RESUMEN
Background: Skeletal fragility is characterized by increased frequency of vertebral fractures (VFs) in acromegaly. Several trials were conducted to identify modifiable risk factors and predictors of VFs, with limited data on the prognostic role of GH receptor (GHR) isoforms. In this study, we investigated the potential role of GHR polymorphism on the occurrence of incidental VFs (i-VFs), in patients treated with second-line medical therapies. Methods: A longitudinal, retrospective, observational study was conducted on a cohort of 45 acromegalic patients not-responsive to first-generation somatostatin receptor ligands (fg-SRLs) and treated with GHR antagonist (Pegvisomant) or with the second-generation SRLs (Pasireotide long-acting release). Results: Second line treatments were Pegvisomant plus fg-SRLs in 26 patients and Pasireotide LAR in 19 patients. From the group treated with fg-SRLs+Peg-V, the fl-GHR isoform was identified in 18 patients (69.2%) and the d3-GHR isoform in 8 patients (30.8%). I-VFs arose exclusively in fl-GHR isoform carriers (p=0.039). From the group treated with Pasireotide LAR, the fl-GHR isoform was identified in 11 patients (57.9%), and the d3-GHR isoform in 8 patients (42.1%). I-VFs arose exclusively in d3-GHR isoform carriers (p=0.018). Patients with fl-GHR isoform had a higher risk for i-VFs if treated with fg-SRL+Peg-V (OR: 1.6 95%IC: 1.1-2.3, p=0.04), and a lower risk if treated with Pasi-LAR (OR: 0.26 IC95%: 0.11-0.66, p=0.038). Conclusions: Our data support a predictive role of the GHR isoforms for the occurrence of i-VFs in acromegalic patients treated with second-line drugs, tailored to the individual patient. The knowledge of the GHR polymorphism may facilitate the choice of second-line therapies, improving the therapeutic approach, in the context of personalized medicine.
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Acromegalia , Hormona de Crecimiento Humana , Receptores de Somatotropina , Somatostatina , Humanos , Acromegalia/tratamiento farmacológico , Masculino , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Proyectos Piloto , Receptores de Somatotropina/genética , Receptores de Somatotropina/metabolismo , Receptores de Somatotropina/antagonistas & inhibidores , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Adulto , Hormona de Crecimiento Humana/uso terapéutico , Hormona de Crecimiento Humana/metabolismo , Hormona de Crecimiento Humana/análogos & derivados , Anciano , Polimorfismo Genético , Estudios LongitudinalesRESUMEN
Sensory experiences and learning induce long-lasting changes in both excitatory and inhibitory synapses, thereby providing a crucial substrate for memory. However, the co-tuning of excitatory long-term potentiation (eLTP) or depression (eLTD) with the simultaneous changes at inhibitory synapses (iLTP/iLTD) remains unclear. Herein, we investigated the co-expression of NMDA-induced synaptic plasticity at excitatory and inhibitory synapses in hippocampal CA1 pyramidal cells (PCs) using a combination of electrophysiological, optogenetic, and pharmacological approaches. We found that inhibitory inputs from somatostatin (SST) and parvalbumin (PV)-positive interneurons onto CA1 PCs display input-specific long-term plastic changes following transient NMDA receptor activation. Notably, synapses from SST-positive interneurons consistently exhibited iLTP, irrespective of the direction of excitatory plasticity, whereas synapses from PV-positive interneurons predominantly showed iLTP concurrent with eLTP, rather than eLTD. As neuroplasticity is known to depend on the extracellular matrix, we tested the impact of metalloproteinases (MMP) inhibition. MMP3 blockade interfered with GABAergic plasticity for all inhibitory inputs, whereas MMP9 inhibition selectively blocked eLTP and iLTP in SST-CA1PC synapses co-occurring with eLTP but not eLTD. These findings demonstrate the dissociation of excitatory and inhibitory plasticity co-expression. We propose that these mechanisms of plasticity co-expression may be involved in maintaining excitation-inhibition balance and modulating neuronal integration modes.
