Integrated Single-Cell Transcriptomic Atlas of Human Kidney Endothelial Cells

Key Points

Background

Kidney endothelial cells are exposed to different microenvironmental conditions that support specific physiologic processes. However, the heterogeneity of human kidney endothelial cells has not yet been systematically described.

Methods

We reprocessed and integrated seven human kidney control single-cell/single-nucleus RNA sequencing datasets of >200,000 kidney cells in the same process.

Results

We identified five major cell types, 29,992 of which were endothelial cells. Endothelial cell reclustering identified seven subgroups that differed in molecular characteristics and physiologic functions. Mapping new data to a normal kidney endothelial cell atlas allows rapid data annotation and analysis. We confirmed that endothelial cell types in the human kidney were also highly conserved in the mouse kidney and identified endothelial marker genes that were conserved in humans and mice, as well as differentially expressed genes between corresponding subpopulations. Furthermore, combined analysis of single-cell transcriptome data with public genome-wide association study data showed a significant enrichment of endothelial cells, especially arterial endothelial cells, in BP heritability. Finally, we identified M1 and M12 from coexpression networks in endothelial cells that may be deeply involved in BP regulation.

Conclusions

We created a comprehensive reference atlas of normal human kidney endothelial cells that provides the molecular foundation for understanding how the identity and function of kidney endothelial cells are altered in disease, aging, and between species. Finally, we provide a publicly accessible online tool to explore the datasets described in this work (https://vascularmap.jiangnan.edu.cn).

Single-Cell RNA-Seq Reveals Coronary Heterogeneity and Identifies CD133+TRPV4high Endothelial Subpopulation in Regulating Flow-Induced Vascular Tone in Mice

BACKGROUND

Single-cell RNA-Seq analysis can determine the heterogeneity of cells between different tissues at a single-cell level. Coronary artery endothelial cells (ECs) are important to coronary blood flow. However, little is known about the heterogeneity of coronary artery ECs, and cellular identity responses to flow. Identifying endothelial subpopulations will contribute to the precise localization of vascular endothelial subpopulations, thus enabling the precision of vascular injury treatment.

METHODS

Here, we performed a single-cell RNA sequencing of 31 962 cells and functional assays of 3 branches of the coronary arteries (right coronary artery/circumflex left coronary artery/anterior descending left coronary artery) in wild-type mice.

RESULTS

We found a compendium of 7 distinct cell types in mouse coronary arteries, mainly ECs, granulocytes, cardiac myocytes, smooth muscle cells, lymphocytes, myeloid cells, and fibroblast cells, and showed spatial heterogeneity between arterial branches. Furthermore, we revealed a subpopulation of coronary artery ECs, CD133+TRPV4high ECs. TRPV4 (transient receptor potential vanilloid 4) in CD133+TRPV4high ECs is important for regulating vasodilation and coronary blood flow.

CONCLUSIONS

Our study elucidates the nature and range of coronary arterial cell diversity and highlights the importance of coronary CD133+TRPV4high ECs in regulating coronary vascular tone.

Cost-effective core@shell structured zero-valent iron nanoparticles @ magnetic (nZVI@Fe3O4) for Cr(vi) removal from aqueous solutions: preparation by disproportionation of Fe(ii)

Nanoscale zero-valent iron (nZVI) and its composites are known for their excellent ability to remove Cr(vi), but their preparation can be expensive due to the reduction processes. This study presents a cost-effective method to prepare core@shell structured nZVI@Fe3O4 nanocomposites using a novel Fe(ii) disproportionation reaction. The nZVI@Fe3O4 was thoroughly characterized using various techniques, including FESEM, HRTEM, EDS, XPS, XRD, FTIR, and VSM. Batch experiments were performed to evaluate the removal efficiency of nZVI@Fe3O4 in eliminating Cr(vi) ions from aqueous solutions, while classical models were employed to investigate the influencing factors associated with the removal process. The results showed that a 0.7 mg per ml NaOH solution reacted with Fe(ii) at 150 °C for 0.5 h could be used to prepare nZVI@Fe3O4 composites efficiently and inexpensively. nZVI@Fe3O4 was able to remove more than 99% of Cr(vi) from both simulated Cr(vi) solutions and real electroplating wastewater, and the recovery and preparation could be easily performed using external magnets to separate it from the solution. At pH 6.0, the maximum adsorption capacity (qmax) for Cr(vi) reached 58.67 mg g-1. The reaction mechanism was discussed from the perspective of electron transfer. Overall, the results suggest that nZVI@Fe3O4, an efficient adsorbent prepared using an environmentally friendly and inexpensive Fe(ii) disproportionation reaction, is a promising option for the treatment of Cr(vi) from industrial wastewater and other contaminated water sources.

Laser-direct-drive fusion target design with a high-Z gradient-density pusher shell

Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.

Different Concentrations of Albumin Versus Crystalloid in Patients with Sepsis and Septic Shock: A Meta-Analysis of Randomized Clinical Trials

OBJECTIVE

The best type of resuscitation fluids for sepsis and septic shock patients remains unclear. The aim of this study was to evaluate the efficacy of different concentrations of albumin on reducing the mortality rate of theses patients by meta-analysis.

