Despite their crucial role in health and disease, our knowledge of immune cells within human tissues remains limited. We surveyed the immune compartment of 16 tissues from 12 adult donors by ...single-cell RNA sequencing and VDJ sequencing generating a dataset of ~360,000 cells. To systematically resolve immune cell heterogeneity across tissues, we developed CellTypist, a machine learning tool for rapid and precise cell type annotation. Using this approach, combined with detailed curation, we determined the tissue distribution of finely phenotyped immune cell types, revealing hitherto unappreciated tissue-specific features and clonal architecture of T and B cells. Our multitissue approach lays the foundation for identifying highly resolved immune cell types by leveraging a common reference dataset, tissue-integrated expression analysis, and antigen receptor sequencing.
Statins have been proposed to be a potential treatment for pulmonary arterial hypertension. If introduced into clinical practice, the statin would have to be used in conjunction with established ...therapy. We investigated the effects of combining simvastatin with a phosphodiesterase type-5 inhibitor, sildenafil, in the rat model of hypoxia-induced pulmonary hypertension. Rats were allocated to either: 1) a prevention protocol, to receive simvastatin 20 mg x kg(-1) x day(-1) by intraperitoneal injection or sildenafil 75 mg x kg(-1) x day(-1) orally or the combination (or vehicle) for 2 weeks beginning at the start of exposure to hypoxia (10% inspired oxygen); or 2) a treatment protocol, where the same agents were administered in the last 2 weeks of a 4-week period of hypoxia. In both protocols, the combination of sildenafil and simvastatin lowered pulmonary artery pressure and produced a significantly greater reduction in right ventricular hypertrophy and pulmonary vascular muscularisation than either drug alone. Moreover, the combination augmented significantly endothelial nitric oxide synthase expression and cGMP levels in the lung and right ventricle above that produced by either drug independently and resulted in greater inhibition of RhoA activity. These data suggest that simvastatin can be usefully combined with sildenafil in the treatment of pulmonary arterial hypertension to achieve greater therapeutic benefit.
We have investigated whether regions of the genome showing signs of positive selection in scans based on haplotype structure also show evidence of positive selection when sequence-based tests are ...applied, whether the target of selection can be localized more precisely, and whether such extra evidence can lead to increased biological insights. We used two tools: simulations under neutrality or selection, and experimental investigation of two regions identified by the HapMap2 project as putatively selected in human populations. Simulations suggested that neutral and selected regions should be readily distinguished and that it should be possible to localize the selected variant to within 40 kb at least half of the time. Re-sequencing of two ~300 kb regions (chr4:158Mb and chr10:22Mb) lacking known targets of selection in HapMap CHB individuals provided strong evidence for positive selection within each and suggested the micro-RNA gene hsa-miR-548c as the best candidate target in one region, and changes in regulation of the sperm protein gene
SPAG6
in the other.
Previous studies have suggested a genetic component in susceptibility to hypoxia-induced pulmonary hypertension. We therefore estimated the prevalence of high-altitude pulmonary hypertension (HAPH) ...in a Kyrgyz population and whether the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene associates with HAPH. An electrocardiographic survey of 741 highlanders demonstrated electrocardiogram signs of cor pulmonale in 14% of subjects. Pulmonary artery hemodynamics measured in an independent group of 136 male highlanders with symptoms of dyspnea at altitude revealed established pulmonary hypertension (mean pulmonary artery pressure MPAP > or = 25 mm Hg) in 20%. However, 26% of the normal subjects demonstrated an exaggerated response (twofold or greater increase in MPAP) to inhalation of 11% oxygen, and were classified as hyperresponsive. Ten-year follow-up of this group revealed increases in the MPAP, but not in normal subjects. Comparison of ACE I/D genotypes in the catheterized group revealed a threefold higher frequency of the I/I genotype in highlanders with HAPH, compared with normal highlanders (chi2 = 11.59, p = 0.003). In addition, MPAP was higher in highlanders with the I/I genotype (26.9 +/- 4.0 mm Hg) compared with the I/D genotype (20.6 +/- 1.2 mm Hg) or the D/D genotype (18.3 +/- 0.9 mm Hg) (p < 0.05). We conclude that HAPH is associated with ACE I/D genotype among Kyrgyz highlanders and the development of HAPH in this population and may be predicted by hyperresponsiveness to acute hypoxia.