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Interneuronas , Plasticidad Neuronal , Células Piramidales , Animales , Plasticidad Neuronal/fisiología , Interneuronas/metabolismo , Células Piramidales/metabolismo , Células Piramidales/fisiología , N-Metilaspartato/metabolismo , N-Metilaspartato/farmacología , Hipocampo/metabolismo , Hipocampo/fisiología , Parvalbúminas/metabolismo , Masculino , Ratones , Somatostatina/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapsis/metabolismo , Sinapsis/fisiología , Potenciación a Largo Plazo , Neuronas GABAérgicas/metabolismo , Neuronas GABAérgicas/efectos de los fármacos , Región CA1 Hipocampal/metabolismo , Región CA1 Hipocampal/fisiología , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/genéticaRESUMEN
We provide a brief (and unabashedly biased) overview of the pre-transcriptomic history of somatostatin interneuron taxonomy, followed by a chronological summary of the large-scale, NIH-supported effort over the last ten years to generate a comprehensive, single-cell RNA-seq-based taxonomy of cortical neurons. Focusing on somatostatin interneurons, we present the perspective of experimental neuroscientists trying to incorporate the new classification schemes into their own research while struggling to keep up with the ever-increasing number of proposed cell types, which seems to double every two years. We suggest that for experimental analysis, the most useful taxonomic level is the subdivision of somatostatin interneurons into ten or so "supertypes," which closely agrees with their more traditional classification by morphological, electrophysiological and neurochemical features. We argue that finer subdivisions ("t-types" or "clusters"), based on slight variations in gene expression profiles but lacking clear phenotypic differences, are less useful to researchers and may actually defeat the purpose of classifying neurons to begin with. We end by stressing the need for generating novel tools (mouse lines, viral vectors) for genetically targeting distinct supertypes for expression of fluorescent reporters, calcium sensors and excitatory or inhibitory opsins, allowing neuroscientists to chart the input and output synaptic connections of each proposed subtype, reveal the position they occupy in the cortical network and examine experimentally their roles in sensorimotor behaviors and cognitive brain functions.
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Interneuronas , Somatostatina , Animales , Somatostatina/metabolismo , Interneuronas/clasificación , Interneuronas/fisiología , Interneuronas/metabolismo , Interneuronas/citología , HumanosRESUMEN
Venomous animals have evolved diverse molecular mechanisms to incapacitate prey and defend against predators. Most venom components disrupt nervous, locomotor, and cardiovascular systems or cause tissue damage. The discovery that certain fish-hunting cone snails use weaponized insulins to induce hypoglycemic shock in prey highlights a unique example of toxins targeting glucose homeostasis. Here, we show that, in addition to insulins, the deadly fish hunter, Conus geographus, uses a selective somatostatin receptor 2 (SSTR2) agonist that blocks the release of the insulin-counteracting hormone glucagon, thereby exacerbating insulin-induced hypoglycemia in prey. The native toxin, Consomatin nG1, exists in several proteoforms with a minimized vertebrate somatostatin-like core motif connected to a heavily glycosylated N-terminal region. We demonstrate that the toxin's N-terminal tail closely mimics a glycosylated somatostatin from fish pancreas and is crucial for activating the fish SSTR2. Collectively, these findings provide a stunning example of chemical mimicry, highlight the combinatorial nature of venom components, and establish glucose homeostasis as an effective target for prey capture.
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Caracol Conus , Glucagón , Glucosa , Homeostasis , Insulina , Receptores de Somatostatina , Somatostatina , Animales , Somatostatina/metabolismo , Homeostasis/efectos de los fármacos , Insulina/metabolismo , Glucosa/metabolismo , Receptores de Somatostatina/metabolismo , Glucagón/metabolismo , Peces/metabolismo , Conducta Predatoria/efectos de los fármacos , Hipoglucemia/metabolismo , Venenos de Moluscos/metabolismo , Humanos , Imitación MolecularRESUMEN
AIMS: This study aimed to evaluate the effectiveness of somatostatin analogues (SA) for cystoid maculopathy (CM) in retinitis pigmentosa (RP) patients. MATERIALS AND METHODS: In this retrospective case series, clinical and imaging characteristics of 28 RP patients with CM, unresponsive to carbonic anhydrase inhibitors, were collected from medical charts. All patients received SA treatment as an alternative (octreotide long-acting release at 20 mg/month or 30 mg/month, or lanreotide at 90 mg/month or 120 mg/month). Outcome measures were mean reduction in foveal thickness (FT) and foveal volume (FV) and mean increase in best-corrected visual acuity at 3, 6 and 12 months of treatment initiation. Linear mixed models were used to calculate the effectiveness over time. RESULTS: 52 eyes of 28 RP patients were included; 39% were male. The median age at the start of treatment was 39 years (IQR 30-53). Median follow-up was 12 months (range 6-12). From baseline to 12 months, the mean FT decreased from 409±136 µm to 334±119 µm and the mean FV decreased from 0.31±0.10 mm3 to 0.25±0.04 mm3. Linear mixed model analyses showed a significant decrease in log FT and log FV at 3, 6 and 12 months after the start of treatment compared with baseline measurements (p<0.001, p<0.001, p<0.001). Mean best-corrected visual acuity did not increase significantly (0.46±0.35 logMAR to 0.45±0.38 logMAR after 12 months). DISCUSSION: SA may be an effective alternative treatment to reduce CM in RP patients.
