Suppression of bile acid synthesis by thyroid hormone in primary human hepatocytes

AIM： It is known that thyroid hormones alter the bile acid metabolism in humans, however the effect on individual enzymes has been difficult to elucidate. This is mainly due to the lack of human liver cell lines producing bile acids. We used cultures of primary human hepatocytes to study the effects of triiodothyronine （T3） on bile acid synthesis.METHODS： Primary hepatocytes were isolated from liver tissue obtained from three different patients undergoing liver resection due to underlying malignancy. The hepatocytes were cultured under serum-free conditions and treated from d 1 to d 5 with culture containing 0.1 - 1000 nmol/L of T3. Bile acid formation and mRNA levels of key enzymes were analysed. RESULTS： The lowest concentration of T3 decreased cholic acid （CA） formation to 43%-53% of controls and chenodeoxycholic acid （CDCA） to 52%-75% of controls on d 5. The highest dose further decreased CA formation to 16%-48% of controls while CDCA formation remained at 50%-117% of controls. Expression of mRNA levels of cholesterol 7α-hydroxylase （CYP7A1） and sterol 12α-hydroxylase （CYPSB1） dose-dependently decreased. Sterol 27-hydroxylase （CYP27A1） levels also decreased, but not to the same extent. CONCLUSION： T3 dose-dependently decreased total bile acid formation in parallel with decreased expression of CYP7A1 and CYP8B1. CA formation is inhibited to a higher degree than CDCA, resulting in a marked decrease in the CA/CDCA ratio.

Hemophagocytic lymphohistiocytosis: Recent progress in the pathogenesis, diagnosis and treatment

Hemophagocytic lymphohistiocytosis(HLH) is a hyperinflammatory syndrome that develops as a primary(familial/hereditary) or secondary(non-familial/hereditary) disease characterized in the majority of the cases by hereditary or acquired impaired cytotoxic T-cell(CTL) and natural killer responses. The molecular mechanisms underlying impaired immune homeostasis have been clarified, particularly for primary diseases. Familial HLH(familial hemophagocytic lymphohistiocytosis type 2-5, Chediak-Higashi syndrome, Griscelli syndrome type 2, Hermansky-Pudlak syndrome type 2) develops due to a defect in lytic granule exocytosis, impairment of(signaling lymphocytic activation molecule)-associated protein, which plays a key role in CTL activity [e.g., X-linked lymphoproliferative syndrome(XLP) 1], or impairment of X-linked inhibitor of apoptosis, a potent regulator of lymphocyte homeostasis(e.g., XLP2). The development of primary HLH is often triggered by infections, but not in all. Secondary HLH develops in association with infection, autoimmune diseases/rheumatological conditions and malignancy. The molecular mechanisms involved in secondary HLH cases remain unknown and the pathophysiology is not the same as primary HLH. For either primary or secondary HLH cases, immunosuppressive therapy should be given to control the hypercytokinemia with steroids, cyclosporine A, or intravenous immune globulin, and if primary HLH is diagnosed, immunochemotherapy with a regimen containing etoposide or anti-thymocyte globulin should be started. Thereafter, allogeneic hematopoietic stem-cell transplantation is recommended for primary HLH or secondary refractory disease(especially EBVHLH).

SPOC domain of mint protein induces hematopoietic differentiation via Bmp4/Smad5 pathway

Mint is a newly identified molecule that mediates signal transduction and modulates chromatin repression. Mint family members contain a highly conserved C-terminus SPOC domain (SpenParalog and OrthologsC-terminal domain) commonly associated with proliferation and related diseases (for example: cancer) due to its role in cell differentiation and apoptosis. In this study, we addressed the SPOC function using a tetracycline-inducible system to express the target domain in Ain V15 embryonic ES cells and bone marrow stem cells from SPOC transenic mice. In vitro differentiation of Ain V15 ES cells as a model of early hematopoietic development, we found expression of SPOC domain induces hematopoietic differentiation via up-regulation of transcription factors Bmp4 and Smad5, which induce the expression of hematopoietic factors Eklf1 and hematopoietic proliferation associated factor Gata2, the SPOC domain also plays the regulation function in the differentiation of hematopoitic progenitor by colony forming Unit (CFU) assays. Further, we determined SPOC expression enhances erythrocyte and granulocyte maturationusing bone marrow cells derived from tiSPOC chimeric mice. Finally, we identified that overexpression of full length Mint in ES cells drive Smad5 and Bmp4 up-regulation under culture conditions, and up-regulation of endogenous Mint when induceshematopoitic differentiation of EML, M1 and WT18 cells. In summary, our study reveals the conserved SPOC domain of Mint protein induces differentiation both in the stages of embryonic stem cells and hematopoietic progenitor cells.