The activities of superoxide dismutase and guaiacol-dependent peroxidase were studied in the ontogenesis of recessive homozygous mutants ofArabidopsis thaliana Heynh.le-2 andnfz24, which are ...characterized by two- to threefold increases in tolerance to the herbicide norflurazone. The mutantsle-2 andnfz24 differed from the initial race Dijon in some phenotypic features, duration of ontogenetic stages, and dynamics of the superoxide dismutase and peroxidase activities in ontogenesis. A single treatment of plants with norflurazone induced an accelerated increase in the level of both enzymes in the mutants as compared to the wild type plants. Under the conditions of multiple treatment with norflurazone, the mutantsle-2 andnfz24 displayed a higher tolerance to the bleaching effect of the herbicide and were characterized by a higher level of superoxide dismutase. The data obtained suggest that the superoxide dismutase and peroxidase activities are controlled by both ontogenetic factors and stress signals. Mutations in the linesle-2 andnfz24 increase sensitivity to a stress signal or increase efficiency of an adaptive response due to long-term maintenance of a high level of the antioxidant enzymes under the conditions of stress.
Selective systems for screening Arabidopsis thaliana (L.) Heynh. mutants with altered sensitivity to the oxidative stress (OS) inductors norflurazon (NF), acifluorfen (AF), and plumbagin (PB) were ...developed and a collection of 28 mutants was obtained. Dwarf and necrotic forms predominated among the NF-tolerant mutants, while pigment mutants and those with changed root morphology prevailed among the AF-tolerant and PB-sensitive mutants, respectively. Genetic and biochemical analysis of certain mutants was performed; quantitative and qualitative changes in the content of superoxide dismutase and peroxidase isoforms have been revealed. These data, complemented by the data on the cross-tolerance (sensitivity) of the mutants to paraquat, indicate a correlation between tolerance to the OS inductors and the functions of antioxidant systems.
The activities of superoxide dismutase and guaiacol-dependent peroxidase were studied in the ontogenesis of recessive homozygous mutants of Arabidopsis thaliana Heynh. le-2 and nfz24, which are ...characterized by two- to threefold increases in tolerance to the herbicide norflurazone. The mutants le-2 and nfz24 differed from the initial race Dijon in some phenotypic features, duration of ontogenetic stages, and dynamics of the superoxide dismutase and peroxidase activities in ontogenesis. A single treatment of plants with norflurazone induced an accelerated increase in the level of both enzymes in the mutants as compared to the wild type plants. Under the conditions of multiple treatment with norflurazone, the mutants le-2 and nfz24 displayed a higher tolerance to the bleaching effect of the herbicide and were characterized by a higher level of superoxide dismutase. The data obtained suggest that the superoxide dismutase and peroxidase activities are controlled by both ontogenetic factors and stress signals. Mutations in the lines le-2 and nfz24 increase sensitivity to a stress signal or increase efficiency of an adaptive response due to long-term maintenance of a high level of the antioxidant enzymes under the conditions of stress.
Psoriatic arthritis (PsA) is a debilitating immune-mediated inflammatory arthritis of unknown pathogenesis commonly affecting patients with skin psoriasis. Here we use complementary single-cell ...approaches to study leukocytes from PsA joints. Mass cytometry demonstrates a 3-fold expansion of memory CD8 T cells in the joints of PsA patients compared to peripheral blood. Meanwhile, droplet-based and plate-based single-cell RNA sequencing of paired T cell receptor alpha and beta chain sequences show pronounced CD8 T cell clonal expansions within the joints. Transcriptome analyses find these expanded synovial CD8 T cells to express cycling, activation, tissue-homing and tissue residency markers. T cell receptor sequence comparison between patients identifies clonal convergence. Finally, chemokine receptor CXCR3 is upregulated in the expanded synovial CD8 T cells, while two CXCR3 ligands, CXCL9 and CXCL10, are elevated in PsA synovial fluid. Our data thus provide a quantitative molecular insight into the cellular immune landscape of psoriatic arthritis.
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