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Retinitis Pigmentosa , Somatostatina , Tomografía de Coherencia Óptica , Agudeza Visual , Humanos , Retinitis Pigmentosa/tratamiento farmacológico , Masculino , Femenino , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Estudios Retrospectivos , Persona de Mediana Edad , Agudeza Visual/efectos de los fármacos , Adulto , Péptidos Cíclicos/uso terapéutico , Octreótido/uso terapéutico , Octreótido/administración & dosificación , Resultado del Tratamiento , Edema Macular/tratamiento farmacológico , Edema Macular/etiologíaRESUMEN
Neuropeptides, including tachykinins, CGRP, and somatostatin, are localized in a peptidergic subgroup of nociceptive primary afferent neurons. Tachykinins and CGRP are pronociceptive, somatostatin is an antinociceptive mediator. Intensive drug research has been performed to develop tachykinin and CGRP antagonists, and somatostatin agonists as analgesics. CGRP receptor antagonists are efficacious and well-tolerated drugs in migraine. Monoclonal antibodies against CGRP or its receptor are used for the prophylactic treatment of migraine. Tachykinin NK1 receptor antagonists failed as analgesics but are used for chemotherapy-induced nausea and vomiting. New, orally active somatostatin 4 receptor agonists are promising drug candidates for treating various pain conditions.
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Dolor Crónico , Neuropéptidos , Humanos , Animales , Dolor Crónico/tratamiento farmacológico , Neuropéptidos/metabolismo , Analgésicos/farmacología , Analgésicos/uso terapéutico , Receptores de Péptido Relacionado con el Gen de Calcitonina/metabolismo , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Taquicininas/metabolismo , Receptores de Somatostatina/metabolismo , Receptores de Somatostatina/antagonistas & inhibidoresRESUMEN
Aging-related biochemical changes in nerve cells lead to dysfunctional synapses and disrupted neuronal circuits, ultimately affecting vital processes such as brain plasticity, learning, and memory. The imbalance between excitation and inhibition in synaptic function during aging contributes to cognitive impairment, emphasizing the importance of compensatory mechanisms. Fear conditioning-related plasticity of the somatosensory barrel cortex, relying on the proper functioning and extensive up regulation of the GABAergic system, in particular interneurons containing somatostatin, is compromised in aging (one-year-old) mice. The present research explores two potential interventions, taurine supplementation, and environmental enrichment, revealing their effectiveness in supporting learning-induced plasticity in the aging mouse brain. They do not act through a mechanism normalizing the Glutamate/GABA balance that is disrupted in aging. Still, they allow for increased somatostatin levels, an effect observed in young animals after learning. These findings highlight the potential of lifestyle interventions and diet supplementation to mitigate age-related cognitive decline by promoting experience-dependent plasticity.
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Envejecimiento , Suplementos Dietéticos , Plasticidad Neuronal , Taurina , Animales , Plasticidad Neuronal/fisiología , Envejecimiento/fisiología , Taurina/metabolismo , Taurina/farmacología , Taurina/administración & dosificación , Ratones , Masculino , Somatostatina/metabolismo , Ratones Endogámicos C57BL , Aprendizaje/fisiología , Ambiente , Miedo/fisiología , Ácido gamma-Aminobutírico/metabolismo , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/prevención & control , Encéfalo/metabolismo , Encéfalo/fisiologíaRESUMEN
Medical treatment of acromegaly is generally positioned as a second line of treatment after pituitary adenoma surgery. With the rising availability and variety of medications for acromegaly increases our understanding of their effectiveness and safety. Volume of the published data on the impact of medical therapy on biochemical control of acromegaly, contrasts a relative lack of publications which comprehensively address pituitary tumor alterations under different drug modalities. Assessment of changes in GH-secreting adenoma volume is often overshadowed by clinicians' focus on GH and IGF-I levels during acromegaly treatment. Close analysis of studies published in the last two decades, reveals that both an increase and decrease in somatotropinoma volume are possible during treatment with any of available drugs for acromegaly. Changes in pituitary tumor size may arise from the biological nature of adenoma itself, independently of the administered medications. Therefore, an individual approach is necessary in the treatment of patients with acromegaly, based on repeated insight to their clinical, biochemical, pathological and imaging characteristics. In this review, we summarize and comment how pituitary tumor size is affected by the treatment with all currently available drugs in acromegaly: long-acting somatostatin receptor ligands of the first generation (octreotide LAR and lanreotide autogel) and the second generation (pasireotide-LAR), as well as pegvisomant (PEG) and cabergoline (CAB).
