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Benzylic C-H bonds next to electron rich aromatic rings are susceptible to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) promoted functionalization. In this work benzylic carbocations formed in this manner are trapped by a pendant carboxylic acid to form a lactone. Indole-3-butyric acids are especially good substrates for the reaction. The lactonization functions well with catalytic amounts of DDQ combined with MnO2 as the stoichiometric oxidant. This cyclization proceeds with a number of indole-3-butyric acids, and yields were generally good as long as the indole was electron rich and free of bulky substituents near the reacting benzylic carbon. Indole-3-butyric acids functionalized with electron withdrawing groups tend to give more moderate yields. Other aromatic substrates also participate as long as the aromatic ring is functionalized with electron donating groups.
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Microglia play a pivotal role in the pathology of Alzheimer's Disease (AD), with the Triggering Receptor Expressed on Myeloid cells 2 (TREM2) central to their neuroprotective functions. The R47H variant of TREM2 has emerged as a significant genetic risk factor for AD, leading to a loss-of-function phenotype in mouse AD models. This study elucidates the roles of TREM2 in human microglia-like HMC3 cells and the regulation of these functions by SH2-containing inositol-5'-phosphatase 1 (SHIP1). Using stable cell lines expressing wild-type TREM2, the R47H variant, and TREM2-deficient lines, we found that functional TREM2 is essential for the phagocytosis of Aß, lysosomal capacity, and mitochondrial activity. Notably, the R47H variant displayed increased phagocytic activity towards apoptotic neurons. Introducing SHIP1, known to modulate TREM2 signaling in other cells, revealed its role as a negative regulator of these TREM2-mediated functions. Moreover, pharmacological inhibition of both SHIP1 and its isoform SHIP2 amplified Aß phagocytosis and lysosomal capacity, independently of TREM2 or SHIP1 expression, suggesting a potential regulatory role for SHIP2 in these functions. The absence of TREM2, combined with the presence of both SHIP isoforms, suppressed mitochondrial activity. However, pan-SHIP1/2 inhibition enhanced mitochondrial function in these cells. In summary, our findings offer a deeper understanding of the relationship between TREM2 variants and SHIP1 in microglial functions, and emphasize the therapeutic potential of targeting the TREM2 and SHIP1 pathways in microglia for neurodegenerative diseases.
Assuntos
Glicoproteínas de Membrana , Microglia , Fagocitose , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Receptores Imunológicos , Animais , Humanos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Apoptose/genética , Linhagem Celular , Lisossomos/metabolismo , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Microglia/metabolismo , Mitocôndrias/metabolismo , Fagocitose/genética , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/genética , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/metabolismo , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Transdução de SinaisRESUMO
The SH2-containing inositol polyphosphate 5-phosphatase 1 (SHIP1) enzyme opposes the activity of PI3K and therefore is of interest in the treatment of inflammatory disorders. Recent results also indicate that SHIP1 promotes phagolysosomal degradation of lipids by microglia, suggesting that the enzyme may be a target for the treatment of Alzheimer's disease. Therefore, small molecules that increase SHIP1 activity may have benefits in these areas. Recently we discovered a bis-sulfonamide that increases the enzymatic activity of SHIP1. A series of similar SHIP1 activators have been synthesized and evaluated to determine structure-activity relationships and improve in vivo stability. Some new analogs have now been found with improved potency. In addition, both the thiophene and the thiomorpholine in the parent structure can be replaced by groups without a low valent sulfur atom, which provides a way to access activators that are less prone to oxidative degradation.
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Monoéster Fosfórico Hidrolases , Monoéster Fosfórico Hidrolases/metabolismoRESUMO
Leishmania major and L. donovani cause cutaneous leishmaniasis and visceral leishmaniasis, respectively. Available chemotherapies suffer from toxicity, drug-resistance or high cost of production prompting the need for the discovery of new anti-leishmanials. Here, we test a novel aminosteriodal compound- 3-alpha-amino-cholestane [3AC] - that shows selective inhibition of SHIP1, an inositol-5'-phosphate-specific phosphatase with potent effects on the immune system. We report that 3AC-sensitive SHIP1 expression increases in Leishmania-infected macrophages. Treatment of BALB/c mice, a Leishmania-susceptible host, with 3AC increased anti-leishmanial, but reduced pro-leishmanial, cytokines' production and reduced the parasite load in both L. major and L. donovani infections. These findings implicate SHIPi as a potential novel immunostimulant with anti-leishmanial function.
