Publications by authors named "Dingfang Bu"

59 Publications

Compensatory role of endogenous sulfur dioxide in nitric oxide deficiency-induced hypertension.

Redox Biol 2021 Nov 18;48:102192. Epub 2021 Nov 18.

Department of Pediatrics, Peking University First Hospital, Beijing, China. Electronic address:

Objective: This study aimed to determine the communicational pattern of gaseous signaling molecules sulfur dioxide (SO) and nitric oxide (NO) between vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs), and elucidate the compensatory role and significance of endogenous SO in the development of hypertension due to NO deficiency.

Approach And Results: Blood pressure was monitored by the tail-cuff and implantable physiological signal telemetry in L-nitro-arginine methyl ester (l-NAME)-induced hypertensive mice, and structural alterations of mouse aortic vessels were detected by the elastic fiber staining method. l-NAME-treated mice showed decreased plasma NO levels, increased SO levels, vascular remodeling, and increased blood pressure, and application of l-aspartate-β-hydroxamate, which inhibits SO production, further aggravated vascular structural remodeling and increased blood pressure. Moreover, in a co-culture system of HAECs and HASMCs, NO from HAECs did not influence aspartate aminotransferase (AAT)1 protein expression but decreased AAT1 activity in HASMCs, thereby resulting in the inhibition of endogenous SO production. Furthermore, NO promoted S-nitrosylation of AAT1 protein in HASMCs and purified AAT1 protein. Liquid chromatography with tandem mass spectrometry showed that the Cys192 site of AAT1 purified protein was modified by S-nitrosylation. In contrast, dithiothreitol or C192S mutations in HASMCs blocked NO-induced AAT1 S-nitrosylation and restored AAT1 enzyme activity.

Conclusion: Endothelium-derived NO inhibits AAT activity by nitrosylating AAT1 at the Cys192 site and reduces SO production in HASMCs. Our findings suggest that SO acts as a compensatory defense system to antagonize vascular structural remodeling and hypertension when the endogenous NO pathway is disturbed.
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http://dx.doi.org/10.1016/j.redox.2021.102192DOI Listing
November 2021

Endogenous Taurine Downregulation Is Required for Renal Injury in Salt-Sensitive Hypertensive Rats via CBS/HS Inhibition.

Oxid Med Cell Longev 2021 25;2021:5530907. Epub 2021 Aug 25.

Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.

Although taurine is known to exert an antihypertensive effect, it is unclear whether it is involved in the mechanism for hypertension-related target organ injury. To reveal the role of endogenous taurine in renal injury formation during salt-sensitive hypertension and clarify its mechanisms, both salt-sensitive Dahl rats and salt-resistant SS-13BN rats were fed a high-salt diet (8% NaCl) and given 2% taurine for 6 weeks. Rat systolic blood pressure (SBP) was measured by the tail-cuff method and artery catheterization. Kidney ultrastructure was observed under an electron microscope. Taurine content and mRNA and protein levels of taurine synthases, cysteine dioxygenase type 1 (CDO1) and cysteine sulfinic acid decarboxylase (CSAD), were decreased in Dahl rats fed a high-salt diet. However, taurine supplementation and the resulting increase in renal taurine content reduced the increased SBP and improved renal function and structural damage in high-salt diet-fed Dahl rats. In contrast, taurine did not affect SS-13BN SBP and renal function and structure. Taurine intervention increased the renal HS content and enhanced cystathionine--synthase (CBS) expression and activity in Dahl rats fed a high-salt diet. Taurine reduced the renin, angiotensin II, and aldosterone contents and the levels of oxidative stress indices in Dahl rat renal tissues but increased antioxidant capacity, antioxidant enzyme activity, and protein expression. However, taurine failed to achieve this effect in the renal tissue of SS-13BN rats fed a high-salt diet. Pretreatment with the CBS inhibitor HA or renal CBS knockdown inhibited HS generation and subsequently blocked the effect of taurine on renin, superoxide dismutase 1 (SOD1), and superoxide dismutase 2 (SOD2) levels in high-salt-stimulated Dahl renal slices. In conclusion, the downregulation of endogenous taurine production resulted in a decrease in the renal CBS/HS pathway. This decrease subsequently promoted renin-angiotensin-aldosterone system (RAAS) activation and oxidative stress in the kidney, ultimately contributing to renal injury in salt-sensitive Dahl rats.
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http://dx.doi.org/10.1155/2021/5530907DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8413057PMC
August 2021

Methylome profiling identifies TCHH methylation in CfDNA as a noninvasive marker of liver metastasis in colorectal cancer.

FASEB J 2021 07;35(7):e21720

Division of General Surgery, Peking University First Hospital, Beijing, China.

Methylation of circulating free DNA (CfDNA) has emerged as an efficient marker of tumor screening and prognostics. However, no efficient methylation marker has been developed for monitoring liver metastasis (LM) in colorectal cancer (CRC). Utilizing methylome profiling and bisulfite sequencing polymerase chain reaction of paired primary and LM sites, significantly increased methylation of TCHH was identified in the process of LM in CRC in the present study. Methylight analysis of TCHH methylation in CfDNA displayed a promisingly discriminative power between CRC with and without LM. Besides, significant coefficient of TCHH methylation and LM tumor volume was also validated. Together, these results indicated the potential of TCHH methylation in CfDNA as a monitoring marker of LM in CRC.
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http://dx.doi.org/10.1096/fj.202100266RDOI Listing
July 2021

Endothelial Cell-Derived SO Controls Endothelial Cell Inflammation, Smooth Muscle Cell Proliferation, and Collagen Synthesis to Inhibit Hypoxic Pulmonary Vascular Remodelling.

Oxid Med Cell Longev 2021 17;2021:5577634. Epub 2021 Apr 17.

Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.

