Accumulating preclinical and preliminary translational evidence shows that the hypothalamic peptide oxytocin reduces food intake, increases energy expenditure, and promotes weight loss. It is currently unknown whether oxytocin administration is effective in treating human obesity.
Multiple sclerosis (MS) is a T cell-mediated organ-specific inflammatory disease leading to central nervous system (CNS) demyelination. On the basis of results obtained in experimental autoimmune encephalomyelitis (EAE) models, MS treatment by administration of antiinflammatory cytokines such as interleukin 4 (IL-4) is promising but is hampered by the limited access of the cytokines to the CNS and by the pleiotropic effects of systemically administered cytokines. We established a cytokine delivery system within the CNS using nonreplicative herpes simplex type 1 (HSV-1) viral vectors engineered with cytokine genes. These vectors injected into the cisterna magna (i.c.) of mice diffuse in all ventricular and subarachnoid spaces and infect with high efficiency the ependymal and leptomeningeal cell layers surrounding these areas, without obvious toxic effects. Heterologous genes contained in the vectors are efficiently transcribed in infected ependymal cells, leading to the production of high amounts of the coded proteins. For example, 4.5 ng of interferon γ (IFN-γ) per milliliter is secreted into the cerebrospinal fluid (CSF) up to day 28 postinjection (p.i.) and reaches the CNS parenchyma in bioactive form, as demonstrated by upregulation of MHC class I expression on CNS-resident cells. We then exploited the therapeutic potential of the vectors in EAE mice. An HSV-1-derived vector containing the IL-4 gene was injected i.c. in Biozzi AB/H mice at the time of EAE induction. We found the following in treated mice: (1) delayed EAE onset, (2) a significant decrease in clinical score, (3) a significant decrease in perivascular inflammatory infiltrates and in the number of macrophages infiltrating the CNS parenchyma and the submeningeal spaces, and (4) a reduction in demyelinated areas and axonal loss. Peripheral T cells from IL-4-treated mice were not affected either in their antigen-specific proliferative response or in cytokine secretion pattern. Our results indicate that CNS cytokine delivery with HSV-1 vectors is feasible and might represent an approach for the treatment of demyelinating diseases. Advantages of this approach over systemic cytokine administration are the high cytokine level reached in the CNS, the absence of effects on the peripheral immune system, and the long-lasting cytokine production in the CNS after a single vector administration. Gene therapy of organ-specific autoimmune diseases can be approached by delivering heterologous genes encoding immunomodulatory molecules either to the target organ or to the peripheral autoreactive T cells. However, when the autoantigen responsible for the disease is unknown only the former option is available. We established a gene delivery system based on CNS administration of nonreplicative HSV-1-derived vectors engineered with cytokine genes. Gene delivery within the CNS by an HSV-1-derived vector showed itself to be feasible and nontoxic. EAE, an inflammatory demyelinating disease of the CNS mimicking human MS, was ameliorated both at clinical and pathological levels when an HSV-1 vector containing the antiinflammatory cytokine gene IL-4 was injected within the CNS. The efficacy in the inhibition of EAE was relatively long-lasting and did not affect peripheral immune responses.
Objective: Anorexia nervosa (AN), a psychiatric disorder characterized by food restriction and distorted body image, is associated with depression, anxiety, and social-emotional functioning deficits. Basal levels of oxytocin, an anorexigenic hormone with antidepressant, anxiolytic, and prosocial properties, are low in women with AN, and a relationship between low oxytocin levels and psychopathology when examined across AN and healthy control groups has been established. We aimed to determine whether oxytocin levels in AN are related to psychopathology, and whether AN subtype (restrictive food intake alone [AN-R] vs. restriction plus binge and/or purge behaviors [AN-BP]) impacts this relationship. Methods: We performed a cross-sectional study of 39 women with AN (age [mean±SEM]: 28.3±8.3 years; BMI: 18.5±1.7 kg/m2; 23 AN-R, 16 AN-BP). We obtained fasting serum oxytocin levels and self-report measures for psychopathology (Eating Disorder Examination Questionnaire [EDE-Q], Beck Depression Inventory-IA [BDI-IA], State-Trait Anxiety Inventory – Trait scale [STAI-T], Dimensional Assessment of Personality Pathology – Basic Questionnaire [DAPP-BQ], Liebowitz Social Anxiety Scale [LSAS], Toronto Alexithymia Scale [TAS-20], and Interpersonal Support Evaluation List [ISEL]). Results: Oxytocin levels and psychopathology scores did not significantly differ in AN-R vs. AN-BP. In AN-R but not AN-BP, oxytocin levels were negatively associated with disordered eating psychopathology (EDE-Q global score: rs=−0.54, p=0.012), depressive and anxiety symptoms (BDI-IA: rs=-0.63, p=0.003; STAI-T: rs=−0.68, p=0.001), and social-emotional symptoms (DAPP BQ Suspiciousness: rs= -0.48, p=0.03; LSAS social fear: rs= -0.71, p=0.0004; LSAS public fear: rs = -0.40, p=0.046; LSAS social avoidance: rs= -0.66, p=0.0016; LSAS public avoidance: rs = -0.54, p= 0.014; TAS-20 total score: rs= -0.45, p=0.049). In both AN-R and AN-BP, oxytocin levels were positively associated with perceived social support (ISEL total score: rs =0.6, p=0.004 in AN-R; rs =0.52, p=0.046 in AN-BP). Conclusions: Low oxytocin levels are associated with severity of psychopathology in AN-R but not AN-BP, suggesting divergent underlying neurobiology.
