RESUMEN
We previously showed that, in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease (PD), vaccination with bacillus Calmette-Guerin (BCG) prior to MPTP exposure limited the loss of striatal dopamine (DA) and dopamine transporter (DAT) and prevented the activation of nigral microglia. Here, we conducted BCG dose studies and investigated the mechanisms underlying BCG vaccination's neuroprotective effects in this model. We found that a dose of 1 × 10(6) cfu BCG led to higher levels of striatal DA and DAT ligand binding (28% and 42%, respectively) in BCG-vaccinated vs. unvaccinated MPTP-treated mice, but without a significant increase in substantia nigra tyrosine hydroxylase-staining neurons. Previous studies showed that BCG can induce regulatory T cells (Tregs) and that Tregs are neuroprotective in models of neurodegenerative diseases. However, MPTP is lymphotoxic, so it was unclear whether Tregs were maintained after MPTP treatment and whether a relationship existed between Tregs and the preservation of striatal DA system integrity. We found that, 21 days post-MPTP treatment, Treg levels in mice that had received BCG prior to MPTP were threefold greater than those in MPTP-only-treated mice and elevated above those in saline-only-treated mice, suggesting that the persistent BCG infection continually promoted Treg responses. Notably, the magnitude of the Treg response correlated positively with both striatal DA levels and DAT ligand binding. Therefore, BCG vaccine-mediated neuroprotection is associated with Treg levels in this mouse model. Our results suggest that BCG-induced Tregs could provide a new adjunctive therapeutic approach to ameliorating pathology associated with PD and other neurodegenerative diseases.
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Vacuna BCG/inmunología , Fármacos Neuroprotectores/inmunología , Trastornos Parkinsonianos/inmunología , Trastornos Parkinsonianos/prevención & control , Linfocitos T Reguladores/inmunología , Animales , Vacuna BCG/administración & dosificación , Encéfalo/inmunología , Encéfalo/patología , Cromatografía Líquida de Alta Presión , Modelos Animales de Enfermedad , Citometría de Flujo , Masculino , Ratones , Ratones Endogámicos C57BL , Fármacos Neuroprotectores/administración & dosificaciónRESUMEN
GABA and GABAA-receptors (GABAA-Rs) play major roles in neurodevelopment and neurotransmission in the central nervous system (CNS). There has been a growing appreciation that GABAA-Rs are also present on most immune cells. Studies in the fields of autoimmune disease, cancer, parasitology, and virology have observed that GABA-R ligands have anti-inflammatory actions on T cells and antigen-presenting cells (APCs), while also enhancing regulatory T cell (Treg) responses and shifting APCs toward anti-inflammatory phenotypes. These actions have enabled GABAA-R ligands to ameliorate autoimmune diseases, such as type 1 diabetes (T1D), multiple sclerosis (MS), and rheumatoid arthritis, as well as type 2 diabetes (T2D)-associated inflammation in preclinical models. Conversely, antagonism of GABAA-R activity promotes the pro-inflammatory responses of T cells and APCs, enhancing anti-tumor responses and reducing tumor burden in models of solid tumors. Lung epithelial cells also express GABA-Rs, whose activation helps maintain fluid homeostasis and promote recovery from injury. The ability of GABAA-R agonists to limit both excessive immune responses and lung epithelial cell injury may underlie recent findings that GABAA-R agonists reduce the severity of disease in mice infected with highly lethal coronaviruses (SARS-CoV-2 and MHV-1). These observations suggest that GABAA-R agonists may provide off-the-shelf therapies for COVID-19 caused by new SARS-CoV-2 variants, as well as novel beta-coronaviruses, which evade vaccine-induced immune responses and antiviral medications. We review these findings and further advance the notions that (1) immune cells possess GABAA-Rs to limit inflammation in the CNS, and (2) this natural "braking system" on inflammatory responses may be pharmacologically engaged to slow the progression of autoimmune diseases, reduce the severity of COVID-19, and perhaps limit neuroinflammation associated with long COVID.