Hypoxic pulmonary vascular remodelling (PVR) is the major pathological basis of aging-related chronic obstructive pulmonary disease and obstructive sleep apnea syndrome. The pulmonary artery endothelial cell (PAEC) inflammation, and pulmonary artery smooth muscle cell (PASMC) proliferation, hypertrophy and collagen remodelling are the important pathophysiological components of PVR. Endogenous sulfur dioxide (SO) was found to be a novel gasotransmitter in the cardiovascular system with its unique biological properties. The study was aimed to investigate the role of endothelial cell- (EC-) derived SO in the progression of PAEC inflammation, PASMC proliferation, hypertrophy and collagen remodelling in PVR and the possible mechanisms. EC-specific aspartic aminotransferase 1 transgenic (EC-AAT1-Tg) mice were constructed . Pulmonary hypertension was induced by hypoxia. Right heart catheterization and echocardiography were used to detect mouse hemodynamic changes. Pathologic analysis was performed in the pulmonary arteries. High-performance liquid chromatography was employed to detect the SO content. Human PAECs (HPAECs) with lentiviruses containing AAT1 cDNA or shRNA and cocultured human PASMCs (HPASMCs) were applied . SO probe and enzyme-linked immunosorbent assay were used to detect the SO content and determine p50 activity, respectively. Hypoxia caused a significant reduction in SO content in the mouse lung and HPAECs and increases in right ventricular systolic pressure, pulmonary artery wall thickness, muscularization, and the expression of PAEC ICAM-1 and MCP-1 and of PASMC Ki-67, collagen I, and -SMA ( < 0.05). However, EC-AAT1-Tg with sufficient SO content prevented the above increases induced by hypoxia ( < 0.05). Mechanistically, EC-derived SO deficiency promoted HPAEC ICAM-1 and MCP-1 and the cocultured HPASMC Ki-67 and collagen I expression, which was abolished by andrographolide, an inhibitor of p50 ( < 0.05). Meanwhile, EC-derived SO deficiency increased the expression of cocultured HPASMC -SMA ( < 0.05). Taken together, these findings revealed that EC-derived SO inhibited p50 activation to control PAEC inflammation in an autocrine manner and PASMC proliferation, hypertrophy, and collagen synthesis in a paracrine manner, thereby inhibiting hypoxic PVR.
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http://dx.doi.org/10.1155/2021/5577634DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8068783PMC
May 2021

Endogenous hydrogen sulfide regulates xCT stability through persulfidation of OTUB1 at cysteine 91 in colon cancer cells.

Neoplasia 2021 05 18;23(5):461-472. Epub 2021 Apr 18.

Division of General Surgery, Peking University First Hospital, Beijing, China. Electronic address:

Increased xCT and transsulfuration pathway has been associated with metabolic reprogramming of colorectal cancer. However, the correlation between these 2 events and the underlying molecular mechanism remains obscure. xCT expression was determined in tissue microarrays of colorectal cancer. RNA sequencing and functional assays in vitro was adopted to delineate the involvement of transsulfuration pathway in the proper function of xCT in maintaining the chemoresistant phenotype. The synthetic lethality of blocking xCT and the transsulfuration pathway was investigated both in vitro and in vivo. The up-regulation of the transsulfuration pathway after inhibiting xCT in colon cancer cells was evident and exogenous HS partially reversed the loss of chemoresistance phenotype after inhibiting xCT. Mechanistically, CTH derived HS increased the stability of xCT through persulfidation of OTU domain-containing ubiquitin aldehyde-binding protein 1 at cysteine 91. AOAA and Erastin resulted in synthetic lethality both in vitro and in vivo, which was mediated through increased ferroptosis and apoptosis. Our findings suggest that a reciprocal regulation exists between xCT and the transsulfuration pathway, which is a targetable metabolic vulnerability. Mechanistically, CTH derived HS increased the stability of xCT through persulfidation of OTU domain-containing ubiquitin aldehyde-binding protein 1 at cysteine 91.
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http://dx.doi.org/10.1016/j.neo.2021.03.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8081877PMC
May 2021

Endogenous SO-dependent Smad3 redox modification controls vascular remodeling.

Redox Biol 2021 05 18;41:101898. Epub 2021 Feb 18.

Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China; Key Laboratory of Cardiovascular Sciences, Ministry of Education, China. Electronic address:

Sulfur dioxide (SO) has emerged as a physiological relevant signaling molecule that plays a prominent role in regulating vascular functions. However, molecular mechanisms whereby SO influences its upper-stream targets have been elusive. Here we show that SO may mediate conversion of hydrogen peroxide (HO) to a more potent oxidant, peroxymonosulfite, providing a pathway for activation of HO to convert the thiol group of protein cysteine residues to a sulfenic acid group, aka cysteine sulfenylation. By using site-centric chemoproteomics, we quantified >1000 sulfenylation events in vascular smooth muscle cells in response to exogenous SO. Notably, ~42% of these sulfenylated cysteines are dynamically regulated by SO, among which is cysteine-64 of Smad3 (Mothers against decapentaplegic homolog 3), a key transcriptional modulator of transforming growth factor β signaling. Sulfenylation of Smad3 at cysteine-64 inhibits its DNA binding activity, while mutation of this site attenuates the protective effects of SO on angiotensin II-induced vascular remodeling and hypertension. Taken together, our findings highlight the important role of SO in vascular pathophysiology through a redox-dependent mechanism.
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http://dx.doi.org/10.1016/j.redox.2021.101898DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7933484PMC
May 2021

Persulfidation of transcription factor FOXO1 at cysteine 457: A novel mechanism by which HS inhibits vascular smooth muscle cell proliferation.

J Adv Res 2021 Jan 1;27:155-164. Epub 2020 Jul 1.

Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.

Introduction: The proliferation of vascular smooth muscle cells (VSMCs) is an important physiological and pathological basis for many cardiovascular diseases. Endogenous hydrogen sulfide (HS), the third gasotransmitter, is found to preserve vascular structure by inhibiting VSMC proliferation. However, the mechanism by which HS suppresses VSMC proliferation has not been fully clear.

Objectives: This study aimed to explore whether HS persulfidates the transcription factor FOXO1 to inhibit VSMC proliferation.

Methods: After the proliferation of VSMC A7r5 cells was induced by endothelin-1 (ET-1), FOXO1 phosphorylation and proliferating cell nuclear antigen (PCNA) expression were detected by Western blotting, the degree of FOXO1 nuclear exclusion and PCNA fluorescent signals in the nucleus were detected by immunofluorescence, and the persulfidation of FOXO1 was measured through a biotin switch assay.

Results: The results showed that ET-1 stimulation increased cell proliferation, FOXO1 phosphorylation and FOXO1 nuclear exclusion to the cytoplasm in the cells. However, pretreatment with NaHS, an HS donor, successfully abolished the ET-1-induced increases in the VSMC proliferation, FOXO1 phosphorylation, and FOXO1 nuclear exclusion to the cytoplasm. Mechanistically, HS persulfidated the FOXO1 protein in A7r5 and 293T cells, and the thiol reductant DTT reversed this effect. Furthermore, the C457S mutation of FOXO1 abolished the HS-induced persulfidation of FOXO1 in the cells and the subsequent inhibitory effects on FOXO1 phosphorylation at Ser256, FOXO1 nuclear exclusion to the cytoplasm and cell proliferation.

Conclusion: Thus, our findings demonstrated that HS might inhibit VSMC proliferation by persulfidating FOXO1 at Cys457 and subsequently preventing FOXO1 phosphorylation at Ser256.
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http://dx.doi.org/10.1016/j.jare.2020.06.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7728583PMC
January 2021

Aminooxyacetic acid (AOAA) sensitizes colon cancer cells to oxaliplatin via exaggerating apoptosis induced by ROS.

J Cancer 2020 20;11(7):1828-1838. Epub 2020 Jan 20.

