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1.
Int J Chron Obstruct Pulmon Dis ; 19: 1233-1245, 2024.
Article En | MEDLINE | ID: mdl-38854590

Purpose: Smoking is a major risk factor for the group 3 PH. NT-proBNP is a biomarker for risk stratification in PH. This study aims to investigate the effects of smoking status and smoking index (SI) on group 3 PH and to evaluate the value of SI and SI combined with NT-proBNP in early diagnosis and prediction of disease severity. Patients and Methods: Four hundred patients with group 3 PH at the First Hospital of Shanxi Medical University between January 2020 and December 2021 were enrolled and divided into two groups: mild (30 mmHg ≤ pulmonary artery systolic pressure (PASP)≤50 mmHg) and non-mild (PASP >50 mmHg). The effect of smoking on group 3 PH was analyzed using univariate analysis, and logistic analysis was conducted to evaluate the risk of group 3 PH according to smoking status and SI. Spearman correlation coefficient was used to test the correlation between SI and the index of group 3 PH severity. The predictive value of SI was evaluated using a receiver operating characteristic (ROC) curve. Results: Correlation and logistic analyses showed that SI was associated with PH severity. Smoking status (P=0.009) and SI (P=0.039) were independent risk factors for non-mild group 3 PH, and ROC showed that the predictive value of SI (AUC:0.596) for non-mild PH was better than that of the recognized pro-brain natriuretic peptide (NT-proBNP) (AUC:0.586). SI can be used as a single predictive marker. SI and NT-proBNP can be formulated as prediction models for screening non-mild clinical cases (AUC:0.628). Conclusion: SI is a potentially ideal non-invasive predictive marker for group 3 PH. SI and NT-proBNP could be used to develop a prediction model for screening non-mild PH cases. This can greatly improve the predictive specificity of the established PH marker, NT-proBNP.


Biomarkers , Hypertension, Pulmonary , Natriuretic Peptide, Brain , Peptide Fragments , Predictive Value of Tests , Severity of Illness Index , Smoking , Humans , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Female , Male , Middle Aged , Retrospective Studies , Biomarkers/blood , Smoking/adverse effects , Smoking/blood , Smoking/epidemiology , Hypertension, Pulmonary/blood , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/etiology , Aged , Risk Factors , Risk Assessment , Prognosis , Pulmonary Disease, Chronic Obstructive/blood , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Disease, Chronic Obstructive/complications , China/epidemiology , Adult , Arterial Pressure
2.
J Pharmacol Exp Ther ; 388(2): 701-714, 2024 01 17.
Article En | MEDLINE | ID: mdl-38129127

Interstitial lung diseases (ILDs) are a group of restrictive lung diseases characterized by interstitial inflammation and pulmonary fibrosis. The incidence of ILDs associated with exposure to multiple hazards such as inhaled particles, fibers, and ingested soluble chemicals is increasing yearly, and there are no ideal drugs currently available. Our previous research showed that the novel and low-toxicity peptide DHα-(4-pentenyl)-ANPQIR-NH2 (DR3penA) had a strong antifibrotic effect on a bleomycin-induced murine model. Based on the druggability of DR3penA, we sought to investigate its effects on respirable particulate silicon dioxide (SiO2)- and soluble chemical paraquat (PQ)-induced pulmonary fibrosis in this study by using western blot, quantitative reverse-transcription polymerase chain reaction (RT-qPCR), immunofluorescence, H&E and Masson staining, immunohistochemistry, and serum biochemical assays. The results showed that DR3penA alleviated the extent of fibrosis by inhibiting the expression of fibronectin and collagen I and suppressed oxidative stress and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Further study revealed that DR3penA may mitigate pulmonary fibrosis by negatively regulating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and mitogen-activated protein kinase (MAPK) pathway. Unexpectedly, through the conversion of drug bioavailability under different routes of administration, DR3penA exerted antifibrotic effects equivalent to those of the positive control drug pirfenidone (PFD) at lower doses. In summary, DR3penA may be a promising lead compound for various fibrotic ILDs. SIGNIFICANCE STATEMENT: Our study verified that DHα-(4-pentenyl)-ANPQIR-NH2 (DR3penA) exhibited positive antifibrotic activity in pulmonary fibrosis induced by silicon dioxide (SiO2) particles and soluble chemical paraquat (PQ) and demonstrated a low-dose advantage compared to the small-molecule drug pirfenidone (PFD). The peptide DR3penA can be further developed for the treatment of multiple fibrotic lung diseases.