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Leishmania donovani , Leishmaniose Visceral , Animais , Camundongos , Leishmaniose Visceral/tratamento farmacológico , Camundongos Endogâmicos BALB CRESUMO
Serine/threonine protein phosphatase-5 (PP5) is involved in tumor progression and survival, making it an attractive therapeutic target. Specific inhibition of protein phosphatases has remained challenging because of their conserved catalytic sites. PP5 contains its regulatory domains within a single polypeptide chain, making it a more desirable target. Here we used an in silico approach to screen and develop a selective inhibitor of PP5. Compound P053 is a competitive inhibitor of PP5 that binds to its catalytic domain and causes apoptosis in renal cancer. We further demonstrated that PP5 interacts with FADD, RIPK1, and caspase 8, components of the extrinsic apoptotic pathway complex II. Specifically, PP5 dephosphorylates and inactivates the death effector protein FADD, preserving complex II integrity and regulating extrinsic apoptosis. Our data suggests that PP5 promotes renal cancer survival by suppressing the extrinsic apoptotic pathway. Pharmacologic inhibition of PP5 activates this pathway, presenting a viable therapeutic strategy for renal cancer.
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Neoplasias Renais , Fosfoproteínas Fosfatases , Humanos , Proteínas Nucleares/metabolismo , Apoptose , Neoplasias Renais/tratamento farmacológicoRESUMO
Here we extend the understanding of how chemical inhibition of SHIP paralogs controls obesity. We compare different classes of SHIP inhibitors and find that selective inhibitors of SHIP1 or SHIP2 are unable to prevent weight gain and body fat accumulation during increased caloric intake. Surprisingly, only pan-SHIP1/2 inhibitors (pan-SHIPi) prevent diet-induced obesity. We confirm that pan-SHIPi is essential by showing that dual treatment with SHIP1 and SHIP2 selective inhibitors reduced adiposity during excess caloric intake. Consistent with this, genetic inactivation of both SHIP paralogs in eosinophils or myeloid cells also reduces obesity and adiposity. In fact, pan-SHIPi requires an eosinophil compartment to prevent diet-induced adiposity, demonstrating that pan-SHIPi acts via an immune mechanism. We also find that pan-SHIPi increases ILC2 cell function in aged, obese mice to reduce their obesity. Finally, we show that pan-SHIPi also reduces hyperglycemia, but not via eosinophils, indicating a separate mechanism for glucose control.
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Inhibition of phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase (SHIP) with small molecule inhibitors leads to apoptosis in tumor cells. Inhibitors that target both SHIP1 and SHIP2 (pan-SHIP1/2 inhibitors) may have benefits in these areas since paralog compensation is not possible when both SHIP paralogs are being inhibited. A series of tryptamine-based pan-SHIP1/2 inhibitors have been synthesized and evaluated for their ability to inhibit the SHIP paralogs. The most active compounds were also evaluated for their effects on cancer cell lines.
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Antineoplásicos , Neoplasias , Humanos , Monoéster Fosfórico Hidrolases/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/metabolismo , Fosforilação , Neoplasias/tratamento farmacológico , Antineoplásicos/farmacologia , Linhagem CelularRESUMO
Humans homozygous for inactivating LRBA (lipopolysaccharide (LPS)-responsive beige-like anchor) mutations or with compound heterozygous mutations exhibit a spectrum of immune-related pathologies including inflammatory bowel disease (IBD). The cause of this pathology remains undefined. Here we show that disruption of the colon epithelial barrier in LRBA-deficient mice by dextran sulfate sodium (DSS) consumption leads to severe and uniformly lethal colitis. Analysis of bone marrow (BM) chimeras showed that susceptibility to lethal colitis is primarily due to LRBA deficiency in the immune compartment and not the gut epithelium. Further dissection of the immune defect in LRBA-deficient hosts showed that LRBA is essential for the expression of CTLA4 by Treg cells and IL22 and IL17 expression by ILC3 cells in the large intestine when the gut epithelium is compromised by DSS. We further show that SHIP1 agonism partially abrogates the severity and lethality of DSS-mediated colitis. Our findings indicate that enteropathy induced by LRBA deficiency has multiple causes and that SHIP1 agonism can partially abrogate the inflammatory milieu in the gut of LRBA-deficient hosts.