MATERIALS AND METHODS

PubMed, EMBASE, and Web of Science databases were used for screening the relevant studies. Randomized controlled trials (RCTs) were eligible if they compared the effects of albumin with crystalloid on mortality in patients with sepsis and septic shock. Data were examined and extracted by two reviewers independently. Any disagreements were resolved by consensus with or without the help from a third reviewer. Data including mortality, sample size of the patients, and resuscitation endpoints were extracted. Meta-analysis was carried based on the corresponding odds ratios with 95% confidence intervals.

RESULTS

Eight studies with a total of 5124 septic patients and 3482 septic shock patients were included in this study. Compared with crystalloid, the use of albumin may represent a trend toward reduced the 90-day mortality of septic patients (OR 0.91 [0.80, 1.02]; P = .11) and significantly improved the outcome of septic shock patients (OR 0.85 [0.74, 0.99]; P = .04). Further analysis showed a potentially beneficial role of both 4% to 5% and 20% albumin on reducing the mortality of septic patients. The use of 20% albumin significantly decreased the 90-day mortality of septic shock patients (OR 0.81 [0.67, 0.98]; P = .03), which was better than 4% to 5% albumin and crystalloid.

CONCLUSIONS

Albumin treatment, particularly 20% albumin, significantly reduced the 90-day mortality in septic shock patients. Both 4% to 5% and 20% of albumin may work better than crystalloid in improving the survival rate of patients with sepsis, but more relative RCTs are required for validation.

Functional role of endothelial TRPV4-KCa3.1 coupling in regulating coronary vascular tone

BACKGROUND AND PURPOSE

High-fat diet (HFD) induces dysregulated pathways in coronary artery endothelial cells (CAECs), which leads to altered regulation of vascular tone, tissue perfusion and increases the risk of coronary artery diseases. Ca²⁺ -activated K⁺ channels (KCa) are known to be associated with transient receptor potential (TRP) channels, which is important for regulating endothelial function. But how TRPV4 interacts with KCa in regulating coronary vascular tone in HFD mice requires further exploration.

EXPERIMENTAL APPROACH

TRPV4 activity was assessed by fluorescent Ca²⁺ imaging. The TRPV4-KCa3.1 interaction was verified by co-immunoprecipitation and Immunofluorescence resonance energy transfer (FRET), and their binding site was found by site-directed mutagenesis. Endothelium-specific TRPV4 knockout (TRPV4_EC ^-/- ) mice were used to study the effect of the TRPV4-KCa3.1 interaction on coronary vascular tone. Coronary blood flow was measured by Doppler ultrasound device.

KEY RESULTS

Here, we reported that TRPV4 was involved in the regulation of coronary vascular tone. Importantly, TRPV4 formed a coupling with Ca²⁺ -sensitive K⁺ channel KCa3.1 in CAECs, regulating vasodilation and coronary blood flow. In HFD mice, the coupling was damaged by a high concentration of plasma 1-heptadecanoyl-2-hydroxy-sn-glycero-3-phosphocholine. Using a bridging approach, we then identified folic acid as an effective drug to repair the uncoupled TRPV4-KCa3.1 and to improve coronary arterial function.

CONCLUSION AND IMPLICATIONS

Our data highlight the importance of TRPV4-KCa3.1 coupling in the regulation of coronary vascular tone and provide a novel strategy for developing new drugs to reduce the incidence of cardiovascular events.

Erratum: A Long Non-coding RNA Lnc712 Regulates Breast Cancer Cell Proliferation: Erratum

[This corrects the article DOI: 10.7150/ijbs.36429.].

Endothelial TRPV4-eNOS coupling as a vital therapy target for treatment of hypertension

BACKGROUND AND PURPOSE

Reduced nitric oxide (NO) level and activity are signs of endothelial dysfunction, which is important in mediating blood pressure up-regulation. Previously, we demonstrated that transient receptor potential channel V4 (TRPV4) could form functional complex with other proteins to mediate vasodilation in the Endothelial cells (ECs). But how TRPV4 interacts with the NO pathway in larger arteries requires further exploration.

EXPERIMENTAL APPROACH

We used single-cell RNA-sequencing to find the CD106⁺ TRPV4^high NOS3^high ECs. The TRPV4-eNOS interaction was verified by co-immunoprecipitation and Immunofluorescence resonance energy transfer (FRET), and their binding site was found by site-directed mutagenesis. Endothelium-specific TRPV4 knockout (TRPV4_EC ^-/- ) mice were used to study the effect of the TRPV4-eNOS interaction on blood pressure. A small molecule, JNc-463 was designed through molecular docking technology.

KEY RESULTS

We uncovered CD106⁺ TRPV4^high NOS3^high ECs in the mouse aorta, which they could regulate vasodilation via a TRPV4-eNOS interaction, and they were essential to regulate blood pressure. The TRPV4-eNOS interaction markedly decreased during the process of hypertension. We further attempted to identify the molecules re-join the TRPV4-eNOS interaction and develop a small-molecule drug, JNc-463, which could increase the TRPV4-eNOS interaction to enhance vasodilation, and exert antihypertensive effects in mice.

CONCLUSION AND IMPLICATIONS

This is the first study integrating single-cell RNA-Seq, single-cell functional study and drug screening in aorta. We identified a subpopulation of CD106⁺ TRPV4^high NOS3^high ECs, in which an impaired TRPV4-eNOS interaction was important in the progress of hypertension and we designed a small molecule, JNc-463 to improve the impaired TRPV4-eNOS interaction in hypertension.