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Acromegalia , Humanos , Acromegalia/tratamiento farmacológico , Acromegalia/patología , Hormona de Crecimiento Humana/análogos & derivados , Hormona de Crecimiento Humana/uso terapéutico , Adenoma/tratamiento farmacológico , Adenoma/patología , Neoplasias Hipofisarias/tratamiento farmacológico , Neoplasias Hipofisarias/patología , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Adenoma Hipofisario Secretor de Hormona del Crecimiento/tratamiento farmacológico , Adenoma Hipofisario Secretor de Hormona del Crecimiento/patologíaRESUMEN
The brain functions as a prediction machine, utilizing an internal model of the world to anticipate sensations and the outcomes of our actions. Discrepancies between expected and actual events, referred to as prediction errors, are leveraged to update the internal model and guide our attention towards unexpected events1-10. Despite the importance of prediction-error signals for various neural computations across the brain, surprisingly little is known about the neural circuit mechanisms responsible for their implementation. Here we describe a thalamocortical disinhibitory circuit that is required for generating sensory prediction-error signals in mouse primary visual cortex (V1). We show that violating animals' predictions by an unexpected visual stimulus preferentially boosts responses of the layer 2/3 V1 neurons that are most selective for that stimulus. Prediction errors specifically amplify the unexpected visual input, rather than representing non-specific surprise or difference signals about how the visual input deviates from the animal's predictions. This selective amplification is implemented by a cooperative mechanism requiring thalamic input from the pulvinar and cortical vasoactive-intestinal-peptide-expressing (VIP) inhibitory interneurons. In response to prediction errors, VIP neurons inhibit a specific subpopulation of somatostatin-expressing inhibitory interneurons that gate excitatory pulvinar input to V1, resulting in specific pulvinar-driven response amplification of the most stimulus-selective neurons in V1. Therefore, the brain prioritizes unpredicted sensory information by selectively increasing the salience of unpredicted sensory features through the synergistic interaction of thalamic input and neocortical disinhibitory circuits.
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Interneuronas , Corteza Visual Primaria , Tálamo , Péptido Intestinal Vasoactivo , Animales , Ratones , Masculino , Péptido Intestinal Vasoactivo/metabolismo , Interneuronas/fisiología , Femenino , Tálamo/fisiología , Tálamo/citología , Corteza Visual Primaria/fisiología , Corteza Visual Primaria/citología , Pulvinar/fisiología , Pulvinar/citología , Modelos Neurológicos , Estimulación Luminosa , Inhibición Neural/fisiología , Somatostatina/metabolismo , Ratones Endogámicos C57BL , Corteza Visual/fisiología , Corteza Visual/citología , Vías Visuales/fisiologíaRESUMEN
Somatostatin (SST) is a peptide expressed in the peripheral and central nervous systems, as well as in endocrine and immune cells. The aim of the current study is to determine the percentage of SST immunoreactive (IR) neurons and their colocalization with choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), neuropeptide Y (NPY), and glial fibrillary acidic protein (GFAP) in the myenteric plexus (MP) and submucous plexus (SP) of the small intestine (SI) and large intestine (LI) of rats across different age groups from newborn to senescence using immunohistochemistry. In the MP of the SI and LI, the percentage of SST-IR neurons significantly increased during early postnatal development from 12 ± 2.4 (SI) and 13 ± 3.0 (LI) in newborn rats to 23 ± 1.5 (SI) and 18 ± 1.6 (LI) in 20-day-old animals, remaining stable until 60 days of age. The proportion of SST-IR cells then decreased in aged 2-year-old animals to 14 ± 2.0 (SI) and 10 ± 2.6 (LI). In the SP, the percentage of SST-IR neurons significantly rose from 22 ± 3.2 (SI) and 23 ± 1.7 (LI) in newborn rats to 42 ± 4.0 in 20-day-old animals (SI) and 32 ± 4.9 in 30-day-old animals (LI), before declining in aged 2-year-old animals to 21 ± 2.6 (SI) and 28 ± 7.4 (LI). Between birth and 60 days of age, 97-98% of SST-IR neurons in the MP and SP colocalized with ChAT in both plexuses of the SI and LI. The percentage of SST/ChAT neurons decreased in old rats to 85 ± 5.0 (SI) and 90 ± 3.8 (LI) in the MP and 89 ± 3.2 (SI) and 89 ± 1.6 (LI) in the SP. Conversely, in young rats, only a few SST-IR neurons colocalized with nNOS, but this percentage significantly increased in 2-year-old rats. The percentage of SST/NPY-IR neurons exhibited considerable variation throughout postnatal development, with no significant differences across different age groups in both the MP and SP of both intestines. No colocalization of SST with GFAP was observed in any of the studied animals. In conclusion, the expression of SST in enteric neurons increases in young rats and decreases in senescence, accompanied by changes in SST colocalization with ChAT and nNOS.
