Gene expression in flow sorted mouse teratocarcinoma X human fibroblast heterokaryons

Abstract. Mouse teratocarcinoma cells and primary human fibroblasts were fluorescently labelled with fluorescein isothiocyanate (F1TC)- and trimethylrhodamine isothiocyanate (TR1TC)-stearylamine respectively. After fusion populations highly enriched for red-green heterokaryons (around 80%) were isolated from the fusion mixture using a FACS II cell sorter.
To study gene expression in the early hybrids [³⁵S] methionine-labelled proteins synthesized by the sorted cells at two and three days after fusion were analysed by two-dimensional gel electrophoresis. Three spots were denser in gels of the fused cells than in those of 1:1 mixtures of parental cells. For one of these proteins it could be demonstrated that this reflects the enhanced synthesis of a mouse-specific protein present only in small amounts in teratocarcinoma cells. All three proteins were synthesized in relatively large amounts by differentiated mouse cells.
Collagen (type I) synthesis by the sorted hybrid cells was studied by analysing the [³H] proline-labelled material secreted into the medium. Analysis by sodium dodecyl sulphate (SDS)-gel electrophoresis and two-dimensional non-equilibrium pH gradient electrophoresis showed that the material secreted by the fused cells five days after fusion was the same as that secreted by the human fibroblasts. No evidence was obtained for synthesis of mouse α2(I) collagen. The amount of collagen produced by the sorted cells five days after fusion was about half the amount produced by the human fibroblasts. Immunofluorescence studies also showed that collagen synthesis was not suppressed after fusion both in heterokaryons and synkaryons.
In conclusion, we did not find evidence for activation of a previously completely silent mouse gene in the fused cells. The results show, however, that the fused cells do resemble the differentiated fibroblasts rather than the undifferentiated teratocarcinoma cells.     

Mass spectrometry analyses of κ and λ fractions result in increased number of complementarity-determining region identifications

Sera from lung cancer patients contain antibodies against tumor-associated antigens. Specific amino acid sequences of the complementarity-determining regions (CDRs) in the antigen-binding fragment (Fab) of these antibodies have potential as lung cancer biomarkers. Detection and identification of CDRs by mass spectrometry can significantly be improved by reduction of the complexity of the immunoglobulin molecule. Our aim was to molecular dissect IgG into κ and λ fragments to reduce the complexity and thereby identify substantially more CDRs than by just total Fab isolation. We purified Fab, Fab-κ, Fab-λ, κ and λ light chains from serum from 10 stage I lung adenocarcinoma patients and 10 matched controls from the current and former smokers. After purification, the immunoglobulin fragments were enzymatically digested and measured by high-resolution mass spectrometry. Finally, we compared the number of CDRs identified in these immunoglobulin fragments with that in the Fab fragments. Twice as many CDRs were identified when Fab-κ, Fab-λ, κ and λ (3330) were combined than in the Fab fraction (1663) alone. The number of CDRs and κ:λ ratio was statistically similar in both cases and controls. Molecular dissection of IgG identifies significantly more CDRs, which increases the likelihood of finding lung cancer-related CDR sequences.     

Investigation of the transport of intact glutathione in human and rat type II pneumocytes

