A lymphocyte-microglia-astrocyte axis in chronic active multiple sclerosis.

Multiple sclerosis (MS) lesions that do not resolve in the months after they form harbour ongoing demyelination and axon degeneration, and are identifiable in vivo by their paramagnetic rims on MRI scans1-3. Here, to define mechanisms underlying this disabling, progressive neurodegenerative state4-6 and foster development of new therapeutic agents, we used MRI-informed single-nucleus RNA sequencing to profile the edge of demyelinated white matter lesions at various stages of inflammation. We uncovered notable glial and immune cell diversity, especially at the chronically inflamed lesion edge. We define 'microglia inflamed in MS' (MIMS) and 'astrocytes inflamed in MS', glial phenotypes that demonstrate neurodegenerative programming. The MIMS transcriptional profile overlaps with that of microglia in other neurodegenerative diseases, suggesting that primary and secondary neurodegeneration share common mechanisms and could benefit from similar therapeutic approaches. We identify complement component 1q (C1q) as a critical mediator of MIMS activation, validated immunohistochemically in MS tissue, genetically by microglia-specific C1q ablation in mice with experimental autoimmune encephalomyelitis, and therapeutically by treating chronic experimental autoimmune encephalomyelitis with C1q blockade. C1q inhibition is a potential therapeutic avenue to address chronic white matter inflammation, which could be monitored by longitudinal assessment of its dynamic biomarker, paramagnetic rim lesions, using advanced MRI methods.

Ultrahigh-resolution MRI Reveals Extensive Cortical Demyelination in a Nonhuman Primate Model of Multiple Sclerosis.

Cortical lesions are a primary driver of disability in multiple sclerosis (MS). However, noninvasive detection of cortical lesions with in vivo magnetic resonance imaging (MRI) remains challenging. Experimental autoimmune encephalomyelitis (EAE) in the common marmoset is a relevant animal model of MS for investigating the pathophysiological mechanisms leading to brain damage. This study aimed to characterize cortical lesions in marmosets with EAE using ultrahigh-field (7 T) MRI and histological analysis. Tissue preparation was optimized to enable the acquisition of high-spatial resolution (50-µm isotropic) T2*-weighted images. A total of 14 animals were scanned in this study, and 70% of the diseased animals presented at least one cortical lesion on postmortem imaging. Cortical lesions identified on MRI were verified with myelin proteolipid protein immunostaining. An optimized T2*-weighted sequence was developed for in vivo imaging and shown to capture 65% of cortical lesions detected postmortem. Immunostaining confirmed extensive demyelination with preserved neuronal somata in several cortical areas of EAE animals. Overall, this study demonstrates the relevance and feasibility of the marmoset EAE model to study cortical lesions, among the most important yet least understood features of MS.

Development and validation of a novel mRNA signature for predicting early relapse in non-small cell lung cancer.

BACKGROUND: Recurrence after initial primary resection is still a major and ultimate cause of death for non-small cell lung cancer patients. We attempted to build an early recurrence associated gene signature to improve prognostic prediction of non-small cell lung cancer. METHODS: Propensity score matching was conducted between patients in early relapse group and long-term survival group from The Cancer Genome Atlas training series (N = 579) and patients were matched 1:1. Global transcriptome analysis was then performed between the paired groups to identify tumour-specific mRNAs. Finally, using LASSO Cox regression model, we built a multi-gene early relapse classifier incorporating 40 mRNAs. The prognostic and predictive accuracy of the signature was internally validated in The Cancer Genome Atlas patients. RESULTS: A total of 40 mRNAs were finally identified to build an early relapse classifier. With specific risk score formula, patients were classified into a high-risk group and a low-risk group. Relapse-free survival was significantly different between the two groups in both discovery (HR: 3.244, 95% CI: 2.338-4.500, P < 0.001) and internal validation series (HR 1.970, 95% CI 1.181-3.289, P = 0.009). Further analysis revealed that the prognostic value of this signature was independent of tumour stage, histotype and epidermal growth factor receptor mutation (P < 0.05). Time-dependent receiver operating characteristic analysis showed that the area under receiver operating characteristic curve of this signature was higher than TNM stage alone (0.771 vs 0.686, P < 0.05). Further, decision curve analysis curves analysis at 1 year revealed the considerable clinical utility of this signature in predicting early relapse. CONCLUSIONS: We successfully established a reliable signature for predicting early relapse in stage I-III non-small cell lung cancer.

