Increased IL-4- and IL-17-producing CD8+ cells are related to decreased CD39+CD4+Foxp3+ cells in allergic asthma

Objective: In allergic asthma, regulatory T cell (Treg) number and function are decreased. Antigen-primed CD8⁺ T cells play an indispensable role in the full development of airway inflammation and airway hyper-responsiveness (AHR) occurring in asthma. In this study, we investigated the relationship between subpopulations of CD8⁺ T cells and CD39⁺ Tregs. Methods: Female C57BL/6 mice were used to develop the model of allergic asthma. Experimental mice were immunized with ovalbumin (OVA) by intra-peritoneal (i.p) injection and then challenged with OVA by intra-tracheal administration. Control mice were immunized with vehicle by i.p injection and challenged with OVA. Airway inflammation was determined by histology and AHR was measured by an invasive method. Levels of interferon (IFN)-γ, IL-4, and IL-17 in bronchoalveolar lavage fluid (BALF) were determined by enzyme-linked immunosorbent assay. The frequencies of CD8⁺IFN-γ⁺ cells (Tc1), CD8⁺IL-4⁺ cells (Tc2), CD8⁺IL-17⁺cells (Tc17), and CD39⁺Tregs were measured by flow cytometry. The correlation between CD39⁺Tregs and Tc subsets was analyzed by Pearson’s test. Results: Experimental mice displayed phenotypes of allergic asthma, including inflammatory cell infiltration into the lungs, goblet cell hyperplasia, increased airway resistance, and increased IL-4 and IL-17 in BALF. Compared to control mice, experimental mice displayed lower CD39⁺Tregs and Tc1 but higher Tc2 and Tc17. There was a negative correlation between CD39⁺Tregs and Tc2 or Tc17. Conclusion: In allergic asthma, increased Tc2 and Tc17 are possibly related to insufficient CD39⁺Tregs.     

Molecular Characterization of a Novel 55.1 kb Gγ(Aγδβ)0-thalassemia Deletion in Two Canadian Families

We report two Canadian families in which there are four carriers of a novel ^Gγ(^Aγδβ)⁰-thalassemia deletion. The patients all have mild microcytosis and hypochromia, and elevated levels of Hb F ranging from 9.7 to 17.3%. The precise endpoints of the deletion have been identified and are unique relative to other forms of ^Gγ(^Aγδβ)⁰-thal reported in the literature. The deletion encompasses ～55.1 kb, beginning ～1.6 kb downstream of the ^Gγ-globin gene and extending ～29.0 kb downstream of the β-globin gene.     

Use of radioactive substances in diagnosis and treatment of neuroendocrine tumors

Abstract

Radionuclides are needed both for nuclear medicine imaging as well as for peptide-receptor radionuclide therapy (PRRT) of neuroendocrine tumors (NET). Imaging is important in the initial diagnostic work-up and for staging NETs. In therapy planning, somatostatin receptor imaging (SRI) is used when treatment is targeted at the somatostatin receptors as with the use of somatostatin analogues or PRRT. SRI with gamma camera technique using the tracer ¹¹¹In-DTPA-octreotide has for many years been the backbone of nuclear imaging of NETs. However, increasingly PET tracers for SRI are now used. ⁶⁸Ga-DOTATATE, ⁶⁸Ga-DOTATOC and ⁶⁸Ga-DOTANOC are the three most often used PET tracers. They perform better than SPECT tracers and should be preferred. FDG-PET is well suited for visualization of most of the somatostatin receptor-negative tumors prognostic in NET patients. Also ¹¹C-5-HTP, ¹⁸F-DOPA and ¹²³I-MIBG may be used in NET. However, with FDG-PET and somatostatin receptor PET at hand we see limited necessity of other tracers. PRRT is an important tool in the treatment of advanced NETs causing complete or partial response in 20% and minor response or tumor stabilization in 60% with response duration of up to 3 years. Grade 3–4 kidney or bone marrow toxicity is seen in 1.5% and 9.5%, respectively, but are completely or partly reversible in most patients. ¹⁷⁷Lu-DOTATATE seems to have less toxicity than ⁹⁰Y-DOTATOC. However, until now only retrospective, non-randomized studies have been performed and the role of PRRT in treatment of NETs remains to be established.     