Deep Sc-RNA sequencing decoding the molecular dynamic architecture of the human retina

The human retina serves as a light detector and signals transmission tissue.Advanced insights into retinal disease mechanisms and therapeutic strategies require a deep understanding of healthy retina molecular events.Here,we sequenced the m RNA of over 0.6 million single cells from human retinas across six regions at nine different ages.Sixty cell sub-types have been identified from the human mature retinas with unique markers.We revealed regional and age differences of gene expression profiles within the human retina.Cell-cell interaction analysis indicated a rich synaptic connection within the retinal cells.Gene expression regulon analysis revealed the specific expression of transcription factors and their regulated genes in human retina cell types.Some of the gene’s expression,such as DKK3,are elevated in aged retinas.A further functional investigation suggested that over expression of DKK3 could impact mitochondrial stability.Overall,decoding the molecular dynamic architecture of the human retina improves our understanding of the vision system.

非高密度脂蛋白胆固醇、载脂蛋白A-I及B100、标准脂质测量、脂质比值以及CRP作为女性心血管病危险因素的临床用途

背景：关于不同脂质测定、非高密度脂蛋白胆固醇（non-HDL-C）、脂质比值、载脂蛋白和C-反应蛋白（CRP）的临床应用，现行心血管危险检测指南仍有争议。 目的：直接比较总胆固醇（totalcholesterol，TC）、低密度脂蛋白胆固醇（LDL-C）、HDL-C、non-HDL-C、载脂蛋白A-I（apoA-I）及B100（apoB100）、高敏C-反应蛋白（高敏CRP）以及TC与HDL-C、LDL-C与HDL-C、apoB100与apoA-I、apoB100与HDL-C比值，在妇女作为将来心血管事件预测指标的临床用途。 设计、地点及参试者：于15 632例起始健康美国妇女进行的前瞻性队列研究。1992年11月至1995年7月人组时年龄≥45岁（4分位范围48～59岁）。所有参试者均经10年随访，观察将来心血管事件的发生情况。 主要观测指标：按照各项生化指标不同基线值而确定的首次主要心血管事件（n=4 764）的风险比（hazard ratios，HRs）及95％可信区间（confidence intervals，CIs）。 结果：在校正年龄、吸烟状况、血压、糖尿病及体重指数后，测量结果在最高5分位者将来发生心血管事件的风险比LDL-C为1．62（95％CI，1．17～2．25），apoA-I为1．75（95％CI，1．30～2．38），TC为2．08（95％CI，1．45～2．97），HDL-C为2．32（95％CI，1．64～3．33），apoB100为2．50（95％CI，1．68～3．72），non-HDL-C为2．51（95％CI，1．69～3．72），高敏CRP为2．98（95％CI，1．90～4．67）（P＜0．001，趋势贯穿所有5分位）。脂质比值风险比，apoBl00与apoA-I为3．01（95％CI，2．01～4．50），LDL-C与HDL-C为3．18（95％CI，2．12～4．75），apoB100与HDL-C为3．56（95％CI，2．31～5．47），TC与HDL-C为3．81（95％CI，2．47～5．86）（P＜0．001，趋势贯穿所有5分位）。高敏CRP与脂质参数的相关系数范围为-0．33到0．15，以CRP＜1、1～3和＞3 ms／L为临床分割点，可对每项脂质测量及脂质比值水平增加提供预后危险信息。 结论：non-HDL-C以及TC与HDL-C比值对将来心血管事件的预测效果与载脂蛋白相同或者更好。校正年龄、血压、吸烟、糖尿病和肥胖后，高敏CRP提供的预后信息超越各项脂质测量。

Epstein-Barr virus infection:the leading cause of multiple sclerosis

In a recent study published in Science,Bjornevik and colleagues demonstrated Epstein-Barr virus(EBV)infection is a trigger for multiple sclerosis(MS)in a longitudinal analysis of more than 10 million US military individuals who were on active duty.1 MS is an autoimmune disease that originates in the central nervous system characterized by inflammatory demyelinating lesions.There is no consensus on the etiology of MS.However,we all know that MS is a multifactorial disease which can be influenced by genetic and environmental factors.Genetic factors associated with MS risk are mainly major histocompatibility class Ⅱ(MHC Ⅱ)alleles(e.g.,HLA-DRB1^(*)15:01,the earliest identified and most dominant risk factor in MS)and MHC I alleles(e.g.,HLA-A^(*)02 and HLA B^(*)44,decreasing MS susceptibility).