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Colite , Imunodeficiência de Variável Comum , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Colite/induzido quimicamente , Colite/genética , Camundongos , Mutação , Linfócitos T ReguladoresRESUMO
AQX-1125 is an indane based SHIP1 agonist that has been evaluated in the clinic for the treatment of bladder pain syndrome/interstitial cystitis. To support our own studies on SHIP1 agonists as potential treatments for IBD and Crohn's disease, a new synthetic route to the SHIP1 agonist AQX-1125 has been developed. This sequence utilizes a hydroxy-acid intermediate which allows for ready differentiation of the C6 and C7 positions. The role of the C17 alkene in the biological activity of the system is also investigated, and this functional group is not required for SHIP1 agonist activity. While AQX-1125 shows SHIP1 agonist activity in enzyme assays, it does not show activity in cell based assays similar to other SHIP1 agonists, which limits the utility of this molecule.
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Cicloexanóis , Monoéster Fosfórico Hidrolases , IndanosRESUMO
Here, we describe the use of artificial intelligence to identify novel agonists of the SH2-containing 5' inositol phosphatase 1 (SHIP1). One of the compounds, K306, represents the most potent agonist identified to date. We find that K306 exhibits selectivity for SHIP1 vs. the paralog enzyme SHIP2, and this activation does not require the C2 domain of SHIP1 which other known SHIP1 agonists require. Thus, K306 represents a new class of SHIP1 agonists with a novel mode of agonism. Importantly, we find that K306 can suppress induction of inflammatory cytokines and iNOS in macrophages or microglia, but not by their SHIP1-deficient counterparts. K306 also reduces TNF-α production in vivo in an LPS-induced endotoxemia assay. Finally, we show that K306 enhances phagolysosomal degradation of synaptosomes and dead neurons by microglia revealing a novel function for SHIP1 that might be exploited therapeutically in dementia.
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N-Alkylation of isatins can be achieved utilizing trichloroacetimidate electrophiles and a Lewis acid catalyst. These reactions provide access to N-alkyl isatins, versatile scaffolds which are often employed in the synthesis of pharmaceutical lead structures as well as natural products. Secondary trichloroacetimidates that are precursors to stabilized carbocations provided excellent yields of the isatin product. Substitution was well tolerated on the isatin, although reduced reactivity was observed with C7-substitution, likely due to the steric effects. Solvent effects can be used to favor O-alkylation under similar reaction conditions.
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Pyrroloindolines and related systems are present in a large number of complex natural products. These core structures have generated considerable synthetic interest, as many of the compounds possess challenging, elaborate structures and interesting biological properties. Recently we have focused on using trichloroacetimidates for the synthesis of these fascinating molecules. Trichloroacetimidates can be used as an electrophilic source of an alkyl group to form the pyrroloindoline directly from tryptamine derivatives. In this manner trichloroacetimidates provide a flexible solution to forming highly functionalized pyrroloindoline core structures, needing only a catalytic amount of a Lewis acid to effect the requisite transformations.
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Tertiary benzylic alcohols react with oxoammonium salts, undergoing a tandem elimination/allylic oxidation to provide an allylic ether product in a single step. This mode of reactivity provides a rapid entry into allylic ethers from certain benzylic tertiary alcohols. The allylic ether may be cleaved under reductive conditions to reveal the allylic alcohol.
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Membrane-anchored and soluble inositol phospholipid species are critical mediators of intracellular cell signaling cascades. Alterations in their normal production or degradation are implicated in the pathology of a number of disorders including cancer and pro-inflammatory conditions. The SH2-containing 5' inositol phosphatases, SHIP1 and SHIP2, play a fundamental role in these processes by depleting PI(3,4,5)P3, but also by producing PI(3,4)P2 at the inner leaflet of the plasma membrane. With the intent of targeting SHIP1 or SHIP2 selectively, or both paralogs simultaneously, small molecule inhibitors and agonists have been developed and tested in vitro and in vivo over the last decade in various disease models. These studies have shown promising results in various pre-clinical models of disease including cancer and tumor immunotherapy. In this review the potential use of SHIP inhibitors in cancer is discussed with particular attention to the molecular structure, binding site and efficacy of these SHIP inhibitors.
