Integrin αV mediated activation of myofibroblast via mechanoparacrine of transforming growth factor β1 in promoting fibrous scar formation after myocardial infarction

BACKGROUND

Myocardial infarction (MI) dramatically changes the mechanical stress, which is intensified by the fibrotic remodeling. Integrins, especially the αV subunit, mediate mechanical signal and mechanoparacrine of transforming growth factor β1 (TGF-β1) in various organ fibrosis by activating CFs into myofibroblasts (MFBs). We investigated a possible role of integrin αV mediated mechanoparacrine of TGF-β1 in MFBs activation for fibrous reparation in mice with MI.

METHODS

Heart samples from MI, sham, or MI plus cilengitide (14 mg/kg, specific integrin αV inhibitor) treated mice, underwent functional and morphological assessments by echocardiography, and histochemistry on 7, 14 and 28 days post-surgery. The mechanical and ultrastructural changes of the fibrous scar were further evaluated by atomic mechanics microscope (AFM), immunofluorescence, second harmonic generation (SHG) imaging, polarized light and scanning electron microscope, respectively. Hydroxyproline assay was used for total collagen content, and western blot for protein expression profile examination. Fibroblast bioactivities, including cell shape, number, Smad2/3 signal and expression of extracellular matrix (ECM) related proteins, were further evaluated by microscopic observation and immunofluorescence in polyacrylamide (PA) hydrogel with adjustable stiffness, which was re-explored in fibroblast cultured on stiff matrix after silencing of integrin αV. The content of total and free TGF-β1 was tested by enzyme-linked immunosorbent assay (ELISA) in both infarcted tissue and cell samples.

RESULT

Increased stiffness with heterogeneity synchronized with integrin αV and alpha smooth muscle actin (α-SMA) positive MFBs accumulation in those less mature fibrous areas. Cilengitide abruptly reduced collagen content and disrupted collagen alignment, which also decreased TGF-β1 bioavailability, Smad2/3 phosphorylation, and α-SMA expression in the fibrous area. Accordingly, fibroblast on stiff but not soft matrix exhibited obvious MFB phenotype, as evidenced by enlarged cell, hyperproliferation, well-developed α-SMA fibers, and elevated ECM related proteins, while silencing of integrin αV almost abolished this switch via attenuating paracrine of TGF-β1 and nuclear translocation of Smad2/3.

CONCLUSION

This study illustrated that increased tissue stiffness activates CFs into MFBs by integrin αV mediated mechanoparacrine of TGF-β1, especially in immature scar area, which ultimately promotes fibrous scar maturation.

[Coronary CT angiography derived fractional flow reserve: the consideration and practice of functional evaluation for cerebral arterial diseases]

Cerebrovascular disease is a significant global public health concern, despite the diagnosis and treatment of stroke has made great progress in recent years, however, its mainly guided by anatomical indicators, which still needs to be further improved, and there is an urgent need to explore a more accurate and comprehensive functional imaging assessment method. Rapid development of coronary CT angiography derived fractional flow reserve (CT-FFR) has become an important technique for noninvasive evaluation of coronary artery disease, and these successful application experiences inspiried neurologists to explore the functional evaluation technique of cerebral arteries and demonstrated broad application prospects. In this paper, by analyzing and comparing the coronary CT-FFR technology, the progress, existing problems and possible solutions of the functional evaluation for cerebral arterial stenosis are discussed from the aspects of coronary CT-FFR study, cerebral artery functional evaluation study, and the comparison and consideration of cerebral arterial and coronary CT-FFR.

