Melanin-concentrating hormone is the cognate ligand for the orphan G-protein-coupled receptor SLC-1

The underlying causes of obesity are poorly understood but probably involve complex interactions between many neurotransmitter and neuropeptide systems involved in the regulation of food intake and energy balance. Three pieces of evidence indicate that the neuropeptide melanin-concentrating hormone (MCH) is an important component of this system. First, MCH stimulates feeding when injected directly into rat brains; second, the messenger RNA for the MCH precursor is upregulated in the hypothalamus of genetically obese mice and in fasted animals; and third, mice lacking MCH eat less and are lean. MCH antagonists might, therefore, provide a treatment for obesity. However, the development of such molecules has been hampered because the identity of the MCH receptor has been unknown until now. Here we show that the 353-amino-acid human orphan G-protein-coupled receptor SLC-1 expressed in HEK293 cells binds MCH with sub-nanomolar affinity, and is stimulated by MCH to mobilize intracellular Ca2+ and reduce forskolin-elevated cyclic AMP levels. We also show that SLC-1 messenger RNA and protein is expressed in the ventromedial and dorsomedial nuclei of the hypothalamus, consistent with a role for SLC-1 in mediating the effects of MCH on feeding.

Crystal structure of the 14-3-3zeta:serotonin N-acetyltransferase complex. a role for scaffolding in enzyme regulation

Serotonin N-acetyltransferase (AANAT) controls the daily rhythm in melatonin synthesis. When isolated from tissue, AANAT copurifies with isoforms epsilon and zeta of 14-3-3. We have determined the structure of AANAT bound to 14-3-3zeta, an association that is phosphorylation dependent. AANAT is bound in the central channel of the 14-3-3zeta dimer, and is held in place by extensive interactions both with the amphipathic phosphopeptide binding groove of 14-3-3zeta and with other parts of the central channel. Thermodynamic and activity measurements, together with crystallographic analysis, indicate that binding of AANAT by 14-3-3zeta modulates AANAT's activity and affinity for its substrates by stabilizing a region of AANAT involved in substrate binding.

Insulin activates a tyrosine-specific protein kinase in extracts of 3T3-L1 adipocytes and human placenta

Insulin activates a tyrosine-specific cAMP-independent protein kinase when added directly to detergent extracts of differentiated 3T3-L1 adipocytes and humal placental membranes. The kinase is also activated by antibody to the insulin receptor and, to a lesser extent, by proinsulin. It catalyzes the phosphorylation of the 92,000-dalton component of the insulin receptor, histone, and casein; in each case, tyrosine is the principal amino acid modified. Under the conditions used to activate the kinase, insulin does not affect the rate of dephosphorylation of the receptor or of histone. The insulin-activated kinase is copurified with the human placental insulin receptor until the final elution from insulin-Sepharose. It remains to be established whether the kinase and the insulin receptor are separate molecules.

Bioeffects of microwave--a brief review

Since the 18th century scientists have been intrigued by the interaction of electromagnetic fields (EMFs) and various life processes. Attention has been focussed on EMFs in different frequency ranges, of which microwave frequency range forms an important part. Microwaves are part of the electromagnetic spectrum and are considered to be that radiation ranging in frequency from 300 million cycles per second (300 MHz) to 300 billion cycles per second (300 GHz), which correspond to a wavelength range of 1 m down to 1 mm. This nonionising electromagnetic radiation is absorbed at molecular level and manifests as changes in vibrational energy of the molecules or heat (Microwaves irradiating the community, Hidden hazards, Bantan Books publisher, Australia, 1991). Identifying and evaluating the biological effects of microwaves have been complex and controversial. Because of the paucity of information on the mechanism of interaction between microwave and biological systems, there has been a persistent view in physical and engineering sciences, that microwave fields are incapable of inducing bioeffects other than by heating (Health Physics 61 (1991) 3). Of late, the nonthermal effects of microwaves on tissue responses are being documented (Physiol. Rev. 61 (1981) 435; Annals of New York Acad. Sci. 247 (1975) 232; J. Microwave Power 14 (1979) 351; Bioelectromagnetics 7 (1986a) 45; Bioelectromagnetics 7 (1986b) 315; Biologic Effects and Health Hazards of Microwave Radiation, Warsaw, Polish Medical Publication (1974) 289; Biologic Effects and Health hazards of the microwave Radiation, Warsaw, Polish Medical Publication (1974) 22; Multidisciplinory perspectives in event-related brain potential research, Washington DC, US Environmental Protection Agency, (1978) 444). The present article is an attempt to familiarise the reader with pertinent information regarding the effects, mainly athermal, of microwave irradiation on biologic systems, especially microorganisms.

