Osteoprotective Effect and Mechanisms of Taxillus chinensis from Different Hosts on Ovariectomized Osteoporotic Rats / 中国实验方剂学杂志

ObjectiveTo compare the effects of Taxillus chinensis from different hosts with different meridian affinity on bone microstructure and bone metabolism in ovariectomized osteoporotic rats， and investigate its mechanism of action. MethodEighty-eight specific-pathogen-free （SPF）-grade female Sprague-Dawley （SD） rats were selected and randomly divided into 11 groups： sham-operated group， model group， low-， medium- and high-dose groups of T. chinensis from Morus alba （2.5， 5， and 10 g·kg-1）， low-， medium- and high-dose groups of T. chinensis from Cinnamomum cassia （2.5， 5， and 10 g·kg-1）， and low-， medium- and high-dose groups of T. chinensis from C. burmannii （2.5， 5， and 10 g·kg-1）. After 12 weeks of drug intervention， the rats were examined for proximal femur bone density and bone microstructure using dual-energy X-ray absorptiometry （DXA） and micro-computed tomography （Micro-CT）. Histopathological changes in rat femur were observed by the hematoxylin-eosin staining （HE）. Contents of serum estradiol （E2）， bone Gla protein （BGP）， bone alkaline phosphatase （BALP）， tartrate-resistant acid phosphatase 5b （TRACP-5b） and pre-collagen type Ⅰ amino-terminal protopeptide （PINP） were measured by the enzyme-linked immunosorbent assay （ELISA）. Real-time quantitative polymerase chain reaction （Real-time PCR） was employed to detect the messenger ribonucleic acid （mRNA） expressions of bone morphogenetic protein-2 （BMP-2）， Smad1， Smad9 and recombinant runt-related transcription factor 2 （Runx2） in rat humerus. Western blot was used to detect the protein expressions of BMP-2， p-Smad1/5/9 and Runx2 in rat humerus. ResultCompared with that in the sham-operated group， the femur microstructure of rats in the model group was significantly disrupted， with significant decreases in bone mineral density （BMD） value， bone volume fraction （BV/TV）， trabecular number （Tb.N）， and trabecular thickness （Tb.Th） （P<0.01）， and significant increases in trabecular separation （Tb.Sp） and structure model index （SMI） （P<0.01）. The serum levels of BGP， BALP， TRACP-5b and PINP were significantly increased （P<0.05， P<0.01）， and E2 levels were significantly decreased （P<0.01）. The mRNA expressions of BMP-2， Smad1， Smad9， and Runx2 were significantly decreased in rat humerus （P<0.01）， and the protein expressions of BMP-2， p-Smad1/5/9， and Runx2 were significantly reduced （P<0.01）. Compared with the model group， the administration groups of T. chinensis from different hosts all elevated the BMD， BV/TV， Tb.N， Tb.Th， Tb.Sp， and SMI levels in the femur， improved bone microstructure， increased serum E2 levels （P<0.05， P<0.01）， lowered the levels of serum BGP， BALP， TRACP-5b， and PINP， upregulated the mRNA expression of BMP-2， Smad1， and Runx2 and upregulated the mRNA expression levels of Smad9 （P<0.05， P<0.01）， and upregulated the protein expressions levels of BMP-2， p-Smad1/5/9， and Runx2 （P<0.01）. The best effect was observed in the group of T. chinensis from C. cassia. ConclusionT. chinensis from different hosts improved osteoporosis in ovariectomized rats， with the group of T. chinensis from C. cassia being the most potent among the administered groups， and its treatment of osteoporosis may regulate the balance of bone conversion by regulating BMP/Smad signaling pathway.