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Neuronas , Somatostatina , Animales , Ratas , Somatostatina/metabolismo , Somatostatina/análisis , Neuronas/metabolismo , Neuronas/citología , Masculino , Inmunohistoquímica , Ratas Sprague-Dawley , Animales Recién NacidosRESUMEN
The subiculum is a key region of the brain involved in the initiation of pathological activity in temporal lobe epilepsy, and local GABAergic inhibition is essential to prevent subicular-originated epileptiform discharges. Subicular pyramidal cells may be easily distinguished into two classes based on their different firing patterns. Here, we have compared the strength of the GABAa receptor-mediated inhibitory postsynaptic currents received by regular- vs. burst-firing subicular neurons and their dynamic modulation by the activation of µ opioid receptors. We have taken advantage of the sequential re-patching of the same cell to initially classify pyramidal neurons according to their firing patters, and then to measure GABAergic events triggered by the optogenetic stimulation of parvalbumin- and somatostatin-expressing interneurons. Activation of parvalbumin-expressing cells generated larger responses in postsynaptic burst-firing neurons whereas the opposite was observed for currents evoked by the stimulation of somatostatin-expressing interneurons. In all cases, events depended critically on ω-agatoxin IVA- but not on ω-conotoxin GVIA-sensitive calcium channels. Optogenetic GABAergic input originating from both parvalbumin- and somatostatin-expressing cells was reduced in amplitude following the exposure to a µ opioid receptor agonist. The kinetics of this pharmacological sensitivity was different in regular- vs. burst-firing neurons, but only when responses were evoked by the activation of parvalbumin-expressing neurons, whereas no differences were observed when somatostatin-expressing cells were stimulated. In conclusion, our results show that a high degree of complexity regulates the organizing principles of subicular GABAergic inhibition, with the interaction of pre- and postsynaptic diversity at multiple levels. KEY POINTS: Optogenetic stimulation of parvalbumin- and somatostatin-expressing interneurons (PVs and SOMs) triggers inhibitory postsynaptic currents (IPSCs) in both regular- and burst-firing (RFs and BFs) subicular pyramidal cells. The amplitude of optogenetically evoked IPSCs from PVs (PV-opto IPSCs) is larger in BFs whereas IPSCs generated by the light activation of SOMs (SOM-opto IPSCs) are larger in RFs. Both PV- and SOM-opto IPSCs critically depend on ω-agatoxin IVA-sensitive P/Q type voltage-gated calcium channels, whereas no major effects are observed following exposure to ω-conotoxin GVIA, suggesting no significant involvement of N-type channels. The amplitude of both PV- and SOM-opto IPSCs is reduced by the probable pharmacological activation of presynaptic µ opioid receptors, with a faster kinetics of the effect observed in PV-opto IPSCs from RFs vs. BFs, but not in SOM-opto IPSCs. These results help us understand the complex interactions between different layers of diversity regulating GABAergic input onto subicular microcircuits.
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Parvalbúminas , Células Piramidales , Somatostatina , Animales , Células Piramidales/fisiología , Ratones , Somatostatina/metabolismo , Parvalbúminas/metabolismo , Interneuronas/fisiología , Potenciales Postsinápticos Inhibidores , Masculino , Neuronas GABAérgicas/fisiología , Neuronas GABAérgicas/metabolismo , Hipocampo/fisiología , Hipocampo/citología , Optogenética , Receptores Opioides mu/metabolismo , Receptores Opioides mu/fisiología , Ratones Endogámicos C57BL , Femenino , Receptores de GABA-A/metabolismo , Receptores de GABA-A/fisiologíaRESUMEN
Engrams, which are cellular substrates of memory traces, have been identified in various brain areas, including the amygdala. While most identified engrams are composed of excitatory, glutamatergic neurons, GABAergic inhibitory engrams have been relatively overlooked. Here, we report the identification of an inhibitory engram in the central lateral amygdala (CeL), a key area for auditory fear conditioning. This engram is primarily composed of GABAergic somatostatin-expressing (SST(+)) and, to a lesser extent, protein kinase C-δ-expressing (PKC-δ(+)) neurons. Fear memory is accompanied by a preferential enhancement of synaptic inhibition onto PKC-δ(+) neurons. Silencing this CeL GABAergic engram disinhibits the activity of targeted extra-amygdaloid areas, selectively increasing the expression of fear. Our findings define the behavioral function of an engram formed exclusively by GABAergic inhibitory neurons in the mammalian brain.