Role of a pineal cAMP-operated arylalkylamine N-acetyltransferase/14-3-3-binding switch in melatonin synthesis

The daily rhythm in melatonin levels is controlled by cAMP through actions on the penultimate enzyme in melatonin synthesis, arylalkylamine N-acetyltransferase (AANAT; serotonin N-acetyltransferase, EC ). Results presented here describe a regulatory/binding sequence in AANAT that encodes a cAMP-operated binding switch through which cAMP-regulated protein kinase-catalyzed phosphorylation [RRHTLPAN --> RRHpTLPAN] promotes formation of a complex with 14-3-3 proteins. Formation of this AANAT/14-3-3 complex enhances melatonin production by shielding AANAT from dephosphorylation and/or proteolysis and by decreasing the K(m) for 5-hydroxytryptamine (serotonin). Similar switches could play a role in cAMP signal transduction in other biological systems.

Weight loss associated with sodium-glucose cotransporter-2 inhibition: a review of evidence and underlying mechanisms

With their novel, insulin-independent mechanism, sodium-glucose cotransporter-2 (SGLT2) inhibitors are a major turning point in the management of type 2 diabetes mellitus. At present, there are several SGLT2 inhibitors available or in development, and these oral anti-hyperglycaemic agents lower plasma glucose through the inhibition of SGLT2-mediated reuptake of filtered glucose in the kidney. This unique mechanism of action is also expected to result in other beneficial effects, such as weight loss and blood pressure reduction. In various studies, including randomized controlled trials and real-world studies, patients treated with SGLT2 inhibitors have reported weight loss of around 1 to 3 kg. This review describes the characteristics of weight loss associated with SGLT2 inhibitor therapy, the clinical factors affecting SGLT2 inhibitor-associated weight loss and the possible underlying mechanisms of SGLT2 inhibitor-associated weight loss, including changes in metabolism and body composition, and the role of a reduction in insulin dose and compensatory hyperphagia. Understanding the weight loss effect of SGLT2 inhibitors, its related factors and underlying mechanisms can aid clinicians in optimal treatment decision-making, provide valuable insight on both obesity and diabetes management and reveal areas of future research and new therapeutic options.

Event generator tunes obtained from underlying event and multiparton scattering measurements

New sets of parameters ("tunes") for the underlying-event (UE) modelling of the pythia8, pythia6 and herwig++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton-proton ([Formula: see text]) data at [Formula: see text] and to UE proton-antiproton ([Formula: see text]) data from the CDF experiment at lower [Formula: see text], are used to study the UE models and constrain their parameters, providing thereby improved predictions for proton-proton collisions at 13[Formula: see text]. In addition, it is investigated whether the values of the parameters obtained from fits to UE observables are consistent with the values determined from fitting observables sensitive to double-parton scattering processes. Finally, comparisons are presented of the UE tunes to "minimum bias" (MB) events, multijet, and Drell-Yan ([Formula: see text] lepton-antilepton+jets) observables at 7 and 8[Formula: see text], as well as predictions for MB and UE observables at 13[Formula: see text].

Amivantamab plus chemotherapy with and without lazertinib in EGFR-mutant advanced NSCLC after disease progression on osimertinib: primary results from the phase III MARIPOSA-2 study

BACKGROUND

Amivantamab plus carboplatin-pemetrexed (chemotherapy) with and without lazertinib demonstrated antitumor activity in patients with refractory epidermal growth factor receptor (EGFR)-mutated advanced non-small-cell lung cancer (NSCLC) in phase I studies. These combinations were evaluated in a global phase III trial.

PATIENTS AND METHODS

A total of 657 patients with EGFR-mutated (exon 19 deletions or L858R) locally advanced or metastatic NSCLC after disease progression on osimertinib were randomized 2 : 2 : 1 to receive amivantamab-lazertinib-chemotherapy, chemotherapy, or amivantamab-chemotherapy. The dual primary endpoints were progression-free survival (PFS) of amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy. During the study, hematologic toxicities observed in the amivantamab-lazertinib-chemotherapy arm necessitated a regimen change to start lazertinib after carboplatin completion.