Kinetics of Red Cell Na+ and K+ Transport in Prague Hypertensive Rats

Kinetics of ouabain-sensitive, furosemide-sensitive (FS), bumetanide-sensitive (BS) and -resistant Na⁺ and K⁺ transport were studied in erythrocytes of Prague hypertensive rats (PHR) and Prague normotensive rats (PNR). Maximal transport rates (V_max) and apparent affinities for either intracellular Na⁺ or extracellular K⁺ (replaced by Rb⁺) were determined in red cells in which Na⁺ content varied around the physiological range and that were incubated in Na⁺ media. No major differences between PHR and PNR were disclosed in the kinetics of ion transport mediated by the Na⁺-K⁺ pump or BS inward Na⁺-K⁺ cotransport. FS Rb⁺ uptake was higher (due to a greater V_max) in red cells of PHR as compared to PNR. In cells with a lowered Na⁺ content this elevation of FS Rb⁺ uptake was largely due to an augmented K⁺-Cl^? cotransport which exhibits a low affinity for Rb⁺_o and is blocked by 1 mM furosemide but not by 10 μM bumetanide. Red cells of PHR and PNR strains did not differ in either Na⁺ or Rb⁺ leaks. A slight increase of red cell Na⁺ content in PHR was evaluated in terms of the pump-leak concept. The present study did not reveal any obvious kinetic abnormalities of red cell cation transport the presence of which in tissues involved in blood pressure regulation would favor the development or the maintenance of genetic hypertension in PHR.     

In Vitro Action of Insulin on Erythrocyte Sodium Transport Mechanisms: Its Possible Role in the Pathogenesis of Arterial Hypertension

The effects of insulin on sodium and potassium metabolism have been well known for many years; clinical observation and laboratory experience showed different results about the insulin effect on the sodium-potassium pump. Moreover, studies about the insulin effect on the sodium-potassium cotransport are not available. Therefore, the effects of insulin on Na,⁺K⁺ pump and Na⁺,K⁺ cotransport were evaluated. Results show that insulin inhibits Na⁺, K⁺ pump, while Na⁺, K⁺ cotransport is markedly activated. The possible link between pathogenesis of arterial hypertension in hyperinsulinemic subjects and present data is examined.     

Diagnosis of a Family with the Novel –α21.9 Thalassemia Deletion

Abstract

The Qinzhou α-thalassemia (α-thal) or –α^21.9 deletion was first described at the Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi, People’s Republic of China (PRC) in 2013. The molecular biological mechanism by which this allele leads to α-thal involves the deletion of a 21.9?kb DNA fragment of the α-globin gene cluster (NG_000006.1), designated as –α^21.9. During routine screening, a new family with –α^21.9 was found by the research group. This is the first time that an adult patient with the –α^21.9/αα genotype and a 6-month-old baby with the –α^21.9/–?–^SEA (Southeast Asian) genotype were detected in one family. The discovery of this family demonstrates that there is a certain risk for the Qinzhou α-thal deletion in the southern regions of Guangxi Province, PRC. The detection of the adult patient with the –α^21.9/αα genotype and the analysis of hematological data are important supplements for –α^21.9 research. Additionally, Hb Bart’s (γ4) and Hb H (β4) were detected in the 6-month-old, confirming that the baby with the –α^21.9/–?–^SEA genotype also carries Hb H disease. The analysis of this family verifies that the –α^21.9 deletion is an α⁺-thal allele.     