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Miedo , Neuronas GABAérgicas , Memoria , Somatostatina , Animales , Miedo/fisiología , Memoria/fisiología , Ratones , Neuronas GABAérgicas/metabolismo , Somatostatina/metabolismo , Proteína Quinasa C-delta/metabolismo , Masculino , Núcleo Amigdalino Central/metabolismo , Núcleo Amigdalino Central/fisiología , Ratones Endogámicos C57BL , Amígdala del Cerebelo/metabolismo , Amígdala del Cerebelo/fisiologíaRESUMEN
Resistance to first-generation somatostatin receptor ligand (fgSRL) treatment in acromegaly is common, making the identification of biomarkers that predict fgSRL response a desired goal. We conducted a retrospective analysis on 21 patients with acromegaly who underwent surgery and subsequent pharmacological treatment. Through immunohistochemistry (IHC), we assessed the expression of the somatostatin receptor subtypes SSTR2 and SSTR5, E-Cadherin, and cytokeratin granulation pattern (sparsely or densely). Patients were divided into responders and non-responders based on their biochemical response to fgSRL and/or the newer agent, Pasireotide, or the GH-blocker, Pegvisomant. Patients resistant to fgSRL (n = 12) exhibited lower SSTR2 and E-Cadherin expressions. Sparsely granulated tumors were more frequent in the non-responder group. SSTR2 (p = 0.024, r = 0.49) and E-Cadherin (p = 0.009, r = 0.64) positively correlated with the Insulin-like Growth Factor 1 (IGF-1) decrease after fgSRL, while SSTR5 (p = 0.107, r = -0.37) showed a trend towards negative correlation. SSTR5 positivity seemed to be associated with Pasireotide response, albeit the number of treated patients was too low (n = 4). No IHC markers correlated with Pegvisomant response. Our findings suggest that densely granulated tumors, with positive SSTR2 and E-Cadherin seem to be associated with favorable fgSRL responses. The strongest predictive value of the studied markers was found for E-Cadherin, which seems to surpass even SSTR2.
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Acromegalia , Cadherinas , Receptores de Somatostatina , Humanos , Receptores de Somatostatina/metabolismo , Acromegalia/tratamiento farmacológico , Acromegalia/metabolismo , Femenino , Masculino , Cadherinas/metabolismo , Persona de Mediana Edad , Adulto , Estudios Retrospectivos , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Somatostatina/metabolismo , Anciano , Factor I del Crecimiento Similar a la Insulina/metabolismo , Resultado del Tratamiento , Hormona de Crecimiento Humana/análogos & derivadosRESUMEN
OBJECTIVE: Childhood sensory abnormalities experience has a crucial influence on the structure and function of the adult brain. The underlying mechanism of neurological function induced by childhood sensory abnormalities experience is still unclear. Our study was to investigate whether the GABAergic neurons in the anterior cingulate cortex (ACC) regulate social disorders caused by childhood sensory abnormalities experience. METHODS: We used two mouse models, complete Freund's adjuvant (CFA) injection mice and bilateral whisker trimming (BWT) mice in childhood. We applied immunofluorescence, chemogenetic and optogenetic to study the mechanism of parvalbumin (PV) neurons and somatostatin (SST) neurons in ACC in regulating social disorders induced by sensory abnormalities in childhood. RESULTS: Inflammatory pain in childhood leads to social preference disorders, while BWT in childhood leads to social novelty disorders in adult mice. Inflammatory pain and BWT in childhood caused an increase in the number of PV and SST neurons, respectively, in adult mice ACC. Inhibiting PV neurons in ACC improved social preference disorders in adult mice that experienced inflammatory pain during childhood. Inhibiting SST neurons in ACC improved social novelty disorders in adult mice that experienced BWT in childhood. CONCLUSIONS: Our study reveals that PV and SST neurons of the ACC may play a critical role in regulating social disorders induced by sensory abnormalities in childhood.