RESULTS

All baseline characteristics were well balanced across the three arms, including by history of brain metastases and prior brain radiation. PFS was significantly longer for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy [hazard ratio (HR) for disease progression or death 0.48 and 0.44, respectively; P < 0.001 for both; median of 6.3 and 8.3 versus 4.2 months, respectively]. Consistent PFS results were seen by investigator assessment (HR for disease progression or death 0.41 and 0.38 for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy, respectively; P < 0.001 for both; median of 8.2 and 8.3 versus 4.2 months, respectively). Objective response rate was significantly higher for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy (64% and 63% versus 36%, respectively; P < 0.001 for both). Median intracranial PFS was 12.5 and 12.8 versus 8.3 months for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy (HR for intracranial disease progression or death 0.55 and 0.58, respectively). Predominant adverse events (AEs) in the amivantamab-containing regimens were hematologic, EGFR-, and MET-related toxicities. Amivantamab-chemotherapy had lower rates of hematologic AEs than amivantamab-lazertinib-chemotherapy.

CONCLUSIONS

Amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy improved PFS and intracranial PFS versus chemotherapy in a population with limited options after disease progression on osimertinib. Longer follow-up is needed for the modified amivantamab-lazertinib-chemotherapy regimen.

Performance of the ATLAS trigger system in 2015

During 2015 the ATLAS experiment recorded [Formula: see text] of proton-proton collision data at a centre-of-mass energy of [Formula: see text]. The ATLAS trigger system is a crucial component of the experiment, responsible for selecting events of interest at a recording rate of approximately 1 kHz from up to 40 MHz of collisions. This paper presents a short overview of the changes to the trigger and data acquisition systems during the first long shutdown of the LHC and shows the performance of the trigger system and its components based on the 2015 proton-proton collision data.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.

Analysis of T-cell proliferation and cytokine secretion in the individuals exposed to arsenic

Over six million people in nine districts of West Bengal, India are exposed to very high levels of arsenic primarily through their drinking water. More than 300,000 people showed arsenic-induced skin lesions in these districts. This is regarded as the greatest arsenic calamity in the world. Chronic arsenicosis causes varied dermatological signs ranging from pigmentation changes, hyperkeratosis to non-melanocytic cancer of skin, and also malignancies in different internal organs. Higher incidences of opportunistic infections are found in the arsenic-exposed individuals, indicating that their immune systems may be impaired somehow. We have thus investigated the effect of arsenic on T-cell proliferation and cytokine secretion in 20 individuals with arsenic-induced skin lesions and compared the results with 18 arsenic-unexposed individuals. A marked dose-dependent suppression of Concanavalin A (Con A) induced T-cell proliferation was observed in the arsenic-exposed individuals compared with the unexposed ( P < 0.001) individuals. This correlated with a significant decrease in the levels of secreted cytokines by the T cells (TNF-α, IFN-γ, IL2, IL10, IL5, and IL4) in the exposed individuals ( P < 0.001). Thus it can be inferred that arsenic exposure can cause immunosuppression in humans.

Production of monoclonal antibodies in COS and CHO cells

Recent advances in the generation of genetically engineered monoclonal antibodies have enhanced the importance of COS cells as expression systems for rapidly producing sufficient quantities of these proteins for preliminary biochemical and biophysical analysis. In order to meet the demand for clinical supplies, a gradual increase has occurred in the usage of dihydrofolate reductase negative (DHFR-) Chinese hamster ovary (CHO) cells for large-scale antibody production. Using a variety of mammalian expression vectors and selection/amplification protocols, CHO cell lines capable of producing monoclonal antibodies at levels exceeding 1 gl-1 can now be obtained in an almost routine fashion. For the applications of monoclonal antibodies to expand into additional therapeutic areas, however, a 5-10-fold increase over current highest expression levels may still need to be achieved.