Pulmonary Fibrosis , Mice , Animals , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/drug therapy , Pulmonary Fibrosis/metabolism , Silicon Dioxide , Paraquat/toxicity , Paraquat/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Fibrosis , Bleomycin/toxicity , Lung
3.
FASEB J ; 37(11): e23225, 2023 11.
Article En | MEDLINE | ID: mdl-37855708

Pulmonary fibrosis (PF), which is caused by continuous alveolar epithelial cell injury and abnormal repair, is referred to as a difficult disease of the lung system by the World Health Organization due to its rapid progression, poor prognosis, and high mortality rate. However, there is still a lack of ideal therapeutic strategies. The peptide DR8 (DHNNPQIR-NH2 ), which is derived from rapeseed, exerted antifibrotic activity in the lung, liver, and kidney in our previous studies. By studying the structure-activity relationship and rational design, we introduced an unnatural hydrophobic amino acid (α-(4-pentenyl)-Ala) into DR8 and screened the novel peptide DR4penA (DHNα-(4-pentenyl)-APQIR-NH2 ), which had higher anti-PF activity, higher antioxidant activity and a longer half-life than DR8. Notably, DR4penA attenuated bleomycin- and paraquat-induced PF, and the anti-PF activity of DR4penA was equivalent to that of pirfenidone. Additionally, DR4penA suppressed the TGF-ß/Smad pathway in TGF-ß1-induced A549 cells and paraquat-induced rats. This study demonstrates that the novel peptide DR4penA is a potential candidate compound for PF therapy, and its antifibrotic activity in different preclinical models of PF provides a theoretical basis for further study.


Pulmonary Fibrosis , Rats , Animals , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/drug therapy , Pulmonary Fibrosis/metabolism , Bleomycin/adverse effects , Paraquat/adverse effects , Lung/metabolism , Transforming Growth Factor beta1/metabolism , Transforming Growth Factor beta/metabolism , Peptides/pharmacology , Peptides/therapeutic use , Signal Transduction
4.
Acta Pharm Sin B ; 13(2): 722-738, 2023 Feb.
Article En | MEDLINE | ID: mdl-36873181

Pulmonary fibrosis (PF) is a pathological change caused by repeated injuries and repair dysfunction of the alveolar epithelium. Our previous study revealed that the residues Asn3 and Asn4 of peptide DR8 (DHNNPQIR-NH2) could be modified to improve stability and antifibrotic activity, and the unnatural hydrophobic amino acids α-(4-pentenyl)-Ala and d-Ala were considered in this study. DR3penA (DHα-(4-pentenyl)-ANPQIR-NH2) was verified to have a longer half-life in serum and to significantly inhibit oxidative damage, epithelial-mesenchymal transition (EMT) and fibrogenesis in vitro and in vivo. Moreover, DR3penA has a dosage advantage over pirfenidone through the conversion of drug bioavailability under different routes of administration. A mechanistic study revealed that DR3penA increased the expression of aquaporin 5 (AQP5) by inhibiting the upregulation of miR-23b-5p and the mitogen-activated protein kinase (MAPK) pathway, indicating that DR3penA may alleviate PF by regulating MAPK/miR-23b-5p/AQP5. Safety evaluation showed that DR3penA is a peptide drug without obvious toxicity or acute side effects and has significantly improved safety compared to DR8. Thus, our findings suggest that DR3penA, as a novel and low-toxic peptide, has the potential to be a leading compound for PF therapy, which provides a foundation for the development of peptide drugs for fibrosis-related diseases.

