Cytotoxic cell function and phenotypic analysis of peripheral blood mononuclear cells in cancer patients treated with low-dose interleukin-2 and mitomycin C

We previously found that the ability of peripheral blood mononuclear cells (PBM) of cancer patients to generate lymphokine-activated killer (LAK) cells became remarkably augmented after mitomycin C administration. On the basis of the clinical finding, we designed a treatment regimen comprised of 12 mg/m² mitomycin C i. v. on day 1 and 700 U/m² recombinant interleukin-2 (IL-2) i.v. every 12 h from day 4 through day 8. Of 25 patients with advanced carcinoma, 9 had a partial response and 3 had a minor response. Cytotoxic cell function, including natural killer activity, lymphokine-activated killer (LAK) activity, and the ability to generate LAK cells, and lymphocyte subsets in PBM was measured 1 day before and after either the first or second course of this therapy. The relationship between these parameters and the clinical antitumor response to this treatment was examined. Although the cytotoxic activities were significantly augmented after either the first or second treatment course, no positive correlation was observed between the changes in these cytotoxic activities and the clinical response to this therapy, when patients who either showed a partial response or whose disease remission was partial or minor were defined as responders. Further, phenotypic analysis showed a significant increase in CD2⁺, CD3⁺ CD4⁺ and CD4⁺Leu8^– cells after the firs course, and CD25⁺ cells after either the first or second course of this treatment. The precentages of CD2⁺ and CD25⁺ cells were significantly elevated only in responders but not in nonresponders, suggesting the increase in these subsets was related to clinical response.     

Dom34:hbs1 plays a general role in quality-control systems by dissociation of a stalled ribosome at the 3' end of aberrant mRNA

Translation arrest leads to an endonucleolytic cleavage of mRNA that is termed no-go decay (NGD). It has been reported that the Dom34:Hbs1 complex stimulates this endonucleolytic cleavage of mRNA induced by translation arrest in vivo and dissociates subunits of a stalled ribosome in vitro. Here we report that Dom34:Hbs1 dissociates the subunits of a ribosome that is stalled at the 3' end of mRNA in vivo, and has a crucial role in both NGD and nonstop decay. Dom34:Hbs1-mediated dissociation of a ribosome that is stalled at the 3' end of mRNA is required for degradation of a 5'-NGD intermediate. Dom34:Hbs1 facilitates the decay of nonstop mRNAs from the 3' end by exosomes and is required for the complete degradation of nonstop mRNA decay intermediates. We propose that Dom34:Hbs1 stimulates degradation of the 5'-NGD intermediate and of nonstop mRNA by dissociating the ribosome that is stalled at the 3' end of the mRNA.     

Thermodynamic analysis of a multifunctional RNA-binding protein, PhoRpp38, in the hyperthermophilic archaeon Pyrococcus horikoshii OT3

The protein component PhoRpp38 of Pyrococcus horikoshii ribonuclease P (RNase P) is known to be a multifunctional RNA-binding protein. Previous biochemical data indicate that it binds to two stem-loops in RNase P RNA (PhopRNA). Thermodynamic analysis revealed that PhoRpp38 and PhopRNA interact with each other with an association constant (Ka) of 1.56×10(7) M(-1). It was further found that PhoRpp38 simultaneously binds two stem-loop structures in PhopRNA with approximately equal affinity. Crystals of PhoRpp38 in complex with the stem-loop were grown and diffracted to a resolution of 7.0 ? on a synchrotron X-ray source.     

Estrogen-Dependent Uterine Secretion of Osteopontin Activates Blastocyst Adhesion Competence

Embryo implantation is a highly orchestrated process that involves blastocyst-uterine interactions. This process is confined to a defined interval during gestation referred to as the “window of embryo implantation receptivity”. In mice this receptive period is controlled by ovarian estrogen and involves a coordination of blastocyst adhesion competence and uterine receptivity. Mechanisms coordinating the acquisition of blastocyst adhesion competence and uterine receptivity are largely unknown. Here, we show that ovarian estrogen indirectly regulates blastocyst adhesion competence. Acquisition of blastocyst adhesion competence was attributed to integrin activation (e.g. formation of adhesion complexes) rather than de novo integrin synthesis. Osteopontin (OPN) was identified as an estrogen-dependent uterine endometrial gland secretory factor responsible for activating blastocyst adhesion competence. Increased adhesion complex assembly in OPN-treated blastocysts was mediated through focal adhesion kinase (FAK)- and phosphatidylinositol 3-kinase (PI3K)-dependent signaling pathways. These findings define for the first time specific regulatory components of an estrogen-dependent pathway coordinating blastocyst adhesion competence and uterine receptivity.     