The aim of the study was to investigate whether there is transmembrane transport of intact glutathione ([³H]-GSH, 0.1 μCi) in rat and human type II pneumocytes (T2P), and if this transport might be dependent on the redox state of the extracellular fluid. The T2P were pretreated with acivicin (250 μM) to inhibit γ-glutamyl-transferase activity and with L-buthionine-[SR]-sulfoximine (1 mM) to inhibit intracellular GSH synthesis. After 48 h in culture, initial GSH influx rate was 0.70 ± 0.20 nmol/min/mg protein (37°C) and 0.35 ± 0.04 nmol/min/mg protein (4°C) during the first 5 min in rat T2P. In human T2P, the initial GSH influx rate was 0.36 ± 0.30 nmol/min/mg protein (37°C) and 0.32 ± 0.06 nmol/min/mg protein (4°C) during the first 10 min. Thereafter no further influx was found. The influx of 1 mM GSH in freshly isolated rat and human T2P in suspension was 2.3 ± 0.3 and 1.2 ± 0.3 nmol/mg protein after 15 min at 37°C, and 2.8 ± 0.2 and 1.0 ± 0.3 nmol/mg protein at 4°C, respectively. When GSH influx was studied at different concentrations between 0 and 40 mM, a linear increase without saturation or difference between 37°C and 4°C was found. Preexposure to ouabain had no effect on GSH influx. Efflux of GSH was stimulated and influx inhibited by preexposure of the cells to reduced thiols, while disulphides inhibited efflux and favoured inward uptake. Thus, in human and rat T2P a GSH-carrier exists which operates as an effluxer. At GSH concentrations in the physiological range no uptake is seen, but some uptake can be observed at GSH concentrations above normal physiological levels. The uptake appears to be energy-independent and non-saturable. Efflux of GSH is stimulated and influx inhibited by reduced thiols, while disulphides inhibit the efflux and favour inward uptake. GSH uptake in T2P thus may depend on concentration gradients and driving forces, such as the redox state of the extracellular fluid.     

Effects of a WHO-guided digital health intervention for depression in Syrian refugees in Lebanon: A randomized controlled trial

BackgroundMost displaced people with mental disorders in low- and middle-income countries do not receive effective care, and their access to care has deteriorated during the Coronavirus Disease 2019 (COVID-19) pandemic. Digital mental health interventions are scalable when digital access is adequate, and they can be safely delivered during the COVID-19 pandemic. We examined whether a new WHO-guided digital mental health intervention, Step-by-Step, in which participants were supported by a nonspecialist helper, was effective in reducing depression among displaced people in Lebanon.Methods and findingsWe conducted a single-blind, 2-arm pragmatic randomized clinical trial, comparing guided Step-by-Step with enhanced care as usual (ECAU) among displaced Syrians suffering from depression and impaired functioning in Lebanon. Primary outcomes were depression (Patient Health Questionnaire, PHQ-9) and impaired functioning (WHO Disability Assessment Schedule-12, WHODAS) at posttreatment. Secondary outcomes included subjective well-being, anxiety, post-traumatic stress, and self-described problems. A total of 569 displaced people from Syria with depression (PHQ-9 ≥ 10) and impaired functioning (WHODAS > 16) were randomized to Step-by-Step (N = 283; lost to follow-up: N = 167) or ECAU (N = 286; lost to follow-up: 133). Participants were considered to be lost to follow-up when they did not fill in the outcome measures at posttest or follow-up. Recruitment started on December 9, 2019 and was completed on July 9, 2020. The last follow-up assessments were collected in December 2020. The study team had access to the online platform, where they could see treatment arm assignment for each participant. All questionnaires were completed by participants online. Intention-to-treat (ITT) analyses showed intervention effects on depression (standardized mean differences [SMDs]: 0.48; 95% CI: 0.26; 0.70; p < 0.001), impaired functioning (SMD: 0.35; 95% CI: 0.14; 0.56; p < 0.001), post-traumatic stress (SMD: 0.36; 95% CI: 0.16; 0.56; p < 0.001), anxiety (SMD: 0.46; 95% CI: 0.24; 0.68; p < 0.001), subjective well-being (SMD: 0.47; 95% CI: 0.26; 0.68; p < 0.001), and self-identified personal problems (SMD: 0.49; 95% CI 0.28; 0.70; p < 0.001). Significant effects on all outcomes were maintained at 3 months follow-up. During the trial, one serious adverse event occurred, unrelated to the intervention. The main limitation of the current trial is the high dropout rate.ConclusionsIn this study, we found that a guided, digital intervention was effective in reducing depression in displaced people in Lebanon. The guided WHO Step-by-Step intervention we examined should be made available to communities of displaced people that have digital access.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03720769","term_id":"NCT03720769"}}NCT03720769.

In a randomized controlled trial, Pim Cuijpers and colleagues evaluate the effects of the Step-by-Step guided digital mental health intervention on depression, impaired functioning, and other mental health outcomes among displaced Syrians living in Lebanon.