan-Meier survival curves revealed that the 1, 3 and 5-years survival of PF-ILD were 90.9, 58.8 and 48.1%, respectively. In addition, the prognosis of patients with PF-ILD was similar to those with IPF, while it was worse than non-PF-ILD ones. Multivariate Cox regression analysis demonstrated that high-resolution computed tomography (HRCT) scores (HR 1.684, 95% CI 1.017-2.788, p = 0.043) and systolic pulmonary artery pressure (SPAP) > 36.5 mmHg (HR 3.619, 95%CI 1.170-11.194, p = 0.026) were independent risk factors for the mortality of PF-ILD. Conclusion: Extent of fibrotic changes on HRCT and pulmonary hypertension were predictors of mortality in patients with PF-ILD.

Effect of Neutral pH Icodextrin Peritoneal Dialysis Fluid on Mesothelial Cells.

Conventional acidic icodextrin peritoneal dialysate (CI) has low biocompatibility due to its low pH, and a neutral pH icodextrin dialysate (NI) was developed. The influence of NI on the peritoneum has not been clarified. The effects of the two dialysates on cultured rat mesothelial cells were examined. CI, but not NI, increased α-smooth muscle actin, collagen type 1 and 3, and P21 mRNA expressions. CI with neutralized pH did not improve these harmful effects. With NI+ glucose degradation products (GDPs: same concentration as CI), mRNA expressions were comparable to those with NI alone. However, if NI + GDPs was acidified, mRNA levels matched those with CI. The proportion in the G2/M phase of the cell cycle was lower with CI than with NI stimulation. From these results, CI stimulated epithelial-mesenchymal transition, fibrotic changes, inhibited cell growth, and induced cell senescence. These effects were attributed to the combined low pH and high GDPs.