Dopamine receptor type 2 (DRD2) agonists are the first-choice treatment for prolactin-secreting pituitary tumors but are poorly effective in nonfunctioning pituitary neuroendocrine tumors ...(NF-PitNETs). DRD2 reduces AKT phosphorylation in lactotrophs, but no data are available in NF-PitNETs. DRD2 effects on AKT are mediated by a β-arrestin 2-dependent mechanism in mouse striatum. The aim of this study was to investigate DRD2 effects on AKT phosphorylation and cell proliferation in human primary cultured NF-PitNET cells and in rat tumoral lactotroph cells MMQ, and to test β-arrestin 2 involvement. We found that the DRD2 agonist BIM53097 induced a reduction of the p-AKT/total-AKT ratio in MMQ (-32.8 ± 17.6%, p < 0.001 vs. basal) and in a subset (n = 15/41, 36.6%) of NF-PitNETs (subgroup 1). In the remaining NF-PitNETs (subgroup 2), BIM53097 induced an increase in p-AKT. The ability of BIM53097 to reduce p-AKT correlated with its antimitotic effect, since the majority of subgroup 1 NF-PitNETs was responsive to BIM53097, and nearly all subgroup 2 NF-PitNETs were resistant. β-Arrestin 2 was expressed in MMQ and in 80% of subgroup 1 NF-PitNETs, whereas it was undetectable in 77% of subgroup 2 NF-PitNETs. In MMQ, β-arrestin 2 silencing prevented DRD2 inhibitory effects on p-AKT and cell proliferation. Accordingly, β-arrestin 2 transfection in subgroup 2 NF-PitNETs conferred to BIM53097 the ability to inhibit both p-AKT and cell growth. In conclusion, we demonstrated that β-arrestin 2 is required for DRD2 inhibitory effects on AKT phosphorylation and cell proliferation in MMQ and NF-PitNETs, paving the way for a potential role of β-arrestin 2 as a biomarker predicting NF-PitNETs' responsiveness to treatment with dopamine agonists.
Leber's hereditary optic neuropathy (LHON) is a maternally inherited blinding disease due to mitochondrial DNA (mtDNA) point mutations in complex I subunit genes, whose incomplete penetrance has been ...attributed to both genetic and environmental factors. Indeed, the mtDNA background defined as haplogroup J is known to increase the penetrance of the 11778/ND4 and 14484/ND6 mutations. Recently it was also documented that the professional exposure to n-hexane might act as an exogenous trigger for LHON. Therefore, we here investigate the effect of the n-hexane neurotoxic metabolite 2,5-hexanedione (2,5-HD) on cell viability and mitochondrial function of different cell models (cybrids and fibroblasts) carrying the LHON mutations on different mtDNA haplogroups. The viability of control and LHON cybrids and fibroblasts, whose mtDNAs were completely sequenced, was assessed using the MTT assay. Mitochondrial ATP synthesis rate driven by complex I substrates was determined with the luciferine/luciferase method. Incubation with 2,5-HD caused the maximal loss of viability in control and LHON cells. The toxic effect of this compound was similar in control cells irrespective of the mtDNA background. On the contrary, sensitivity to 2,5-HD induced cell death was greatly increased in LHON cells carrying the 11778/ND4 or the 14484/ND6 mutation on haplogroup J, whereas the 11778/ND4 mutation in association with haplogroups U and H significantly improved cell survival. The 11778/ND4 mutation on haplogroup U was also more resistant to inhibition of complex I dependent ATP synthesis by 2,5-HD. In conclusion, this study shows that mtDNA haplogroups modulate the response of LHON cells to 2,5-HD. In particular, haplogroup J makes cells more sensitive to its toxic effect. This is the first evidence that an mtDNA background plays a role by interacting with an environmental factor and that 2,5-HD may be a risk element for visual loss in LHON. This proof of principle has broad implications for other neurodegenerative disorders such as Parkinson's disease.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cushing’s disease (CD) is a rare endocrine disorder caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary tumor. Pasireotide is the only pituitary-targeted drug approved for adult ...patients. Nevertheless, many side effects are encountered and curative therapy is still challenging. Ubiquitin-specific peptidase 8 (USP8) plays a crucial role in the modulation of corticotroph cells growth and ACTH secretion. Here, we explored the anticancer potential of the USP8 inhibitor RA-9 in USP8-WT human tumor corticotroph cells and murine AtT-20 cells. Our results showed that RA-9 causes cell proliferation decrease (−24.3 ± 5.2%, P < 0.01) and cell apoptosis increase (207.4 ± 75.3%, P < 0.05) in AtT-20 cells, as observed with pasireotide. Moreover, RA-9 reduced ACTH secretion in AtT-20 cells (−34.1 ± 19.5%, P < 0.01), as well as in AtT-20 cells transfected with USP8 mutants, and in one out of two primary cultures in vitro responsive to pasireotide (−40.3 ± 6%). An RA-9 mediated decrease of pERK1/2 levels was observed in AtT-20 cells (−52.3 ± 13.4%, P < 0.001), comparable to pasireotide, and in primary cultures, regardless of their in vitro responsiveness to pasireotide. Upregulation of p27 was detected upon RA-9 treatment only, both in AtT-20 cells (167.1 ± 36.7%, P < 0.05) and in one primary culture tested (168.4%), whilst pCREB level was similarly halved in AtT-20 cells by both RA-9 and pasireotide. Altogether, our data demonstrate that RA-9 is efficient in exerting cytotoxic effects and inhibitory actions on cell proliferation and hormone secretion by modulating the expression of pERK1/2, pCREB and p27. Inhibition of USP8 might represent a novel strategy to target both USP8-WT and USP8-mutated tumors in CD patients.