5.
bioRxiv ; 2023 Mar 21.
Article En | MEDLINE | ID: mdl-36993179

How distal enhancers physically control promoters over large genomic distances, to enable cell-type specific gene expression, remains obscure. Using single-gene super-resolution imaging and acute targeted perturbations, we define physical parameters of enhancer-promoter communication and elucidate processes that underlie target gene activation. Productive enhancer-promoter encounters happen at 3D distances δ200 nm - a spatial scale corresponding to unexpected enhancer-associated clusters of general transcription factor (GTF) components of the Pol II machinery. Distal activation is achieved by increasing transcriptional bursting frequency, a process facilitated by embedding a promoter into such GTF clusters and by accelerating an underlying multi-step cascade comprising early phases in the Pol II transcription cycle. These findings help clarify molecular/biochemical signals involved in long-range activation and their means of transmission from enhancer to promoter.

6.
Nat Commun ; 13(1): 7672, 2022 12 20.
Article En | MEDLINE | ID: mdl-36539402

Transcription is a dynamic process. To detect the dynamic relationship among protein clusters of RNA polymerase II and coactivators, gene loci, and transcriptional activity, we insert an MS2 repeat, a TetO repeat, and inteins with a selection marker just downstream of the transcription start site. By optimizing the individual elements, we develop the Spliced TetO REpeAt, MS2 repeat, and INtein sandwiched reporter Gene tag (STREAMING-tag) system. Clusters of RNA polymerase II and BRD4 are observed proximal to the transcription start site of Nanog when the gene is transcribed in mouse embryonic stem cells. In contrast, clusters of MED19 and MED22 tend to be located near the transcription start site, even without transcription activity. Thus, the STREAMING-tag system reveals the spatiotemporal relationships between transcriptional activity and protein clusters near the gene. This powerful tool is useful for quantitatively understanding transcriptional regulation in living cells.


RNA Polymerase II , Transcription Factors , Animals , Mice , Transcription Factors/genetics , Transcription Factors/metabolism , RNA Polymerase II/genetics , RNA Polymerase II/metabolism , Nuclear Proteins/metabolism , Gene Expression Regulation , Inteins/genetics , Transcription, Genetic
7.
Soft Matter ; 18(33): 6192-6199, 2022 Aug 24.
Article En | MEDLINE | ID: mdl-35856647

Achieving tough and stable tissue adhesion under a physiological environment is of great significance for the clinical applications of hydrogel adhesives. The current tough hydrogel adhesives face challenges in the preservation of the maximal adhesion for a long time due to swelling. Here, we propose a double-network strategy for tough tissue adhesion by a hydrogel with long-term stability under a physiological environment. A double-network hydrogel consisting of a covalently crosslinked primary network with tunable hydrophilicity and a non-covalently crosslinked secondary network with functional groups is designed. The primary network exhibited hydrophobicity in the physiological environment, which could constrict the secondary network and limit the swelling of the entire hydrogel. The secondary network could form strong interlinks with tissue and provide large energy dissipation through the unzipping of its noncovalent crosslinks when separated by a force. The combination of the two networks resulted in a tough and stable tissue adhesion. A poly(N-isopropylacrylamide)/calcium alginate hydrogel synthesized based on this strategy realized an adhesion energy of 300-500 J m-2 with porcine tissues, and the maximal adhesion could be maintained for over 1000 min after submerging in a PBS solution at 37 °C. The swelling behavior of the hydrogel and changes in mechanical properties under the physiological environment are studied, and its application in repairing the aorta wound is demonstrated.