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Giro del Cíngulo , Ratones Endogámicos C57BL , Parvalbúminas , Somatostatina , Animales , Ratones , Somatostatina/metabolismo , Masculino , Parvalbúminas/metabolismo , Neuronas GABAérgicas/fisiología , Adyuvante de Freund/toxicidad , Vibrisas/fisiología , Vibrisas/inervación , Neuronas , Trastorno de la Conducta Social/etiología , Ratones TransgénicosRESUMEN
The integration of spatial information in the mammalian dentate gyrus (DG) is critical to navigation. Indeed, DG granule cells (DGCs) rely upon finely balanced inhibitory neurotransmission in order to respond appropriately to specific spatial inputs. This inhibition arises from a heterogeneous population of local GABAergic interneurons (INs) that activate both fast, ionotropic GABAA receptors (GABAAR) and slow, metabotropic GABAB receptors (GABABR), respectively. GABABRs in turn inhibit pre- and postsynaptic neuronal compartments via temporally long-lasting G-protein-dependent mechanisms. The relative contribution of each IN subtype to network level GABABR signal setting remains unknown. However, within the DG, the somatostatin (SSt) expressing IN subtype is considered crucial in coordinating appropriate feedback inhibition on to DGCs. Therefore, we virally delivered channelrhodopsin 2 to the DG in order to obtain control of this specific SSt IN subpopulation in male and female adult mice. Using a combination of optogenetic activation and pharmacology, we show that SSt INs strongly recruit postsynaptic GABABRs to drive greater inhibition in DGCs than GABAARs at physiological membrane potentials. Furthermore, we show that in the adult mouse DG, postsynaptic GABABR signaling is predominantly regulated by neuronal GABA uptake and less so by astrocytic mechanisms. Finally, we confirm that activation of SSt INs can also recruit presynaptic GABABRs, as has been shown in neocortical circuits. Together, these data reveal that GABABR signaling allows SSt INs to control DG activity and may constitute a key mechanism for gating spatial information flow within hippocampal circuits.
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Giro Dentado , Interneuronas , Receptores de GABA-B , Somatostatina , Animales , Somatostatina/metabolismo , Interneuronas/metabolismo , Interneuronas/fisiología , Giro Dentado/metabolismo , Receptores de GABA-B/metabolismo , Masculino , Femenino , Optogenética , Ratones Endogámicos C57BL , Ratones , Ratones Transgénicos , Ácido gamma-Aminobutírico/metabolismo , Sinapsis/metabolismoRESUMEN
BACKGROUND: High-output intestinal fistulas and small bowel enterostomies are associated with morbidity and mortality. Current standard treatment for output reduction consists of fluid and dietary restrictions and medical therapy. There is conflicting evidence regarding the use of somatostatin analogues for output reduction. AIM: The aim of this study is to investigate whether lanreotide, added to current standard treatment, further reduces intestinal output in patients with high-output fistulas and enterostomies. METHODS: This was an open-label, multicentre, randomised controlled trial. Adult patients with a high-output intestinal fistula (>500 mL/24 h) or small bowel enterostomy (>1500 mL/24 h) more than 4 weeks post-surgery and receiving standard medical treatment (dietary- and fluid restriction, PPI, loperamide and codeine) for at least 2 weeks were eligible for inclusion. We randomised patients 1:1 between continuing standard treatment (control), and subcutaneous lanreotide 120 mg every 4 weeks with standard treatment. The primary outcome was the number of responders, with response defined as an output reduction of ≥25%, 8 weeks after randomisation. We also investigated the proportional change in output. RESULTS: We randomised 40 patients; 17 had a fistula and 23 a small bowel enterostomy. There were 9/20 responders in the intervention group and 2/20 in the control group (p = 0.013). The proportional output reduction was -26% (IQR -4 to -38) in the intervention group, compared to an increase of 4% (IQR 20 to -13) in the control group (p = 0.004). CONCLUSIONS: In patients with a high-output fistula or small bowel enterostomy, addition of lanreotide to current standard treatment can provide a clinically relevant output reduction. TRIAL REGISTRATION: EudraCT: 2013-003998-10.
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Enterostomía , Fístula Intestinal , Intestino Delgado , Péptidos Cíclicos , Somatostatina , Humanos , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Masculino , Femenino , Persona de Mediana Edad , Anciano , Péptidos Cíclicos/uso terapéutico , Péptidos Cíclicos/administración & dosificación , Enterostomía/métodos , Resultado del Tratamiento , Intestino Delgado/cirugía , Adulto , Fístula Intestinal/tratamiento farmacológico , Fármacos Gastrointestinales/uso terapéuticoRESUMEN
Neuroendocrine neoplasms are a diverse group of neoplasms that can occur in various areas throughout the body. Well-differentiated neuroendocrine tumors (NETs) most often arise in the gastrointestinal tract, termed gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Although GEP-NETs are still uncommon, their incidence and prevalence have been steadily increasing over the past decades. The primary treatment for GEP-NETs is surgery, which offers the best chance for a cure. However, because GEP-NETs are often slow-growing and do not cause symptoms until they have spread widely, curative surgery is not always an option. Significant advances have been made in systemic and locoregional treatment options in recent years, including peptide-receptor radionuclide therapy with α and ß emitters, somatostatin analogs, chemotherapy, and targeted molecular therapies.