Human ESC-derived vascular cells promote vascular regeneration in a HIF-1α dependent manner

Hypoxia-inducible factor (HIF-1α), a core transcription factor responding to changes in cellular oxygen levels, is closely associated with a wide range of physiological and pathological conditions. However, its differential impacts on vascular cell types and molecular programs modulating human vascular homeostasis and regeneration remain largely elusive. Here, we applied CRISPR/Cas9-mediated gene editing of human embryonic stem cells and directed differentiation to generate HIF-1α-deficient human vascular cells including vascular endothelial cells, vascular smooth muscle cells, and mesenchymal stem cells (MSCs), as a platform for discovering cell type-specific hypoxia-induced response mechanisms. Through comparative molecular profiling across cell types under normoxic and hypoxic conditions, we provide insight into the indispensable role of HIF-1α in the promotion of ischemic vascular regeneration. We found human MSCs to be the vascular cell type most susceptible to HIF-1α deficiency, and that transcriptional inactivation of ANKZF1, an effector of HIF-1α, impaired pro-angiogenic processes. Altogether, our findings deepen the understanding of HIF-1α in human angiogenesis and support further explorations of novel therapeutic strategies of vascular regeneration against ischemic damage.

A single-nucleus transcriptomic atlas of primate testicular aging reveals exhaustion of the spermatogonial stem cell reservoir and loss of Sertoli cell homeostasis

The testis is pivotal for male reproduction, and its progressive functional decline in aging is associated with infertility. However, the regulatory mechanism underlying primate testicular aging remains largely elusive. Here, we resolve the aging-related cellular and molecular alterations of primate testicular aging by establishing a single-nucleus transcriptomic atlas. Gene-expression patterns along the spermatogenesis trajectory revealed molecular programs associated with attrition of spermatogonial stem cell reservoir, disturbed meiosis and impaired spermiogenesis along the sequential continuum. Remarkably, Sertoli cell was identified as the cell type most susceptible to aging, given its deeply perturbed age-associated transcriptional profiles. Concomitantly, downregulation of the transcription factor Wilms' Tumor 1 (WT1), essential for Sertoli cell homeostasis, was associated with accelerated cellular senescence, disrupted tight junctions, and a compromised cell identity signature, which altogether may help create a hostile microenvironment for spermatogenesis. Collectively, our study depicts in-depth transcriptomic traits of non-human primate (NHP) testicular aging at single-cell resolution, providing potential diagnostic biomarkers and targets for therapeutic interventions against testicular aging and age-related male reproductive diseases.

Chemical Components and Pharmacological Effect of Trib. Lorantheae in China： A Review / 中国实验方剂学杂志

Trib. Lorantheae used as traditional Chinese materia medica has a long history. There are 41 genera of Trib. Lorantheae， of which 6 belong to China， all have medicinal value， mainly distributed in Southwest， Southern， and Central and Southern China， with abundant resources. Twenty-two species of Trib. Lorantheae are used as medicinal materials or herbs in China. It mainly includes Taxillus. chinensis， T. sutchuenensis， Scurrula parasitica， Loranthus tanakae， Dendrophthoe pentandra， S. ferruginea， etc.， of which T. chinensis is the most widely used. The main chemical components of Trib. Lorantheae include flavonoids， terpenoids， sterols， phenylpropanoids， curcumins， phenolic acids， violate oils， sugars， and other compounds. Modern studies show that the extracts and monomer compounds of Trib. Lorantheae have various pharmacological effects such as anti-inflammation， anti-tumor， anti-oxidation， anti-osteoporosis， bacteriostasis， anti-virus， and lowering blood sugar， blood pressure， and lipid. It is believe that most active components related to their pharmacological effects are flavonoids， most of which are the main pharmacodynamic substances of the parasitic plants of Trib. Lorantheae， playing an important role in anti-inflammation， anti-tumor， anti-oxidation， anti-osteoporosis， and other pharmacological effect. This paper systematically summarized the literature and data on plants of Trib. Lorantheae and reviewed their chemical components and pharmacological effects， which provided references for the research， development， and utilization of Trib. Lorantheae.