Single-cell transcriptome analysis reveals cellular heterogeneity in the ascending aortas of normal and high-fat diet-fed mice

The aorta contains numerous cell types that contribute to vascular inflammation and thus the progression of aortic diseases. However, the heterogeneity and cellular composition of the ascending aorta in the setting of a high-fat diet (HFD) have not been fully assessed. We performed single-cell RNA sequencing on ascending aortas from mice fed a normal diet and mice fed a HFD. Unsupervised cluster analysis of the transcriptional profiles from 24,001 aortic cells identified 27 clusters representing 10 cell types: endothelial cells (ECs), fibroblasts, vascular smooth muscle cells (SMCs), immune cells (B cells, T cells, macrophages, and dendritic cells), mesothelial cells, pericytes, and neural cells. After HFD intake, subpopulations of endothelial cells with lipid transport and angiogenesis capacity and extensive expression of contractile genes were defined. In the HFD group, three major SMC subpopulations showed increased expression of extracellular matrix-degradation genes, and a synthetic SMC subcluster was proportionally increased. This increase was accompanied by upregulation of proinflammatory genes. Under HFD conditions, aortic-resident macrophage numbers were increased, and blood-derived macrophages showed the strongest expression of proinflammatory cytokines. Our study elucidates the nature and range of the cellular composition of the ascending aorta and increases understanding of the development and progression of aortic inflammatory disease.

Puerarin induces mouse mesenteric vasodilation and ameliorates hypertension involving endothelial TRPV4 channels

Puerarin (Pue) is an isoflavone derived from the root of Pueraria lobata, which has been widely used as food and a herb for treating cardiovascular and cerebrovascular diseases. Transient receptor potential vanilloid 4 (TRPV4), a Ca2+-permeable channel with multiple modes of activation, plays an important role in vascular endothelial function and vasodilation. However, no reports have shown the effects of Pue on TRPV4 channels and mouse small mesenteric arteries. In the present study, we performed a molecular docking assay by using Discovery Studio 3.5 software to predict the binding of Pue to TRPV4 protein. The activation of TRPV4 by Pue was determined by intracellular Ca2+ concentration ([Ca2+]i), live-cell fluorescent Ca2+ imaging and patch clamp assays. Molecular docking results indicated a high possibility of Pue-TPRV4 binding. [Ca2+]i and Ca2+ imaging assays showed that Pue activated TRPV4 channels and increased [Ca2+]i in TRPV4-overexpressing HEK293 (TRPV4-HEK293) cells and primary mouse mesenteric artery endothelial cells (MAECs). Patch clamp assay demonstrated that Pue stimulated the TRPV4-mediated cation currents. Additionally, Pue relaxed mouse mesenteric arteries involving the TRPV4-small-conductance Ca2+-activated K+ channel (SKCa)/intermediate-conductance Ca2+-activated K+ channel (IKCa) pathway, and reduced systolic blood pressure (SBP) in high-salt-induced hypertensive mice. Our study found for the first time that Pue acts as a TRPV4 agonist, induces endothelium-dependent vasodilation in mouse mesenteric arteries, and attenuates blood pressure in high-salt-induced hypertensive mice, highlighting the beneficial effect of Pue in treating endothelial dysfunction-related cardiovascular diseases.

Aortic heterogeneity across segments and under high fat/salt/glucose conditions at the single-cell level

The aorta, with ascending, arch, thoracic and abdominal segments, responds to the heartbeat, senses metabolites and distributes blood to all parts of the body. However, the heterogeneity across aortic segments and how metabolic pathologies change it are not known. Here, a total of 216 612 individual cells from the ascending aorta, aortic arch, and thoracic and abdominal segments of mouse aortas under normal conditions or with high blood glucose levels, high dietary salt, or high fat intake were profiled using single-cell RNA sequencing. We generated a compendium of 10 distinct cell types, mainly endothelial (EC), smooth muscle (SMC), stromal and immune cells. The distributions of the different cells and their intercommunication were influenced by the hemodynamic microenvironment across anatomical segments, and the spatial heterogeneity of ECs and SMCs may contribute to differential vascular dilation and constriction that were measured by wire myography. Importantly, the composition of aortic cells, their gene expression profiles and their regulatory intercellular networks broadly changed in response to high fat/salt/glucose conditions. Notably, the abdominal aorta showed the most dramatic changes in cellular composition, particularly involving ECs, fibroblasts and myeloid cells with cardiovascular risk factor-related regulons and gene expression networks. Our study elucidates the nature and range of aortic cell diversity, with implications for the treatment of metabolic pathologies.

Menthol relieves acid reflux inflammation by regulating TRPV1 in esophageal epithelial cells

Transient receptor potential cation channel subfamily V member 1 (TRPV1) plays an important role in pain and inflammatory responses. Previous studies have shown that the expression of TRPV1 increases in the sensory neurons of the esophagus during the development of gastroesophageal reflux disease and esophagitis, but the response of TRPV1 in esophageal epithelial cells (EECs), which directly confront the refluxed acid, is still unknown. Here, we found that acid reflux triggered esophageal damage, which was accompanied by increased expression of TRPV1 in EECs and TRPV1 channel activity in these cells. Furthermore, menthol inhibited the Ca2+ influx induced by acid stimulation in EECs. After menthol treatment, the expression of TRPV1 in EECs was significantly reduced, and their hyperplasia was significantly reduced; finally, the inflammation pathway elicited in EECs was diminished in mice with acid reflux. These results suggest that menthol improves the clinical symptoms caused by gastroesophageal acid reflux by interfering with TRPV1 in EECs.