Division of General Surgery, Peking University First Hospital, Peking University, 8 Xi Shiku Street, Beijing, 100034, People's Republic of China.

As the third confirmed gaseous transmitter, the role of hydrogen sulfide (HS) in the pathogenesis of multiple types of cancer has been attracting increasing attention. Increased expression of cystathionine β-synthase (CBS) and HS in colon cancer tissue samples has been validated and tumor-derived HS, mainly produced by CBS, stimulates bioenergetics, cell proliferation, and angiogenesis in colon cancer. Recently, the therapeutic manipulation of HS has been proposed as a promising anticancer approach. However, the effect of aminooxyacetic acid (AOAA), which has been widely used as an inhibitor of CBS dependent synthesis of HS, on the chemotherapeutic effect of oxaliplatin (OXA) and the underlying mechanisms remain to be illustrated. We examined the expression of CBS in human colorectal cancer specimens and matched normal mucosa by immunohistochemistry. The effect of AOAA on the sensitivity of colon cancer cells to OXA and the level of apoptosis induced by caspase cascade was investigated in both HCT116 and HT29 cell lines utilizing CCK-8 assays, flow cytometry analysis and western blot analysis. The endogenous levels of reactive oxygen species (ROS) were detected fluorescently by DCF-DA, and glutathione (GSH) levels were measured by a Total GSH Detection Kit. Tumor bearing xenograft mouse models and imaging systems were further used to investigate the effect of AOAA and immunohistochemistry (IHC) and TUNEL analysis were performed. In the current study, we confirmed CBS, the main target of AOAA, is overexpressed in human colorectal cancer by immunohistochemistry. The inhibitory effect of AOAA on the synthesis of HS was validated utilizing fluorescent probe and specific electrode. AOAA significantly reduced the IC50 values of OXA in both colon cancer cell lines. Co-incubation with AOAA elicited increased apoptosis induced by OXA, featured by increased activation of caspase cascade. Besides, AOAA further increased the levels of ROS induced by OXA and attenuated the synthesis of glutathione (GSH), which is a vital antioxidant. Besides, the results of imaging and following IHC and TUNEL analysis were in accordance with cellular experiments, indicating that AOAA sensitizes colon cancer cells to OXA via exaggerating intrinsic apoptosis. The results suggested that CBS is overexpressed in colorectal cancer tissues and AOAA sensitizes colon cancer cells to OXA via exaggerating apoptosis both and . Decreasing the endogenous level of GSH and consequently impaired detoxification of ROS might be one of the mechanisms underlying the effect of AOAA.
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http://dx.doi.org/10.7150/jca.35375DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7052847PMC
January 2020

The novel long noncoding RNA CRART16 confers cetuximab resistance in colorectal cancer cells by enhancing ERBB3 expression via miR-371a-5p.

Cancer Cell Int 2020 4;20:68. Epub 2020 Mar 4.

1Department of General Surgery, Peking University First Hospital, Beijing, 100034 People's Republic of China.

Background: Long noncoding RNAs (lncRNAs) have been shown to participate in multiple biological processes and confer drug resistance. However, it remains unclear whether lncRNAs are involved in conferring cetuximab resistance in colorectal cancer (CRC) cells.

Methods: Cell Counting Kit-8 (CCK-8) assays were performed to assess the sensitivity of CRC cell lines to cetuximab treatment. We incubated Caco-2 cells, which are partially responsive to cetuximab, with increasing concentrations of cetuximab for approximately 6 months to generate Caco-2 cetuximab-resistant (Caco-2 CR) cells. Microarray analysis comparing Caco-2 CR with Caco-2 cells was used to identify lncRNAs that were potentially related to cetuximab resistance. Caco-2 cells were stably transduced with cetuximab resistance-associated RNA transcript 16 (CRART16) or an empty vector using lentiviral infection; the cells were designated Caco-2-CRART16 and Caco-2-NC, respectively, and were analyzed with RNA sequencing (RNA-seq). Quantitative real-time PCR (qRT-PCR) was performed to investigate RNA expression. Flow cytometry and TUNEL assays were used to assess apoptosis levels induced by cetuximab. The cell cycle, stemness biomarkers and membrane proteins of CRC cells were assessed via flow cytometry. RNA fluorescence in situ hybridization (FISH) was used to examine CRART16 localization and expression. Bioinformatics analysis was performed to predict the potential mechanism of CRART16, which was further validated by a dual-luciferase reporter assay. Differences in measurement data were compared using Student's t test, one-way ANOVA followed by Dunnett's test and two-way ANOVA.

Results: The novel lncRNA CRART16 was upregulated in Caco-2 CR cells. CRART16 overexpression reversed the effects of cetuximab on cell viability and reduced cetuximab-induced apoptosis. Meanwhile, CRART16 overexpression led to increases in the proportion of CD44/CD133 cells. In addition, CRART16 acts as a competing endogenous RNA (ceRNA) for miR-371a-5p to regulate V-Erb-B2 Erythroblastic Leukemia Viral Oncogene Homolog 3 (ERBB3) expression. MiR-371a-5p mimics counteracted the cetuximab resistance induced by CRART16 overexpression. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that after CRART16 was overexpressed, the resulting differentially expressed mRNAs were mainly enriched in the MAPK signaling pathway.

Conclusions: CRART16 overexpression may contribute to cetuximab resistance through the miR-371a-5p/ERBB3/MAPK pathway. Additionally, CRART16 contributes to the acquisition of stemness properties.
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http://dx.doi.org/10.1186/s12935-020-1155-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057486PMC
March 2020

Negative auto-regulation of sulfur dioxide generation in vascular endothelial cells: AAT1 S-sulfenylation.

Biochem Biophys Res Commun 2020 Feb 19. Epub 2020 Feb 19.

Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China. Electronic address:

Recently, endogenous sulfur dioxide (SO) has been found to exert an important function in the cardiovascular system. However, the regulatory mechanism for SO generation has not been entirely clarified. Hence, we aimed to explore the possible auto-regulation of endogenous SO generation and its mechanisms in vascular endothelial cells. We showed that SO did not affect the protein expression of aspartate aminotransferase 1 (AAT1), a major SO synthesis enzyme, but significantly inhibited AAT activity in primary human umbilical vein endothelial cells (HUVECs) and porcine purified AAT1 protein. An AAT1 enzymatic kinetic study showed that SO reduced the Vmax (1.89 ± 0.10 vs 2.55 ± 0.12, μmol/mg/min, P < 0.05) and increased the Km (35.97 ± 9.54 vs 19.33 ± 1.76 μmol/L, P < 0.05) values. Furthermore, SO induced S-sulfenylation of AAT1 in primary HUVECs and purified AAT1 protein. LC-MS/MS analysis indicated that SO sulfenylated AAT1 at Cys192. Mechanistically, thiol reductant DTT treatment or C192S mutation prevented SO-induced AAT1 sulfenylation and the subsequent inhibition of AAT activity in purified AAT1 protein and primary HUVECs. Our findings reveal, for the first time, a mechanism of auto-regulation of SO generation through sulfenylation of AAT1 at Cys192 to suppress AAT activity in vascular endothelial cells. These findings will greatly deepen the understanding of regulatory mechanisms in the cardiovascular homeostasis.
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http://dx.doi.org/10.1016/j.bbrc.2020.02.040DOI Listing
February 2020

PAR2 Mediates Itch via TRPV3 Signaling in Keratinocytes.