Single-cell profiling reveals a potent role of quercetin in promoting hair regeneration

Hair loss affects millions of people at some time in their life, and safe and efficient treatments for hair loss are a significant unmet medical need. We report that topical delivery of quercetin (Que) stimulates resting hair follicles to grow with rapid follicular keratinocyte proliferation and replenishes perifollicular microvasculature in mice. We construct dynamic single-cell transcriptome landscape over the course of hair regrowth and find that Que treatment stimulates the differentiation trajectory in the hair follicles and induces an angiogenic signature in dermal endothelial cells by activating HIF-1α in endothelial cells. Skin administration of a HIF-1α agonist partially recapitulates the pro-angiogenesis and hair-growing effects of Que. Together, these findings provide a molecular understanding for the efficacy of Que in hair regrowth, which underscores the translational potential of targeting the hair follicle niche as a strategy for regenerative medicine, and suggest a route of pharmacological intervention that may promote hair regrowth.

Single-nucleus transcriptomics reveals a gatekeeper role for FOXP1 in primate cardiac aging

Aging poses a major risk factor for cardiovascular diseases, the leading cause of death in the aged population. However, the cell type-specific changes underlying cardiac aging are far from being clear. Here, we performed single-nucleus RNA-sequencing analysis of left ventricles from young and aged cynomolgus monkeys to define cell composition changes and transcriptomic alterations across different cell types associated with age. We found that aged cardiomyocytes underwent a dramatic loss in cell numbers and profound fluctuations in transcriptional profiles. Via transcription regulatory network analysis, we identified FOXP1, a core transcription factor in organ development, as a key downregulated factor in aged cardiomyocytes, concomitant with the dysregulation of FOXP1 target genes associated with heart function and cardiac diseases. Consistently, the deficiency of FOXP1 led to hypertrophic and senescent phenotypes in human embryonic stem cell-derived cardiomyocytes. Altogether, our findings depict the cellular and molecular landscape of ventricular aging at the single-cell resolution, and identify drivers for primate cardiac aging and potential targets for intervention against cardiac aging and associated diseases.

Single-cell transcriptomic atlas of mouse cochlear aging

Progressive functional deterioration in the cochlea is associated with age-related hearing loss (ARHL). However, the cellular and molecular basis underlying cochlear aging remains largely unknown. Here, we established a dynamic single-cell transcriptomic landscape of mouse cochlear aging, in which we characterized aging-associated transcriptomic changes in 27 different cochlear cell types across five different time points. Overall, our analysis pinpoints loss of proteostasis and elevated apoptosis as the hallmark features of cochlear aging, highlights unexpected age-related transcriptional fluctuations in intermediate cells localized in the stria vascularis (SV) and demonstrates that upregulation of endoplasmic reticulum (ER) chaperon protein HSP90AA1 mitigates ER stress-induced damages associated with aging. Our work suggests that targeting unfolded protein response pathways may help alleviate aging-related SV atrophy and hence delay the progression of ARHL.

4E-BP1 counteracts human mesenchymal stem cell senescence via maintaining mitochondrial homeostasis

Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders, the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown. Here, we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem cells (hMSCs). Genetic inactivation of 4E-BP1 in hMSCs compromises mitochondrial respiration, increases mitochondrial reactive oxygen species (ROS) production, and accelerates cellular senescence. Mechanistically, the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes, especially several key subunits of complex III including UQCRC2. Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs. These f indings together demonstrate that 4E-BP1 functions as a geroprotector to mitigate human stem cell senescence and maintain mitochondrial homeostasis, particularly for the mitochondrial respiration complex III, thus providing a new potential target to counteract human stem cell senescence.