Alginates , Hydrogels , Animals , Hydrophobic and Hydrophilic Interactions , Mechanical Phenomena , Swine , Tissue Adhesions
8.
J Pharmacol Exp Ther ; 382(2): 100-112, 2022 08.
Article En | MEDLINE | ID: mdl-35772783

Pulmonary fibrosis (PF), which is characterized by enhanced extracellular matrix (ECM) deposition, is an interstitial lung disease that lacks an ideal clinical treatment strategy. It has an extremely poor prognosis, with an average survival of 3-5 years after diagnosis. Our previous studies have shown that the antioxidant peptide DR8 (DHNNPQIR-NH2), which is extracted and purified from rapeseed, can alleviate PF and renal fibrosis. However, natural peptides are easily degraded by proteases in vivo, which limits their potency. We have since synthesized a series of DR8 analogs based on amino acid scanning substitution. DR7dA [DHNNPQ (D-alanine) R-NH2] is an analog of DR8 in which L-isoleucine (L-Ile) is replaced with D-alanine (D-Ala), and its half-life is better than that of DR8. In the current study, we verified that DR7dA ameliorated tumor growth factor (TGF)-ß1-induced fibrogenesis and bleomycin-induced PF. The results indicated that DR7dA reduced the protein and mRNA levels of TGF-ß1 target genes in TGF-ß1-induced models. Surprisingly, DR7dA blocked fibrosis in a lower concentration range than DR8 in cells. In addition, DR7dA ameliorated tissue pathologic changes and ECM accumulation in mice. BLM caused severe oxidative damage, but administration of DR7dA reduced oxidative stress and restored antioxidant defense. Mechanistic studies suggested that DR7dA inhibits ERK, P38, and JNK phosphorylation in vivo and in vitro All results indicated that DR7dA attenuated PF by inhibiting ECM deposition and oxidative stress via blockade of the mitogen-activated protein kinase (MAPK) pathway. Hence, compared with its parent peptide, DR7dA has higher druggability and could be a candidate compound for PF treatment in the future. SIGNIFICANCE STATEMENT: In order to improve druggability of DR8, we investigated the structure-activity relationship of it and replaced the L-isoleucine with D-alanine. We found that the stability and antifibrotic activity of DR7dA were significantly improved than DR8, as well as DR7dA significantly attenuated tumor growth factor (TGF)-ß1-induced fibrogenesis and ameliorated bleomycin-induced fibrosis by inhibiting extracellular matrix deposition and oxidative stress via blockade of the MAPK pathway, suggesting DR7dA may be a promising candidate compound for the treatment of PF.


Antioxidants , Pulmonary Fibrosis , Alanine/chemistry , Angiotensin II , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , Bleomycin , Fibrosis , Isoleucine/chemistry , Lung/metabolism , Mice , Mitogen-Activated Protein Kinases , Peptides/chemistry , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/drug therapy , Pulmonary Fibrosis/metabolism , Transforming Growth Factor beta1
9.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 38(5): 559-563, 2022 Sep.
Article Zh | MEDLINE | ID: mdl-37088770

OBJECTIVE: To investigate the effects of chronic intermittent hypoxia (CIH) on the expression of transforming growth factor-ß (TGF-ß), P-samd3, serum laminin (LN) and hyaluronidase (HA) in mouse lung tissues and the protective effects of Bu Zhong Yi Qi decoction on lung interstitial deposition damage in CIH mice. METHODS: Fifty SPF-grade C57BL mice were randomly divided into five groups (n=10): blank control group, CIH model group, and CIH+ low, medium and high doses of Bu Zhong Yi Qi decoction group. Mice were placed under normoxia or CIH conditions, respectively. The Chinese medicine group was given the corresponding doses of drugs. HE staining was performed to assess pathological changes and Masson staining was performed to assess collagen deposition. Western blot was performed to detect the expressions of channel proteins such as TGF-ß1, P-smad3 and down stream α-SMA and Collagen I. ELISA was performed to detect the serum levels of TGF-ß1, LN and HA. RESULTS: HE staining showed alveolar collapse, septal thickening and epithelial cell necrosis in CIH mice, Masson showed massive collagen fiber proliferation and deposition in lung interstitium, while the above changes in lung tissues were significantly improved in the CIH + Bu Zhong Yi Qi decoction groups compared with the CIH group. TGF-ß1, P-smad3 and Collagen I, Collagen Ⅲ, and α-SMA expression levels were increased compared with the blank control group (P<0.05), and the expressions of TGF-ß1 and LN in serum were upregulated (P<0.05). The expressions of TGF-ß1, P-smad3, Collagen I protein and SMA-α in the lung tissues of the CIH+ Bu Zhong Yi Qi decoction groups were downregulated significantly compared with those of the CIH group (P<0.05), and the improvement of multiple indexes in the CIH+high-dose CIH intervention group was better than those of the low-dose group (P<0.05). CONCLUSION: Bu Zhong Yi Qi decoction can inhibit alveolar structural changes and excessive collagen deposition in the interstitium of CIH mice, and then improve lung function in CIH mice. The mechanism may be related to the down-regulation of protein expression related to TGF-ß/smads signaling pathway by Bu Zhong Yi Qi decoction.