[Risk factors associated with acute kidney injury caused by pesticide poisoning]

Objective: To analyze the clinical characteristics of pesticide poisoning patients and explore the risk factors of acute kidney injury (AKI) . Methods: In September 2020, the clinical data of 155 patients with pesticide poisoning in the department of nephropathy, the Affiliated Hospital of Southwest Medical University from September 2018 to August 2020 were retrospectively analyzed. The patients were divided into AKI group (44 cases) and non AKI group (111 cases) according to the occurrence of AKI. The clinical characteristics, organ or system involvement and auxiliary examination results of the two groups were analyzed. Logistic regression was used to analyze the risk factors of AKI in patients with pesticide poisoning. Results: The types of pesticides causing poisoning mainly included herbicides, insecticides and biochemical pesticides. Compared with non AKI group, patients in AKI group had higher proportion of blood purification treatment and ICU monitoring treatment (P<0.05) , and were more likely to be complicated with acute respiratory failure, pulmonary fibrosis, myocardial injury, multiple organ dysfunction syndrome (MODS) , acute pancreatitis and coagulation abnormalities (P<0.05) . The mortality of AKI group (18.2%, 8/14) was significantly higher than that of non AKI group (0.9%, 1/111) (P<0.05) . Univariate analysis showed that the time from poisoning to treatment > 6 h, high WBC count, neutrophil count, alanine aminotransferase, aspartate aminotransferase, high sensitive troponin T, myoglobin and creatine kinase isoenzyme were the risk factors of AKI in patients with pesticide poisoning (P<0.05) . Multivariate logistic regression analysis showed that the time from poisoning to treatment >6 h was an independent risk factor for AKI in patients with pesticide poisoning (P<0.05) . Conclusion: The mortality of AKI secondary to pesticide poisoning is high. Attention should be paid to the time from poisoning to treatment, inflammatory state and changes of liver and myocardial function.

KRT19 directly interacts with β-catenin/RAC1 complex to regulate NUMB-dependent NOTCH signaling pathway and breast cancer properties

Studies have reported that interactions between keratins (KRTs) and other proteins initiate signaling cascades that regulate cell migration, invasion, and metastasis. In the current study, we found that expression of KRT19 was specifically high in breast cancers and significantly correlated with their invasiveness. Moreover, knockdown of KRT19 led to increased proliferation, migration, invasion, drug resistance, and sphere formation in breast cancer cells via an upregulated NOTCH signaling pathway. This was owing to reduced expression of NUMB, an inhibitory protein of the NOTCH signaling pathway. In addition, we found that KRT19 interacts with β-catenin/RAC1 complex and enhances the nuclear translocation of β-catenin. Concordantly, knockdown of KRT19 suppressed the nuclear translocation of β-catenin as well as β-catenin-mediated NUMB expression. Furthermore, modulation of KRT19-mediated regulation of NUMB and NOTCH1 expression led to the repression of the cancer stem cell properties of breast cancer patient-derived CD133high/CXCR4high/ALDH1high cancer stem-like cells (CSLCs), which showed very low KRT19 and high NOTCH1 expression. Taken together, our study suggests a novel function for KRT19 in the regulation of nuclear import of the β-catenin/RAC1 complex, thus modulating the NUMB-dependent NOTCH signaling pathway in breast cancers and CSLCs, which might bear potential clinical implications for cancer or CSLC treatment.

[Prenatal diagnosis of chromosome abnormalities and nine microdeletion syndromes using both traditional karyotyping and BoBs]

OBJECTIVE

To evaluate a new prenatal diagnosis model of chromosomal abnormalities and nine microdeletion syndromes by using both traditional karyotyping and a newly-developed rapid prenatal diagnosis technology, BACs-on-Beads (BoBs) technique.

METHODS

From June 2012 to December 2014, 807 pregnant women with high risk after screening or with other indicators, were performed amniocentesis. Traditional karyotyping and BoBs were employed simultaneously for prenatal diagnosis.

RESULTS

Thirty-two cases with chromosome aneupoidies were successfully detected both by BoBs and karyotyping, including 18 cases of trisomy 21, 6 cases of trisomy 18, 1 case of trisomy 13, and 7 cases with sex chromosome abnormality. All 8 fetuses with chromosome structural abnormalities detected by karyotyping were missed by BoBs; while BoBs contributed more in detection of five microdeletion syndrome cases, including 3 cases of DiGeorge syndromes (two with microduplication and one with microdeletion), one case of Miller-Dieker syndrome, and one case of Wolf-Hirschhorn syndrome.

CONCLUSION

Combined use of traditional karyotyping and BoBs, is a rapid and effective prenatal diagnosis model that may enlarge our horizon on chromosomal diseases and should be widely used in future clinical service.