25-hydroxycholesterol enhances cytokine release and toll-like receptor 3 response in airway epithelial cells

Background

25-hydroxycholesterol (25-HC) is one of the oxysterols, which are oxidized derivatives of cholesterol, and has been reported to be involved in the pathogenesis of atherosclerosis and Alzheimer’s disease. In lung, the possible involvement of 25-HC in airway diseases has been revealed. In the present study, we examined whether 25-HC affects the release of cytokines and also modulates the responses of toll-like receptor 3 (TLR3) in airway epithelial cells.

Methods

The effect of 25-HC on the release of cytokines from primary human bronchial epithelial cells after stimulation with or without polyinosine-polycytidylic acid [poly(I:C)], a ligand for TLR3, and the signal transduction were examined.

Results

25-HC significantly potentiated the release of interleukin-8 (IL-8) and IL-6 from the cells. This effect was more potent compared with that of other oxysterols, 22-HC and 27-HC. GW3965 and TO901317, synthetic agonists of liver X receptors that are receptors for oxysterols, did not augment the IL-8 release. 25-HC enhanced the nuclear factor-kappa B (NF-κB) DNA binding activity and translocation of phosphorylated c-Jun into the nucleus. The release of IL-8 was inhibited by the NF-κB inhibitor, caffeic acid phenethyl ester (CAPE), an inhibitor of nuclear factor kappa-B alpha (IκBα) inhibitor, BAY 11–7085, and an inhibitor of nuclear factor kappa-B kinase-2 (IKK-2) inhibitor, SC-514, but not by a c-Jun N-terminal kinase (JNK) inhibitory peptide, L-JNKi1. 25-HC significantly potentiated IL-8 release in poly(I:C)-treated cells and the augmentation was inhibited by CAPE, BAY 11–7085, and SC-514. Furthermore, 25-HC potentiated the translocation of interferon regulatory factor 3 into the nucleus and the release of interferon-beta (IFN-β) in poly(I:C)-treated cells.

Conclusions

These data demonstrated that 25-HC augments the release of IL-8 and IL-6 via NF-κB signalling pathway and enhances the release of IL-8 and IFN-β after stimulation of TLR3 in airway epithelial cells. 25-HC may be involved in the neutrophilic airway inflammation through the stimulant effect of IL-8 and IL-6 release and also potentiate the TLR3-mediated innate immunity in airway diseases.     

Sarcomere length nanometry in rat neonatal cardiomyocytes expressed with α-actinin–AcGFP in Z discs

Nanometry is widely used in biological sciences to analyze the movement of molecules or molecular assemblies in cells and in vivo. In cardiac muscle, a change in sarcomere length (SL) by a mere ∼100 nm causes a substantial change in contractility, indicating the need for the simultaneous measurement of SL and intracellular Ca²⁺ concentration ([Ca²⁺]_i) in cardiomyocytes at high spatial and temporal resolution. To accurately analyze the motion of individual sarcomeres with nanometer precision during excitation–contraction coupling, we applied nanometry techniques to primary-cultured rat neonatal cardiomyocytes. First, we developed an experimental system for simultaneous nanoscale analysis of single sarcomere dynamics and [Ca²⁺]_i changes via the expression of AcGFP in Z discs. We found that the averaging of the lengths of sarcomeres along the myocyte, a method generally used in today’s myocardial research, caused marked underestimation of sarcomere lengthening speed because of the superpositioning of different timings for lengthening between sequentially connected sarcomeres. Then, we found that after treatment with ionomycin, neonatal myocytes exhibited spontaneous sarcomeric oscillations (cell-SPOCs) at partial activation with blockage of sarcoplasmic reticulum functions, and the waveform properties were indistinguishable from those obtained in electric field stimulation. The myosin activator omecamtiv mecarbil markedly enhanced Z-disc displacement during cell-SPOC. Finally, we interpreted the present experimental findings in the framework of our mathematical model of SPOCs. The present experimental system has a broad range of application possibilities for unveiling single sarcomere dynamics during excitation–contraction coupling in cardiomyocytes under various settings.     