Quantitation of glycosaminoglycan metabolism in anatomically intact articular cartilage of the mouse patella: in vitro and in vivo studies with 35S-sulfate, 3H-glucosamine,and 3H-acetate

Summary We investigated the usefulness of the whole mouse patella to quantitate the synthesis of the glycosaminoglycan (GAG) backbone and its sulfation by intact murine articular cartilage, both in vitro and in vivo. Using ³⁵S-sulfate, ³H-glucosamine, or ³H-acetate as precursors of GAG synthesis, it was found that more than 90% of the incorporated radioactivity was confined to the patellar cartilage layer compared to the whole patella. Overnight papain digestion was enough to liberate more than 95% of the incorporated radiolabels, except for ³H-acetate for which 15–25% was not digestable. Comparison of radioactivity in the patella and that in quantitatively isolated GAGs revealed that for ³⁵S-sulfate incorporation studies the whole patella can be used as a reliable measure for sulfated GAG synthesis. The situation was different for the GAG backbone precursors ³H-glucosamine and ³H-acetate; more than 50% of the ³H labels were incorporated into compounds other than GAGs or non-covalently associated with matrix components. Hence, in studying GAG-backbone metabolism, polysaccharides must be isolated quantitatively from cartilage. In vivo studies made it clear that both ³⁵S-sulfate and ³H-glucosamine are incorporated into patellar GAGs in amounts high enough to enable proper quantitation and that the route of administration (intraperitoneally or intravenously) is of minor importance. Due to its low specificity for cartilage GAGs, ³H-acetate is not suitable for such studies.     

INTERACTION OF THE α2 POLYADENYLATION SIGNAL MUTATION (AATAAA → AATA– –) AND α0-THALASSEMIA (– –SEA), RESULTING IN Hb H DISEASE IN A THAI PATIENT

We report a Thai boy with a compound heterozygosity for the α2 polyadenylation signal mutation (AATAAA → AATA– –) and α⁰-thalassemia (– –^SEA), who suffered from Hb H disease with more severe clinical symptoms than those usually observed with deletional Hb H disease. His Hb H level was as high as 52% of total hemoglobin. The hematologic data of this unusual case of Hb H disease was compared with those of Hb H disease with a homozygosity for the α2 polyadenylation signal mutation, and compound heterozygosity of the α2 polyadenylation signal mutation and α⁰-thalassemia. A simple DNA assay based on an allele specific polymerase chain reaction for the detection of this polyadenylation signal mutation is described.     

β+-Thalassemia Trait Due to a Novel Mutation in the β-Globin Gene Promoter: −26 (A>C) [HBB c.−76A>C]

We report the case of a woman with β⁺-thalassemia (β⁺-thal) trait, in which there were two sequence variants within the β-globin gene promoter: ?54 (G>A) [HBB c.?104G>A] and ?26 (A>C) [HBB c.?76A>C]. Data from other patients indicate that the ?54 substitution is a non pathogenic sequence variant. Therefore, the β-thal phenotype is most likely due to the ?26 mutation that is adjacent to the conserved ATAA box.     

Complex Interaction of Hb Q-Thailand with α0- and β0-Thalassemia in a Chinese Family

Hb Q-Thailand [α74(EF3)Asp→His (α1); HBA1: c.223?G>C] is an abnormal hemoglobin (Hb), variant found mainly in China and Southeast Asian countries. The association of the α^Q-Thailand allele with other globin gene disorders has important implications in diagnosis. Here, we report a hitherto undescribed condition of patients with a double heterozygosity for Hb Q-Thailand with α⁰-thalassemia (α⁰-thal) and in combination with β⁰-thalassemia (β⁰-thal) in a Chinese family. Our study will provide some clinical manifestations, laboratory diagnosis and genetic counseling for complex hemoglobinopathies.     

Identification of the −α2.4 Deletion in One Family and in One Hb H Disease Patient in Guangxi,People’s Republic of China

The 2.4?kb (or ?α^2.4) deletion in the α-globin gene cluster (NG_000006.1) is an α⁺-thalassemia (α⁺-thal) allele. The molecular basis of ?α^2.4 is a deletion from 36860 to 39251 of the α-globin gene cluster. It was reported by three research groups in 2005, 2012 and 2014, respectively. In routine thalassemia screening studies by this research group, we found an individual with the ?α^2.4/αα genotype and an Hb H (β4) disease patient whose genotype was –?–^SEA/?α^2.4. Samples from the parents of the carrier of the ?α^2.4/αα genotype were collected to perform pedigree analysis, and the proband’s mother’s genotype was diagnosed to be –?–^SEA/?α^2.4. The research revealed that the ?α^2.4 allele exists in the population of southern Guangxi, People’s Republic of China.     