We study the Riemann–Hilbert problem attached to an uncoupled BPS structure proposed by Bridgeland in (“Riemann–Hilbert problems from Donaldson–Thomas theory I”). We show that it has “essentially” ...unique meromorphic solutions given by a product of Gamma functions. We reconstruct the corresponding connection.
CHD8
represents one of the highest confidence genetic risk factors implied in Autism Spectrum Disorders, with most mutations leading to
CHD8
haploinsufficiency and the insurgence of specific ...phenotypes, such as macrocephaly, facial dysmorphisms, intellectual disability, and gastrointestinal complaints. While extensive studies have been conducted on the possible consequences of
CHD8
suppression and protein coding RNAs dysregulation during neuronal development, the effects of transcriptional changes of long non-coding RNAs (lncRNAs) remain unclear. In this study, we focused on a peculiar class of natural antisense lncRNAs, SINEUPs, that enhance translation of a target mRNA through the activity of two RNA domains, an embedded transposable element sequence and an antisense region. By looking at dysregulated transcripts following
CHD8
knock down (KD), we first identified
RAB11B-AS1
as a potential SINEUP RNA for its domain configuration. Then we demonstrated that such lncRNA is able to increase endogenous RAB11B protein amounts without affecting its transcriptional levels. RAB11B has a pivotal role in vesicular trafficking, and mutations on this gene correlate with intellectual disability and microcephaly. Thus, our study discloses an additional layer of molecular regulation which is altered by
CHD8
suppression. This represents the first experimental confirmation that naturally occurring SINEUP could be involved in ASD pathogenesis and underscores the importance of dysregulation of functional lncRNAs in neurodevelopment.
Integrative medicine is a holistic approach to health care that acknowledges multiple dimensions of health, including its physical, emotional, and spiritual aspects. It approaches health not just as ...absence of disease but as a state of optimal vitality, and utilizes all appropriate evidence-based modalities, including lifestyle interventions, complementary treatments, and conventional allopathic methods, in one paradigm. Utilization of non-conventional therapies by women and interest in integrative care is very high. Much disinformation exists and many women engage in non-conventional therapies without medical advice, sometimes benefiting from them, but also possibly delaying needed care or placing themselves at risk. Research and clinical interest in non-conventional methods also is rising within the medical community, with increased recognition of the value of an integrative health model for individuals and communities. Obstetrician–gynecologists are in a unique position to support their patients in holistic health optimization by choosing beneficial integrative strategies while identifying potentially harmful practices.