J Invest Dermatol 2020 08 29;140(8):1524-1532. Epub 2020 Jan 29.

Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, St. Louis, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, USA; Department of Psychiatry, Washington University School of Medicine, St. Louis, USA; Department of Developmental Biology, Washington University School of Medicine, St. Louis, USA. Electronic address:

Animal studies have suggested that transient receptor potential ion channels and G-protein coupled receptors play important roles in itch transmission. TRPV3 gain-of-function mutations have been identified in patients with Olmsted syndrome, which is associated with severe pruritus. However, the mechanisms causing itch remain poorly understood. Here, we show that keratinocytes lacking TRPV3 impair the function of protease-activated receptor 2 (PAR2), resulting in reduced neuronal activation and scratching behavior in response to PAR2 agonists. Moreover, we show that TRPV3 and PAR2 were upregulated in skin biopsies from patients and mice with atopic dermatitis, whereas their inhibition attenuated scratching and inflammatory responses in mouse atopic dermatitis models. These results reveal a previously unrecognized link between TRPV3 and PAR2 in keratinocytes to convey itch information and suggest that a blockade of PAR2 or TRPV3 individually or both may serve as a potential approach for antipruritic therapy in atopic dermatitis.
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http://dx.doi.org/10.1016/j.jid.2020.01.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7387154PMC
August 2020

Endogenous hydrogen sulfide sulfhydrates IKKβ at cysteine 179 to control pulmonary artery endothelial cell inflammation.

Clin Sci (Lond) 2019 10;133(20):2045-2059

Department of Pediatrics, Peking University First Hospital, Beijing, China.

Background: Pulmonary artery endothelial cell (PAEC) inflammation is a critical event in the development of pulmonary arterial hypertension (PAH). However, the pathogenesis of PAEC inflammation remains unclear.

Methods: Purified recombinant human inhibitor of κB kinase subunit β (IKKβ) protein, human PAECs and monocrotaline-induced pulmonary hypertensive rats were employed in the study. Site-directed mutagenesis, gene knockdown or overexpression were conducted to manipulate the expression or activity of a target protein.

Results: We showed that hydrogen sulfide (H2S) inhibited IKKβ activation in the cell model of human PAEC inflammation induced by monocrotaline pyrrole-stimulation or knockdown of cystathionine γ-lyase (CSE), an H2S generating enzyme. Mechanistically, H2S was proved to inhibit IKKβ activity directly via sulfhydrating IKKβ at cysteinyl residue 179 (C179) in purified recombinant IKKβ protein in vitro, whereas thiol reductant dithiothreitol (DTT) reversed H2S-induced IKKβ inactivation. Furthermore, to demonstrate the significance of IKKβ sulfhydration by H2S in the development of PAEC inflammation, we mutated C179 to serine (C179S) in IKKβ. In purified IKKβ protein, C179S mutation of IKKβ abolished H2S-induced IKKβ sulfhydration and the subsequent IKKβ inactivation. In human PAECs, C179S mutation of IKKβ blocked H2S-inhibited IKKβ activation and PAEC inflammatory response. In pulmonary hypertensive rats, C179S mutation of IKKβ abolished the inhibitory effect of H2S on IKKβ activation and pulmonary vascular inflammation and remodeling.

Conclusion: Collectively, our in vivo and in vitro findings demonstrated, for the first time, that endogenous H2S directly inactivated IKKβ via sulfhydrating IKKβ at Cys179 to inhibit nuclear factor-κB (NF-κB) pathway activation and thereby control PAEC inflammation in PAH.
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http://dx.doi.org/10.1042/CS20190514DOI Listing
October 2019

Inhibition of hydrogen sulfide synthesis reverses acquired resistance to 5-FU through miR-215-5p-EREG/TYMS axis in colon cancer cells.

Cancer Lett 2019 12 19;466:49-60. Epub 2019 Sep 19.

Division of General Surgery, Peking University First Hospital, Beijing, China. Electronic address:

Acquired resistance to 5-fluorouracil (5-FU) is a major barrier to benefit from chemotherapy in colon cancer patients. Hydrogen sulfide (HS), mainly produced by cystathionine-β-synthase (CBS), has been reported to promote the proliferation and migration of colon cancer cells. In this study, the effect of inhibiting HS synthesis on the sensitivity of colon cancer cell lines to 5-FU was investigated. Increased expression of CBS was validated in online database and tissue microarrays. Inhibiting HS synthesis significantly sensitized colon cancer cell lines to 5-FU both in vitro and in vivo. Decreasing HS synthesis utilizing shRNA lentiviruses significantly reversed the acquired resistance to 5-FU. MicroRNA sequencing was performed and miR-215-5p was revealed as one of the miRNAs with most significantly altered expression levels after CBS knock down. Epiregulin (EREG) and thymidylate synthetase (TYMS) were predicted to be potential targets of miR-215-5p. Decreasing HS synthesis significantly decreased the expression of EREG and TYMS. These results demonstrate that inhibiting HS synthesis can reverse the acquired resistance to 5-FU in colon cancer cells.
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http://dx.doi.org/10.1016/j.canlet.2019.09.006DOI Listing
December 2019

A Novel Broad Allele-Specific TaqMan Real-Time PCR Method To Detect Triazole-Resistant Strains of Aspergillus fumigatus, Even with a Very Low Percentage of Triazole-Resistant Cells Mixed with Triazole-Susceptible Cells.

J Clin Microbiol 2019 09 26;57(9). Epub 2019 Aug 26.