Single-nucleus profiling unveils a geroprotective role of the FOXO3 in primate skeletal muscle aging

Age-dependent loss of skeletal muscle mass and function is a feature of sarcopenia, and increases the risk of many aging-related metabolic diseases. Here, we report phenotypic and single-nucleus transcriptomic analyses of non-human primate skeletal muscle aging. A higher transcriptional fluctuation was observed in myonuclei relative to other interstitial cell types, indicating a higher susceptibility of skeletal muscle fiber to aging. We found a downregulation of FOXO3 in aged primate skeletal muscle, and identified FOXO3 as a hub transcription factor maintaining skeletal muscle homeostasis. Through the establishment of a complementary experimental pipeline based on a human pluripotent stem cell-derived myotube model, we revealed that silence of FOXO3 accelerates human myotube senescence, whereas genetic activation of endogenous FOXO3 alleviates human myotube aging. Altogether, based on a combination of monkey skeletal muscle and human myotube aging research models, we unraveled the pivotal role of the FOXO3 in safeguarding primate skeletal muscle from aging, providing a comprehensive resource for the development of clinical diagnosis and targeted therapeutic interventions against human skeletal muscle aging and the onset of sarcopenia along with aging-related disorders.

The value of preoperative inflammatory markers in predicting recurrence of hepatocellular carcinoma after liver transplantation / 中华消化外科杂志

Objective:To investigate the value of aspartate aminotransferase/lymphocyte ratio (ALR), γ-glutamyltranspeptidase/lymphocyte ratio (GLR) and aspartate aminotransferase/alanine aminotransferase ratio (AAR) in predicting the recurrence of hepatocellular carcinoma after liver transplantation.Methods:The retrospective cohort study was conducted. The clinicopathological data of 178 patients with hepatocellular carcinoma who underwent liver transplantation in Tianjin First Central Hospital from July 2014 to June 2018 were collected. There were 156 males and 22 females, aged (54±9)years. All patients received the first time of orthotopic liver transplantation. Observation indicators: (1) follow-up; (2) the predictive value and cutoff value of each index for tumor recur-rence of patients with hepatocellular carcinoma after liver transplantation; (3) analysis of risk factors for tumor recurrence of patients with hepatocellular carcinoma after liver transplantation; (4) cons-truction and evaluation of the predictive model for tumor recurrence of patients with hepatocellular carcinoma after liver transplantation. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was conducted using the Mann-Whitney U test. Count data were expressed as absolute numbers, and comparison between groups was conducted using the chi-square test or Fisher exact probability. The Kaplan-Meier method was used to draw survival curve and the Log-rank test was used for survival analysis. Factors with P<0.05 in univariate analysis were included in multivariate analysis. Univariate analysis and multivariate analysis were performed by COX proportional risk regression model with forward method. The regression coefficient was used to build the prediction model. The receiver operating characteristic curve was drawn, and the area under curve (AUC) was used to evaluate the predictive ability of prediction model. Results:(1) Follow-up. All 178 patients with hepatocellular carcinoma were followed up for 36(range, 1?74)months after liver transplantation. During the follow-up, there were 41 patients died, 61 patients with tumor recurrence and 117 cases without tumor recurrence. The 3-, 5-year overall survival rates and 3-, 5-year tumor recurrence free survival rates of patients after liver transplantation were 72.8%, 69.9% and 57.3%, 52.8%, respectively. (2) The predictive value and cutoff value of each index for tumor recurrence of patients with hepatocellular carcinoma after liver transplantation. The AUC of preoperative serum alpha fetoprotein (AFP), tumor diameter, ALR, GLR, neutrophil to lymphocyte ratio, AAR in recipients were 0.76, 0.70, 0.69, 0.65, 0.64, 0.65 (95% confidence interval as 0.68?0.83, 0.61?0.79, 0.61?0.77, 0.57?0.74, 0.56?0.73, 0.56?0.74, P<0.05), and the corresponding best cutoff value of each index were 228.00 μg/L, 5.25 cm, 92.90, 122.40, 3.00, 2.42. (3) Analysis of risk factors for tumor recurrence of patients with hepato-cellular carcinoma after liver transplantation. Results of multivariate analysis showed the preoperative serum AFP >228.88 μg/L, number of tumor as multiple, tumor diameter >5.25 cm, ALR >92.90, AAR >2.42 were indepen-dent risk factors for tumor recurrence of hepatocellular carcinoma after liver transplantation ( hazard ratio=3.13, 1.90, 2.66, 2.40, 2.75, 95% confidence interval as 1.81?5.41, 1.08?3.35, 1.49?4.74, 1.40?4.11, 1.54?4.91, P<0.05). (4) Construction and evaluation of the predictive model for tumor recurrence of patients with hepatocellular carcinoma after liver transplantation. According to the results of multivariate analysis, the preoperative serum AFP, number of tumor, tumor diameter, ALR, AAR were used to construct the predictive model for tumor recurrence of hepatocellular carcinoma after liver transplantation. The AUC, best cutoff value, specificity and sensitivity of the predictive model were 0.83 (95% confidence interval as 0.76?0.89, P<0.05), 5.5, 80.3% and 73.8%. Of the 178 patients, there were 110 patients with low risk of tumor recurrence (scoring as 0?5) and 68 patients with high risk of tumor recurrence (scoring as 6?16) after liver transplantation. The 1-, 3-, 5-year tumor recurrence free survival rates and 1-, 3-, 5-year overall survival rates of patients with high risk of tumor recurrence were 27.7%, 18.2%, 18.2% and 63.7%, 48.9%, 48.9%, respectively. The above indicators of patients with low risk of tumor recurrence were 92.3%, 82.4%, 74.6% and 90.4%, 87.7%, 83.6%, respectively. There were significant differences of the above indicators between patients with high risk of tumor recurrence and low risk of tumor recurrence ( χ2=67.83, 21.95, P<0.05). Conclusions:The preoperative serum AFP, number of tumor, tumor diameter, ALR, AAR are independent influencing factors for tumor recurrence of hepato-cellular carcinoma after liver transplantation. The predictive model constructed based on the above indexes has a good prediction efficiency.