Protective role of the lipid phosphatase Fig4 in the adult nervous system.

The signaling lipid phosphatidylinositol 3,5-bisphosphate, PI(3,5)P2, functions in vesicular trafficking through the endo-lysosomal compartment. Cellular levels of PI(3,5)P2 are regulated by an enzyme complex comprised of the kinase PIKFYVE, the phosphatase FIG4, and the scaffold protein VAC14. Mutations of human FIG4 cause inherited disorders including Charcot-Marie-Tooth disease type 4J, polymicrogyria with epilepsy, and Yunis-Varón syndrome. Constitutive Fig4-/- mice exhibit intention tremor, spongiform degeneration of neural tissue, hypomyelination, and juvenile lethality. To determine whether PI(3,5)P2 is required in the adult, we generated Fig4flox/-; CAG-creER mice and carried out tamoxifen-induced gene ablation. Global ablation in adulthood leads to wasting, tremor, and motor impairment. Death follows within 2 months of tamoxifen treatment, demonstrating a life-long requirement for Fig4. Histological examinations of the sciatic nerve revealed profound Wallerian degeneration of myelinated fibers, but not C-fiber axons in Remak bundles. In optic nerve sections, myelinated fibers appear morphologically intact and carry compound action potentials at normal velocity and amplitude. However, when iKO mice are challenged with a chemical white matter lesion, repair of damaged CNS myelin is significantly delayed, demonstrating a novel role for Fig4 in remyelination. Thus, in the adult PNS Fig4 is required to protect myelinated axons from Wallerian degeneration. In the adult CNS, Fig4 is dispensable for fiber stability and nerve conduction, but is required for the timely repair of damaged white matter. The greater vulnerability of the PNS to Fig4 deficiency in the mouse is consistent with clinical observations in patients with Charcot-Marie-Tooth disease.

A low cost surrogate eye model for corneal foreign body removal.

BACKGROUND: Patients commonly present to the Emergency Department with a corneal foreign body (FB). There is currently a lack of adequate training for junior doctors in the management of this condition. Our self-made surrogate eye model aims to address this void in our junior doctors' knowledge. METHODS: Participants were guided through a hands-on session with a slit-lamp using our eye model, which is made of a hemispherical agar embedded with pencil lead fragments simulating as FBs. Using a 7-point Likert scale, all participants completed a questionnaire both before and after training, for: (1) knowledge in corneal FB removal, (2) confidence in corneal FB removal, and (3) effectiveness of the model. RESULTS: Out of 73 participants, 82.2% (60/73) had no prior experience in corneal FBs removal. After the training session, their knowledge improved from a median score of 2 (interquartile range [IQR] 1 to 3) to 5 (IQR 5 to 6), with improvement in confidence levels from 2 (IQR 1 to 2) to 5 (IQR 4 to 6). The effectiveness of our eye model scored a median of 6 (IQR 5 to 7). CONCLUSIONS: Our surrogate eye model is low-cost, quick and easy to reproduce. After use, our learners expressed greater confidence in managing the removal of corneal FBs and use of slit lamp. With a recent focus in patient safety and quality, teaching this procedure via simulation is a safe way of bridging the gap between traditional didactic teaching and the clinical environment.

Osteoprotegerin contributes to the metastatic potential of cells with a dysfunctional TSC2 tumor-suppressor gene.

In addition to its effects on bone metabolism, osteoprotegerin (OPG), a soluble member of the tumor necrosis factor family of receptors, promotes smooth muscle cell proliferation and migration and may act as a survival factor for tumor cells. We hypothesized that these cellular mechanisms of OPG may be involved in the growth and proliferation of lymphangioleiomyomatosis (LAM) cells, abnormal smooth muscle-like cells with mutations in one of the tuberous sclerosis complex tumor-suppressor genes (TSC1/TSC2) that cause LAM, a multisystem disease characterized by cystic lung destruction, lymphatic infiltration, and abdominal tumors. Herein, we show that OPG stimulated proliferation of cells cultured from explanted LAM lungs, and selectively induced migration of LAM cells identified by the loss of heterozygosity for TSC2. Consistent with these observations, cells with TSC2 loss of heterozygosity expressed the OPG receptors, receptor activator of NF-κB ligand, syndecan-1, and syndecan-2. LAM lung nodules showed reactivities to antibodies to tumor necrosis factor-related apoptosis-inducing ligand, receptor activator of NF-κB ligand, syndecan-1, and syndecan-2. LAM lung nodules also produced OPG, as shown by expression of OPG mRNA and colocalization of reactivities to anti-OPG and anti-gp100 (HMB45) antibodies in LAM lung nodules. Serum OPG was significantly higher in LAM patients than in normal volunteers. Based on these data, it appears that OPG may have tumor-promoting roles in the pathogenesis of lymphangioleiomyomatosis, perhaps acting as both autocrine and paracrine factors.