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A series of O(2)-glycosylated diazeniumdiolate-based derivatives of oleanolic acid (4-19) were synthesized and their anti-human hepatocellular carcinoma (HCC) activities were evaluated. Compound 6 selectively inhibited HCC, but not non-tumor liver cell proliferation. This inhibition was attributed to high levels of nitric oxide (NO) released in HCC cells. Importantly, 6 exhibited low acute toxicity (LD(50) = 173.3 mg kg(-1)) and potent inhibition of HCC tumor growth in mice (3 mg kg(-1) iv). Furthermore, 6 induced HCC cell apoptosis, which was accompanied by lower mitochondrial membrane potentials and Bcl2 expression, but with higher cytochrome C release, Bax, caspase 3 and 9 expression activities in HCC cells. Collectively, 6 may be a promising candidate drug for the intervention of HCC.
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Antineoplásicos/síntesis química , Compuestos Azo/química , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Ácido Oleanólico/análogos & derivados , Animales , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Femenino , Glicosilación , Humanos , Neoplasias Hepáticas/patología , Masculino , Ratones , Estructura Molecular , Ácido Oleanólico/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Studies of mice lacking MHC class I (MHC I)-associated proteins have demonstrated a role for MHC I in neurodevelopment. A central question arising from these observations is whether neuronal recognition of MHC I has specificity for the MHC I allele product and the peptide presented. Using a well-established embryonic retina explant system, we observed that picomolar levels of a recombinant self-MHC I molecule inhibited neurite outgrowth. We then assessed the neurobiological activity of a panel of recombinant soluble MHC Is, consisting of different MHC I heavy chains with a defined self- or nonself-peptide presented, on cultured embryonic retinas from mice with different MHC I haplotypes. We observed that self-MHC I allele products had greater inhibitory neuroactivity than nonself-MHC I molecules, regardless of the nature of the peptide presented, a pattern akin to MHC I recognition by some innate immune system receptors. However, self-MHC I molecules had no effect on retinas from MHC I-deficient mice. These observations suggest that neuronal recognition of MHC I may be coordinated with the inherited MHC I alleles, as occurs in the innate immune system. Consistent with this notion, we show that MHC I and MHC I receptors are coexpressed by precursor cells at the earliest stages of retina development, which could enable such coordination.
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Alelos , Presentación de Antígeno , Antígenos de Histocompatibilidad Clase I/genética , Neuronas/inmunología , Péptidos/inmunología , Animales , Autoantígenos/inmunología , Células Madre Embrionarias , Inmunidad Innata , Ratones , Neuritas/inmunología , Neuronas/citología , Retina/embriologíaRESUMEN
We have proposed that antigen-specific immunotherapies (ASIs) for autoimmune diseases could be enhanced by administering target cell antigen epitopes (determinants) that are immunogenic but ignored by autoreactive T cells because these determinants may have large pools of naïve cognate T cells available for priming towards regulatory responses. Here, we identified an immunogenic preproinsulin determinant (PPIL4-20) that was ignored by autoimmune responses in type 1 diabetes (T1D)-prone NOD mice. The size of the PPIL4-20-specific splenic naive T cell pool gradually increased from 2-12 weeks in age and remained stable thereafter, while that of the major target determinant insulin B-chain9-23 decreased greatly after 12 weeks in age, presumably due to recruitment into the autoimmune response. In 15-16 week old mice, insulin B-chain9-23/alum immunization induced modest-low level of splenic T cell IL-10 and IL-4 responses, little or no spreading of these responses, and boosted IFNγ responses to itself and other autoantigens. In contrast, PPIL4-20/alum treatment induced robust IL-10 and IL-4 responses, which spread to other autoantigens and increased the frequency of splenic IL-10-secreting Treg and Tr-1-like cells, without boosting IFNγ responses to ß-cell autoantigens. In newly diabetic NOD mice, PPIL4-20, but not insulin B-chain9-23 administered intraperitoneally (with alum) or intradermally (as soluble antigen) supplemented with oral GABA induced long-term disease remission. We discuss the potential of personalized ASIs that are based on an individual's naïve autoantigen-reactive T cell pools and the use of HLA-appropriate ignored autoantigen determinants to safely enhance the efficacy of ASIs.