女性总体心血管疾病危险评估改良算法的推导及验证：雷诺危险评分

背景：尽管人们对动脉粥样硬化血栓形成已有新的认识，但是，预测女性心血管事件的方法在很大程度上仍依赖于传统的危险因素。 目的：根据新旧危险因素对女性心血管疾病危险评估法进行改进并予验证。 设计、地点及参试者：于24558名健康的≥45岁的美国女性中对35个危险因素进行评估分析。随访中位时间为10．2年（截至2004年5月），观察心血管事件（复合终点包括心肌梗死、缺血性卒中、冠状动脉血运重建以及心血管死亡）的发生率。随机使用三分之二女性队列（推导队列，n=16400）的资料推导新的危险计算方法，然后将其结果与其余三分之一女性队列（验证队列，n=8158）的实际情况进行比较，借此对新计算方法的有效性进行验证。 主要观测指标：根据BIC（Bayes Information Criterion）最小化原则在推导队列中建立最适简易预测模型。在验证队列中比较10年心血管事件的预测发生率与实际发生率。对新的计算方法和根据成人胆固醇治疗计划Ⅲ（ATP-Ⅲ）危险评分协变量产生的模型亦进行比较。 结果：与ATP-Ⅲ危险评分协变量模型相比，在推导队列中，有1个最适模型（模型A）和1个临床简化模型（模型B，雷诺危险评分）具有较低的BIC评分。在验证队列中，应用模型A及模型B时，所有拟和、判别及校准指标均获改善。举例而言，根据ATP-Ⅲ危险评分标准，在非糖尿病女性参试者中，有603人10年心血管疾病危险为5％～10％，156人10年心血管疾病危险为10％～20％；而根据模型A，则可将其中的379人（50％）重新归类为更符合实际事件发生率的更高或更低的危险级别；根据年龄、收缩压、糖化血红蛋白A1c（如果患糖尿病）、吸烟、总胆固醇和高密度脂蛋白胆固醇、超敏C-反应蛋白以及60岁前心肌梗死家族史产生的简化模型B也能达到相似的效果。对于ATP-Ⅲ评分划归为极低危险组女性，采用两种新的计算方法并无明显不同。 结论：我们推出了两种可大大改善心血管事件危险预测准确性的临床计算方法。验证结果表明，这两种方法可将40％～50％的传统中危组女性重新划归为高危组或低危组。

Mitophagy deficiency activates stimulator of interferon genes activation and aggravates pathogenetic cardiac remodeling

Stimulator of interferon genes(STING)has recentlybeen found to play a crucial role in cardiac sterile inflammation and dysfunction.The role of stimulator of interferon genes(STING)in cardiac sterile inflammation and dysfunction has been recently discovered.This study aims to examine the involvement of STING in pathological cardiac remodeling and the mechanisms that govern the activation of the STING pathway.To investigate this,transverse aortic constriction(TAC)was performed on STING knockout mice to induce pressure over-load-induced cardiac remodeling.Subsequently,cardiac function,remodeling,and inflammation levels were evaluated.The STING pathway was found to be activated in the pressure overload-stressed heart and angiotensin II(Ang Il)-stimulated cardiac fibroblasts.Loss of STING expression led to a significant reduction in inflammatory responses,mitochondrial fragmenta-tion,and oxidative stress in the heart,resulting in attenuated cardiac remodeling and dysfunc-tion.Furthermore,the exacerbation of pressure overload-induced sTING-mediated inflammation and pathological cardiac remodeling was observed when mitophagy was sup-pressed through the silencing of Parkin,an E3 ubiquitin ligase.Taken together,these findings indicate that STING represents a newly identified and significant molecule implicated in the process of pathological cardiac remodeling and that mitophagy is an upstream mechanism that regulates STING activation.Targeting STING may therefore provide a novel therapeutic strategy for pathological cardiac remodeling and heart failure.