Prognostic value of inflammatory nutritional scores in locally advanced esophageal squamous cell carcinoma patients undergoing neoadjuvant chemoimmunotherapy: a multicenter study in China.

Objective: This study investigates the prognostic significance of inflammatory nutritional scores in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC) undergoing neoadjuvant chemoimmunotherapy. Methods: A total of 190 LA-ESCC patients were recruited from three medical centers across China. Pre-treatment laboratory tests were utilized to calculate inflammatory nutritional scores. LASSO regression and multivariate logistic regression analyses were conducted to pinpoint predictors of pathological response. Kaplan-Meier and Cox regression analyses were employed to assess disease-free survival (DFS) prognostic factors. Results: The cohort comprised 154 males (81.05%) and 36 females (18.95%), with a median age of 61.4 years. Pathological complete response (pCR) was achieved in 17.38% of patients, while 44.78% attained major pathological response (MPR). LASSO and multivariate logistic regression analyses identified that hemoglobin, albumin, lymphocyte, and platelet (HALP) (P=0.02) as an independent predictors of MPR in LA-ESCC patients receiving neoadjuvant chemoimmunotherapy. Kaplan-Meier and log-rank tests indicated that patients with low HALP, MPR, ypT1-2, ypN0 and, ypTNM I stages had prolonged DFS (P < 0.05). Furthermore, univariate and multivariate Cox regression analyses underscored HALP (P = 0.019) and ypT (P = 0.029) as independent predictive factors for DFS in ESCC. Conclusion: Our study suggests that LA-ESCC patients with lower pre-treatment HALP scores exhibit improved pathological response and reduced recurrence rate. As a comprehensive index of inflammatory nutritional status, pre-treatment HALP may be a reliable prognostic marker in ESCC patients undergoing neoadjuvant chemoimmunotherapy.

Lipofuscin-like autofluorescence within microglia and its impact on studying microglial engulfment.

Engulfment of cellular material and proteins is a key function for microglia, a resident macrophage of the central nervous system (CNS). Among the techniques used to measure microglial engulfment, confocal light microscopy has been used the most extensively. Here, we show that autofluorescence (AF) likely due to lipofuscin (lipo-AF) and typically associated with aging, can also be detected within microglial lysosomes in the young mouse brain by light microscopy. This lipo-AF signal accumulates first within microglia and it occurs earliest in white versus gray matter. Importantly, in gray matter, lipo-AF signal can confound the interpretation of antibody-labeled synaptic material within microglia in young adult mice. We further show that there is an age-dependent accumulation of lipo-AF inside and outside of microglia, which is not affected by amyloid plaques. We finally implement a robust and cost-effective strategy to quench AF in mouse, marmoset, and human brain tissue.

A 4D transcriptomic map for the evolution of multiple sclerosis-like lesions in the marmoset brain.

Single-time-point histopathological studies on postmortem multiple sclerosis (MS) tissue fail to capture lesion evolution dynamics, posing challenges for therapy development targeting development and repair of focal inflammatory demyelination. To close this gap, we studied experimental autoimmune encephalitis (EAE) in the common marmoset, the most faithful animal model of these processes. Using MRI-informed RNA profiling, we analyzed ~600,000 single-nucleus and ~55,000 spatial transcriptomes, comparing them against EAE inoculation status, longitudinal radiological signals, and histopathological features. We categorized 5 groups of microenvironments pertinent to neural function, immune and glial responses, tissue destruction and repair, and regulatory network at brain borders. Exploring perilesional microenvironment diversity, we uncovered central roles of EAE-associated astrocytes, oligodendrocyte precursor cells, and ependyma in lesion formation and resolution. We pinpointed imaging and molecular features capturing the pathological trajectory of WM, offering potential for assessing treatment outcomes using marmoset as a platform.

