MODULAZIONE DELLA SECREZIONE DI GLP-1 E FUNZIONALITA' ALFA-CELLULARE PANCREATICA: EFFETTO DELL'INIBIZIONE DEL COTRASPORTATORE SODIO-GLUCOSIO

Il diabete mellito è una sindrome eterogenea comprendente varie forme cliniche, di cui le più frequenti sono il diabete di tipo 1, caratterizzato da deficit più o meno totale di secrezione di insulina, dovuto alla distruzione autoimmune delle cellule beta delle isole di Langerhans, e il diabete di tipo 2 in cui sono presenti, oltre alla carenza di insulina, fenomeni di resistenza all’azione dell’ormone. In questi ultimi anni sono stati fatti notevoli progressi nello studio e nella valutazione funzionale delle isole pancreatiche, che costituiscono non più dell’1-2% della massa pancreatica complessiva. Sono strutture che contengono vari tipi di cellule endocrine, di cui le più rappresentate sono le cellule beta producenti insulina (60-80%) e le cellule alfa producenti glucagone (20-30%). In questi anni i ricercatori hanno focalizzato la propria attenzione principalmente sullo studio delle cellule beta-pancreatiche, andando a studiarne i meccanismi che regolano la funzionalità e la sopravvivenza. Tuttavia, in letteratura sono presenti pochi studi riguardo al ruolo delle cellule alfa nella funzionalità insulare. Il glucagone è il risultato finale di una serie di modifiche a carico del proglucagone, che rappresenta il reale polipeptide derivante dalla trascrizione del gene corrispondente. L’azione di enzimi proteolitici con specificità tissutale porta, infatti, attraverso clivaggi successivi, dal proglucagone al glucagone nelle cellule alfa e al GLP-1 (Glucagon-Like Peptide 1) e GLP-2 (Glucagon-Like Peptide 2) nelle cellule L dell’intestino. Recentemente, nel nostro laboratorio è stato condotto uno studio in cui è stata valutata la secrezione e la funzione del GLP-1 in una linea cellulare di alfa cellule murine esposte o meno a perturbazioni metaboliche tipiche del diabete mellito tipo 2, i cui risultati preliminari sembrano indicare che l’iperglicemia potrebbe indurre nelle alfa cellule pancreatiche un incremento dell’espressione dell’enzima PC1/3, con aumento della secrezione di GLP-1 nella sua forma totale e attiva. Questo potrebbe avere un effetto protettivo sulle alfa cellule stesse, mediato da un aumento della concentrazione di GLP-1 attivo nel terreno di coltura, associato ad una riduzione della necrosi, un aumento della vitalità ed un aumento della funzionalità cellulare

Serum TSH Levels Normalisation in Patients Affected by Autoimmune Atrophic Gastritis, After the Switch From Oral L-T4 in Tablet Form to L-T4 in Liquid Formulation

Abstract Patients affected by autoimmune atrophic gastritis could have some issues in L-thyroxine (L-T4) absorption, due to drug malabsorption, induced by the increased gastric pH. Different factors influence L-T4 absorption, such as dietary habits, interference with other drugs, absorption kinetics, age of the patient, adherence to therapy, and others. We enrolled 36 patients affected by autoimmune atrophic gastritis with high serum thyrotropin (TSH) levels under therapy with L-T4 in the tablet formulation. L-T4 tablets were changed to an oral liquid L-T4 preparation, maintaining the same dose. The switch from L-T4 in tablet formulation to the liquid one, at the same L-T4 dosage, led to the normalisation/reduction of circulating TSH levels. Then 14 patients, who were switched back again to receive L-T4 in tablets (with the same dose), had a worsening of TSH values, falling in the hypothyroid range. In conclusion, our findings led to hypothesize that the pH alteration issue caused by autoimmune atrophic gastritis could be overcome by the oral L-T4 liquid formulation administration

The protective effect of myo-inositol on human thyrocytes

Patients affected by autoimmune thyroiditis reached positive effects on indices of thyroid autoimmunity and/or thyroidal function, after following a treatment with selenomethionine (Se) alone, or Se in combination with Myo-inositol (Myo-Ins). Our purpose was to investigate if Myo-Ins alone, or a combination of Se + Myo-Ins, is effective in protecting thyroid cells from the effects given by cytokines, or hydrogen peroxide (H2O2). We assessed the interferon (IFN)-γ-inducible protein 10 (IP-10/CXCL10) secretion by stimulating primary thyrocytes (obtained from Hashimoto's thyroiditis or from control patients) with cytokines in presence/absence of H2O2. Our results confirm: 1) the toxic effect of H2O2 in primary thyrocytes that leads to an increase of the apoptosis, to a decrease of the proliferation, and to a slight reduction of cytokines-induced CXCL10 secretion; 2) the secretion of CXCL10 chemokine induced by IFN-γ + tumor necrosis factor alpha (TNF)-α has been decreased by Myo + Ins, both in presence or absence of H2O2; 3) no effect has been shown by the treatment with Se. Therefore, a protective effect of Myo-Ins on thyroid cells has been suggested by our data, which exact mechanisms are at the basis of this effect need to be furtherly investigated