A Long Non-coding RNA Lnc712 Regulates Breast Cancer Cell Proliferation

Great quantity of intergenic noncoding RNAs (lncRNAs) have been identified in the mammalian genome and involved in various biological processes, especially in the development and metastasis of cancer. In this study, we identified one lncRNA, lncRNA NONHSAT028712 (Lnc712), was highly expressed in breast cancer cell lines and tissues based on microarray screening. Knockdown of Lnc712 largely inhibited breast cancer cell proliferation. Mechanistically, Lnc712 bound specifically to heat-shock protein 90 (HSP90). Interaction between Lnc712 and HSP90 is required for HSP90 binding to cell division cycle 37 (Cdc37). The Lnc712/HSP90/Cdc37 complex regulated cyclin-dependent kinase 2 (CDK2) activation and then triggered breast cancer cell proliferation. In summary, our results identified a new lncRNA regulate breast cancer proliferation though interaction with HSP90.

Curcumin Induces Endothelium-Dependent Relaxation by Activating Endothelial TRPV4 Channels

It is well-known that curcumin, as a plant substance, has vascular protective effects. TRPV4 (transient receptor potential vanilloid 4) is a highly Ca²⁺-selective channel in vascular endothelium. In our study, fluorescent Ca²⁺ imaging in mesenteric arterial endothelial cells (MAECs) and overexpressed TRPV4 human embryonic kidney (HEK293) cells showed that curcumin dose-dependently stimulated Ca²⁺ influx. Whole-cell patch clamp proved that curcumin stimulated the TRPV4-mediated currents in TRPV4-HEK293 cells. The TRPV4-specific blocker HC067047 markedly decreased the whole-cell current. Molecular modeling and docking showed that the binding site of curcumin and TRPV4 was mainly in the amino acid sequence LYS340-LEU349 of TRPV4 protein. Furthermore, curcumin dose-dependently induced the endothelium-dependent vessel dilatation in small mesenteric arteries. Therefore, our results demonstrated that curcumin stimulates Ca²⁺ entry in endothelial cells and improves endothelium-dependent vessel relaxation by activating TRPV4 channels. Moreover, we identified the specific binding sites of curcumin and TRPV4, thereby highlighting its potential therapeutic target of cardiovascular diseases.

Morin induces endothelium-dependent relaxation by activating TRPV4 channels in rat mesenteric arteries

Morin, a natural flavonol, has been reported to have beneficial pharmacological effects. Although its vascular protective effects have been studied, little is known about its effects on the mesenteric artery and the underlying mechanisms. Transient receptor potential vanilloid type 4 (TRPV4) channels are one of the most important Ca²⁺-permeable cation channels in vascular endothelial cells and play an important role in regulating rat mesenteric vascular tone. In the present study, the myogenic effects of morin were investigated using wire and pressure myography in the isolated mesenteric artery. Morin induced endothelium-dependent relaxation of isolated rat mesenteric arteries in a concentration-dependent manner. In addition, morin stimulated relaxation by activating TRPV4-mediated Ca²⁺ influx without affecting the nitric oxide (NO), hydrogen peroxide (H₂O₂), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) pathways. In primary cultured rat mesenteric artery endothelial cells and over-expressing TRPV4 HEK 293 cells, the TRPV4 inhibitor HC067047 significantly reduced the morin-induced increase in intracellular Ca²⁺ concentration. Furthermore, in rats with hypertension induced by N^Ꞷ-nitro-L-arginine methyl ester (L-NAME), oral administration of morin (50 mg/kg/day) decreased systolic blood pressure. In L-NAME-induced hypertensive rats, morin significantly improved the relaxation response of the arteries to acetylcholine. Thus, we demonstrated that morin induces endothelium-dependent relaxation in the rat mesenteric artery by acting on TRPV4 channels to mediate Ca²⁺ influx and attenuate blood pressure in L-NAME-induced hypertension, thereby highlighting the potential of morin in the treatment of hypertension.

The TRPC5 channel regulates angiogenesis and promotes recovery from ischemic injury in mice

Ischemia-related diseases are a leading cause of death worldwide, and promoting therapeutic angiogenesis is key for effective recovery from hypoxia-ischemia. Given the limited success of angiogenic factors, such as vascular endothelial growth factor, in clinical trials, it is important to find more promising angiogenic targets. Here, using both cell- and tissue-based assays and a mouse model of injury-induced ischemia, we investigated the involvement of the transient receptor potential canonical 5 (TRPC5) ion channel in angiogenesis and the effects of a TRPC5 activator, the Food and Drug Administration-approved drug riluzole, on recovery from ischemic injury. We demonstrate that TRPC5 is involved in endothelial cell sprouting, angiogenesis, and blood perfusion in an oxygen-induced retinopathy model and a hind limb ischemia model. We found a potential regulatory link between nuclear factor of activated T cell isoform c3 and angiopoietin-1 that could provide the mechanistic basis for the angiogenic function of TRPC5. Importantly, treatment with riluzole, which can activate TRPC5 in endothelial cells, improved recovery from ischemia in mice. Our study reveals TRPC5 as a potential angiogenic target and suggests riluzole as a promising drug for managing ischemic diseases.