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INTRODUCTION: The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED: This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION: A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Aciltransferases/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Grelina/metabolismo , Aciltransferases/metabolismo , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/enzimologia , Desenvolvimento de Medicamentos , Humanos , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/enzimologia , Obesidade/tratamento farmacológico , Obesidade/enzimologia , Patentes como AssuntoRESUMO
Modulating the activity of the Src Homology 2 (SH2) - containing Inositol 5'-Phosphatase (SHIP) enzyme family with small molecule inhibitors provides a useful and unconventional method of influencing cell signaling in the PI3K pathway. The development of small molecules that selectively target one of the SHIP paralogs (SHIP1 or SHIP2) as well as inhibitors that simultaneously target both enzymes have provided promising data linking the phosphatase activity of the SHIP enzymes to disorders and disease states that are in dire need of new therapeutic targets. These include cancer, immunotherapy, diabetes, obesity, and Alzheimer's disease. In this mini-review, we will provide a brief overview of research in these areas that support targeting SHIP1, SHIP2 or both enzymes for therapeutic purposes.
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Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Animais , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/metabolismo , Descoberta de Drogas , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/química , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/metabolismoRESUMO
We show here that both SHIP1 (Inpp5d) and its paralog SHIP2 (Inppl1) are expressed at protein level in microglia. To examine whether targeting of SHIP paralogs might influence microglial physiology and function, we tested the capacity of SHIP1-selective, SHIP2-selective and pan-SHIP1/2 inhibitors for their ability to impact on microglia proliferation, lysosomal compartment size and phagocytic function. We find that highly potent pan-SHIP1/2 inhibitors can significantly increase lysosomal compartment size, and phagocytosis of dead neurons and amyloid beta (Aß)1-42 by microglia in vitro We show that one of the more-potent and water-soluble pan-SHIP1/2 inhibitors, K161, can penetrate the blood-brain barrier. Consistent with this, K161 increases the capacity of CNS-resident microglia to phagocytose Aß and apoptotic neurons following systemic administration. These findings provide the first demonstration that small molecule modulation of microglia function in vivo is feasible, and suggest that dual inhibition of the SHIP1 and 2 paralogs can provide a novel means to enhance basal microglial homeostatic functions for therapeutic purposes in Alzheimer's disease and, possibly, other types of dementia where increased microglial function could be beneficial.
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Doença de Alzheimer , Microglia , Peptídeos beta-Amiloides , Homeostase , Humanos , FagocitoseRESUMO
2-Substituted indoles may be directly transformed to 3,3-dialkyl indolenines with trichloroacetimidate electrophiles and the Lewis acid TMSOTf. These reactions provide rapid access to complex indolenines which are present in a variety of complex natural products and medicinally relevant small molecule structures. This method provides an alternative to the use of transition metal catalysis. The indolenines are readily transformed into spiroindoline systems which are privileged scaffolds in medicinal chemistry.
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Acetamidas/química , Cloroacetatos/química , Indóis/química , Ácidos de Lewis/química , Catálise , EstereoisomerismoRESUMO
Substituted indole scaffolds are often utilized in medicinal chemistry as they regularly possess significant pharmacological activity. Therefore the development of simple, inexpensive and efficient methods for alkylating the indole heterocycle continues to be an active research area. Reported are reactions of trichloroacetimidate electrophiles and indoles to address the challenges of accessing alkyl decorated indole structures. These alkylations perform best when either the indole or the imidate is functionalized with electron withdrawing groups to avoid polyalkylation.
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Trichloroacetimidates are useful reagents for the synthesis of esters under mild conditions that do not require an exogenous promoter. These conditions avoid the undesired decomposition of substrates with sensitive functional groups that are often observed with the use of strong Lewis or Brønsted acids. With heating, these reactions have been extended to benzyl esters without electron-donating groups. These inexpensive and convenient methods should find application in the formation of esters in complex substrates.