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Diabetes Mellitus Tipo 1 , Interleucina-10 , Animales , Autoantígenos , Epítopos , Inmunoterapia/efectos adversos , Insulina , Interleucina-4 , Ratones , Ratones Endogámicos NODRESUMEN
Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic infiltrates in the salivary and lachrymal glands resulting in oral and ocular dryness. There are no clinically approved therapies to slow the progression of SS. Immune cells possess receptors for the neurotransmitter GABA (GABA-Rs) and their activation has immunoregulatory actions. We tested whether GABA administration has potential for amelioration of SS in NOD.B10-H2b and C57BL/6.NOD-Aec1Aec2 mice, two spontaneous SS models. Oral GABA treatment was initiated (1) after the development of sialadenitis but before the onset of overt symptoms, or (2) after the appearance of overt symptoms. When assessed weeks later, GABA-treated mice had greater saliva and tear production, as well as quicker times to salvia flow, in both SS mouse models. This was especially evident when GABA treatment was initiated after the onset of overt disease. This preservation of exocrine function was not accompanied by significant changes in the number or area of lymphocytic foci in the salivary or lachrymal glands of GABA-treated mice and we discuss the possible reasons for these observations. Given that GABA-treatment preserved saliva and tear production which are the most salient symptoms of SS and is safe for consumption, it may provide a new approach to help ameliorate SS.
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Gamma-aminobutyric acid (GABA) and GABA-receptors (GABA-Rs) form a major neurotransmitter system in the brain. GABA-Rs are also expressed by 1) cells of the innate and adaptive immune system and act to inhibit their inflammatory activities, and 2) lung epithelial cells and GABA-R agonists/potentiators have been observed to limit acute lung injuries. These biological properties suggest that GABA-R agonists may have potential for treating COVID-19. We previously reported that GABA-R agonist treatments protected mice from severe disease induced by infection with a lethal mouse coronavirus (MHV-1). Because MHV-1 targets different cellular receptors and is biologically distinct from SARS-CoV-2, we sought to test GABA therapy in K18-hACE2 mice which develop severe pneumonitis with high lethality following SARS-CoV-2 infection. We observed that GABA treatment initiated immediately after SARS-CoV-2 infection, or 2 days later near the peak of lung viral load, reduced pneumonitis severity and death rates in K18-hACE2 mice. GABA-treated mice had reduced lung viral loads and displayed shifts in their serum cytokine/chemokine levels that are associated with better outcomes in COVID-19 patients. Thus, GABA-R activation had multiple effects that are also desirable for the treatment of COVID-19. The protective effects of GABA against two very different beta coronaviruses (SARS-CoV-2 and MHV-1) suggest that it may provide a generalizable off-the-shelf therapy to help treat diseases induced by new SARS-CoV-2 variants and novel coronaviruses that evade immune responses and antiviral medications. GABA is inexpensive, safe for human use, and stable at room temperature, making it an attractive candidate for testing in clinical trials. We also discuss the potential of GABA-R agonists for limiting COVID-19-associated neuroinflammation.