Drugs, Chinese Herbal , Pulmonary Fibrosis , Mice , Animals , Transforming Growth Factor beta1/metabolism , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , Mice, Inbred C57BL , Transforming Growth Factor beta/metabolism , Fibrosis
10.
Curr Opin Syst Biol ; 312022 Sep.
Article En | MEDLINE | ID: mdl-37091742

Decades of in vitro biochemical reconstitution, genetics and structural biology studies have established a vast knowledge base on the molecular mechanisms of chromatin regulation and transcription. A remaining challenge is to understand how these intricate biochemical systems operate in the context of the 3D genome organization and in the crowded and compartmentalized nuclear milieu. Here we review recent progress in this area based on high-resolution imaging approaches.

11.
Nat Biotechnol ; 39(11): 1385-1393, 2021 11.
Article En | MEDLINE | ID: mdl-34635835

Live cell imaging with high spatiotemporal resolution and high detection sensitivity facilitates the study of the dynamics of cellular structure and function. However, extracting high-resolution 4D (3D space plus time) information from live cells remains challenging, because current methods are slow, require high peak excitation intensities or suffer from high out-of-focus background. Here we present 3D interferometric lattice light-sheet (3D-iLLS) imaging, a technique that requires low excitation light levels and provides high background suppression and substantially improved volumetric resolution by combining 4Pi interferometry with selective plane illumination. We demonstrate that 3D-iLLS has an axial resolution and single-particle localization precision of 100 nm (FWHM) and <10 nm (1σ), respectively. We illustrate the performance of 3D-iLLS in a range of systems: single messenger RNA molecules, nanoscale assemblies of transcription regulators in the nucleus, the microtubule cytoskeleton and mitochondria organelles. The enhanced 4D resolution and increased signal-to-noise ratio of 3D-iLLS will facilitate the analysis of biological processes at the sub-cellular level.


Imaging, Three-Dimensional , Interferometry , Imaging, Three-Dimensional/methods , Microscopy, Fluorescence/methods , Mitochondria
12.
Eur J Pharm Sci ; 167: 106009, 2021 Dec 01.
Article En | MEDLINE | ID: mdl-34537373

Pulmonary fibrosis is a chronic progressive lung disease that lacks effective treatments in clinic. It is characterized by repair disorder of epithelial cells, formation of fibroblast foci as well as destruction of alveolar structure. Previously we first determined that parent peptide DR8 (DHNNPQIR-NH2) has anti-fibrotic activity in bleomycin-induced mice. In order to further improve the druggability of DR8, including anti-fibrotic activity, stability and security, the structure-activity relationship was investigated using a series of D-amino acid and alanine scanning analogs of DR8. The results indicated that peptides DR8-3D and DR8-8A exhibited potent anti-fibrotic activity and better stability. Further mechanism research revealed that DR8-3D and DR8-8A ameliorated lung fibrosis by inhibiting TGF-ß1 mediated epithelial-mesenchymal transition process and ERK1/2 signaling pathway in vitro and in vivo. Moreover, we found that anti-fibrotic activity of DR8 was closely related to the residues aspartic acid (Asp)1, histidine (His)2, proline (Pro)5 and glutamine (Gln)6, which suggested that the position of residues asparagine (Asn)3, asparagine (Asn)4, isoleucine (Ile)7 and arginine (Arg)8 could be further modified to optimized its anti-fibrotic effect. Therefore, we consider that DR8-3D and DR8-8A not only could be used as a potential leading compound for the treatment of bleomycin-induced lung fibrosis but also laid a foundation for the development of new anti-fibrotic drugs.