SIK1 is part of a cell sodium-sensing network that regulates active sodium transport through a calcium-dependent process

In mammalian cells, active sodium transport and its derived functions (e.g., plasma membrane potential) are dictated by the activity of the Na(+),K(+)-ATPase (NK), whose regulation is essential for maintaining cell volume and composition, as well as other vital cell functions. Here we report the existence of a salt-inducible kinase-1 (SIK1) that associates constitutively with the NK regulatory complex and is responsible for increases in its catalytic activity following small elevations in intracellular sodium concentrations. Increases in intracellular sodium are paralleled by elevations in intracellular calcium through the reversible Na(+)/Ca(2+) exchanger, leading to the activation of SIK1 (Thr-322 phosphorylation) by a calcium calmodulin-dependent kinase. Activation of SIK1 results in the dephosphorylation of the NK alpha-subunit and an increase in its catalytic activity. A protein phosphatase 2A/phosphatase methylesterase-1 (PME-1) complex, which constitutively associates with the NK alpha-subunit, is activated by SIK1 through phosphorylation of PME-1 and its dissociation from the complex. These observations illustrate the existence of a distinct intracellular signaling network, with SIK1 at its core, which is triggered by a monovalent cation (Na(+)) and links sodium permeability to its active transport.     

HERG K<Superscript>+</Superscript> channel expression in CD34<Superscript>+</Superscript>/CD38<Superscript>−</Superscript>/CD123<Superscript>high</Superscript> cells and primary leukemia cells and analysis of its regulation in leukemia cells

The human ether-a-go-go-related (herg) gene encoding K⁺ channels (HERG) belongs to an evolutionarily conserved multigene family of voltage activated K⁺ channels. The functional properties of HERG K⁺ channels are complex and their contribution to the repolarization of the cardiac action potential are well understood. Recent studies revealed that HERG K⁺ channels are preferentially expressed in different histogenesis of tumor cells. Leukemia is a cancer that originates in the bone marrow hematopoietic stem cells (HSCs). Leukemia stem cells (LSCs) are critical in the perpetuation of the disease. A better understanding of LSCs and molecular biology will allow the design of more effective therapies. We report in this study that herg was expressed in CD34⁺/CD38⁻/CD123^high LSCs but not expressed in normal bone marrow CD34⁺/CD38⁻ HSCs. In addtion, herg is also expressed in leukemia cell lines K562 and HL-60 and almost all the primary leukemia cells whereas not in the normal bone marrow cells. In addition, the expression of herg mRNA was not associated with the clinical and cytogenetic feature of leukemia. Moreover, HERG K⁺ channels can regulate leukemia cells proliferation and cell cycle. These data provide evidence for the oncogenic potential of HERG K⁺ channels and it may be a novel, potential pharmacological target for leukemia therapy in the future.     

Ancient helium and tungsten isotopic signatures preserved in mantle domains least modified by crustal recycling