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Tratamiento Farmacológico de COVID-19 , Neumonía , Ratones , Humanos , Animales , SARS-CoV-2 , Carga Viral , Ácido gamma-AminobutíricoRESUMEN
There is an urgent need for new approaches to limit the severity of coronavirus infections. Many cells of the immune system express receptors for the neurotransmitter γ-aminobutyric acid (GABA), and GABA-receptor (GABA-R) agonists have anti-inflammatory effects. Lung epithelial cells also express GABA-Rs, and GABA-R modulators have been shown to limit acute lung injuries. There is currently, however, no information on whether GABA-R agonists might impact the course of a viral infection. Here, we assessed whether clinically applicable GABA-R agonists could be repurposed for the treatment of a lethal coronavirus (murine hepatitis virus 1, MHV-1) infection in mice. We found that oral GABA administration before, or after the appearance of symptoms, very effectively limited MHV-1-induced pneumonitis, severe illness, and death. GABA treatment also reduced viral load in the lungs, suggesting that GABA-Rs may provide a new druggable target to limit coronavirus replication. Treatment with the GABAA-R-specific agonist homotaurine, but not the GABAB-R-specific agonist baclofen, significantly reduced the severity of pneumonitis and death rates in MHV-1-infected mice, indicating that the therapeutic effects were mediated primarily through GABAA-Rs. Since GABA and homotaurine are safe for human consumption, they are promising candidates to help treat coronavirus infections.
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Infecciones por Coronavirus/tratamiento farmacológico , Agonistas de Receptores de GABA-A/uso terapéutico , Virus de la Hepatitis Murina/efectos de los fármacos , Neumonía/tratamiento farmacológico , Animales , Infecciones por Coronavirus/mortalidad , Infecciones por Coronavirus/virología , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/virología , Ratones , Virus de la Hepatitis Murina/patogenicidad , Neumonía/mortalidad , Neumonía/virología , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Carga Viral/efectos de los fármacos , Pérdida de Peso/efectos de los fármacos , Ácido gamma-Aminobutírico/uso terapéuticoRESUMEN
Most multiple sclerosis (MS) patients given currently available disease-modifying drugs (DMDs) experience progressive disability. Accordingly, there is a need for new treatments that can limit the generation of new waves T cell autoreactivity that drive disease progression. Notably, immune cells express GABAA-receptors (GABAA-Rs) whose activation has anti-inflammatory effects such that GABA administration can ameliorate disease in models of type 1 diabetes, rheumatoid arthritis, and COVID-19. Here, we show that oral GABA, which cannot cross the blood-brain barrier (BBB), does not affect the course of murine experimental autoimmune encephalomyelitis (EAE). In contrast, oral administration of the BBB-permeable GABAA-R-specific agonist homotaurine ameliorates monophasic EAE, as well as advanced-stage relapsing-remitting EAE (RR-EAE). Homotaurine treatment beginning after the first peak of paralysis reduced the spreading of Th17 and Th1 responses from the priming immunogen to a new myelin T cell epitope within the CNS. Antigen-presenting cells (APC) isolated from homotaurine-treated mice displayed an attenuated ability to promote autoantigen-specific T cell proliferation. The ability of homotaurine treatment to limit epitope spreading within the CNS, along with its safety record, makes it an excellent candidate to help treat MS and other inflammatory disorders of the CNS.
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Sistema Nervioso Central/patología , Esclerosis Múltiple/inmunología , Linfocitos T/inmunología , Taurina/análogos & derivados , Animales , Presentación de Antígeno/efectos de los fármacos , Células Presentadoras de Antígenos/efectos de los fármacos , Células Presentadoras de Antígenos/inmunología , Proliferación Celular/efectos de los fármacos , Sistema Nervioso Central/efectos de los fármacos , Sistema Nervioso Central/inmunología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/patología , Femenino , Ratones Endogámicos C57BL , Esclerosis Múltiple/patología , Proteína Proteolipídica de la Mielina/inmunología , Fragmentos de Péptidos/inmunología , Recurrencia , Bazo/patología , Linfocitos T/efectos de los fármacos , Taurina/farmacología , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
The treatment of ischemic stroke (IS) remains a big challenge in clinics, and it is urgently needed to develop novel, safe, and effective medicines against IS. Here, we report the design, synthesis, and biological evaluation of organic NO2- donors as potential agents for the treatment of IS. The representative compound 4a was able to slowly generate low concentrations of NO2- by reaction with a thiol-containing nucleophile, and the NO2- was selectively converted into NO under ischemic/hypoxia conditions to protect primary rat neurons from oxygen-glucose deprivation and recovery (OGD/R)-induced cytotoxicity by enhancing the Nrf2 signaling and activating the NO/cGMP/PKG pathway. Treatment with 4a at 2 h before or after ischemia mitigated the ischemia/reperfusion-induced brain injury in middle cerebral artery occlusion (MCAO) rats by producing NO and enhancing Nrf2 signaling. Furthermore, 4a significantly promoted endothelial cell proliferation and angiogenesis within the ischemic penumbra. Our findings suggest that this type of NO2- donors, like 4a, may be valuable to fight IS and other ischemic diseases.