SPZ1 is critical for chemoresistance and aggressiveness in drug-resistant breast cancer cells

It is believed that chemotherapeutic agents can enhance the malignancy of treated cancer cells in clinical situations, which is a major problem for chemotherapy. However, the underlying molecular mechanisms are still not fully understood. Here, we demonstrated that chemotherapy up-regulates the levels of spermatogenic bHLH transcription factor zip 1 (SPZ1), and knockdown of SPZ1 in drug resistant breast cancers showed that SPZ1 is critical for regulating the chemoresistance, migration, invasion and epithelial-mesenchymal transition (EMT) in a Twist1-dependent manner. Moreover, suppressing SPZ1-Twist1 axis decreased the growth of tumor xenografts. Notably, we found a positive correlation between SPZ1 and Twist1 in breast cancer samples from patients with anthracycline or taxane-based chemotherapy. Thus, our results revealed a novel role of SPZ1 as an inducer of chemoresistance and aggressiveness under chemotherapy, and this suggests that therapeutic targeting of SPZ1 may not only enhance the sensitivity of breast cancer to chemotherapy, but also suppress breast cancer invasion and metastases.

Treatment of hypertension by increasing impaired endothelial TRPV4-KCa2.3 interaction

The currently available antihypertensive agents have undesirable adverse effects due to systemically altering target activity including receptors, channels, and enzymes. These effects, such as loss of potassium ions induced by diuretics, bronchospasm by beta‐blockers, constipation by Ca²⁺ channel blockers, and dry cough by ACEI, lead to non‐compliance with therapies (Moser, 1990). Here, based on new hypertension mechanisms, we explored a new antihypertensive approach. We report that transient receptor potential vanilloid 4 (TRPV4) interacts with Ca²⁺‐activated potassium channel 3 (KCa2.3) in endothelial cells (ECs) from small resistance arteries of normotensive humans, while ECs from hypertensive patients show a reduced interaction between TRPV4 and KCa2.3. Murine hypertension models, induced by high‐salt diet, N(G)‐nitro‐l‐arginine intake, or angiotensin II delivery, showed decreased TRPV4‐KCa2.3 interaction in ECs. Perturbation of the TRPV4‐KCa2.3 interaction in mouse ECs by overexpressing full‐length KCa2.3 or defective KCa2.3 had hypotensive or hypertensive effects, respectively. Next, we developed a small‐molecule drug, JNc‐440, which showed affinity for both TRPV4 and KCa2.3. JNc‐440 significantly strengthened the TRPV4‐KCa2.3 interaction in ECs, enhanced vasodilation, and exerted antihypertensive effects in mice. Importantly, JNc‐440 specifically targeted the impaired TRPV4‐KCa2.3 interaction in ECs but did not systemically activate TRPV4 and KCa2.3. Together, our data highlight the importance of impaired endothelial TRPV4‐KCa2.3 coupling in the progression of hypertension and suggest a novel approach for antihypertensive drug development.

Detection of porcine circovirus-like virus P1 in Hebei, China

Porcine circovirus-like virus P1 is a novel unclassified circovirus that was first detected in China and may be associated with post-weaning multisystemic wasting syndrome (PMWS) and congenital tremor. In this study, we detected P1 infection in pigs in Hebei Province, China, in 2017. One hundred and forty of 500 (28.0%) serum samples from 25 pig farms with different PMWS status in seven cities were P1 positive on PCR. Twelve P1 strains were sequenced, and the complete genomes of 11 P1 strains were 648 nucleotides (nt) in length, whereas that of strain ZJK02 was 647 nt, with a G deletion at position of 183 in its genome. The complete genomic and capsid protein sequences of the 12 P1 strains analysed in this study shared 98.8%-100.0% and 86.5%-100.0% identity, respectively. A phylogenetic analysis based on the complete genomic and capsid sequences of 26 P1 strains showed that the 12 P1 sequences from Hebei Province clustered on two small branches. Further studies of the evolution and pathogenesis of P1 are required.

TRPV4 (Transient Receptor Potential Vanilloid 4) Mediates Endothelium-Dependent Contractions in the Aortas of Hypertensive Mice

The role of TRPV4 (transient receptor potential vanilloid 4) in regulating vascular contraction in hypertensive mice is poorly established. We tested the hypothesis that TRPV4 regulates endothelium-dependent contractions in aortas from hypertensive mice through the activation of cytosolic cPLA₂ (phospholipase A₂) and COX2 (cyclooxygenase 2) and identified the possible endothelium-derived contracting factor generated by COX2. Using myography, we demonstrated that GSK1016790A (a TRPV4 agonist) and acetylcholine (ACh) trigger endothelium-dependent contractions in aortas from hypertensive mice, and the contractions were abolished with TRPV4 deletion. PLA₂ assay and Western blotting showed that cPLA₂ activity was higher in salt-induced hypertension and HC067047 or a Ca²⁺ chelator inhibited cPLA₂ activity. Contractions induced by TRPV4 and ACh were inhibited by the cPLA₂ inhibitor or removal of extracellular Ca²⁺ COX2 expression was enhanced in the endothelium from hypertensive mice and contractions induced by TRPV4 or ACh were inhibited by the COX2 inhibitor. Enzyme immunoassay showed that the release of prostaglandin F_2α (PGF_2α) was increased in hypertensive mice. GSK1016790A or ACh triggered the release of PGF_2α and this was inhibited by HC067047, the cPLA₂ inhibitor, and COX2 inhibitor. GSK1016790A, ACh, and PGF_2α induced contractions were significantly reduced by S18886 in salt-induced hypertensive mice. The present study demonstrates that PGF_2α generated by COX2 in the endothelium is the most likely endothelium-derived contracting factor underlying endothelium-dependent, TRPV4-mediated contraction in hypertensive mice. This contraction involved increased intracellular Ca²⁺ concentrations and cPLA₂ activity. These results suggested an important role of TRPV4 in endothelium-dependent contraction in mice during hypertension.