GSH-responsive camptothecin prodrug-based hybrid micellar nanoparticles enable antitumor chemo-immunotherapy by PD-L1 knockdown

The combinational chemo-immunotherapy as a novel treatment strategy has been widely studied and applied in clinic to enhance antitumor therapeutic efficacy and relieve side effects.RNA interference(RNAi)targeting PD-L1 via inhibiting novo production of PD-L1 will overcome the innate and adaptive PD-L1 expression during chemotherapy,thus enable sustained and efficient immune checkpoint blockade(ICB)to active antitumor immune response.Herein,we designed a glutathione(GSH)-responsive camptothecin(CPT)prodrug-based hybrid micellar nanoparticles(siPD-L1@HM-CPT)to achieve synergistic antitumor chemoimmunotherapy by PD-L1 knockdown.siPD-L1@HM-CPT derived from the one-step loading PD-L1 siRNA(siPD-L1)into the CPT prodrug-based hybrid micelles(HM-CPT)which were co-assembled from biodegradable polyphosphoesters-based prodrug CPT-ss-PAEEP15 and stabilizer DSPE-PEG,showed high loading efficiency,GSH-responsive drug release,and excellent stability and biosafety.siPD-L1@HM-CPT achieved simultaneously the co-delivery of CPT and siPD-L1 in vitro and in vivo,high accumulation at the tumor sites,and rapid intracellular release to promote antitumor efficacy via sensitizing CPT chemotherapy,inducing strong immunogenic cell death(ICD)and sustained ICB to improve intratumoral CD8+T cells infiltration.In addition,the antitumor immunity response limited by the differentiated immunogenicity,intrinsic PD-L1 expression,and intracellular GSH level was facilitated by efficient ICD and ICB from silencing PD-L1 and synergistic CPT chemosensitization in our experimental B16-F10 and 4T1 tumor models.Our study might offer a perspective on designing novel co-delivery nanoparticles by convenient and controllable preparation for antitumor chemo-immunotherapy.

颅内出血患者抗栓药逆转指南美国神经重症监护学会和美国重症医学会对医疗卫生专业人员的声明

背景抗栓药的使用，包括抗凝药、抗血小板药和溶栓药，在过去10年中日益增多并且预计将继续上升。虽然抗栓药相关性颅内出血可能是灾难性的，但快速逆转凝血功能障碍可能有助于限制血肿增大和改善转归。方法美国神经重症监护学会联合美国重症医学会组建了一个国际性多机构委员会，涉及的专业领域包括神经重症监护、神经内科、神经外科、卒中、血液学、血液病理学、急诊医学、药学、护理和指南制定，目的是进行文献评价并制定一份循证实践指南。该委员会进行了正式的文献检索，并对符合标准的研究进行了评价。结果利用GRADE方法学，委员会提出了在颅内出血情况下逆转维生素K拮抗药、直接Xa因子拮抗药、直接凝血酶抑制药、普通肝素、低分子肝素、类肝素、戊多糖、溶栓药和抗血小板药的推荐意见。结论该指南提供了及时和循证的抗栓药逆转策略以协助临床医生治疗抗栓药相关性颅内出血。

Dynamic blood single-cell immune responses in patients with COVID-19

The 2019 coronavirus disease(COVID-19)outbreak caused by the SARS-CoV-2 virus is an ongoing global health emergency.However,the virus'pathogenesis remains unclear,and there is no cure for the disease.We investigated the dynamic changes of blood immune response in patients with COVID-19 at different stages by using 5'gene expression,T cell receptor(TCR),and B cell receptors(BCR)V(D)J transcriptome analysis at a single-cell resolution.We obtained single-cell mRNA sequencing(scRNA-seq)data of 341,420 peripheral blood mononuclear cells(PBMCs)and 185,430 donotypic T cells and 28,802 donotypic B cells from 25 samples of 16 patients with COVID-19 for dynamic studies.In addition,we used three control samples.We found expansion of dendritic cells(DCs),CD14+monocytes,and megakaryocytes progenitor cells(MP)/platelets and a reduction of naive CD4+T lymphocytes in patients with COVID-19,along with a significant decrease of CD8+T lymphocytes,and natural killer cells(NKs)in patients in critical condition.The type I interferon(IFN-I),mitogen-activated protein kinase(MAPK),and ferroptosis pathways were activated while the disease was active,and recovered gradually after patient conditions improved.Consistent with this finding,the mRNA level of IFN-I signal-induced gene IFI27 was significantly increased in patients with COVID-19 compared with that of the controls in a validation cohort that included 38 patients and 35 controls.The concentration of interferon-a(IFN-a)in the serum of patients with COVID-19 increased significantly compared with that of the controls in an additional cohort of 215 patients with COVID-19 and 106 controls,further suggesting the important role of the IFN-I pathway in the immune response of COVID-19.TCR and BCR sequences analyses indicated that patients with COVID-19 developed specific immune responses against SARS-CoV-2 antigens.Our study reveals a dynamic landscape of human blood immune responses to SARS-CoV-2 infection,providing clues for therapeutic potentials in treating COVID-19.