Asunto(s)
Diseño de Fármacos , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Nitritos/farmacología , Animales , Relación Dosis-Respuesta a Droga , Infarto de la Arteria Cerebral Media/metabolismo , Masculino , Estructura Molecular , Factor 2 Relacionado con NF-E2/antagonistas & inhibidores , Factor 2 Relacionado con NF-E2/metabolismo , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/química , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/biosíntesis , Nitritos/síntesis química , Nitritos/química , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
Some immune system cells express type A and/or type B γ-aminobutyric acid receptors (GABAA-Rs and/or GABAB-Rs). Treatment with GABA, which activates both GABAA-Rs and GABAB-Rs), and/or a GABAA-R-specific agonist inhibits disease progression in mouse models of type 1 diabetes (T1D), multiple sclerosis, rheumatoid arthritis, and COVID-19. Little is known about the clinical potential of specifically modulating GABAB-Rs. Here, we tested lesogaberan, a peripherally restricted GABAB-R agonist, as an interventive therapy in diabetic NOD mice. Lesogaberan treatment temporarily restored normoglycemia in most newly diabetic NOD mice. Combined treatment with a suboptimal dose of lesogaberan and proinsulin/alum immunization in newly diabetic NOD mice or a low-dose anti-CD3 in severely hyperglycemic NOD mice greatly increased T1D remission rates relative to each monotherapy. Mice receiving combined lesogaberan and anti-CD3 displayed improved glucose tolerance and, unlike mice that received anti-CD3 alone, had some islets with many insulin+ cells, suggesting that lesogaberan helped to rapidly inhibit ß-cell destruction. Hence, GABAB-R-specific agonists may provide adjunct therapies for T1D. Finally, the analysis of microarray and RNA-Seq databases suggested that the expression of GABAB-Rs and GABAA-Rs, as well as GABA production/secretion-related genes, may be a more common feature of immune cells than currently recognized.
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A series of novel furoxan-based nitric oxide (NO)-releasing derivatives of glycyrrhetinic acid (GA) were designed, synthesized, and evaluated for their in vitro cytotoxicity against human hepatocellular carcinoma (HCC) and non-tumor liver cells. Five furoxan/GA hybrids, 7b-d, 7f, and 7g, displayed potent cytotoxicity against HCC cells (IC(50): 0.25-1.10 µM against BEL-7402 cells and 1.32-6.78 µM against HepG2 cells), but had a little effect on the growth of LO2 cells, indicating that these compounds had selective cytotoxicity against HCC cells. Furthermore, these compounds produced high concentrations of NO in HCC cells, but low in LO2 cells and treatment with hemoglobin partially reduced the cytotoxicity of the hybrid in HCC cells. Apparently, the high concentrations of NO produced by NO donor moieties and the bioactivity of GA synergistically contribute to the cytotoxicity, but the NO is a major player against HCC cells in vitro. Potentially, our findings may aid in the design of new chemotherapeutic reagents for the intervention of human HCC at clinic.