Nomogram-based prediction model for survival of COVID-19 patients: A clinical study.

The study aim to construct an effective model for predicting the survival period of COVID-19 patients. METHODS: Clinical data of 386 COVID-19 patients were collected from December 2022 to January 2023. The patients were randomly divided into training and validation cohorts in a 7:3 ratio. LASSO regression and multivariate Cox regression analyses were used to identify prognostic factors, and a nomogram was constructed. Nomogram was evaluated using decision curve analysis, receiver operating characteristic curve, consistency index (c-index), and calibration curve. RESULTS: 86 patients (22.3%) died. A new nomogram for predicting the survival was established based on age, resting oxygen saturation, Blood urea nitrogen (BUN), c-reactive protein-to-albumin ratio (CAR), and pneumonia visual score. The decision curve indicated high clinical applicability. The nomogram c-indexes in the training and validation cohorts were 0.846 and 0.81, respectively. The area under the curves (AUCs) for the 15-day and 30-day survival probabilities were 0.906 and 0.869 in the training cohort, and 0.851 and 0.843 in the validation cohort. The calibration curves demonstrated consistency between predicted and actual survival probabilities. CONCLUSIONS: Our nomogram has the capacity to assist clinical practitioners in estimating the survival rate of COVID-19 patients, thereby facilitating more optimal management strategies and therapeutic interventions with substantial clinical applicability.

Combination of neutrophil-to-lymphocyte ratio and albumin concentration to predict the prognosis of esophageal squamous cell cancer patients undergoing esophagectomy.

Background: Esophageal squamous cell cancer (ESCC) is an aggressive cancer with high incidence and mortality. It is crucial to predict prognosis of these patients individually. Neutrophil-to-lymphocyte ratio (NLR) has been reported as a prognostic indicator in several tumors, including esophageal cancer. Besides inflammatory factors, nutritional status can impact survival of cancer patients. Albumin (Alb) concentration is an easily obtained indicator to reflect nutritional status. Methods: In this study, we retrospectively collected the data of patients with ESCC and used univariate and multivariate analysis to investigate the relationship between combination of NLR and Alb (NLR-Alb) and survival. Meanwhile, we compared clinical features among NLR-Alb cohorts. Results: Univariate analysis showed that age (P=0.013), gender (P=0.021), surgical type (P=0.031), preoperative therapy (P=0.007), NLR-Alb (P=0.001), and tumor-node-metastasis (TNM) status (P<0.001) were associated with 5-year overall survival (OS). In multivariate analysis, NLR-Alb [hazard ratio (HR) =2.53, 95% confidence interval (95% CI): 1.38-4.63, P=0.003] and TNM status (HR =4.76, 95% CI: 3.09-7.33, P<0.001) were independent predictive factors for 5-year OS. The 5-year OS rates were 83%, 62%, and 55% for NLR-Alb 1, NLR-Alb 2, and NLR-Alb 3, respectively (P=0.001). Conclusions: In summary, pre-operative NLR-Alb is a favorable and cost-effective index to predict prognosis of patients with ESCC individually.

Mitophagy-related gene signature predicts prognosis, immune infiltration and chemotherapy sensitivity in colorectal cancer.

BACKGROUND: Mitophagy plays essential role in the development and progression of colorectal cancer (CRC). However, the effect of mitophagy-related genes in CRC remains largely unknown. AIM: To develop a mitophagy-related gene signature to predict the survival, immune infiltration and chemotherapy response of CRC patients. METHODS: Non-negative matrix factorization was used to cluster CRC patients from Gene Expression Omnibus database (GSE39582, GSE17536, and GSE37892) based on mitophagy-related gene expression. The CIBERSORT method was applied for the evaluation of the relative infiltration levels of immune cell types. The performance signature in predicting chemotherapeutic sensitivity was generated using data from the Genomics of Drug Sensitivity in Cancer database. RESULTS: Three clusters with different clinicopathological features and prognosis were identified. Higher enrichment of activated B cells and CD4+ T cells were observed in cluster III patients with the most favorable prognosis. Next, a risk model based on mitophagy-related genes was developed. Patients in training and validation sets were categorized into low-risk and high-risk subgroups. Low risk patients showed significantly better prognosis, higher enrichment of immune activating cells and greater response to chemotherapy (oxaliplatin, irinotecan, and 5-fluorouracil) compared to high-risk patients. Further experiments identified CXCL3 as novel regulator of cell proliferation and mitophagy. CONCLUSION: We revealed the biological roles of mitophagy-related genes in the immune infiltration, and its ability to predict patients' prognosis and response to chemotherapy in CRC. These interesting findings would provide new insight into the therapeutic management of CRC patients.