Department of Dermatology, Peking University First Hospital, Beijing, China

Invasive aspergillosis caused by triazole-resistant strains of is a growing public health concern, as is the occurrence of mixed infections with triazole-resistant and -susceptible strains. Therefore, it is crucial to develop robust methods to identify triazole-resistant strains of , even in mixtures of triazole-resistant and -susceptible strains of In this work, we developed a robust, highly selective, and broad-range allele-specific TaqMan real-time PCR platform consisting of 7 simultaneous assays that detect TR (a 34-bp tandem repeat in the promoter region), TR, G54W (a change of G to W at position 54), G54R, L98H, Y121F, and M220I mutations in the gene of The method is based on the widely used TaqMan real-time PCR technology and combines allele-specific PCR with a blocking reagent (minor groove binder [MGB] oligonucleotide blocker) to suppress amplification of the wild-type alleles. We used this method to detect triazole-resistant clinical strains of with a variety of gene mutations, as well as the triazole-resistant strains in mixtures of triazole-resistant and -susceptible strains of The method had high efficiency and sensitivity (300 fg/well, corresponding to about 100 CFU per reaction mixture volume). It could promptly detect triazole resistance in a panel of 30 clinical strains of within about 6 h. It could also detect -associated resistance alleles, even in mixtures containing only 1% triazole-resistant strains. These results suggest that this method is robustly able to detect -associated resistance alleles even in mixtures of triazole-resistant and -susceptible strains of and that it should have important clinical applications.
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http://dx.doi.org/10.1128/JCM.00604-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711921PMC
September 2019

Decreased Expression of Cystathionine β-Synthase Exacerbates Intestinal Barrier Injury in Ulcerative Colitis.

J Crohns Colitis 2019 Aug;13(8):1067-1080

Division of General Surgery, Peking University First Hospital, Beijing, China.

Background And Aims: Endogenous H2S regulates multiple physiological and pathological processes in colon epithelial tissues. The current study investigated the role of cystathionine β-synthase [CBS], a major producer of H2S in colon epithelial cells, in the pathogenesis of ulcerative colitis [UC]-related intestinal barrier injury. The expression and DNA methylation level of CBS were investigated in inflamed and non-inflamed colon tissues collected from UC patients, and the effect of decreased CBS levels on Caco-2 monolayer barrier injury and altered status of tight junctions elicited by tumour necrosis factor/interferon [TNF/IFN] was determined.

Methods: The expression of CBS and the methylation level of the CBS promoter were assessed in non-inflamed and inflamed colon epithelial tissue samples collected from UC patients. Barrier function, status of tight junction proteins and activation of the NF-κB p65-mediated MLCK-P-MLC signalling pathway were further investigated in Caco-2 monolayers.

Results: Decreased expression of CBS and elevated methylation levels of the CBS promoter were observed in inflamed sites compared with in non-inflamed sites in the colon epithelial samples from UC patients. In Caco-2 monolayers, decreased expression of CBS exacerbated TNF/IFN-induced barrier injury and altered localization of tight junction proteins. Decreased expression of CBS predisposed Caco-2 monolayers to injury elicited by TNF/IFN via augmentation of the NF-κB p65-mediated MLCK-P-MLC signalling pathway.

Conclusions: Decreased expression of CBS propagates the pathogenesis of UC by exacerbating inflammation-induced intestinal barrier injury. Elevated methylation of the CBS promoter might be one of the mechanisms underlying the decreased expression of CBS in inflamed sites of colon epithelial tissues from UC patients.
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http://dx.doi.org/10.1093/ecco-jcc/jjz027DOI Listing
August 2019

Gain-of-Function Mutations in TRPM4 Activation Gate Cause Progressive Symmetric Erythrokeratodermia.

J Invest Dermatol 2019 05 5;139(5):1089-1097. Epub 2018 Dec 5.

Department of Dermatology, Peking University First Hospital, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China. Electronic address:

Transient receptor potential (TRP) channels respond to various chemical and physical stimuli by mediating cation influx. The skin expresses abundant TRP channels of different subtypes, which play an essential role in the maintenance of skin functionality. Here, we report cases of mutations in TRPM4, which encodes TRPM4, a Ca-activated monovalent cation channel, as a cause of an autosomal dominant form of progressive symmetric erythrokeratodermia. In three separate families with progressive symmetric erythrokeratodermia, we identified two missense mutations (c.3099C>G and c.3119T>C) that produce p.Ile1033Met and p.Ile1040Thr, both of which are located in the S6 transmembrane domain of the TRPM4 protein. The substitutions are expected to directly affect activation gating of TRPM4 according to the cryo-EM structures. Electrophysiological studies of the mutants showed substantial hyperactivity, as evidenced by pronounced baseline activity, enhanced sensitivity to intracellular Ca, and an elevated resting membrane potential. In vitro studies showed enhanced proliferation in keratinocytes overexpressing either of the mutants. We also detected an up-regulation of markers for proliferation and differentiation of keratinocytes in the affected skin tissues. Our study identified TRPM4 as an important player in the pathogenesis of skin TRP channelopathies and a potential target for treatment of skin hyperkeratotic disorders.
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http://dx.doi.org/10.1016/j.jid.2018.10.044DOI Listing
May 2019

Sulfhydration-associated phosphodiesterase 5A dimerization mediates vasorelaxant effect of hydrogen sulfide.

Oncotarget 2017 May;8(19):31888-31900

Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.

The study was designed to examine if the vasorelaxant effect of hydrogen sulfide was mediated by sulfhydration-associated phosphodiesterase (PDE) 5A dimerization. The thoracic aorta of rat was separated and the vasorelaxant effects were examined with in vitro vascular perfusion experiments. The dimerization and sulfhydration of PDE 5A and soluble guanylatecyclase (sGC) were measured. PDE 5A and protein kinase G (PKG) activities were tested. Intracellular cGMP content was detected by enzyme-linked immunosorbent assay (ELISA). The results showed that NaHS relaxed isolated rat vessel rings at an EC50 of (1.79 ± 0.31)×10-5mol/L, associated with significantly increased PKG activity and cGMP content in vascular tissues. Sulfhydration of sGC β1 was increased, while the levels of sGC αβ1 dimers were apparently decreased after incubation with NaHS in vascular tissues. Moreover, PDE 5A homodimers were markedly decreased, and accordingly the PDE 5A activity demonstrated by the content of 5'-GMP was significantly decreased after incubation with NaHS or GYY4137. Mechanistically, both NaHS and GYY4137 significantly enhanced the PDE 5A sulfhydration in vascular tissues. DTT partially abolished the effects of NaHS on PDE 5A activity, cGMP content and vasorelaxation. Therefore, the present study for the first time suggested that H2S exerted vasorelaxant effect probably via sulfhydration-associated PDE 5A dimerization.
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http://dx.doi.org/10.18632/oncotarget.16649DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5458256PMC
May 2017

H19 Overexpression Induces Resistance to 1,25(OH)2D3 by Targeting VDR Through miR-675-5p in Colon Cancer Cells.

Neoplasia 2017 03 8;19(3):226-236. Epub 2017 Feb 8.