Asunto(s)
Neoplasias Intestinales , Tumores Neuroendocrinos , Neoplasias Pancreáticas , Neoplasias Gástricas , Humanos , Tumores Neuroendocrinos/terapia , Tumores Neuroendocrinos/patología , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/patología , Neoplasias Gástricas/terapia , Neoplasias Gástricas/patología , Neoplasias Intestinales/terapia , Neoplasias Intestinales/patología , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Terapia Molecular Dirigida/métodosRESUMEN
BACKGROUND: Energy allocation between growth and reproduction determines puberty onset and fertility. In mammals, peripheral hormones such as leptin, insulin and ghrelin signal metabolic information to the higher centres controlling gonadotrophin-releasing hormone neurone activity. However, these observations could not be confirmed in lower vertebrates, suggesting that other factors may mediate the energetic trade-off between growth and reproduction. A bioinformatic and experimental study suggested co-regulation of the circadian clock, reproductive axis and growth-regulating genes in zebrafish. While loss-of-function of most of the identified co-regulated genes had no effect or only had mild effects on reproduction, no such information existed about the co-regulated somatostatin, well-known for its actions on growth and metabolism. RESULTS: We show that somatostatin signalling is pivotal in regulating fecundity and metabolism. Knock-out of zebrafish somatostatin 1.1 (sst1.1) and somatostatin 1.2 (sst1.2) caused a 20-30% increase in embryonic primordial germ cells, and sst1.2-/- adults laid 40% more eggs than their wild-type siblings. The sst1.1-/- and sst1.2-/- mutants had divergent metabolic phenotypes: the former had 25% more pancreatic α-cells, were hyperglycaemic and glucose intolerant, and had increased adipocyte mass; the latter had 25% more pancreatic ß-cells, improved glucose clearance and reduced adipocyte mass. CONCLUSIONS: We conclude that somatostatin signalling regulates energy metabolism and fecundity through anti-proliferative and modulatory actions on primordial germ cells, pancreatic insulin and glucagon cells and the hypothalamus. The ancient origin of the somatostatin system suggests it could act as a switch linking metabolism and reproduction across vertebrates. The results raise the possibility of applications in human and animal fertility.
Asunto(s)
Metabolismo Energético , Reproducción , Transducción de Señal , Somatostatina , Pez Cebra , Animales , Femenino , Fertilidad , Reproducción/fisiología , Somatostatina/metabolismo , Somatostatina/genética , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/metabolismo , Proteínas de Pez Cebra/genéticaRESUMEN
Background: 177Lu-oxodotreotide peptide receptor therapy (LuPRRT) is an efficient treatment for midgut neuroendocrine tumors (NETs) of variable radiological response. Several clinical, biological, and imaging parameters may be used to establish a relative disease prognosis but none is able to predict early efficacy or toxicities. We investigated expression levels for mRNA and miRNA involved in radiosensitivity and tumor progression searching for correlations related to patient outcome during LuPRRT therapy. Methods: Thirty-five patients received LuPRRT for G1/G2 midgut NETs between May 2019 and September 2021. Peripheral blood samples were collected prior to irradiation, before and 48 h after the second and the fourth LuPRRT, and at 6-month follow-up. Multiple regression analyses and Pearson correlations were performed to identify the miRNA/mRNA signature that will best predict response to LuPRRT. Results: Focusing on four mRNAs and three miRNAs, we identified a miRNA/mRNA signature enabling the early identification of responders to LuPRRT with significant reduced miRNA/mRNA expression after the first LuPRRT administration for patients with progressive disease at 1 year (p < 0.001). The relevance of this signature was reinforced by studying its evolution up to 6 months post-LuPRRT. Moreover, nadir absolute lymphocyte count within the first 2 months after the first LuPRRT administration was significantly related to low miRNA/mRNA expression level (p < 0.05) for patients with progressive disease. Conclusion: We present a pilot study exploring a miRNA/mRNA signature that correlates with early hematologic toxicity and therapeutic response 12 months following LuPRRT. This signature will be tested prospectively in a larger series of patients.