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Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Carcinoma Hepatocelular/patología , Ácido Glicirretínico/síntesis química , Ácido Glicirretínico/farmacología , Neoplasias Hepáticas/patología , Óxido Nítrico/metabolismo , Oxadiazoles/química , Antineoplásicos/química , Línea Celular Tumoral , Ácido Glicirretínico/química , HumanosRESUMEN
Fourteen new 3-[4-(amino/methylsulfonyl)phenyl]methylene-indolin-2-one derivatives were synthesized. Six compounds displayed potent inhibitory activities against COX-1/2 and 5-LOX with IC(50) in the range of 0.10-9.87 µM. Particularly, 10f exhibited well balanced inhibitory action on these enzymes (IC(50)=0.10-0.56 µM). More importantly, 10f and several other compounds had comparable or stronger anti-inflammatory and analgesic activities, but better gastric tolerability in vivo, as compared with darbufelone mesilate and tenidap sodium. Therefore, our findings may aid in the design of new and safe anti-inflammatory reagents for the intervention of painful inflammatory diseases, such as rheumatoid arthritis at clinic.
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Araquidonato 5-Lipooxigenasa/química , Compuestos de Bencilideno/síntesis química , Ciclooxigenasa 1/química , Inhibidores de la Ciclooxigenasa 2/síntesis química , Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa/síntesis química , Indoles/síntesis química , Inhibidores de la Lipooxigenasa/síntesis química , Analgésicos/síntesis química , Analgésicos/química , Analgésicos/farmacología , Animales , Antiinflamatorios/síntesis química , Antiinflamatorios/química , Antiinflamatorios/farmacología , Araquidonato 5-Lipooxigenasa/metabolismo , Compuestos de Bencilideno/química , Compuestos de Bencilideno/farmacología , Ciclooxigenasa 1/metabolismo , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa 2/farmacología , Inhibidores de la Ciclooxigenasa/química , Inhibidores de la Ciclooxigenasa/farmacología , Indoles/química , Indoles/farmacología , Inhibidores de la Lipooxigenasa/química , Inhibidores de la Lipooxigenasa/farmacología , Masculino , Ratones , Ratas , Relación Estructura-ActividadRESUMEN
A series of nitric oxide (NO)-releasing glycosyl derivatives () of oleanolic acid were synthesized to improve the aqueous solubility and cytotoxicity of the parent compound . Derivative exhibited better solubility and strong cytotoxicity against human hepatocellular carcinoma (HCC) in vitro. Furthermore, displayed low acute toxicity to mice and significantly inhibited the growth of HCC tumors in vivo, indicating that may be a promising candidate for the treatment of human HCC.
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Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Óxido Nítrico/química , Ácido Oleanólico/síntesis química , Ácido Oleanólico/farmacología , Animales , Antineoplásicos/uso terapéutico , Antineoplásicos/toxicidad , Carcinoma Hepatocelular/tratamiento farmacológico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Descubrimiento de Drogas , Femenino , Glicosilación , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Masculino , Ratones , Ácido Oleanólico/uso terapéutico , Ácido Oleanólico/toxicidad , Solubilidad , Relación Estructura-Actividad , Agua/química , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Novel furoxan-based nitric oxide (NO)-releasing derivatives (11a-p) of farnesylthiosalicylic acid (FTA) were synthesized. Compounds 11d, 11f, 11k, and 11m-o displayed anti-tumor activities superior to FTA and sorafenib in most cancer cells tested. Analysis of six compounds revealed that 11d, 11f, 11n, 11o, and 11p, but not 11a that had low anti-tumor activity, produced high levels of NO, associated with their strong anti-tumor activity. Furthermore, the anti-tumor activity of 11f was partially mimicked by the furoxan moiety, but reduced by pre-treatment with hemoglobin. Importantly, treatment with 11f inhibited Ras-related signaling in cancer cells. Apparently, the high anti-tumor activity of 11f was attributed to the synergic effect of high levels of NO production and inhibition of Ras-related signaling in cancer cells. Our findings suggest that the furoxan/FTA hybrids may hold greater promise as therapeutic agents for the intervention of human cancers.