Rare high-³He/⁴He signatures in ocean island basalts (OIB) erupted at volcanic hotspots derive from deep-seated domains preserved in Earth’s interior. Only high-³He/⁴He OIB exhibit anomalous ¹⁸²W—an isotopic signature inherited during the earliest history of Earth—supporting an ancient origin of high ³He/⁴He. However, it is not understood why some OIB host anomalous ¹⁸²W while others do not. We provide geochemical data for the highest-³He/⁴He lavas from Iceland (up to 42.9 times atmospheric) with anomalous ¹⁸²W and examine how Sr-Nd-Hf-Pb isotopic variations—useful for tracing subducted, recycled crust—relate to high ³He/⁴He and anomalous ¹⁸²W. These data, together with data on global OIB, show that the highest-³He/⁴He and the largest-magnitude ¹⁸²W anomalies are found only in geochemically depleted mantle domains—with high ¹⁴³Nd/¹⁴⁴Nd and low ²⁰⁶Pb/²⁰⁴Pb—lacking strong signatures of recycled materials. In contrast, OIB with the strongest signatures associated with recycled materials have low ³He/⁴He and lack anomalous ¹⁸²W. These observations provide important clues regarding the survival of the ancient He and W signatures in Earth’s mantle. We show that high-³He/⁴He mantle domains with anomalous ¹⁸²W have low W and ⁴He concentrations compared to recycled materials and are therefore highly susceptible to being overprinted with low ³He/⁴He and normal (not anomalous) ¹⁸²W characteristic of subducted crust. Thus, high ³He/⁴He and anomalous ¹⁸²W are preserved exclusively in mantle domains least modified by recycled crust. This model places the long-term preservation of ancient high ³He/⁴He and anomalous ¹⁸²W in the geodynamic context of crustal subduction and recycling and informs on survival of other early-formed heterogeneities in Earth’s interior.