Development of a new model for predicting recurrence after liver transplantation for hepatocellular carcinoma beyond Milan criteria / 临床肝胆病杂志

Objective To develop a new model for predicting recurrence after liver transplantation for hepatocellular carcinoma (HCC) beyond Milan criteria based on related preoperative and postoperative indicators. Methods A retrospective analysis was performed for the clinical data of the patients with HCC beyond Milan criteria who underwent orthotopic liver transplantation for the first time in Tianjin First Central Hospital from August 2014 to July 2018, and according to the presence or absence of recurrence during follow-up, the patients were divided into recurrence group and no-recurrence group. The t -test or the Mann-Whitney U test was used for comparison of continuous data between groups, and the chi-square test or the Fisher's exact test was used for comparison of categorical data between groups. The Kaplan-Meier method was used to plot survival curves, and the log-rank test was used for comparison of survival curves. Univariate and multivariate Cox proportional hazards regression analyses were used to identify the risk factors for recurrence-free survival after surgery. A new model was developed for recurrence after liver transplantation in the patients with HCC beyond Milan criteria based on the risk factors identified. The area under the receiver operating characteristic curve (AUC) was used to evaluate predictive performance, and the Hosmer-Lemeshow test was used to assess the goodness of fit of the model. Results A total of 117 patients with HCC beyond Milan criteria were enrolled in this study, with a median follow-up time of 24 (1-74) months. A total of 53 patients (45.3%) experienced recurrence after surgery, among whom 52 (98.1%) had recurrence within 3 years after surgery, with a median time to recurrence of 6 (1-52) months. The Cox proportional hazards regression analysis showed that preoperative serum alpha-fetoprotein (AFP) >769 ng/mL, neutrophil-lymphocyte ratio (NLR) >3.75, and ki67 index >0.25 were independent risk factors for recurrence-free survival after liver transplantation. The model established based on these three risk factors had an AUC of 0.843, with good sensitivity (88.7%) and specificity (70.3%). The optimal cut-off value was selected according to the maximization of Youden index, and then the patients were divided into low-risk group (0-1 point) and high-risk group (1.5-4 points). The log-rank test showed that the low-risk group had significantly higher 3-and 5-year recurrence-free survival rates than the high-risk group (84.1%/72.0% vs 10.9%/10.9%, χ 2 =29.425, P < 0.001). Conclusion Liver transplantation for HCC beyond Milan criteria should be performed with caution, and the predictive model established based on preoperative AFP, NLR, and ki67 index can accurately assess the indication for liver transplantation in such patients.