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Antineoplásicos/farmacología , Farnesol/análogos & derivados , Óxido Nítrico/farmacología , Oxadiazoles/farmacología , Salicilatos/farmacología , Transducción de Señal/efectos de los fármacos , Antineoplásicos/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Diseño de Fármacos , Farnesol/química , Farnesol/metabolismo , Farnesol/farmacología , Genes ras/efectos de los fármacos , Humanos , Oxadiazoles/metabolismo , Salicilatos/química , Salicilatos/metabolismo , Relación Estructura-ActividadRESUMEN
To find novel antihepatitis drugs, a series of nitrate-oleanolic acid (OA) hybrids (10a, 10b, 11a-11e and 12a-12c) were designed and synthesized on the basis of previous studies using OA as lead compound, which is widely found in natural plants and liver-specific metabolism. In the present study, ten novel NO-releasing derivatives of OA were synthesized by connecting nitrate to the OA-3-OH through varying lengths of linkers containing antioxidants which were designed to increase the ability of these target compounds to scavenge free radicals. The structures of these objective compounds were determined by IR, MS, 1H NMR and elemental analysis. Their protective effects on anti-Fas mediated HepG2 cell apoptosis were in vitro evaluated by LDH assay. Compound 12a is the most potent inhibitor. Its effect on anti-Fas mediated HepG2 cell apoptosis and amount of NO-releasing in vitro are similar to those of positive control NCX-1000.
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Apoptosis/efectos de los fármacos , Nitratos , Donantes de Óxido Nítrico , Ácido Oleanólico , Antioxidantes/química , Células Hep G2 , Humanos , Nitratos/síntesis química , Nitratos/química , Nitratos/farmacología , Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/química , Ácido Oleanólico/síntesis química , Ácido Oleanólico/química , Ácido Oleanólico/farmacología , Relación Estructura-Actividad , Ácido Ursodesoxicólico/análogos & derivados , Ácido Ursodesoxicólico/farmacologíaRESUMEN
There is an urgent need for new treatments to prevent and ameliorate severe illness and death induced by SARS-CoV-2 infection in COVID-19 patients. The coronavirus mouse hepatitis virus (MHV)-1 causes pneumonitis in mice which shares many pathological characteristics with human SARS-CoV infection. Previous studies have shown that the amino acid gamma-aminobutyric acid (GABA) has anti-inflammatory effects. We tested whether oral treatment with GABA could modulate the MHV-1 induced pneumonitis in susceptible A/J mice. As expected, MHV-1-inoculated control mice became severely ill (as measured by weight loss, clinical score, and the ratio of lung weight to body weight) and >60% of them succumbed to the infection. In contrast, mice that received GABA immediately after MHV-1 inoculation became only mildly ill and all of them recovered. When GABA treatment was initiated after the appearance of illness (3 days post-MHV-1 infection), we again observed that GABA treatment significantly reduced the severity of illness and greatly increased the frequency of recovery. Therefore, the engagement of GABA receptors (GABA-Rs) prevented the MHV-1 infection-induced severe pneumonitis and death in mice. Given that GABA-R agonists, like GABA and homotaurine, are safe for human consumption, stable, inexpensive, and available worldwide, they are promising candidates to help prevent severe illness stemming from SARS-CoV-2 infection and other coronavirus strains.
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Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a lipid phosphatase. PTEN inhibits the action of phosphatidylinositol-3-kinase and reduces the levels of phosphatidylinositol triphosphate, a crucial second messenger for cell proliferation and survival, as well as insulin signaling. In this study, we deleted Pten specifically in the insulin producing beta cells during murine pancreatic development. Pten deletion leads to increased cell proliferation and decreased cell death, without significant alteration of beta-cell differentiation. Consequently, the mutant pancreas generates more and larger islets, with a significant increase in total beta-cell mass. PTEN loss also protects animals from developing streptozotocin-induced diabetes. Our data demonstrate that PTEN loss in beta cells is not tumorigenic but beneficial. This suggests that modulating the PTEN-controlled signaling pathway is a potential approach for beta-cell protection and regeneration therapies.