Lipofuscin-like autofluorescence within microglia and its impact on studying microglial engulfment.

Engulfment of cellular material and proteins is a key function for microglia, a resident macrophage of the central nervous system (CNS). Among the techniques used to measure microglial engulfment, confocal light microscopy has been used the most extensively. Here, we show that autofluorescence (AF), likely due to lipofuscin and typically associated with aging, can also be detected within microglial lysosomes in the young mouse brain by light microscopy. This lipofuscin-AF signal accumulates first within microglia and increases with age, but it is not exacerbated by amyloid beta-related neurodegeneration. We further show that this lipofuscin-AF signal within microglia can confound the interpretation of antibody-labeled synaptic material within microglia in young adult mice. Finally, we implement a robust strategy to quench AF in mouse, marmoset, and human brain tissue.

Combination of the platelet-to-lymphocyte ratio and fibrinogen may predict 5-year overall survival of patient in non-small cell lung cancer treated with surgery.

Background: Non-small cell lung cancer (NSCLC) is a major type of lung cancer with high incidence and mortality. Systemic inflammatory response (SIR) and an imbalance of the coagulation system are both associated with the tumor progression. However, few studies have investigated the prognostic utility of a combination of inflammation and the coagulation system in NSCLC. The combination of platelet-to-lymphocyte ratio (PLR) and fibrinogen (FIB) (PLR-FIB; defined as PLR × FIB) is an indicator reflecting SIR and coagulation concurrently, which have potentiality to predict prognosis of NSCLC. Methods: This retrospective, single-center study included 314 NSCLC patients with surgery. According to a cutoff value for the PLR-FIB, we divided participants into a low-PLR-FIB group and a high-PLR-FIB group. We retrospectively collected the data on 314 patients and used univariate and multivariate analyses to investigate the relationship between the PLR-FIB and survival. Results: Univariate analysis showed that adenosquamous carcinoma (ASC) (P=0.002), high PLR-FIB (P=0.023), and tumor-node-metastasis (TNM) stage III-IV (P<0.001) were associated with a poor outcome. On multivariate analysis, low PLR-FIB [hazard ratio (HR), 0.587; 95% confidence interval (CI): 0.359-0.985; P=0.044], and TNM stage I-II (HR, 0.380; 95% CI: 0.245-0.590; P<0.001) were independent factors of a better prognosis. ASC type was an independent prognostic factor of poor outcome (HR, 5.513; 95% CI: 1.895-16.034; P=0.002). There were no significant differences in patient demographics or clinical characteristics between the two PLR-FIB groups (P>0.05). The 5-year overall survival (OS) rates were 80.8% and 67.9% for the low-PLR-FIB group and high-PLR-FIB group, respectively (P=0.02). Conclusions: Preoperative PLR-FIB was found to be an independent prognostic factor for 5-year overall survival in patients with NSCLC treated with surgery.

Human apolipoprotein E genotypes differentially modify house dust mite-induced airway disease in mice.

Apolipoprotein E (apoE) is an endogenous negative regulator of airway hyperreactivity (AHR) and mucous cell metaplasia in experimental models of house dust mite (HDM)-induced airway disease. The gene encoding human apoE is polymorphic, with three common alleles (ε2, ε3, and ε4) reflecting single amino acid substitutions at amino acids 112 and 158. The objective of this study was to assess whether the human apoE alleles modify airway responses to repeated nasal HDM challenges. Mice expressing the human apoE ε2 (huApoE2), ε3 (huApoE3), or ε4 (huApoE4) alleles received nasal HDM challenges, and airway responses were compared with mice expressing the endogenous murine apoE gene (muApoE). huApoE3 mice displayed significant reductions in AHR, mucous cell metaplasia, and airway inflammation compared with muApoE mice. The attenuated severity of airway inflammation in huApoE3 mice was associated with reductions in lung mRNA levels of Th2 and Th17 cytokines, as well as chemokines (CCL7, CCL11, CCL24). huApoE4 mice had an intermediate phenotype, with attenuated AHR and IgE production, compared with muApoE mice, whereas airway inflammation and mucous cell metaplasia were not reduced. In contrast, HDM-induced airway responses were not modified in mice expressing the huApoE2 allele. We conclude that the polymorphic huApoE alleles differentially modulate HDM-induced airway disease, which can be stratified, in rank order of increasing disease severity, ε3 < ε4 < ε2. These results raise the possibility that the polymorphic apoE alleles may modify disease severity in human asthma.