IL-12 has been shown to be involved in the pathogenesis of Th1-mediated autoimmune diseases, but its role in antibody-mediated autoimmune pathologies is still unclear. We investigated the effects of exogenous and endogenous IL-12 in experimental autoimmune myasthenia gravis (EAMG). EAMG is an animal model for myasthenia gravis, a T cell-dependent, autoantibody-mediated disorder of neuromuscular transmission caused by antibodies to the muscle nicotinic acetylcholine receptor (AChR). Administration of IL-12 with Torpedo AChR (ToAChR) to C57BL/6 (B6) mice resulted in increased ToAChR-specific IFN-gamma production and increased anti-ToAChR IgG2a serum antibodies compared with B6 mice primed with ToAChR alone. These changes were associated with earlier and greater neurophysiological evidence of EAMG in the IL-12-treated mice, and reduced numbers of AChR. By contrast, when IL-12-deficient mice were immunized with ToAChR, ToAChR-specific Th1 cells and anti-ToAChR IgG2a serum antibodies were reduced compared to ToAChR-primed normal B6 mice, and the IL-12-deficient mice showed almost no neurophysiological evidence of EAMG and less reduction in AChR. These results indicate an important role of IL-12 in the induction of an antibody-mediated autoimmune disease, suggest that Th1-dependent complement-fixing IgG2a anti-AChR antibodies are involved in the pathogenesis of EAMG, and help to account for the lack of correlation between anti-AChR levels and clinical disease seen in many earlier studies.
Objective Anorexia nervosa (AN) is commonly associated with depression, anxiety, and deficits in socioemotional functioning. Basal levels of oxytocin, a neurohormone with antidepressant, anxiolytic, and prosocial properties, are low in women with AN. However, the relationship between oxytocin and psychopathology of AN/atypical AN has not been examined in individuals with primarily food restriction (AN/AtypAN-R) or those with restriction plus binge/purge behaviors (AN/AtypAN-BP) alone, which is important to further elucidate the neurobiology of different AN presentations. We investigated whether oxytocin levels are related to eating, affective, and socioemotional psychopathology in women with AN/AtypAN-R and separately AN/AtypAN-BP. Methods In a cross-sectional study of 53 women with low-weight AN or atypical AN based on DSM-5 (AN/AtypAN-R: n=21, AN/AtypAN-BP: n=32), we obtained fasting serum oxytocin levels and self-report measures of psychopathology, including the Eating Disorder Examination–Questionnaire (EDE-Q), Beck Depression Inventory-IA (BDI), State-Trait Anxiety Inventory (STAI), and Toronto Alexithymia Scale (TAS-20). Results In individuals with AN/AtypAN-R, oxytocin levels were negatively associated with eating psychopathology (EDE-Q Global Score: r=-0.49, p=0.024), depressive and anxiety symptoms (BDI Total Score: r=-0.55, p=0.009; STAI Trait Score: r=-0.63, p=0.002), and socioemotional symptoms (TAS-20 Difficulty Identifying Feelings Score: r=-0.49, p=0.023). In contrast, in those with AN/AtypAN-BP oxytocin levels were negatively associated with depressive symptoms only (BDI Total Score: r=-0.52, p=0.049). Conclusions These findings support the notion that AN/AtypAN-R and AN/AtypAN-BP might have divergent underlying neurobiology. Understanding these differences is crucial to develop targeted treatments for a population with high levels of chronicity, for which no specific pharmacological treatments are currently available. Clinical trial registration https://clinicaltrials.gov , identifier: NCT01121211.