Asunto(s)
Diabetes Mellitus Experimental/inducido químicamente , Resistencia a Medicamentos , Eliminación de Gen , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/efectos de los fármacos , Fosfohidrolasa PTEN/deficiencia , Fosfohidrolasa PTEN/genética , Animales , Muerte Celular , Proliferación Celular , Diabetes Mellitus Experimental/patología , Glucosa/metabolismo , Homeostasis , Células Secretoras de Insulina/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Mutantes , Tamaño de los Órganos , Estrés Oxidativo/efectos de los fármacos , Fosfohidrolasa PTEN/metabolismo , Estreptozocina/farmacologíaRESUMEN
A major goal of T1D research is to develop new approaches to increase ß-cell mass and control autoreactive T cell responses. GABAA-receptors (GABAA-Rs) are promising drug targets in both those regards due to their abilities to promote ß-cell replication and survival, as well as inhibit autoreactive T cell responses. We previously showed that positive allosteric modulators (PAMs) of GABAA-Rs could promote rat ß-cell line INS-1 and human islet cell replication in vitro. Here, we assessed whether treatment with alprazolam, a widely prescribed GABAA-R PAM, could promote ß-cell survival and replication in human islets after implantation into NOD/scid mice. We observed that alprazolam treatment significantly reduced human islet cell apoptosis following transplantation and increased ß-cell replication in the xenografts. Evidently, the GABAA-R PAM works in conjunction with GABA secreted from ß-cells to increase ß-cell survival and replication. Treatment with both the PAM and GABA further enhanced human ß-cell replication. Alprazolam also augmented the ability of suboptimal doses of GABA to inhibit antigen-specific T cell responses in vitro. Thus, combined GABAA-R agonist and PAM treatment may help control inflammatory immune responses using reduced drug dosages. Together, these findings suggest that GABAA-R PAMs represent a promising drug class for safely modulating islet cells toward beneficial outcomes to help prevent or reverse T1D and, together with a GABAA-R agonist, may have broader applications for ameliorating other disorders in which inflammation contributes to the disease process.
Asunto(s)
Alprazolam/farmacología , Supervivencia Celular , Inflamación , Células Secretoras de Insulina/citología , Receptores de GABA/metabolismo , Linfocitos T/metabolismo , Animales , Apoptosis , División Celular , Proliferación Celular , Humanos , Islotes Pancreáticos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones SCID , Muramidasa , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
There has been considerable debate as to whether obesity can act as an accelerator of type 1 diabetes (T1D). We assessed this possibility using transgenic mice (MIP-TF mice) whose ß-cells express enhanced green fluorescent protein (EGFP). Infecting these mice with EGFP-expressing murine herpes virus-68 (MHV68-EGFP) caused occasional transient elevation in their blood glucose, peri-insulitis, and Th1 responses to EGFP which did not spread to other ß-cell antigens. We hypothesized that obesity-related systemic inflammation and ß-cell stress could exacerbate the MHV68-EGFP-induced ß-cell autoreactivity. We crossed MIP-TF mice with Avy mice which develop obesity and provide models of metabolic disease alongside early stage T2D. Unlike their MIP-TF littermates, MHV68-EGFP-infected Avy/MIP-TF mice developed moderate intra-insulitis and transient hyperglycemia. MHV68-EGFP infection induced a more pronounced intra-insulitis in older, more obese, Avy/MIP-TF mice. Moreover, in MHV68-EGFP-infected Avy/MIP-TF mice, Th1 reactivity spread from EGFP to other ß-cell antigens. Thus, the spreading of autoreactivity among ß-cell antigens corresponded with the transition from peri-insulitis to intra-insulitis and occurred in obese Avy/MIP-TF mice but not lean MIP-TF mice. These observations are consistent with the notion that obesity-associated systemic inflammation and ß-cell stress lowers the threshold necessary for T cell autoreactivity to spread from EGFP to other ß-cell autoantigens.