Myo-inositol in autoimmune thyroiditis, and hypothyroidism

Myo-inositol (Myo-Ins) plays an important role in thyroid function and autoimmunity. Myo-Ins is the precursor for the synthesis of phosphoinositides, which takes part in the phosphatidylinositol (PtdIns) signal transduction pathway, and plays a decisive role in several cellular processes. In the thyroid cells, PtdIns is involved in the intracellular thyroid-stimulating hormone (TSH) signaling, via Phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P3) (PIP-3). Moreover, the phosphatidyl inositol 3 kinases (PI3K) family of lipid kinases regulates diverse aspects of T, B, and Tregs lymphocyte behaviour. Different mouse models deficient for the molecules involved in the PIP3 pathway suggest that impairment of PIP3 signaling leads to dysregulation of immune responses and, sometimes, autoimmunity. Studies have shown that cytokines modulate Myo-Ins in thyroid cells. Moreover, clinical studies have shown that after treatment with Myo-inositol plus seleniomethionine (Myo-Ins + Se), TSH levels significantly declined in patients with subclinical hypothyroidism due to autoimmune thyroiditis. The treatment was accompanied by a decline of antithyroid autoantibodies. After treatment serum CXCL10 levels declined, confirming the immune-modulatory effect of Myo-Ins. Additional research is necessary in larger population to evaluate the effect on the quality of life, and to study the mechanism of the effect on chemokines

Lenvatinib exhibits antineoplastic activity in anaplastic thyroid cancer in vitro and in vivo

Lenvatinib is an oral, multitargeted tyrosine kinase inhibitor (TKI) of VEGFR1-VEGFR3, FGFR1-FGFR4, PDGFRα, RET and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) signaling networks involved in tumor angiogenesis. We have evaluated the antitumor activity of lenvatinib in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C (undifferentiated thyroid cancer) and in an ATC-cell line (AF). The AF cell line was obtained from the primary ATC cultures and was the one that grew over 50 passages. The effect of lenvatinib (1 and 100 nM; and 1, 10, 25 and 50 μM) was investigated in primary ATC, 8305C and AF cells as well as in AF cells in CD nu/nu mice. Lenvatinib significantly reduced ATC cell proliferation (P<0.01, ANOVA) and increased the percentage of apoptotic ATC cells (P<0.001, ANOVA). Furthermore, lenvatinib inhibited migration (P<0.01) and invasion (P<0.001) in ATC. In addition, lenvatinib inhibited EGFR, AKT and ERK1/2 phosphorylation and downregulated cyclin D1 in the ATC cells. Lenvatinib also significantly inhibited 8305C and AF cell proliferation, increasing apoptosis. AF cells were subcutaneously injected into CD nu/nu mice and tumor masses were observed 20 days later. Tumor growth was significantly inhibited by lenvatinib (25 mg/kg/day), as well as the expression of VEGF-A and microvessel density in the AF tumor tissues. In conclusion, the antitumor and antiangiogenic activities of lenvatinib may be promising for the treatment of anaplastic thyroid cancer, and may consist a basis for future clinical therapeutic applications

Vandetanib has antineoplastic activity in anaplastic thyroid cancer, in vitro and in vivo

The antitumor activity of vandetanib [a multiple signal transduction inhibitor including the RET tyrosine kinase, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) receptor (VEGFR), ERK and with antiangiogenic activity], in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C [undifferentiated thyroid cancer (TC)] and in an ATC-cell line (AF), was investigated in the present study. Vandetanib (1 and 100 nM; 1, 10, 25 and 50 μM) was tested by WST-1, apoptosis, migration and invasion assays: in primary ATC cells, in the 8305C continuous cell line, and in AF cells; and in 8305C cells in CD nu/nu mice. Vandetanib significantly reduced ATC cell proliferation (P<0.01, ANOVA), induced apoptosis dose-dependently (P<0.001, ANOVA), and inhibited migration (P<0.01) and invasion (P<0.001). Furthermore, vandetanib inhibited EGFR, AKT and ERK1/2 phosphorylation and downregulated cyclin D1 in ATC cells. In 8305C and AF cells, vandetanib significantly inhibited the proliferation, inducing also apoptosis. 8305C cells were injected subcutaneously in CD nu/nu mice and tumor masses became detectable after 30 days. Vandetanib (25 mg/kg/day) significantly inhibited tumor growth and VEGF-A expression and microvessel density in 8305C tumor tissues. In conclusion, the antitumor and antiangiogenic activity of vandetanib is very auspicious in ATC, opening the way to a future clinical evaluation

Antineoplastic Effect of Lenvatinib and Vandetanib in Primary Anaplastic Thyroid Cancer Cells Obtained From Biopsy or Fine Needle Aspiration