A Simple Route to Synthesize Cu@Ag Core-Shell Bimetallic Nanoparticles and Their Surface-Enhanced Raman Scattering Properties

Water-dispersed Cu@Ag core-shell nanoparticles (NPs) with 15 nm-diameter Cu core and 5 nm-thick Ag shell can be synthesized by a facile one-step chemical reduction at room temperature without any protective atmosphere. To obtain a homogeneous Ag coating on Cu, the influence of [Cu/Ag] molar ratio was investigated. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed that Ag formed a dense coating on the surface of Cu, and that phase-pure spherical Cu@Ag core-shell bimetallic NPs were prepared when the [Cu/Ag] molar ratio was between 1/0.5 and 1/0.75. The time dependence of ultraviolet-visible (UV-Vis) spectra and XRD patterns of six-month stored Cu@Ag NPs showed that the as-prepared Cu@Ag NPs have a long-term antioxidant activity. Also, the surface-enhanced Raman scattering (SERS) signals had a high stability and reproducibility for the substrates. Hence, the as-prepared Cu@Ag nanostructures can be used as an efficient substrate for SERS signals.

Role of 5 Saponins in Secretion of Cytokines by PRRSV-induced Endothelial Cells

The aim of the research presented here was to investigate the immunoloregulatory effects of 5 saponins: Saikosaponins A (SSA) and D (SSD) from Bupleurum chinese DC (Umbelliferae), Panax Notoginseng Saponin (PNS) and Notoginsenoside R1 from Panax notoginseng (Araliaceae) (SR1), and Anemoside B4 from Pulsatilla chinensis Regel (Ranunculaceae) (AB4). To achieve this, endothelial cells were challenged with 10(5) TCID50/mL PRRSV for 24 h then treated respectively with 5 saponins at 3 concentrations (1, 5 and 10 μg/mL). The cells were incubated at 37°C in a cell incubator for 24 h. The supernatants were collected and analyzed the levels of interleukin-4 (IL-4), IL-10, IL-2, and γ-interferon (IFN-γ) by ELISA kits. The results revealed that PNS and SR1 inhibited the production of IL-4; PNS, SR1 and SSD inhibited the secretion of IL-10; SSA, SSD and AB4 up-regulated IL-2 expression; SSA and SSD increased the level of IFN-γ. All these changes were significant. Taken together, the data suggested that these 5 saponins might effectively regulate immune responses via changes in the levels of these select cytokines.

Nanopatterning using a simple bi-layer lift-off process for the fabrication of a photonic crystal nanostructure

A simple and versatile method for fabricating nanopatterns by a lift-off procedure is demonstrated. The technique involves the use of molecular transfer lithography based on water-soluble templates to form a nanopatterned UV-curable material on a PMGI layer, which serves as an underlying resin suitable for lift-off processes. This bi-layer procedure is used for the fabrication of nickel patterns, which are subsequently used as a hard mask for plasma etch processing. Using this procedure, a two-dimensional TiO(2) photonic crystal layer with a 450 nm lattice constant is fabricated on Y(3)Al(5)O(12):Ce(3+) (YAG:Ce) yellow ceramic plate phosphor to enhance its forward emission. The yellow emission in the forward direction is improved by a factor of 3.5 compared to that of a conventional non-scattering YAG:Ce phosphor plate excited by a blue LED.

The hypothesis of an effective strategy for resistance of hepatocellular carcinoma to therapy-autophagy

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours and its five-year survival rate remains low. Autophagy is a catabolic process conserved among all eukaryotes ranging from yeast to mammals. Recently, many studies show that tumour cells can utilize autophagy as a cellular defence mechanism when facing metabolic stress. Thus, we hypothesize that autophagy may play an important role in the resistance of hepatocellular carcinomas to therapy. Although the exact role of autophagy on tumour cells is still complex and further studies are needed to prove the impact of autophagy on HCC, it suggests that autophagy may be a new therapeutic target for the resistance to therapy of HCC.

Efficacy and safety of extended-release niacin/laropiprant plus statin vs. doubling the dose of statin in patients with primary hypercholesterolaemia or mixed dyslipidaemia

BACKGROUND

Co-administration of niacin with statin offers the potential for additional lipid management and cardiovascular risk reduction. However, niacin is underutilised because of the side effects of flushing, mediated primarily by prostaglandin D(2) (PGD(2)). A combination tablet containing extended-release niacin and laropiprant (ERN/LRPT), a PGD(2) receptor (DP1) antagonist, offers improved tolerability. This study assessed the efficacy and safety of ERN/LRPT added to statin vs. doubling the dose of statin in patients with primary hypercholesterolaemia or mixed dyslipidaemia who were not at their National Cholesterol Education Program Adult Treatment Panel III low-density lipoprotein cholesterol (LDL-C) goal based on their coronary heart disease risk category (high, moderate or low).