Division of General Surgery, Peking University First Hospital, Peking University, 8 Xi ShiKu Street, Beijing 100034, People's Republic of China. Electronic address:

The long noncoding (lnc) RNA H19 was involved in the tumorigenesis of many types of cancer. However, the role of H19 in the tumorigenesis of colon cancer has not been fully illustrated. Recent studies suggested a potential relationship between H19 and vitamin D receptor (VDR) signaling. Considering the pivotal role of VDR signaling in the colon epithelium both physiologically and pathologically, the correlation between H19 and VDR signaling may have an important role in the development of colon cancer. In this study, the correlation between H19 and vitamin D receptor (VDR) signaling and the underlying mechanisms in colon cancer were investigated both in vitro and in vivo. The results suggested that VDR signaling was able to inhibit the expression of H19 through regulating C-Myc/Mad-1 network. H19, on the other hand, was able to inhibit the expression of VDR through micro RNA 675-5p (miR-675-5p). Furthermore, H19 overexpression induced resistance to the treatment with 1,25(OH)2D3 both in vitro and in vivo. Together, these results suggested that H19 overexpression might be one of the mechanisms underlying the development of resistance to the treatment with 1,25(OH)2D3 in the advanced stage of colon cancer.
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http://dx.doi.org/10.1016/j.neo.2016.10.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300698PMC
March 2017

Stabilizing mutations of KLHL24 ubiquitin ligase cause loss of keratin 14 and human skin fragility.

Nat Genet 2016 12 31;48(12):1508-1516. Epub 2016 Oct 31.

School of Pharmaceutical Sciences, Center for Infectious Disease Research, School of Medicine, Tsinghua University, Tsinghua-Peking Center for Life Sciences, Beijing, China.

Skin integrity is essential for protection from external stress and trauma. Defects in structural proteins such as keratins cause skin fragility, epitomized by epidermolysis bullosa (EB), a life-threatening disorder. Here we show that dominant mutations of KLHL24, encoding a cullin 3-RBX1 ubiquitin ligase substrate receptor, cause EB. We have identified start-codon mutations in the KLHL24 gene in five patients with EB. These mutations lead to truncated KLHL24 protein lacking the initial 28 amino acids (KLHL24-ΔN28). KLHL24-ΔN28 is more stable than its wild-type counterpart owing to abolished autoubiquitination. We have further identified keratin 14 (KRT14) as a KLHL24 substrate and found that KLHL24-ΔN28 induces excessive ubiquitination and degradation of KRT14. Using a knock-in mouse model, we have confirmed that the Klhl24 mutations lead to stabilized Klhl24-ΔN28 and cause Krt14 degradation. Our findings identify a new disease-causing mechanism due to dysregulation of autoubiquitination and open new avenues for the treatment of related disorders.
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http://dx.doi.org/10.1038/ng.3701DOI Listing
December 2016

GYY4137 ameliorates intestinal barrier injury in a mouse model of endotoxemia.

Biochem Pharmacol 2016 Oct 20;118:59-67. Epub 2016 Aug 20.

Division of General Surgery, Peking University First Hospital, Peking University, 8 Xi ShiKu Street, Beijing 100034, People's Republic of China. Electronic address:

Intestinal barrier injury has been reported to play a vital role in the pathogenesis of endotoxemia. This study aimed to investigate the protective effect of GYY4137, a newly synthesized HS donor, on the intestinal barrier function in the context of endotoxemia both in vitro and in vivo. Caco-2 (a widely used human colon cancer cell line in the study of intestinal epithelial barrier function) monolayers incubated with lipopolysaccharide (LPS) or TNF-α/IFN-γ and a mouse model of endotoxemia were used in this study. The results suggested that GYY4137 significantly attenuated LPS or TNF-α/IFN-γ induced increased Caco-2 monolayer permeability. The decreased expression of TJ (tight junction) proteins induced by LPS and the altered localization of TJs induced by TNF-α/IFN-γ was significantly inhibited by GYY4137; similar results were obtained in vivo. Besides, GYY4137 promoted the clinical score and histological score of mice with endotoxemia. Increased level of TNF-α/IFN-γ in the plasma and increased apoptosis in colon epithelial cells was also attenuated by GYY4137 in mice with endotoxemia. This study indicates that GYY4137 preserves the intestinal barrier function in the context of endotoxemia via multipathways and throws light on the development of potential therapeutic approaches for endotoxemia.
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http://dx.doi.org/10.1016/j.bcp.2016.08.016DOI Listing
October 2016

Endogenous sulfur dioxide is a novel adipocyte-derived inflammatory inhibitor.

Sci Rep 2016 06 1;6:27026. Epub 2016 Jun 1.

Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.

The present study was designed to determine whether sulfur dioxide (SO2) could be endogenously produced in adipocyte and served as a novel adipocyte-derived inflammatory inhibitor. SO2 was detected in adipose tissue using high-performance liquid chromatography with fluorescence detection. SO2 synthase aspartate aminotransferase (AAT1 and AAT2) mRNA and protein expressions in adipose tissues were measured. For in vitro study, 3T3-L1 adipocytes were cultured, infected with adenovirus carrying AAT1 gene or lentivirus carrying shRNA to AAT1, and then treated with tumor necrosis factor-α (TNF-α). We found that endogenous SO2/AAT pathway existed in adipose tissues including perivascular, perirenal, epididymal, subcutaneous and brown adipose tissue. AAT1 overexpression significantly increased SO2 production and inhibited TNF-α-induced inflammatory factors, monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) secretion from 3T3-L1 adipocytes. By contrast, AAT1 knockdown decreased SO2 production and exacerbated TNF-α-stimulated MCP-1 and IL-8 secretion. Mechanistically, AAT1 overexpression attenuated TNF-α-induced IκBα phosphorylation and degradation, and nuclear factor-κB (NF-κB) p65 phosphorylation, while AAT1 knockdown aggravated TNF-α-activated NF-κB pathway, which was blocked by SO2. NF-κB inhibitors, PDTC or Bay 11-7082, abolished excessive p65 phosphorylation and adipocyte inflammation induced by AAT1 knockdown. This is the first report to suggest that endogenous SO2 is a novel adipocyte-derived inflammatory inhibitor.
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http://dx.doi.org/10.1038/srep27026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4887903PMC
June 2016

The Polymorphisms in LNK Gene Correlated to the Clinical Type of Myeloproliferative Neoplasms.

PLoS One 2016 25;11(4):e0154183. Epub 2016 Apr 25.

Department of Hematology, Peking University First Hospital, Beijing, China.

Objective: LNK is an adapter protein negatively regulating the JAK/STAT cell signaling pathway. In this study, we observed the correlation between variation in LNK gene and the clinical type of myeloproliferative neoplasms (MPN).

Methods: A total of 285 MPN cases were recruited, including essential thrombocythemia (ET) 154 cases, polycythemia vera (PV) 76 cases, primary myelofibrosis (PMF) 19 cases, and chronic myeloid leukemia (CML) 36 cases. Ninety-three healthy individuals were used as normal controls. V617F mutation in JAK2 was identified by allele-specific PCR method, RT-PCR was used for the detection of BCR/ABL1 fusion gene, and mutations and variations in coding exons and their flanking sequences of LNK gene were examined by PCR-sequencing.