Local surgery improves survival in elderly patients with stage IV breast cancer: a population-based retrospective cohort study.

Background: Little is known about the role of local therapy in elderly patients with stage IV breast cancer. This study aimed to evaluate the effect of local therapy including surgery and radiotherapy in this kind of population by using the Surveillance, Epidemiology, and End Results (SEER) database. Methods: Eligible patients diagnosed between 2010 and 2015 were selected from the SEER database. Baseline characteristics, way of local therapy and survival information were collected for survival and analysis of prognostic factors. Cause-specific survival (CSS) curves were calculated using the Kaplan-Meier (KM) method and compared by the log-rank test. Cox regression and multivariate competing risk analyses were used to analyze prognosis factors. Results: A total of 1,900 patients were enrolled with the median age of 71 (range, 65 to 95) years. The 5-year CSS of patients with surgery was significantly better than that of those who did not (36.5% vs. 22.4%, P<0.001). Moreover, surgery was an independent protective factor for CSS in both multivariate Cox regression analysis [hazard ratio (HR), 0.588; 95% confidence interval (CI), 0.485-0.643; P<0.001] and multivariate competing risk analysis [subdistribution HR (SHR), 0.620; 95% CI, 0.535-0.718; P<0.001]. Stratified analysis showed that most subgroup patients could benefit from surgery. The 5-year CSS of patients with radiotherapy was comparable to those without radiotherapy (28.9% vs. 26.5%, P=0.060), and radiotherapy was not an independent prognostic factor for CSS (SHR, 1.005; 95% CI, 0.846-1.202; P=0.954). However, subgroup analysis found that patients with moderate grade in histopathology, luminal A, or triple-negative breast cancer (TNBC) subtype could benefit from radiotherapy (all P<0.05). Conclusions: Elderly patients with stage IV breast cancer can benefit from surgical treatment. This study helps to select the appropriate group for local surgery or radiotherapy according to the personal situation of the elderly to obtain the maximum benefit.

TRPV3 inhibits colorectal cancer cell proliferation and migration by regulating the MAPK signaling pathway.

Background: The aim of this study was to investigate the inhibiting effect of transient receptor potential vanilloid 3 (TRPV3) on the proliferation and migration of colorectal cancer (CRC) cells and to explore the underlying mechanism. Methods: A microarray dataset from the publicly available Gene Expression Omnibus (GEO) database was used to investigate the prognostic value of TRPV3 in CRC. In addition, 100 CRC tissue samples were collected at our center to further validate its prognostic value at the protein level. Cell proliferation ability was detected by Cell Counting Kit-8 (CCK-8) assay, and cell migration ability was detected by transwell assay. Gene set variation analysis (GSVA) was performed to identify the potential pathways regulated by TRPV3. Results: Based on the largest microarray dataset (GSE39582), low expression of TRPV3 was found to be significantly associated with poor prognosis in CRC patients, and this result was successfully validated at our cancer center. Functional experiments showed that knockdown of TRPV3 enhanced cell proliferation and migration, while enforced TRPV3 expression exhibited the opposite effect. GSEA based on public microarray data revealed that the mitogen-activated protein kinase (MAPK) signaling pathway was notably activated in patients with low expression of TRPV3. Further experiments in vivo confirmed that TRPV3 silencing promoted cell proliferation and migration by activating the MAPK signaling pathway. Conclusions: Low expression of TRPV3, which stimulates cell proliferation and migration by provoking the MAPK signaling pathway, indicated poor prognosis in CRC patients.

Transcriptomic architecture of nuclei in the marmoset CNS.