Cell growth and proliferation require coordinated ribosomal biogenesis and translation. Eukaryotic initiation factors (eIFs) control translation at the rate-limiting step of initiation. So far, only ...two eIFs connect extracellular stimuli to global translation rates: eIF4E acts in the eIF4F complex and regulates binding of capped messenger RNA to 40S subunits, downstream of growth factors, and eIF2 controls loading of the ternary complex on the 40S subunit and is inhibited on stress stimuli. No eIFs have been found to link extracellular stimuli to the activity of the large 60S ribosomal subunit. eIF6 binds 60S ribosomes precluding ribosome joining in vitro. However, studies in yeasts showed that eIF6 is required for ribosome biogenesis rather than translation. Here we show that mammalian eIF6 is required for efficient initiation of translation, in vivo. eIF6 null embryos are lethal at preimplantation. Heterozygous mice have 50% reduction of eIF6 levels in all tissues, and show reduced mass of hepatic and adipose tissues due to a lower number of cells and to impaired G1/S cell cycle progression. eIF6+/- cells retain sufficient nucleolar eIF6 and normal ribosome biogenesis. The liver of eIF6+/- mice displays an increase of 80S in polysomal profiles, indicating a defect in initiation of translation. Consistently, isolated hepatocytes have impaired insulin-stimulated translation. Heterozygous mouse embryonic fibroblasts recapitulate the organism phenotype and have normal ribosome biogenesis, reduced insulin-stimulated translation, and delayed G1/S phase progression. Furthermore, eIF6+/- cells are resistant to oncogene-induced transformation. Thus, eIF6 is the first eIF associated with the large 60S subunit that regulates translation in response to extracellular signals.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Somatostatin receptor ligands (SRLs) with high affinity for somatostatin receptors 2 and 5 (SSTR2 and SSTR5) are poorly efficacious in NF-PitNETs, expressing high levels of SSTR3. ITF2984 is a ...pan-SSTR ligand with high affinity for SSTR3, able to induce SSTR3 activation and to exert antitumoral activity in the MENX rat model. The aim of this study was to test ITF2984's antiproliferative and proapoptotic effects in NF-PitNET primary cultured cells derived from surgically removed human tumors and to characterize their SSTR expression profile. We treated cells derived from 23 NF-PitNETs with ITF2984, and a subset of them with octreotide, pasireotide (SRLs with high affinity for SSTR2 or 5, respectively), or cabergoline (DRD2 agonist) and we measured cell proliferation and apoptosis. SSTR3, SSTR2, and SSTR5 expression in tumor tissues was analyzed by qRT-PCR and Western blot. We demonstrated that ITF2984 reduced cell proliferation (-40.8 (17.08)%,
< 0.001 vs. basal,
= 19 NF-PitNETs) and increased cell apoptosis (+41.4 (22.1)%,
< 0.001 vs. basal,
= 17 NF-PitNETs) in all tumors tested, whereas the other drugs were only effective in some tumors. In our model, SSTR3 expression levels did not correlate with ITF2984 antiproliferative nor proapoptotic effects. In conclusion, our data support a possible use of ITF2984 in the pharmacological treatment of NF-PitNET.
Objective
The best approach to patients with adrenal incidentaloma (AI) and possible autonomous cortisol secretion (PACS) is debated. The aim of this study was to assess the metabolic effect of ...adrenalectomy in AI patients with PACS in relation to cortisol secretion parameters, peripheral activation, and glucocorticoid sensitivity.
Design
This is a multicenter randomized study (NCT number: NCT04860180).
Methods
Sixty-two AI outpatients (40–75 years) with AI >1 cm and cortisol after overnight dexamethasone suppression test (F-1mgDST) between 50 and 138 nmol/L were randomized to adrenalectomy (Arm A) or a conservative approach (Arm B). Fifty-five patients completed the 6-month follow-up, 25 patients in Arm A (17 female patients, aged 62.5 ± 10.4 years) and 30 patients in Arm B (24 female patients, 66.1 ± 9.1 years). Plasma adrenocorticotroph hormone (ACTH), 24-h urinary free cortisol, 24-h urinary free cortisone, F-1mgDST, glucose, lipids, glycated hemoglobin (HbA1c) levels, blood pressure (BP), body weight, and treatment variations were assessed. The 24-h urinary free cortisol/cortisone ratio (an 11-beta hydroxysteroid dehydrogenase type 2 activity marker), BclI, and the N363S variants of glucocorticoid receptor (GR) polymorphisms were also evaluated.
Results
BP control improved in 68% and 13% of the subjects in Arm A and Arm B, respectively (
p
= 0.001), and the glycometabolic control improved in 28% and 3.3% of the subjects in Arm A and Arm B patients, respectively (
p
= 0.02). Arm A subjects more rarely showed the BP and/or glycometabolic control worsening than Arm B patients (12% and 40%, respectively,
p
= 0.03). The surgical approach was independently associated with BP amelioration (OR 3.0, 95% CI 3.8–108.3,
p
< 0.001) but not with age, F-1mgDST levels, BMI, and hypertension and diabetes mellitus presence at baseline. The 24-h urinary free cortisol/cortisone ratio and the presence of sensitizing GR polymorphisms were not associated with the surgical outcome. The receiver operating characteristic (ROC) curve analysis showed that the BP control amelioration was associated with F-1mgDST area under the curve (AUC), 0.82 ± 0.09
p
= 0.012. The F-1mgDST cutoff with the best compromise in predicting the BP amelioration was set at 75 nmol/L (sensitivity 77%, specificity 75%).
Conclusions
AI patients with PACS benefit from surgery in terms of BP and glycometabolic control.
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