Results: Missense mutations of A300V, V402M, and R415H in LNK were found in 8 patients including ET (4 cases, all combined with JAK2-V617F mutation), PV (2 cases, one combined with JAK2-V617F mutation), PMF (one case, combined with JAK2-V617F mutation) and CML (one case, combined with BCR/ABL1 fusion gene). The genotype and allele frequencies of the three SNPs (rs3184504, rs111340708 and rs78894077) in LNK were significantly different between MPN patients and controls. For rs3184504 (T/C, in exon2), the T allele (p.262W) and TT genotype were frequently seen in ET, PV and PMF (P<0.01), and C allele (p.262R) and CC genotype were frequently seen in CML (P<0.01). For rs78894077 (T/C, in exon1), the T allele (p.242S) was frequently found in ET (P<0.05). For rs111340708 (TGGGGx5/TGGGGx4, in intron 5), the TGGGG x4 allele was infrequently found in ET, PMF and CML(P<0.01).

Conclusion: Mutations in LNK could be found in some of MPN patients in the presence or absence of JAK2-V617F mutation. Several polymorphisms in LNK gene may affect the clinical type or the genetic predisposition of MPN.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0154183PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4844169PMC
March 2017

[Analysis of the relationship between mitochondrial DNA deletion and clinical complexity of mitochondrial disease].

Zhonghua Yi Xue Za Zhi 2015 Nov;95(42):3449-53

Email:

Objective: To analyze the relationship between proportion of mitochondrial DNA 4 977 bp deletion (ΔmtDNA(4977)) or copy number in blood and the clinical complexity to find the pathogenesis of mitochondrial disease.

Methods: A total of 160 patients with mitochondrial disease and 101 healthy controls of Peking University First Hospital from December 2003 to December 2013 were collected in this study. Their peripheral blood showed no hot-point mutation which detected by polymerase chain reaction-restriction fragment length polymorphism. All the patients were divided into younger group (age<10y) and elder group (10y≤age<20y). The incidence of ΔmtDNA(4977) was detected by real-time quantitative PCR. Internal gene was used to calculate the number of mitochondrial DNA in each cell. Statistical analysis were carried out by the independent t-test, one-way ANOVA and Spearman's bivariate correlation analysis.

Results: ΔmtDNA (4977) proportion in the younger group was (2.66 ± 0.63)% and in the elder group was (3.09 ± 0.74)%, both of them were higher than that of healthy control group with the same age (the younger group: t=8.57, P<0.01; the elder group: t=4.38, P<0.01); ΔmtDNA(4977) copy number per cell in the younger group was (2.79 ± 0.50) copy and in the elder group was (2.97 ± 0.48) copy, both of them were higher than that of healthy control group with the same age (the younger group: t=4.50, P<0.01; the elder group: t=-3.67, P<0.01). The ΔmtDNA (4977) proportion was positively correlated with the complexity of the mitochondrial disease(the younger group: r=0.519, P<0.01; the elder group: r=0.772, P<0.01). The ΔmtDNA (4977) copy number per cell was positively correlated with the complexity of the mitochondrial disease(the younger group: r=0.389, P<0.01; the elder group: r=0.607, P<0.05). However, the total mtDNA copy number per cell was negatively correlated with the complexity of the mitochondrial disease (the younger group: r=-0.260, P<0.01; the elder group: r=-0.430, P<0.05).

Conclusions: The proportion or copy number of ΔmtDNA (4977) or total mtDNA copy number in blood are correlated with the complexity of mitochondrial diseases, especially the proportion of ΔmtDNA (4977).
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November 2015

Deletion of a 4977-bp Fragment in the Mitochondrial Genome Is Associated with Mitochondrial Disease Severity.

PLoS One 2015 29;10(5):e0128624. Epub 2015 May 29.

Department of Central Laboratory, Peking University First Hospital, No. 8, West District, Beijing, 100034, China.

Large deletions in mitochondrial DNA (mtDNA) may be involved in the pathogenesis of mitochondrial disease. In this study, we investigated the relationship between a 4,977-bp deletion in the mitochondrial genome (ΔmtDNA(4977)) and the severity of clinical symptoms in patients with mitochondrial disease lacking known point mutations. A total of 160 patients with mitochondrial disease and 101 healthy controls were recruited for this study. The copy numbers of ΔmtDNA(4977) and wild-type mtDNA were determined by real-time quantitative PCR and analyzed using Spearman's bivariate correlation analysis, t-tests, or one-way ANOVA. The overall ΔmtDNA(4977) copy number per cell and the proportion of mtDNA(4977) relative to the total wild-type mtDNA, increased with patient age and symptom severity. Surprisingly, the total mtDNA copy number decreased with increasing symptom severity. Our analyses revealed that increases in the proportion and total copy number of ΔmtDNA(4977) in the blood may be associated with disease severity in patients with mitochondrial dysfunction.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0128624PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449107PMC
March 2016

L-cystathionine inhibits oxidized low density lipoprotein-induced THP-1-derived macrophage inflammatory cytokine monocyte chemoattractant protein-1 generation via the NF-κB pathway.

Sci Rep 2015 May 28;5:10453. Epub 2015 May 28.

Department of Pediatrics, Peking University First Hospital, Beijing 100034, P. R. China.

This study aimed to explore whether and how L-cystathionine had any regulatory effect on the inflammatory response in THP-1-derived macrophages cultured in vitro under oxidized low-density lipoprotein (ox-LDL) stimulation. The human monocyte line THP-1 cell was cultured in vitro and differentiated into macrophages after 24 hours of PMA induction. Macrophages were pretreated with L-cystathionine and then treated with ox-LDL. The results showed that compared with the controls, ox-LDL stimulation significantly upregulated the expression of THP-1-derived macrophage MCP-1 by enhancing NF-κB p65 phosphorylation, nuclear translocation and DNA binding with the MCP-1 promoter. Compared with the ox-LDL group, 0.3 mmol/L and 1.0 mmol/L L-cystathionine significantly inhibited the expression of THP-1-derived macrophage MCP-1. Mechanistically, 0.3 mmol/L and 1.0 mmol/L L-cystathionine suppressed phosphorylation and nuclear translocation of the NF-κB p65 protein, as well as the DNA binding activity and DNA binding level of NF-κB with the MCP-1 promoter, which resulted in a reduced THP-1-derived macrophage MCP-1 generation. This study suggests that L-cystathionine could inhibit the expression of MCP-1 in THP-1-derived macrophages induced by ox-LDL via inhibition of NF-κB p65 phosphorylation, nuclear translocation, and binding of the MCP-1 promoter sequence after entry into the nucleus.
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http://dx.doi.org/10.1038/srep10453DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4447071PMC
May 2015

Donors with HLA-B*58:01/TNFα − 308A haplotype are unfavorable to haploidentical hematopoietic stem cell transplantation in acute lymphoblastic leukemia.