Aging weakens Th17 cell pathogenicity and ameliorates experimental autoimmune uveitis in mice

Aging-induced changes in the immune system are associated with a higher incidence of infection and vaccination failure. Lymph nodes, which filter the lymph to identify and fight infections, play a central role in this process. However, careful characterization of the impact of aging on lymph nodes and associated autoimmune diseases is lacking. We combined single-cell RNA sequencing (scRNA-seq) with flow cytometry to delineate the immune cell atlas of cervical draining lymph nodes (CDLNs) of both young and old mice with or without experimental autoimmune uveitis (EAU). We found extensive and complicated changes in the cellular constituents of CDLNs during aging. When confronted with autoimmune challenges, old mice developed milder EAU compared to young mice. Within this EAU process, we highlighted that the pathogenicity of T helper 17 cells (Th17) was dampened, as shown by reduced GM-CSF secretion in old mice. The mitigated secretion of GM-CSF contributed to alleviation of IL-23 secretion by antigen-presenting cells (APCs) and may, in turn, weaken APCs' effects on facilitating the pathogenicity of Th17 cells. Meanwhile, our study further unveiled that aging downregulated GM-CSF secretion through reducing both the transcript and protein levels of IL-23R in Th17 cells from CDLNs. Overall, aging altered immune cell responses, especially through toning down Th17 cells, counteracting EAU challenge in old mice.

Exploration and practice of patient satisfaction evaluation management in multi-campus public hospitals / 中华医院管理杂志

Patient satisfaction is one of the core indicators to measure the service quality of medical institutions. To this end, a multi-campus public hospital in Shanghai constructed a management system of patient satisfaction evaluation. Since 2021, its call center has conducted a full coverage satisfaction assessment for discharged patients from its three campuses and collected dissatisfaction information feedback. The hospital organized relevant clinical departments and functional departments to fully communicate with the dissatisfied patients according to the feedback information, followed by a joint rectification. The hospital regularly conducts in-depth analysis of all complaints for timely discovery of common problems in different campuses for continuous improvement. This practice can provide reference for multi-campus hospitals to promote homogeneous management, to improve management efficiency, service quality and patient satisfaction.

Single-nucleus transcriptomic landscape of primate hippocampal aging

The hippocampus plays a crucial role in learning and memory, and its progressive deterioration with age is functionally linked to a variety of human neurodegenerative diseases. Yet a systematic profiling of the aging effects on various hippocampal cell types in primates is still missing. Here, we reported a variety of new aging-associated phenotypic changes of the primate hippocampus. These include, in particular, increased DNA damage and heterochromatin erosion with time, alongside loss of proteostasis and elevated inflammation. To understand their cellular and molecular causes, we established the first single-nucleus transcriptomic atlas of primate hippocampal aging. Among the 12 identified cell types, neural transiently amplifying progenitor cell (TAPC) and microglia were most affected by aging. In-depth dissection of gene-expression dynamics revealed impaired TAPC division and compromised neuronal function along the neurogenesis trajectory; additionally elevated pro-inflammatory responses in the aged microglia and oligodendrocyte, as well as dysregulated coagulation pathways in the aged endothelial cells may contribute to a hostile microenvironment for neurogenesis. This rich resource for understanding primate hippocampal aging may provide potential diagnostic biomarkers and therapeutic interventions against age-related neurodegenerative diseases.