METHODS

After a 2- to 6-week run-in statin (simvastatin 10 or 20 mg or atorvastatin 10 mg) period, 1216 patients were randomised equally to one of two treatment groups in a double-blind fashion: group 1 received ERN/LRPT (1 g) plus the run-in statin dose and advanced to ERN/LRPT (2 g) after 4 weeks for an additional 8 weeks, with no adjustments to the run-in statin dose; group 2 received simvastatin or atorvastatin at twice their run-in statin dose and remained on this stable dose for 12 weeks.

RESULTS

ERN/LRPT added to statin (pooled across statin and statin dose) significantly improved key lipid parameters vs. the doubled statin dose (pooled): the between-treatment group difference in least squares mean per cent change [95% confidence interval (CI)] from baseline to week 12 in LDL-C (primary end-point) was -4.5% (-7.7, -1.3) and in high-density lipoprotein cholesterol (HDL-C) was 15.6% (13.4, 17.9) and in median per cent change for triglyceride (TG) was -15.4% (-19.2, -11.7). Treatment-related adverse experiences (AEs) related to flushing, pruritis, rash, gastrointestinal upset and elevations in liver transaminases and fasting serum glucose occurred more frequently with ERN/LRPT added to statin vs. statin dose doubled.

CONCLUSIONS

The addition of ERN/LRPT to ongoing statin treatment produced significantly improved lipid-modifying benefits on LDL-C, HDL-C and TG and all other lipid parameters compared with doubling the statin dose in patients with primary hypercholesterolaemia or mixed dyslipidaemia. The types of AEs that occurred at a greater frequency in the ERN/LRPT group were those typically associated with niacin.

A semi-automated method for measuring the potential for protein covalent binding in drug discovery

INTRODUCTION

Covalent protein binding of metabolically reactive intermediates of drugs has been implicated in drug toxicity including the occurrence of idiosyncratic drug toxicity. Investigators therefore would prefer to avoid developing compounds that produce significant amounts of reactive metabolites. By incubating the radiolabeled drug of interest with liver microsomes it is possible to evaluate the propensity of a drug candidate to covalently bind to proteins.

METHODS

Here we present a semi-automated method in which a Brandel cell harvester is used to collect and wash proteins that have been incubated with radiolabeled drug. This method utilizes glass fiber filter paper to capture precipitated protein, rather than the more traditional exhaustive extraction/centrifugation approach. Using model compounds (including [14C]diclofenac, [3H]imipramine, [14C]naphthalene, and [14C]L-746530) we compare the covalent binding results obtained using this method to results generated using the traditional method and we performed cross-laboratory testing of assay reproducibility.

RESULTS

It was found that results from new method correlated highly with the traditional method (R2=0.89). The cross-laboratory testing of the method showed an average interlaboratory coefficient of variation of only 18.4%.

DISCUSSION

This method provides comparable results to the more traditional centrifugation-based method with considerable time and labor savings.

Species and gender differences in the formation of an active metabolite of a substituted 2,4-thiazolidinedione insulin sensitizer

1. The metabolism of a substituted 2,4-thiazolidinedione (P1) with dual PPARalpha/gamma activity was evaluated in male and female rats, dogs and monkeys. A para-hydroxylated metabolite (M1) with potent PPARgamma-selective agonist, was a major circulating drug-related component in female rats, dogs and monkeys, but not in male rats (M1-to-P1 exposure ratio of <1, 3-5, 5 and 5-11 in male rat, monkey, female rat, and dog, respectively). 2. M1 (%) formed in vitro (5, 53, 57-65, 67 and 67% in male rat, monkey, female rat, dog, and human liver microsomes, respectively), rank ordered with M1 (%) formed in vivo (24-45, 53-57, 78, 75-85%, for male rat, monkey, female rat and dog, respectively, after oral administration of P1). 3. The plasma clearance of M1 was higher in male rats (32 ml min(-1) kg(-1) compared with 6, 7 and 2 ml min(-1) kg(-1) in female rat, male monkey and male dogs, respectively). 4. The low amounts of M1 observed in male rats, with the appearance of products of the cleavage of the propyl group between the phenyl groups was probably due to the presence of the sex-specific CYP2C11, which cleaves P1 at the propyl bridge. None of the CYPs present in female rats cleaved P1 at this site and M1 was only produced by CYP2C6. In humans, only CYP2C8 and the polymorphic CYP2C19 produced M1.

Use of on-line hydrogen/deuterium exchange to facilitate metabolite identification

Biotransformation studies performed on an investigational compound (I, represented by R1-CH(NH(2))-CO-N(R2)-CH(2)-S-R3) led to the identification of five metabolites (M1-M5). Based on LC/MS (liquid chromatography/mass spectrometry) analysis which included the use of H(2)O and D(2)O in the mobile phases, they were identified as the sulfoxide (M1), sulfone (M2), carbamoyl glucuronide (M3), N-glucuronide (M4), and N-glucoside (M5) metabolites, respectively. The structure of M3, a less commonly seen carbamoyl glucuronide metabolite, was established using on-line H/D (hydrogen/deuterium) exchange experiments conducted by LC/MS. H/D exchange experiments were also used to distinguish the S-oxidation structures of M1 and M2 from hydroxylation. Herein, the application of deuterium oxide as the LC/MS mobile phase for structural elucidation of drug metabolites in biological matrices is demonstrated.