Transpl Immunol 2015 Mar 26;32(2):92-8. Epub 2014 Dec 26.

Department of Hematology, Peking University First Hospital, China. Electronic address:

We investigated the clinical characteristics of acute lymphoblastic leukemia (ALL) patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) using haploidentical donors carrying HLA-B*58:01/TNFα − 308A (B*58:01-TNF2) haplotype. A total of 136 B-ALL and 29T/NK-ALL cases were recruited. DNA samples from the patients and their family members were assayed for HLA typing and genotyping of TNFα -308 (rs1800629). The B*58:01-TNF2 haplotype in related donors was determined by their family relationships. Outcomes within 2 years, disease course, and complications within 100 days were compared among patients using haploidentical donors carrying B*58:01-TNF2 haplotype (21 cases), those using haploidentical donors without B*58:01-TNF2 haplotype (100 cases), and those using HLA-identical sibling donors with or without B*58:01-TNF2 haplotype (44 cases). Compared with the other two groups, patients using haploidentical donors carrying B*58:01-TNF2 haplotype had higher overall mortality (adjusted P = 0.039) and non-relapse mortality (adjusted P = 0.001) within 2 years, delayed platelet engraftment (adjusted P < 0.0001), higher incidences of severe acute graft-versus-host disease (aGVHD) (P = 0.007), severe late-onset hemorrhagic cystitis (P = 0.002), blood stream infection (P = 0.017), and invasive fungal disease (P = 0.004) within 100 days. Therefore, donors carrying the B*58:01-TNF2 haplotype may cause more serious complications and poorer outcomes to ALL recipients.
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http://dx.doi.org/10.1016/j.trim.2014.12.003DOI Listing
March 2015

Higher prevalence of novel mutations in VHL gene in Chinese Von Hippel-Lindau disease patients.

Urology 2014 Mar;83(3):675.e1-5

Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, People's Republic of China. Electronic address:

Objective: To observe the clinical and molecular characteristics in Chinese Von Hippel-Lindau (VHL) disease patients.

Materials And Methods: Using polymerase chain reaction (PCR)-direct sequencing and universal primer quantitative fluorescent multiplex-PCR, we examined mutations in VHL gene in 19 VHL disease families recruited from the Department of Urology, Peking University First Hospital in the period from 2009 to 2012.

Results: Of the 19 VHL disease families, VHL disease type I was identified in 14 families, type IIA in 1 family, and type IIB in 4 families. Mutation detection found missense point mutations in 7 families, nonsense point mutations in 3 families, small indels in 6 families, and large deletions in 3 families. Novel mutations were detected in 9 families (47.4%), in which 6 had no family history; previously reported mutations were found in 10 families, in which 3 had no family history.

Conclusion: The prevalence of novel mutations without family history was higher in this group of patients, presumably demonstrating the higher prevalence of de novo mutations in VHL gene in Chinese VHL disease patients.
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http://dx.doi.org/10.1016/j.urology.2013.09.069DOI Listing
March 2014

Hydrogen sulfide suppresses oxidized low-density lipoprotein (ox-LDL)-stimulated monocyte chemoattractant protein 1 generation from macrophages via the nuclear factor κB (NF-κB) pathway.

J Biol Chem 2014 Apr 18;289(14):9741-53. Epub 2014 Feb 18.

From the Department of Pediatrics and.

This study was designed to examine the role of hydrogen sulfide (H2S) in the generation of oxidized low-density lipoprotein (ox-LDL)-stimulated monocyte chemoattractant protein 1 (MCP-1) from macrophages and possible mechanisms. THP-1 cells and RAW macrophages were pretreated with sodium hydrosulfide (NaHS) and hexyl acrylate and then treated with ox-LDL. The results showed that ox-LDL treatment down-regulated the H2S/cystathionine-β-synthase pathway, with increased MCP-1 protein and mRNA expression in both THP-1 cells and RAW macrophages. Hexyl acrylate promoted ox-LDL-induced inflammation, whereas the H2S donor NaHS inhibited it. NaHS markedly suppressed NF-κB p65 phosphorylation, nuclear translocation, DNA binding activity, and recruitment to the MCP-1 promoter in ox-LDL-treated macrophages. Furthermore, NaHS decreased the ratio of free thiol groups in p65, whereas the thiol reductant DTT reversed the inhibiting effect of H2S on the p65 DNA binding activity. Most importantly, site-specific mutation of cysteine 38 to serine in p65 abolished the effect of H2S on the sulfhydration of NF-κB and ox-LDL-induced NF-κB activation. These results suggested that endogenous H2S inhibited ox-LDL-induced macrophage inflammation by suppressing NF-κB p65 phosphorylation, nuclear translocation, DNA binding activity, and recruitment to the MCP-1 promoter. The sulfhydration of free thiol group on cysteine 38 in p65 served as a molecular mechanism by which H2S inhibited NF-κB pathway activation in ox-LDL-induced macrophage inflammation.
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http://dx.doi.org/10.1074/jbc.M113.517995DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3975021PMC
April 2014

Brg1-dependent epigenetic control of vascular smooth muscle cell proliferation by hydrogen sulfide.

Biochim Biophys Acta 2013 Jun 13;1833(6):1347-55. Epub 2013 Mar 13.

Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China.

Hydrogen sulfide (H2S) can modulate the proliferation of vascular smooth muscle cells. This study was designed to investigate the epigenetic control of vascular smooth muscle cell proliferation in response to H2S. Microarray analysis indicated that Brahma-related gene 1 (Brg1) and proliferation-related genes including proliferating cell nuclear antigen (Pcna), neurotrophin 3 (Ntf3) and platelet-derived growth factor subunit A (Pdgfα) were significantly downregulated by H2S in endothelin-1-stimulated proliferative vascular smooth muscle cells. Brg1 is the central catalytic subunit of the SWI/SNF apparatus (an ATP-dependent chromatin remodeling complex). Overexpression and knockdown of Brg1 confirmed that Brg1 was crucial for H2S-induced inhibition of vascular smooth muscle cell proliferation. A luciferase reporter assay, real-time PCR and Western blotting demonstrated that H2S inhibited Brg1 transcription and expression. A DNase I hypersensitivity assay revealed that H2S reversed endothelin-1-stimulated Pcna, Ntf3 and Pdgfα chromatin remodeling and vascular smooth muscle cell proliferation. A chromatin immunoprecipitation assay indicated that H2S inhibited the recruitment of Brg1 to the Pcna, Ntf3 and Pdgfα promoters. The results of this study indicate that H2S inhibits vascular smooth muscle cell proliferation via an epigenetic mechanism involving the inhibition of Brg1 transcription and expression, and by reducing the recruitment of Brg1 to the Pcna, Ntf3 and Pdgfα promoter regions.
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http://dx.doi.org/10.1016/j.bbamcr.2013.03.002DOI Listing
June 2013
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