Pulmonary Fibrosis , Transforming Growth Factor beta1 , Animals , Bleomycin , Epithelial-Mesenchymal Transition , Lung/metabolism , MAP Kinase Signaling System , Mice , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/drug therapy , Transforming Growth Factor beta1/metabolism
13.
Biochem Soc Trans ; 49(3): 1299-1309, 2021 06 30.
Article En | MEDLINE | ID: mdl-34060610

Establishing cell-type-specific gene expression programs relies on the action of distal enhancers, cis-regulatory elements that can activate target genes over large genomic distances - up to Mega-bases away. How distal enhancers physically relay regulatory information to target promoters has remained a mystery. Here, we review the latest developments and insights into promoter-enhancer communication mechanisms revealed by live-cell, real-time single-molecule imaging approaches.


Enhancer Elements, Genetic/genetics , Promoter Regions, Genetic/genetics , Single Molecule Imaging/methods , Transcription Factors/metabolism , Transcription, Genetic , Animals , Binding Sites/genetics , Gene Expression Regulation , Humans , Protein Binding
14.
Life Sci ; 276: 119403, 2021 Jul 01.
Article En | MEDLINE | ID: mdl-33785339

AIMS: Many dietary NASH models require a long duration to establish (4-6 months). Chronic intermittent hypoxia (CIH), a cardinal hallmark of obstructive sleep apnea (OSA), may accelerate the progression of pediatric nonalcoholic fatty liver disease (NAFLD). However, diet-induced obese (DIO) mice exposed to CIH have not been perceived as a fast or reliable tool in NASH research. This study was designed to establish a rapid juvenile murine NASH model, and determine whether the combination of CIH and a western-style diet (hypercaloric fatty diet plus high fructose) can fully display key pathologic features of NASH. METHODS: C57BL/6 N mice (3 weeks old) fed a control diet or western diet (WD) were exposed to CIH (9% nadir of inspired oxygen levels) or room air for 6 and 12 weeks. KEY FINDINGS: The Control/CIH group mainly exhibited hyperinsulinemia and insulin resistance (IR). In contrast, mice fed a WD developed weight gain after 3 weeks, microvesicular steatosis in 6 weeks, and indices of metabolic disorders at 12 weeks. Furthermore, CIH exposure accelerated WD- induced macromicrovesicular steatosis (liver triglycerides and de novo lipogenesis), liver injury (ballooned hepatocytes and liver enzymes), lobular/portal inflammation (inflammatory cytokines and macrophage recruitment), and fibrogenesis (hydroxyproline content and TGF-ß protein). Notably, only the WD/CIH group exhibited elevated hepatic MDA content, protein levels of NOX4, α-SMA and collagen I, as well as reduced Nrf2 and HO-1 protein expression. SIGNIFICANCE: WD/CIH treatment rapidly mimics the histological characteristics of pediatric NASH with metabolic dysfunction and fibrosis, representing an appropriate experimental model for NASH research.


Diet, Western/adverse effects , Hypoxia/physiopathology , Inflammation/pathology , Insulin Resistance , Non-alcoholic Fatty Liver Disease/pathology , Oxidative Stress , Animals , Animals, Newborn , Inflammation/etiology , Inflammation/metabolism , Male , Mice , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/etiology , Non-alcoholic Fatty Liver Disease/metabolism
15.
Stem Cell Res Ther ; 12(1): 102, 2021 02 03.
Article En | MEDLINE | ID: mdl-33536064

Spinal cord injury (SCI) often leads to serious motor and sensory dysfunction of the limbs below the injured segment. SCI not only results in physical and psychological harm to patients but can also cause a huge economic burden on their families and society. As there is no effective treatment method, the prevention, treatment, and rehabilitation of patients with SCI have become urgent problems to be solved. In recent years, mesenchymal stem cells (MSCs) have attracted more attention in the treatment of SCI. Although MSC therapy can reduce injured volume and promote axonal regeneration, its application is limited by tumorigenicity, a low survival rate, and immune rejection. Accumulating literature shows that exosomes have great potential in the treatment of SCI. In this review, we summarize the existing MSC-derived exosome studies on SCI and discuss the advantages and challenges of treating SCI based on exosomes derived from MSCs.