Plate tectonic motions deliver oceanic and continental crust into the mantle at subduction zones. Following residence times of ∼2 Ga, subducted crustal material is returned to the shallow mantle in buoyantly upwelling conduits of hot mantle material, known as mantle plumes, where they are partially melted and erupted as ocean island basalts (OIB) at volcanic hotspots (1–3). Recycled materials contribute to a variety of geochemically distinct mantle components often referred to as EM1 (enriched mantle I), EM2 (enriched mantle II), and HIMU (high “μ” or high ²³⁸U/²⁰⁴Pb) (1–3). While there is debate surrounding the exact nature of the recycled protoliths responsible for these mantle endmembers (4–7), they are likely generated by input of shallow geochemical reservoirs into the deep Earth. The three mantle components have ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ¹⁷⁶Hf/¹⁷⁷Hf, and ²⁰⁶Pb/²⁰⁴Pb distinct from the depleted mantle (DM) sampled by basalts erupted at midocean ridges (MORB). In three-dimensional (3D) Sr-Nd-Pb isotopic space, these four geochemical endmembers can be used to define the apices of a tetrahedron (8) (Fig. 1) and have low ³He/⁴He, similar to, or lower than, MORB (8 ± 2 Ra, ratio to atmosphere) (9). An additional mantle component is found internal to the other four and, like DM, is characterized by geochemically depleted compositions that relate to long-term crustal extraction from the mantle, which changes the parent–daughter ratios that govern key radiogenic isotopic systems, resulting in high ¹⁴³Nd/¹⁴⁴Nd and ¹⁷⁶Hf/¹⁷⁷Hf coupled with low ⁸⁷Sr/⁸⁶Sr and ²⁰⁶Pb/²⁰⁴Pb. Existing long-lived radiogenic isotopic data show that this fifth component is geochemically depleted (8, 10) and has been variously referred to as FOZO [focus zone (8)], PHEM [primordial helium mantle (11)], or C [common (12)]. In contrast to DM, this geochemically depleted mantle composition was argued to exhibit elevated ³He/⁴He (8), signaling the preservation of an ancient reservoir in the deep Earth (13).Open in a separate windowFig. 1.Mantle tetrahedron showing that most of the highest ³He/⁴He lavas in Iceland, and global hotspots, do not overlap with the common mantle component [shown as ellipsoid (27)]. Four different high-³He/⁴He (>25 Ra) components in Iceland (Vestfirðir, ERZ, SIVZ, and Baffin Island) are shown. The highest ³He/⁴He (>30 Ra) samples from each global oceanic hotspot with available Sr-Nd-Pb isotopes—Galapagos, Hawaii, and Samoa—are also shown (data sources for these additional lavas are in SI Appendix, Fig. S4). EM1, EM2, and HIMU apices of the tetrahedron are published elsewhere (27), as is MORB (63), but EM2 extends to more extreme compositions (36) (indicated by arrow). Data for the highest ³He/⁴He lavas with available Sr-Nd-Pb isotopes from the different Iceland high-³He/⁴He (>25 Ra) localities are from Dataset S1; the Baffin Island lava is the highest ³He/⁴He (39.9 Ra) lava that is the least crustally contaminated (23). Measured values are shown for all lavas except for Baffin Island, where both age-corrected (c) and measured compositions are shown: The calculated present-day Baffin Island mantle source is indistinguishable from the measured composition in the figure [see (23) and SI Appendix, Fig. S4 legend for details of the age correction and present-day source calculation].Recent discoveries employing the short-lived ¹⁸²Hf-¹⁸²W isotopic systematics have demonstrated the presence of anomalous, negative μ¹⁸²W (where μ is the deviation of ¹⁸²W/¹⁸⁴W from the terrestrial standard in parts per million) in modern OIB (14–17), and the anomalies are found uniquely in lavas with high ³He/⁴He (14–16). ¹⁸²W anomalies were generated only while the parent nuclide (¹⁸²Hf → ¹⁸²W + 2β⁻, half-life = 8.9 million years) was extant (i.e., <60 Ma following Solar System formation), so the observation of anomalous ¹⁸²W signals in the modern mantle implies that these signatures have been preserved in Earth since the early Hadean. This is consistent with the discovery of heterogeneous ¹²⁹Xe and ¹⁴²Nd—which are products of the short-lived isotopes ¹²⁹I and ¹⁴⁶Sm, respectively, extant only in the Hadean (18, 19)—in the modern mantle, further supporting the observation of chemical heterogeneities preserved in Earth’s interior since the Hadean.An important recent observation is that ¹⁸²W and ³He/⁴He data from oceanic basalts define a negatively sloping array, with anomalous ¹⁸²W signatures in OIB uniquely associated with lavas that exhibit high ³He/⁴He (14–16). This fundamental advance relates primordial high ³He/⁴He with an early-formed isotopic heterogeneity. However, several outstanding questions regarding ¹⁸²W systematics in the modern mantle remain: 1) What is the mechanism responsible for the unique association of anomalous μ¹⁸²W with high-³He/⁴He hotspot lavas, and why do low-³He/⁴He lavas lack ¹⁸²W anomalies? 2) Do the geodynamic processes of subduction and recycling impact the ¹⁸²W-³He/⁴He mantle array? 3) Do ¹⁸²W systematics exhibit relationships with isotopic tracers (i.e., Sr-Nd-Pb) sensitive to crustal subduction and recycling, or are ¹⁸²W systematics somehow insensitive to these geodynamic processes such that Sr-Nd-Pb isotope systematics are decoupled from ¹⁸²W?In order to address these outstanding questions, we provide a large geochemical dataset on high-³He/⁴He lavas from the Iceland hotspot and examine the data in the context of new global OIB datasets combining He, Sr, Nd, Hf, and Pb isotopes with W isotopes. The data and analysis provide insights into the mechanisms for preservation of anomalous ¹⁸²W and high-³He/⁴He signatures in the mantle.     

Desirable pharmacokinetic properties of 13C-uracil as a breath test probe of gastric emptying in comparison with 13C-acetate and 13C-octanoate in rats

Objective. To investigate the possible use of a ¹³C-uracil breath test for gastric emptying by evaluating the pharmacokinetic properties of ¹³C-uracil in a breath test in rats, in comparison with ¹³C-acetate and ¹³C-octanoate, traditional ¹³C-probes for gastric emptying. Material and methods. Absorption of the ¹³C-probes from different parts of the gastrointestinal tract was evaluated in fasted rats. ¹³C-Uracil breath tests for gastric emptying were carried out in conditions where delayed gastric emptying was induced by clonidine, quinpirole, and propantheline, and in a postoperative ileus model. Following oral administration, we measured residual ¹³C-uracil in the stomach and correlated the amount with the breath response. Results. All the ¹³C-probes employed were well absorbed from the intestine after intraduodenal administration. After intragastric administration, ¹³C-uracil was not absorbed from the stomach, but ¹³C-acetate and ¹³C-octanoate were partly absorbed from the stomach. The cumulative ¹⁴C-uracil recovery (%) at 168 h was 92.3, 6.3, or 0.5%, from expired gases, urine, and feces, respectively. Δ¹³C values in ¹³C-uracil breath tests were decreased in conditions characterized by delayed gastric emptying. A highly negative correlation was observed between the breath response and the residual ratio of ¹³C-uracil in the stomach after oral administration of ¹³C-uracil, indicating that ¹³C-uracil can be used as an in vivo probe for evaluating gastric emptying in a quantitative manner. Conclusions. This study showed that ¹³C-uracil has desirable pharmacokinetic properties as an in vivo probe of gastric emptying. It is thus suggested that the ¹³C-uracil breath test may be useful for the measurement of gastric emptying in humans.     