Cell cycle regulation of mouse H3 histone mRNA metabolism

The mechanisms responsible for the periodic accumulation and decay of histone mRNA in the mammalian cell cycle were investigated in mouse erythroleukemia cells, using a cloned mouse H3 histone gene probe that hybridizes with most or all H3 transcripts. Exponentially growing cells were fractionated into cell cycle-specific stages by centrifugal elutriation, a method for purifying cells at each stage of the cycle without the use of treatments that arrest growth. Measurements of H3 histone mRNA content throughout the cell cycle show that the mRNA accumulates gradually during S phase, achieving its highest value in mid-S phase when DNA synthesis is maximal. The mRNA content then decreases as cells approach G2. These results demonstrate that the periodic synthesis of histones during S phase is due to changes in the steady-state level of histone mRNA. They are consistent with the conventional view in which histone synthesis is regulated coordinately with DNA synthesis in the cell cycle. The periodic accumulation and decay of H3 histone mRNA appear to be controlled primarily by changes in the rate of appearance of newly synthesized mRNA in the cytoplasm, determined by pulse-labeling whole cells with [3H]uridine. Measurements of H3 mRNA turnover by pulse-chase experiments with cells in S and G2 did not provide evidence for changes in the cytoplasmic stability of the mRNA during the period of its decay in late S and G2. Furthermore, transcription measurements carried out by brief pulse-labeling in vivo and by in vitro transcription in isolated nuclei indicate that the rate of H3 gene transcription changes to a much smaller extent than the steady-state levels of the mRNA or the appearance of newly synthesized mRNA in the cytoplasm. The results suggest that post-transcriptional processes make an important contribution to the periodic accumulation and decay of histone mRNA and that these processes may operate within the nucleus.

A comparative study of nitroglycerin and propranolol

The action of sublingual nitroglycerin (0.6 mg) and intravenous propranolol (0.1 mg/kg) on shortening of right ventricular fibers was investigated in patients with and without coronary artery disease. This was accomplished with a newly devised strain gauge catheter. Hemodynamic parameters and changes in the oxidation-reduction potential of heart muscle were determined. Nitroglycerin results in decrease in shortening and velocity of shortening of ventricular fibers, heart rate, left ventricular end-diastolic and systemic pressure, dp/dt, tension-time index, stroke index, peripheral resistance, and left ventricular minute work in normal and arteriosclerotic subjects. Intravenous propranolol leads to a fall in velocity of shortening of myocardial fibers, heart rate, dp/dt, stroke index, and left ventricular minute work. However, there is an increase in tension-time index and peripheral resistance with no change in systemic pressure. Left ventricular end-diastolic pressure rises significantly in arteriosclerotic patients. The myocardial oxidation-reduction potential increases after nitroglycerin whereas it falls after propranolol in normal and arteriosclerotic patients.

Role of estradiol metabolism and CYP1A1 polymorphisms in breast cancer risk

The endogenous metabolism of estrogens is primarily oxidative and involves hydroxylation of the steroid at either C2 (2-OHE1) or C16 (16-OHE1). While the 2-OHE1 metabolites are essentially devoid of peripheral biological activity, 16-OHE1 is an estrogen agonist. There is evidence of an association between the 2-OHE1/16-OHE1 metabolites ratio and breast cancer risk. The CYP1A1 gene may play a role in the 2-hydroxylation (2-OH) of estradiol. African-American women with the wild-type CYP1A1 gene showed a significant increase in the 2-OHE1/16-OHE1 ratio, from 1.35 +/- 0.56 at baseline to 2.39 +/- 0.98 (p = 0.006) after 5 days of treatment with indole-3-carbinol (400 mg/day), a 2-OHE1 inducer. Women with the Msp1 polymorphism showed no significant increase, (0.37% +/- 0.17%). In a case-control study involving 57 women with breast cancer and 312 female controls, the frequency of the homozygous Msp1 polymorphism was 4.2% in African-American controls and 16% in African-American breast cancer cases. The odds ratio of breast cancer with the Msp1 homozygous variant was 8.4 (95% confidence interval: 1.7-41.7). This association was not observed in Caucasian women. The other CYP1A1 polymorphisms were not associated with breast cancer. The CYP1A1 Msp1 polymorphism may be a marker of altered estradiol metabolism and of increased susceptibility to estrogen-related breast cancer in African-Americans.