Exosomes , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Spinal Cord Injuries , Humans , Spinal Cord , Spinal Cord Injuries/therapy
16.
J Phys Condens Matter ; 33(13)2021 Jan 25.
Article En | MEDLINE | ID: mdl-33412528

Photoelectron spectroscopy is used to show that thick adamantane films on Cu(111) have a negative electron affinity of -0.3 ± 0.1 eV. The ionization potential is obtained as 8.55 ± 0.15 eV resulting in a band gap of 8.9 ± 0.1 eV. For films of about 1.4 monolayer thickness the electron affinity is close to zero and the valence bands are shifted toward the Fermi energy due to charge transfer from Cu 3d bands.

17.
Nat Struct Mol Biol ; 27(11): 1032-1040, 2020 11.
Article En | MEDLINE | ID: mdl-32958948

Transcription activation by distal enhancers is essential for cell-fate specification and maintenance of cellular identities. How long-range gene regulation is physically achieved, especially within complex regulatory landscapes of non-binary enhancer-promoter configurations, remains elusive. Recent nanoscopy advances have quantitatively linked promoter kinetics and ~100- to 200-nm-sized clusters of enhancer-associated regulatory factors (RFs) at important developmental genes. Here, we further dissect mechanisms of RF clustering and transcription activation in mouse embryonic stem cells. RF recruitment into clusters involves specific molecular recognition of cognate DNA and chromatin-binding sites, suggesting underlying cis-element clustering. Strikingly, imaging of tagged genomic loci, with ≤1 kilobase and ~20-nanometer precision, in live cells, reveals distal enhancer clusters over the extended locus in frequent close proximity to target genes-within RF-clustering distances. These high-interaction-frequency enhancer-cluster 'superclusters' create nano-environments wherein clustered RFs activate target genes, providing a structural framework for relating genome organization, focal RF accumulation and transcription activation.


Enhancer Elements, Genetic , Mouse Embryonic Stem Cells/metabolism , Optical Imaging , Promoter Regions, Genetic , Transcriptional Activation , Animals , Cell Line , Genetic Loci , Genomics/methods , Male , Mice , Mice, Inbred C57BL , Optical Imaging/methods
18.
J Phys Chem Lett ; 11(10): 3882-3888, 2020 May 21.
Article En | MEDLINE | ID: mdl-32338921

A significant, fundamental challenge in the field of valleytronics is how to generate and regulate valley-polarized currents in practical ways. Here, we discover a new mechanism for producing valley polarization in a monolayer transition metal dichalcogenide superlattice, in which valley-resolved gaps are formed at the supercell Brillouin zone boundaries and centers due to intervalley scattering. When the incident energy of the electron lies in the gaps, the available states are valley polarized, thus providing a valley-polarized current from the superlattice. We show that the direction and strength of the valley polarization may be further tuned by varying the potential applied to the superlattice. The transmission can have a net valley polarization of 55% for a four-period heterostructure. Moreover, two such valley filters in series may function as an electrostatically controlled giant valleyresistance device, representing a zero-magnetic field counterpart to the familiar giant magnetoresistance device.