Method Establishment of Content Determination of Three Toxic Impurities in Glycerophosphorylcholine Raw Materials / 中国药房

OBJECTIVE： To establish GC-MS method for the content determination of three toxic impurities in glycerophosphorylcholine raw materials ，such as epichlorohydrin ，glycidyl，3-chloro-1，2-propanediol. METHODS ：Four batches of glycerophosphorylcholine raw materials were used as test samples. The determination was performed on ZB-WAXplus TM column， and the injector temperature was 200 ℃；the sample injection adopted splitless injection mode ，using helium （He）as carrier gas ， in constant current mode ；the temperature program for the column was initially heating at 30 ℃ for 1 min，rising to 220 ℃ at a speed of 30 ℃/min then remaining 5 min. The ion source was electrospray ion source （EI），the ion source temperature was 200 ℃，and the ionization energy was 70 eV；transmission interface temperature was 250 ℃，and mass spectrum monitoring mode was selected ion （SIM）. Detection ions were epichlorhydrin [mass charge ratio （m/z）49，57，62]，glycidyl（m/z 31，43，44）， 3-chloro-1，2-propanediol（m/z 44，61，79）. The solvent delay time was 3 min. RESULTS ：The linear range of epichlorhydrin ， glycidyl and 3-chloro-1，2-propanediol were 29.86-746.48，172.91-922.18，21.18-211.85 ng/mL，respectively（all r＞0.999 0）. The detection limits were 19.91，115.27，10.59 ng/mL，respectively. The limits of quantitation were 29.86，172.91，21.18 ng/mL， respectively. RSDs of precision （n＝6），reproducibility （n＝6） and stability （placed at room temperature for 12 h，n＝8） tests were all lower than 10％. The average recoveries were 93.88％，91.45％，91.86％，and RSDs were 5.10％，3.10％，2.49％ （n＝9），respectively. In the 4 batches of glycerophosphorylcholine raw materials ，three toxic impurities were all not detected. CONCLUSIONS：Established GC-MS method is simple ，efficient，accurate and repeatable ，and it can be used to determine the contents of three toxic impurities in glycerophosphorylcholine raw materials ，such as epichlorohydrin ，glycidyl，3-chloro-1， 2-propanediol.

SIRT7 antagonizes human stem cell aging as a heterochromatin stabilizer

SIRT7, a sirtuin family member implicated in aging and disease, is a regulator of metabolism and stress responses. It remains elusive how human somatic stem cell populations might be impacted by SIRT7. Here, we found that SIRT7 expression declines during human mesenchymal stem cell (hMSC) aging and that SIRT7 deficiency accelerates senescence. Mechanistically, SIRT7 forms a complex with nuclear lamina proteins and heterochromatin proteins, thus maintaining the repressive state of heterochromatin at nuclear periphery. Accordingly, deficiency of SIRT7 results in loss of heterochromatin, de-repression of the LINE1 retrotransposon (LINE1), and activation of innate immune signaling via the cGAS-STING pathway. These aging-associated cellular defects were reversed by overexpression of heterochromatin proteins or treatment with a LINE1 targeted reverse-transcriptase inhibitor. Together, these findings highlight how SIRT7 safeguards chromatin architecture to control innate immune regulation and ensure geroprotection during stem cell aging.

A human circulating immune cell landscape in aging and COVID-19

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.

SIRT7 antagonizes human stem cell aging as a heterochromatin stabilizer

SIRT7, a sirtuin family member implicated in aging and disease, is a regulator of metabolism and stress responses. It remains elusive how human somatic stem cell populations might be impacted by SIRT7. Here, we found that SIRT7 expression declines during human mesenchymal stem cell (hMSC) aging and that SIRT7 deficiency accelerates senescence. Mechanistically, SIRT7 forms a complex with nuclear lamina proteins and heterochromatin proteins, thus maintaining the repressive state of heterochromatin at nuclear periphery. Accordingly, deficiency of SIRT7 results in loss of heterochromatin, de-repression of the LINE1 retrotransposon (LINE1), and activation of innate immune signaling via the cGAS-STING pathway. These aging-associated cellular defects were reversed by overexpression of heterochromatin proteins or treatment with a LINE1 targeted reverse-transcriptase inhibitor. Together, these findings highlight how SIRT7 safeguards chromatin architecture to control innate immune regulation and ensure geroprotection during stem cell aging.

A human circulating immune cell landscape in aging and COVID-19

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.

A human circulating immune cell landscape in aging and COVID-19

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.