[Finite element analysis of different load mode on tooth movement for space closure in patient with bimaxillary protrusion]

OBJECTIVE

To investigate the stress distribution on the maxillary anterior teeth retracted with sliding mechanics and micro-implant anchorage using different retraction hook heights and positions.

METHODS

DICOM image data including maxilla and upper teeth were obtained with cone-beam CT. The three-dimensional finite element model was constructed using Mimics software. Brackets and archwire model were constructed using Creo software. The models were instantiated using Pro/Engineer software. Abaqus software was used to simulate the sliding mechanics by loading 2 N force on 0, 2, 4, 6, 8, 10 mm retraction hooks and three different positions, repectively. Rotation of the occlusal plane, the initial displacement and stress distribution of teeth were analyzed.

RESULTS

Lingual rotation of maxillary central incisor(0.021°), gingival movement of the maxillary first molar(0.005 mm), and clockwise rotation of the maxillary occlusal plane(0.012°) were observed when the force application point located at the archwire level (0 mm). In contrast, 0.235° labial rotation of the maxillary central incisor, 0.015 mm occlusal movement of the maxillary first molar, and 0.075° anti-clockwise rotation of the maxillary occlusal plane were observed when the force application point located at the higher level(10 mm retraction hook). The more the force application point was located posteriorly at the archwire level, the less lingual rotation of the maxillary central incisor and the more buccal displacement of maxillary first molar was observed.

CONCLUSIONS

Maxillary anterior tooth rotation and retraction, vertical displacement of posterior segment, and rotation of the occlusal plane could be controlled by adjusting the height and position of the retraction hook in space closure using miniscrew and sliding mechanics.

[Study on mitochondrial ultrastructure, trace elements and correlative factors of gastric mucosa in patients with spleen deficiency syndrome]

Eighty-eight gastropathic patients with Spleen deficiency syndrome by using transmission electron microscope (TEM), X-ray energy disperse analysis system (EDAX), histochemical staining and radioimmuno methods were examined. The authors found that the gastric mucosa cAMP, SOD level, the quantity of mitochondria and its crista, the ratio of diameter between ventricle and cavity of mitochondria and the content of Zn, Cu of mitochondria were reduced in the trend of healthy control group, Spleen Qi deficiency group, Spleen deficiency with Qi stagnation group; chronic superficial gastritis group, chronic atrophic gastritis group, gastric cancer group: complete small intestinal metaplasia group, incomplete small intestinal metaplasia group, complete colonic intestinal metaplasia group, incomplete colonic intestinal metaplasia group (P < 0.05-0.001). While the degeneration rate of mitochondria, the Cu/Zn ratio of mitochondria, the metaplasia rate of gastric, the rate of incomplete colonic intestinal metaplasia and the content of serum LPO were increased in the above turn. It is suggested that the comprehensive effect of the degeneration of mitochondria and the quantitative changes of its correlative factors is the physiopathologic base for inducing Spleen deficiency disease, gastric mucosa metaplasia and canceration. Much attention must be paid in clinic to the cancerization trend of gastric disease with Spleen deficiency syndrome.

[Effect of zhuchun pill on immunity and endocrine function of elderly with kidney-yang deficiency]

After randomly dividing 45 elderly males with Kidney-Yang Deficiency into Zhuchun Pill (ZCP) group and placebo (starch capsule) group by single blind method, and treating them for 3 months, we found that ZCP could greatly improve the main symptoms of Kidney-Yang Deficiency, P < 0.01 by comparison with control group: the 3H-TdR lymphocyte transformation (3H-TdR LCT) rate, level of serum C3, IgA, IgD, IgG & IgM went up (P < 0.01); contents of plasma adrenocortical hormone (ACTH), testosterone (T) and cyclic adenosine monophosphate (cAMP) increased (P < 0.01-0.001): the level of superoxide dismutase (SOD) in serum also increased while lipid peroxide (LPO) in plasma decreased (P < 0.01). But for control group, there were no remarkable changes after treatment, so it revealed that the improvement of Kidney-Yang Deficiency by ZCP is realized through regulating the organism's immunity and endocrine function as well as through scavenging the free radical agents.