19.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(5): 414-418, 2020 Sep.
Article Zh | MEDLINE | ID: mdl-33629553

Objective: To explore the role of transforming growth factor-ß (TGF-ß) signaling pathway in xiaotan huayu liqiao traditional Chinese medicine compound (XC)'s anti-myocardial fibrosis in chronic intermittent hypoxia (CIH) rats. Methods: Forty SD rats were randomly divided into normoxia group, oxygen + traditional Chinese medicine compound group ( TCMC), Chronic intermittent hypoxia model group (CIH), TCMC + CIH, 10 in each group. CIH cabin was built by filling with nitrogen and oxygen. Firstly, the volume fraction of oxygen in the cabin reduced from 21% to 9% in 90 s by filling the cabin with nitrogen. And then it gradually rose to 21% by reoxygenating in 90s, as a cycle. CIH and TCMC+CIH group rats were placed in the CIH device, while normoxia and TCMC group rats were placed in the normal oxygen chamber. In addition, rats in TCMC +CIH group and TCMC group were treated with XC crude drug (24 g/kg) daily by gavage, while rats in CIH group and normoxia group were given equal volume normal saline. Using sirius red staining, the collagen in myocardial interstitium was visualized. The protein expressions of collagen I, collagen III and fibronectin were detected by Western blot, p-Smad3, p-Smad2 and TGF-ß protein in the TGF-ß/Smads signaling pathway were also analyzed by Western blot. The mRNA expressions of matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of metalloproteinase -2(TIMP-2) were measured by real-time quantitative polymerase chain reaction (PCR). Results: Compared with the rats exposed to normoxia, the CIH rats showed obvious collagen deposition, protein expressions of collagen I, collagen III and fibronectin were significantly increased in the myocardial tissue (P<0.01). The protein expression levels of TGF-ß, p-smad2 and p-smad3 in the myocardial tissue of the CIH rats were also significantly increased (P<0.01). The up-regulation of TIMP-2 mRNA in the myocardial tissues resulted in the decrease of MMP-2 mRNA(P<0.01). XC reduced myocardial fibrosis of CIH rats and inhibited the expressions of collagen I and collagen III and fibronectin protein (P<0.05,P<0.01,P<0.05, respectively). The further mechanism study showed that XC inhibited the expression of TGF-ß (P<0.01), which down-regulated the expressions of p-smad2, p-smad3 and TIMP-2 (P<0.05). Conclusion: XC could reduce the expression of TGF-ß and smad2/3 phosphorylation, down-regulate the expression of TIMP-2, which would inhibit the formation of myocardial fibrosis in CIH rats, and improve the myocardial function of CIH rats.


Matrix Metalloproteinase 2 , Medicine, Chinese Traditional , Animals , Fibrosis , Hypoxia , Rats , Rats, Sprague-Dawley , Transforming Growth Factor beta1
20.
Brain ; 142(8): 2215-2229, 2019 08 01.
Article En | MEDLINE | ID: mdl-31199454

Charcot-Marie-Tooth disease is a hereditary motor and sensory neuropathy exhibiting great clinical and genetic heterogeneity. Here, the identification of two heterozygous missense mutations in the C1orf194 gene at 1p21.2-p13.2 with Charcot-Marie-Tooth disease are reported. Specifically, the p.I122N mutation was the cause of an intermediate form of Charcot-Marie-Tooth disease, and the p.K28I missense mutation predominately led to the demyelinating form. Functional studies demonstrated that the p.K28I variant significantly reduced expression of the protein, but the p.I122N variant increased. In addition, the p.I122N mutant protein exhibited the aggregation in neuroblastoma cell lines and the patient's peroneal nerve. Either gain-of-function or partial loss-of-function mutations to C1ORF194 can specify different causal mechanisms responsible for Charcot-Marie-Tooth disease with a wide range of clinical severity. Moreover, a knock-in mouse model confirmed that the C1orf194 missense mutation p.I121N led to impairments in motor and neuromuscular functions, and aberrant myelination and axonal phenotypes. The loss of normal C1ORF194 protein altered intracellular Ca2+ homeostasis and upregulated Ca2+ handling regulatory proteins. These findings describe a novel protein with vital functions in peripheral nervous systems and broaden the causes of Charcot-Marie-Tooth disease, which open new avenues for the diagnosis and treatment of related neuropathies.


Charcot-Marie-Tooth Disease/genetics , Animals , Calcium/metabolism , Gene Knock-In Techniques , Humans , Mice , Mice, Transgenic , Mutation, Missense , Pedigree
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