To understand the cellular composition and region-specific specialization of white matter - a disease-relevant, glia-rich tissue highly expanded in primates relative to rodents - we profiled transcriptomes of ~500,000 nuclei from 19 tissue types of the central nervous system of healthy common marmoset and mapped 87 subclusters spatially onto a 3D MRI atlas. We performed cross-species comparison, explored regulatory pathways, modeled regional intercellular communication, and surveyed cellular determinants of neurological disorders. Here, we analyze this resource and find strong spatial segregation of microglia, oligodendrocyte progenitor cells, and astrocytes. White matter glia are diverse, enriched with genes involved in stimulus-response and biomolecule modification, and predicted to interact with other resident cells more extensively than their gray matter counterparts. Conversely, gray matter glia preserve the expression of neural tube patterning genes into adulthood and share six transcription factors that restrict transcriptome complexity. A companion Callithrix jacchus Primate Cell Atlas (CjPCA) is available through https://cjpca.ninds.nih.gov .

Genome-wide association meta-analysis for total serum bilirubin levels.

Variation in serum bilirubin is associated with altered cardiovascular disease risk and drug metabolism. We aimed to identify genetic contributors to variability in serum bilirubin levels by combining results from three genome-wide association studies (Framingham heart study, n = 3424; Rotterdam study, n = 3847; Age, Gene, Environment and Susceptibility-Reykjavik, n = 2193). Meta-analysis showed strong replication for a genetic influence on serum bilirubin levels of the UGT1A1 locus (P < 5 x 10(-324)) and a 12p12.2 locus. The peak signal in the 12p12.2 region was a non-synonymous SNP in SLCO1B1 (rs4149056, P = 6.7 x 10(-13)), which gives rise to a valine to alanine amino acid change leading to reduced activity for a hepatic transporter with known affinity for bilirubin. There were also suggestive associations with several other loci. The top variants in UGT1A1 and SLCO1B1 explain approximately 18.0 and approximately 1.0% of the variation in total serum bilirubin levels, respectively. In a conditional analysis adjusted for individual genotypes for the top UGT1A1 variant, the top SLCO1B1 variant remained highly significant (P = 7.3 x 10(-13)), but no other variants achieved genome-wide significance. In one of the largest genetic studies of bilirubin to date (n = 9464), we confirm the substantial genetic influence of UGT1A1 variants, consistent with past linkage and association studies, and additionally provide strong evidence of a role for allelic variation in SLCO1B1. Given the involvement of bilirubin in a number of physiological and disease processes, and the roles for UGT1A1 and SLCO1B1 in drug metabolism, these genetic findings have potential clinical importance. In analyses for association with gallbladder disease or gallstones, top bilirubin SNPs in UGT1A1 and SLCO1B1 were not associated.

Chemokine-enhanced chemotaxis of lymphangioleiomyomatosis cells with mutations in the tumor suppressor TSC2 gene.

Lymphangioleiomyomatosis (LAM) is characterized by cystic lung destruction caused by LAM cells (smooth-muscle-like cells) that have mutations in the tumor suppressor genes tuberous sclerosis complex (TSC) 1 or 2 and have the capacity to metastasize. Since chemokines and their receptors function in chemotaxis of metastatic cells, we hypothesized that LAM cells may be recruited by chemokine(s) in the lung. Quantification of 25 chemokines in bronchoalveolar lavage fluid from LAM patients and healthy volunteers revealed that concentrations of CCL2, CXCL1, and CXCL5 were significantly higher in samples from LAM patients than those from healthy volunteers. In vitro, CCL2 or MCP-1 induced selective migration of cells, showing loss of heterozygosity of TSC2 from a heterogeneous population of cells grown from explanted LAM lungs. Additionally, the frequencies of single-nucleotide polymorphisms in the CCL2 gene promoter region differed significantly in LAM patients and healthy volunteers (p = 0.018), and one polymorphism was associated significantly more frequently with the decline of lung function. The presence (i.e., potential functionality) of chemokine receptors was evaluated using immunohistochemistry in lung sections from 30 LAM patients. Expression of chemokines and these receptors varied among LAM patients and differed from that seen in some cancers (e.g., breast cancer and melanoma cells). These observations are consistent with the notion that chemokines such as CCL2 may serve to determine mobility and specify the site of metastasis of the LAM cell.