Anaplastic thyroid carcinoma (ATC) is a malignant tumor of the thyroid gland, infrequent but with a very poor prognosis, as it rapidly causes death (mean survival of about 6 months). ATC treatment includes a multimodal protocol consisting of surgery, chemotherapy (doxorubicin and cisplatin), and hyperfractionated accelerated external beam radiotherapy (median patient survival of 10 months). For this reason, the identification of an effective systemic treatment for ATC would be a major advance in the management of this deadly thyroid cancer. The opportunity to test the sensitivity to different drugs of primary cells from ATC (pATC) cultures, obtained from each patients, could improve the effectiveness of the treatment. Then, the administration of inactive therapeutics could be avoided. Our aim is to investigate the antineoplastic effect of two tyrosine kinase inhibitors (TKIs; lenvatinib, vandetanib) in pATC obtained both from biopsy (biop-pATC), and from fine needle aspiration (FNA-pATC). The antiproliferative activity of lenvatinib and vandetanib was evaluated in 6 ATC patients, on biop-pATC, such as on FNA-pATC. A significant reduction of proliferation (obtained by WST-1 assay) vs. control was shown with lenvatinib and vandetanib in FNA-pATC, as well as in biop-pATC. The percentage of apoptosis in FNA-pATC, or biop-pATC, increased with both compounds dose-dependently. pATC cells from FNA, or biopsy, had a similar sensitivity to lenvatinib and vandetanib. In conclusion, primary cells (biop-pATC or FNA-pATC) have a similar sensitivity to TKIs, and lenvatinib and vandetanib are effective in reducing cell growth, increasing apoptosis in ATC. The possibility to test the sensitivity to different TKIs in each patient could open the way to personalized treatments, avoiding the administration of ineffective, and potentially dangerous, drugs

Covid-19 And Rheumatic Autoimmune Systemic Diseases: Role of Pre-Existing Lung Involvement and Ongoing Treatments

The Covid-19 pandemic may have a deleterious impact on patients with autoimmune systemic diseases (ASD) due to their deep immune-system alterations

Carcinoma anaplastico della tiroide: una sfida terapeutica e il ruolo dei riarrangiamenti del gene ALK

Il carcinoma della tiroide è il più comune tumore maligno del sistema endocrino. La maggior parte delle neoplasie tiroidee sono patologicamente differenziate con una buona prognosi e una sopravvivenza a cinque anni > 98%. Il carcinoma anaplastico della tiroide (ATC) rappresenta l’l-4% di tutti i tumori tiroidei ed è invece un tumore indifferenziato con una sopravvivenza media di soli sei mesi. L'ATC è quindi una sfida clinica significativa poichè è altamente aggressivo e resistente alle terapie standard. La conoscenza dei meccanismi molecolari alla base dello sviluppo e della crescita dell’ATC ha consentito trattamenti mirati indirizzati verso le vie di segnalazione interessate, attraverso l’utilizzo degli inibitori tirosin-chinasici (TKI). Crizotinib è un inibitore orale dei recettori TK, come ALK e MET; attualmente approvato per il trattamento del carcinoma polmonare non a piccole cellule ALK-positivo. I riarrangiamenti ALK sono coinvolti nello sviluppo di circa il 10% dell’ATC e rappresentano un bersaglio terapeutico. L’obiettivo di questo elaborato è valutare l’attività antineoplastica di crizotinib in vitro su linee cellulari primarie umane di ATC (con/senza STRN-ALK) e in linee cellulari continue (8305C, linee cellulari AF) e TFC. Dai risultati emerge che crizotinib inibisce la proliferazione, la migrazione e l’invasione, e induce l'apoptosi in tutte le linee cellulari primarie umane di ATC con STRN-ALK, risultando quindi una promettente opzione terapeutica futura

Th1 chemokines in autoimmune endocrine disorders

CONTEXT: The chemokine receptor (CXCR)3 and its chemokines CXCL10, CXCL9 and CXCL11 are implicated in the pathogenesis of autoimmune diseases. Here, we review these chemokines in "autoimmune thyroiditis" (AT), "Graves' disease" (GD), "thyroid eye disease (TED), "Type 1 diabetes" (T1D), "Addison's disease" (AAD). EVIDENCE ACQUISITION: A PubMed revision of the literature was conducted searching for the above mentioned chemokines in combitation with AT, GD, TED, T1D, AAD. EVIDENCE SYNTHESIS: Thyroid follicular cells in AT and GD, retroorbital cells in TED (fibroblasts, preadipocytes, myoblasts), β cells and islets in T1D, and adrenal cells in AAD, respond to IFN-γ stimulation producing large amounts of these chemokines. Furthermore, lymphocytes and PBMC are in part responsible for the secreted Th1 chemokines. In AT, GD, TED, T1D, AAD circulating levels of these chemokines have been shown to be high. Furthermore these chemokines have been associated with the early phases of the autoimmune response in all the above mentioned disorders. High levels of these chemokines have been associated also with the "active phase" of the disease in GD, and also in TED. Other studies have shown an association with the severity of hypothyroidism in AD, of hyperthyroidism in GD, with severity of TED, or with fulminant T1D. CONCLUSION: The above mentioned data have shown the importance of the Th1 immune response in different endocrine autoimmune diseases, and many studies have suggested that CXCR3, and its chemokines, might be considered potential targets of new drugs for the treatment of these disorders