Fossilized high pressure from the Earth's deep interior: the coesite-in-diamond barometer

Mineral inclusions in diamonds provide an important source of information about the composition of the continental lithosphere at depths exceeding 120-150 km, i.e., within the diamond stability field. Fossilized high pressures in coesite inclusions from a Venezuela diamond have been identified and measured by using laser Raman and synchrotron x-ray microanalytical techniques. Micro-Raman measurements on an intact inclusion of remnant vibrational band shifts give a high confining pressure of 3.62 (+/-0.18) GPa. Synchrotron single-crystal diffraction measurements of the volume compression are in accord with the Raman results and also revealed direct structural information on the state of the inclusion. In contrast to olivine and garnet inclusions, the thermoelasticity of coesite favors accurate identification of pressure preservation. Owing to the unique combination of physical properties of coesite and diamond, this "coesite-in-diamond" geobarometer is virtually independent of temperature, allowing an estimation of the initial pressure of Venezuela diamond formation of 5.5 (+/-0.5) GPa.

Pressure-enhanced ortho-para conversion in solid hydrogen up to 58 GPa

We measured the ortho-para conversion rate in solid hydrogen by using Raman scattering in a diamond-anvil cell, extending previous measurements by a factor of 60 in pressure. We confirm previous experiments that suggested a decrease in the conversion rate above about 0.5 GPa. We observe a distinct minimum at 3 GPa followed by a drastic increase in the conversion rate to our maximum pressure of 58 GPa. This pressure enhancement of conversion is not predicted by previous theoretical treatments and must be due to a new conversion pathway.

Slow deformation and lower seismic hazard at the new madrid seismic zone

Global Positioning System (GPS) measurements across the New Madrid seismic zone (NMSZ) in the central United States show little, if any, motion. These data are consistent with platewide continuous GPS data away from the NMSZ, which show no motion within uncertainties. Both these data and the frequency-magnitude relation for seismicity imply that had the largest shocks in the series of earthquakes that occurred in 1811 and 1812 been magnitude 8, their recurrence interval should well exceed 2500 years, longer than has been assumed. Alternatively, the largest 1811 and 1812 earthquakes and those in the paleoseismic record may have been much smaller than typically assumed. Hence, the hazard posed by great earthquakes in the NMSZ appears to be overestimated.

Space geodetic observations of nazca-south america convergence across the central andes

Space geodetic data recorded rates and directions of motion across the convergent boundary zone between the oceanic Nazca and continental South American plates in Peru and Bolivia. Roughly half of the overall convergence, about 30 to 40 millimeters per year, accumulated on the locked plate interface and can be released in future earthquakes. About 10 to 15 millimeters per year of crustal shortening occurred inland at the sub-Andean foreland fold and thrust belt, indicating that the Andes are continuing to build. Little (5 to 10 millimeters per year) along-trench motion of coastal forearc slivers was observed, despite the oblique convergence.

Transient loss of dopamine autoreceptor control in the presence of highly potent dopamine agonists

The concentrations of endogenous ligands generally remain in a bounded range around a basal level, a manifestation of control. The dopaminergic system is an excellent example of a control system in which a negative feedback signal is associated with receptor occupancy of a D2-like dopamine autoreceptor. A consequence of the control theory is that autoreceptor occupancy by an agonist results in dopamine levels below the basal, whereas similar stimulation by a dopamine competitive antagonist results in an increase of dopamine to levels above the basal. These consequences of control theory were tested and verified in the rat striatum by infusing graded doses of either the agonist, quinpirole, or the antagonist, sulpiride, into the rat striatum via a microdialysis probe and sampling dopamine and metabolite levels at various times after the start of infusion. Control was maintained even at the very highest doses of these compounds, i.e., striatal dopamine concentration rose in response to the antagonist and fell in response to the agonist. In contrast, administration of each of two high affinity dopamine agonists, 7-OH-DPAT and PPHT showed dose-dependent control only up to certain doses. Above these doses the dopamine concentration actually increased to levels well above basal, an indication of loss of control. These findings suggest that the control of this endogenous ligand does not extend to the very highest levels of autoreceptor occupancy.

Interaction of echicetin with a high affinity thrombin binding site on platelet glycoprotein GPIb

Echicetin, a protein isolated from Echis carinatus snake venom, inhibited platelet aggregation and secretion induced by low concentrations of thrombin ( < 0.2 U/ml), by binding to platelet glycoprotein Ib (GPIb). The inhibition was not observed when the platelets were stimulated with higher concentrations of thrombin ( > 0.2 U/ml). Echicetin competed with thrombin for binding to the high affinity site on GPIb. Thrombin also inhibited 50% of the binding of 125I-echicetin to the platelets.

The relationship between vessel wall tension and the magnitude and frequency of oscillation in rat aorta

Aortic rings from adult normotensive rats display spontaneous rhythmic activity that is enhanced by vasoconstricting agents. Graded doses of norepinephrine as well as combinations of norepinephrine and vasodilators produced levels of tension that were inversely related to the magnitude of oscillation and directly related to the frequency. A similar result occurred with KCl stimulation. Oscillations were only slightly affected by removal of the endothelium. These results, when combined with other reported studies, suggest that the oscillations in rat aorta are a manifestation of feedback control that may involve the cyclic release of one or more agents affecting calcium channels.