Type IV renal tubular acidosis (RTA) is the only RTA characterized by hyperkalemia, and it is caused by a true aldosterone deficiency or renal tubular aldosterone hyporesponsiveness. It is frequent among hospitalized patients as it is related to type 2 diabetes mellitus (T2DM) and common medications such as ACE-inhibitors (ACE-is) and trimethoprim-sulfamethoxazole (TMP-SMX). Drug-induced RTA commonly manifests in patients with predisposing conditions such as mild renal insufficiency and certain pharmacological therapies. ACE-i use and chronic adrenal insufficiency (cAI) are other significant risk factors. Chronic ACTH suppression is thought to induce global adrenal atrophy, including the zona glomerulosa, thus affecting aldosterone secretion as well. Furthermore, in the setting of cAI, treatment with ACE-is further suppresses aldosterone production. This case report describes a patient with cAI secondary to corticosteroid use for years who developed type IV RTA in the setting of lisinopril use. Potassium (K) elevation persisted despite removing underlying conditions and metabolic acidosis correction. The patient required long-term treatment with mineralocorticoids in addition to sodium bicarbonate to maintain normal K levels and acid-base status. Mineralocorticoid administration is a second-line treatment for type IV RTA, but it might be necessary for a subgroup of high-risk patients. In fact, it is important to consider patients with chronic adrenal insufficiency and on ACE-is treatment at increased risk for refractory hyperkalemia in the setting of type IV RTA. Indeed, this subgroup of patients can have severe hypoaldosteronism.
Abstract GH-secreting pituitary adenomas can cause gigantism or acromegaly, determined by onset before or after epiphyseal fusion of the distal ends of the radius and ulna. Overlapping phenotypes can occur when the condition presents peripubertally. Gigantism is associated with identifiable hereditary causes and genetic mutations in almost 50% of cases; genetic testing should be considered in patients with gigantism and early-onset acromegaly, especially (but not only) when pituitary tumors have aggressive features and/or are refractory to standard treatments. Here, we present a case of a young adult with a giant somatotroph adenoma resistant to multiple treatment modalities and negative for mutations in AIP, which encodes aryl hydrocarbon receptor-interacting protein.
Continuous administration of soluble protein antigen to BALB/c mice inhibits the development of Th1 and induces selective differentiation of Th2 cells. Here we show that interleukin (IL)-12, administered together with soluble protein through a mini-osmotic pump implanted s.c., not only prevents the inhibition of Th1 cell development, but stimulates higher interferon (IFN)-γ production than in mice receiving IL-12 alone. In parallel to co-stimulation of Th1 cell development, co-administration of IL-12 blocks the Th2 response induced by soluble protein. IL-12 administered in adjuvant with antigen or intraperitoneally 2 days after the immunization does not break the inhibition of Th1 but can still decrease the Th2 response induced by pretreatment with soluble protein antigen. In contrast to IL-12, co-administration of IL-2 or IFN-γ does not affect the diversion to Th2 induced by soluble antigen. Thus IL-12, but not IL-2 nor IFN-γ, converts in vivo the inhibitory signal for Th1 cell development delivered by soluble antigen into an immunogenic one, while blocking a positive signal for Th2 cell differ entiation. A molecular basis for the co-stimulation of Th1 priming and the prevention of Th2 differentiation by IL-12 in vivo is provided by the observation that transcripts encoding the IL-12 receptor β2 chain, which is required for IL-12 signaling and Th1 cell development, are selectively inhibited by soluble antigen but are enhanced by IL-12 co-administration.
Interleukin-12 is a key regulatory cytokine produced by antigen-presenting cells (APC) which drives the development of interferon-gamma (IFN-gamma)-producing cells and promotes cell-mediated immunity. Following subcutaneous immunization with protein antigen in adjuvant, dendritic cells (DC) but not small nor large B cells in immune lymph nodes express antigenic complexes and secrete substantial amounts of bioactive IL-12 p75 upon antigen-specific interaction with T cells. We have analyzed secretion of IL-12 p40 and p75 by cell populations enriched in DC, macrophages or B cells in response to nonspecific stimulation or to interaction with antigen-specific CD4+ cells. These APC populations do not produce IL-12 constitutively but, upon stimulation with heat-fixed Staphylococcus aureus and IFN-gamma, IL-12 p40 and p75 are secreted by DC and macrophages, whereas B cells fail to produce IL-12. B cells also fail to secrete IL-12 in response to stimulation with LPS and IFN-gamma. Co-culture with CD4+ T hybridoma cells and antigen induces IL-12 secretion by DC. Up-regulation of IL-12 secretion by interaction with antigen-specific CD4+ T cells is abrogated by anti-class II monoclonal antibodies (mAb), by soluble CD40 molecules and by anti-CD40 ligand mAb, demonstrating a positive feedback between T cells and DC mediated by TCR-peptide/class II and by CD40-CD40 ligand interactions. Expression of class II and CD40 molecules is comparable in B cells and DC, and both APC types activate CD4+ T cells. Yet, even upon interaction with antigen-specific T cells, B cells fail to secrete IL-12. The capacity of B cells to present antigen but not to secrete IL-12 may explain their propensity to selectively drive T helper type 2 cell development.