Comparison of cytochrome P-450 species which catalyze the hydroxylations of the aromatic ring of estradiol and estradiol 17-sulfate

For identification of microsomal cytochrome P-450 (P-450) enzymes which catalyze 2- or 4-hydroxylations of estrogens in the rat liver, estradiol (E₂) and estradiol 17-sulfate (E₂-17-S) were selected as the substrates and incubated with various kinds of purified P-450 enzymes: PB-1, PB-2, PB-4 and PB-5 obtained from phenobarbital-treated male rats (Sprague-Dawley); MC-1 and MC-5 from 3-methylcholanthrene-treated male rats; and UT-1, UT-2, UT-4 and UT-5 from untreated animals. The reactions were carried out under the P-450-reconstructed system, and the resulting products were determined by HPLC using electrochemical detection. All the enzymes tested were shown to have varying degrees of catalytic activities for 2-hydroxylation of the two substrates; UT-1 and UT-2 had the highest activity. Of the induced P-450 enzymes, PB-2 and MC-1 showed fairly high catalytic activity for 4-hydroxylation of E₂. The P-450 enzymes obtained from the untreated male rats, especially UT-4, showed the highest catalytic activity for 4-hydroxylation of the two substrates. From these results and also from kinetic experiments, the P-450 enzymes which catalyze 2- and 4-hydroxylations of estrogen were considered to be different species. A part of E₂ was converted to such metabolites as estrone and those having a hydroxyl group at positions 6β, 15 or 16, each production of which was estimated to be catalyzed by single or multiple P-450s.     

Immunohistochemical distribution of simple-epithelial-type keratins and other intermediate filament proteins in the developing human pituitary gland

Summary An immunohistochemical study of the production of the intermediate filaments [vimentin, cytokeratin, and glial filament acidic protein (GFAP)] during development of the pituitary gland was made by use of fetal and adult human pituitary tissue. Among these intermediate filament proteins in the anterior and intermediate lobes of the pituitary, cytokeratin is the first to appear, followed by GFAP and vimentin. However, only cytokeratin is seen during the period of morphogenesis of the pituitary gland, with the type-II subfamily cytokeratin 8 being the earliest to appear. Among the simple-epithelial-type cytokeratins, cytokeratins 8 and 19 were observed within the pituitary primordium during morphogenesis. Cells immunoreactive for cytokeratins 8 and 19 showed a heterogeneous three-dimensional distribution pattern in Rathke's pouch. Both cytokeratins 8 and 19 tended to be strongly positive at sites in the pituitary primordium where cells had become more loosely arranged (i.e., areas far from the diencephalon) but were only weakly positive in areas in which the epithelial cells were densely packed (i.e., areas closely associated with the diencephalon). It is concluded that, during the period of morphogenesis, Rathke's pouch has the intermediate filaments characteristic of simple epithelium and shows different immunoreactivity for simple-epithelial-type cytokeratins from place to place according to the extent of cellular differentiation.     

Evidence of Chikungunya virus seroprevalence in Myanmar among dengue-suspected patients and healthy volunteers in 2013, 2015, and 2018

IntroductionChikungunya virus (CHIKV) is a mosquito-borne virus known to cause acute febrile illness associated with debilitating polyarthritis. In 2019, several institutions in Myanmar reported a CHIKV outbreak. There are no official reports of CHIKV cases between 2011 and 2018. Therefore, this study sought to determine the seroprevalence of CHIKV infection before the 2019 outbreak.MethodsA total of 1,544 serum samples were collected from healthy volunteers and patients with febrile illnesses in Yangon, Mandalay, and the Myeik district in 2013, 2015, and 2018. Participants ranged from one month to 65 years of age. Antibody screening was performed with in-house anti-CHIKV IgG and IgM ELISA. A neutralization assay was used as a confirmatory test.ResultsThe seroprevalence of anti-CHIKV IgM and anti-CHIKV IgG was 8.9% and 28.6%, respectively, with an overall seropositivity rate of 34.5%. A focus reduction neutralization assay confirmed 32.5% seroprevalence of CHIKV in the study population. Age, health status, and region were significantly associated with neutralizing antibodies (NAbs) and CHIKV seropositivity (p < 0.05), while gender was not (p = 0.9). Seroprevalence in 2013, 2015, and 2018 was 32.1%, 28.8%, and 37.3%, respectively. Of the clinical symptoms observed in participants with fevers, arthralgia was mainly noted in CHIKV-seropositive patients.ConclusionThe findings in this study reveal the circulation of CHIKV in Myanmar’s Mandalay, Yangon, and Myeik regions before the 2019 CHIKV outbreak. As no treatment or vaccine for CHIKV exists, the virus must be monitored through systematic surveillance in Myanmar.