Endothelin-1 induced hypertrophic effect in neonatal rat cardiomyocytes: involvement of Na+/H+ and Na+/Ca2+ exchangers

Endothelin-1 (ET-1) is a potent agonist of cell growth that also stimulates Na(+)/H(+) exchanger isoform 1 (NHE-1) activity. It was hypothesized that the increase in intracellular Na(+) ([Na(+)](i)) mediated by NHE-1 activity may induce the reverse mode of Na(+)/Ca(2+) exchanger (NCX(rev)) increasing intracellular Ca(2+) ([Ca(2+)](i)) which in turn will induce hypertrophy. The objective of this work was to test whether the inhibition of NHE-1 or NCX(rev) prevents ET-1 induced hypertrophy in neonatal rat cardiomyocytes (NRVMs). NRVMs were cultured (24 h) in the absence (control) and presence of 5 nmol/L ET-1 alone, or combined with 1 mumol/L HOE 642 or 5 mumol/L KB-R7943. Cell surface area, (3)H-phenylalanine incorporation and atrial natriuretic factor (ANF) mRNA expression were increased to 131 +/- 3, 220 +/- 12 and 190 +/- 25% of control, respectively (P < 0.05) by ET-1. [Na(+)](i) and total [Ca(2+)](i) were higher (8.1 +/- 1.2 mmol/L and 636 +/- 117 nmol/L, respectively) in ET-1-treated than in control NRVMs (4.2 +/- 1.3 and 346 +/- 85, respectively, P < 0.05), effects that were cancelled by NHE-1 inhibition with HOE 642. The rise in [Ca(2+)](i) induced by extracellular Na(+) removal (NCX(rev)) was higher in ET-1-treated than in control NRVMs and the effect was prevented by co-treatment with HOE 642 or KB-R7943 (NCX(rev) inhibitor). The ET-1-induced increase in cell area, ANF mRNA expression and (3)H-phenylalanine incorporation in ET-1-treated NRVM were decreased by NHE-1 or NCX(rev) inhibition. Our results provide the first evidence that NCX(rev) is, secondarily to NHE-1 activation, involved in ET-1-induced hypertrophy in NRVMs.     

Decrease in CD4+CD25+ and CD8+CD28+ T cells in interstitial pneumonitis associated with rheumatic disease

Abstract

The expression of CD25 or CD28 on T cells was examined in patients with rheumatic diseases associated with interstitial pneumonitis (IP), in order to investigate the conditions of CD4⁺CD25⁺ regulatory T cells and CD8⁺CD28^? suppressor T cells. Fifty-five patients with various rheumatic diseases and 23 normal controls were enrolled. CD4⁺CD25⁺ T cells of patients with IP were significantly decreased in comparison with non-IP patients, and the ratio of CD8⁺CD28^? T cells in patients with IP was significantly higher than that in non-IP patients or normal controls. These results for CD8⁺CD28^? T cells were in accord with the decrease in CD8⁺CD28⁺ T cells, and may be related to activation-induced CD8⁺CD28⁺ T-cell death. Thus, the abnormality of CD4⁺CD25⁺ regulatory T cells may be related to the pathogenesis of IP, and the survival and activation of CD8⁺ T cells.