Heavy chain dimers as well as complete antibodies are efficiently formed and secreted from Drosophila via a BiP-mediated pathway

We have constructed a stable Drosophila cell line co-expressing heavy chain (HC) and light chain (LC) immunoglobulins of a humanized monoclonal antibody (mAb) that recognizes the F antigen of respiratory syncytial virus (Tempest, P. R., Bremmer, P., Lambert, M., Taylor, G., Furze, J. M., Carr, F. J., and Harris, W. J. (1991) Bio/Technology 9, 266-271. These cells efficiently secrete antibody with substrate binding activity indistinguishable from that produced from vertebrate cell lines. Significantly, the Drosophila homologue of the immunoglobulin binding chaperone protein (BiP), hsc72, was found to interact specifically with the immunoglobulin HC in an ATP-dependent fashion, similar to the BiP-HC interaction known to occur in vertebrate cells. This is, in fact, the first substrate ever shown to interact specifically with Drosophila hsc72. Most surprisingly, expression of heavy chains in the absence of LC led to the efficient secretion of heavy chain dimers. Moreover, this secretion occurred in association with hsc72. This dramatically contrasts with what is seen in vertebrate cells where in the absence of LC, HC remains sequestered inside the cell in stable association with BiP. Our results clearly suggest that Drosophila BiP can substitute for its mammalian counterpart and chaperone the secretion of active IgG. However, the finding that Drosophila BiP can also uniquely chaperone heavy chain dimers indicates mechanistic differences that may relate to the evolved need for retaining immature IgGs in vertebrates.

Modulation of TEL transcription activity by interaction with the ubiquitin-conjugating enzyme UBC9

The E-26 transforming specific (ETS)-related gene TEL, also known as ETV6, is involved in a large number of chromosomal rearrangements associated with leukemia and congenital fibrosarcoma. The encoded protein contains two functional domains: a helix-loop-helix (HLH) domain (also known as pointed domain) located at the N terminus and a DNA-binding domain located at the C terminus. The HLH domain is involved in protein-protein interaction with itself and other members of the ETS family of transcription factors such as FLI1. TEL is a transcription factor, and we and others have shown that it is a repressor of gene expression. To understand further the role of TEL in the cell, we have used an in vivo interaction system to identify proteins that interact with TEL. We show that a protein, UBC9, interacts specifically with TEL in vitro and in vivo. UBC9 is a member of the family of ubiquitin-conjugating enzymes. These enzymes usually are involved in proteosome-mediated degradation; however, our data suggest that interaction of TEL with UBC9 does not lead to TEL degradation. Our studies show that UBC9 binds to TEL exclusively through the HLH domain of TEL. We also show that TEL expressed as fusion to the DNA-binding domain of Gal4 completely represses a Gal4-responsive promoter, but that the coexpression of UBC9 in the same system restores the activity of the promoter. Targeted point mutation of conserved amino acids in UBC9 essential for enzymatic ubiquitination of proteins does not affect interaction nor transcriptional activity. Based on our data, we conclude that UBC9 physically interacts with TEL through the HLH domain and that the interaction leads to modulation of the transcription activity of TEL.

Characterization of cDNA for the large subunit of the transcription initiation factor TFIIF

At least six chromatographically resolvable general transcription factors may participate in accurate initiation by RNA polymerase II in HeLa cell-derived systems. TFIIF (also termed FC, RAP30/74 and beta/gamma) can bind directly to RNA polymerase II in solution and decrease the affinity of RNA polymerase II for nonspecific DNA. From studies on the kinetics of transcription initiation, on the composition of transcription initiation complexes fractionated by acrylamide gel electrophoresis, and on template competition experiments, TFIIF is known to act at an intermediate stage in initiation complex formation. It acts after TFIID firmly associates with DNA, but coincidentally with or immediately after RNA polymerase II binding to DNA, and before the recruitment of factor TFIIE. TFIIF may or may not have DNA helicase activity. The small subunit (RAP30) of TFIIF has been cloned and shows some amino-acid sequence homology to bacterial sigma factors. We have partially sequenced the RAP74 protein from purified HeLa cells, cloned its complementary DNA and shown that its translation product can interact with RAP30 in vitro as well as in vivo. The cDNA predicts an amino-acid sequence that lacks obvious DNA or RNA helicase motifs. It has regions rich in charged amino acids, including segments containing a higher content of acidic amino acids than are found in strong transcriptional activators such as VP16.