In this work we investigated, for the first time, the reactivity of sulfinimidate esters as an electrophilic sulfinimidoyl motif source. The reaction of such sulfinimidate esters with Grignard ...reagents enables the preparation of protected sulfilimines in high yields and with a remarkable structural variability. Moreover, the transformation can be performed in CPME (cyclopentyl methyl ether) as a green solvent under environmentally responsible conditions.
The formation of hydrazinium salts by N−N bond formation has typically involved the use of hazardous and difficult to handle reagents. Here, mild and operationally simple conditions for the synthesis ...of hydrazinium salts are reported. Electrophilic nitrogen transfer to the nitrogen atom of tertiary amines is achieved using iodosylbenzene as oxidant and ammonium carbamate as the N‐source. The resulting process is highly chemoselective and tolerant to other functional groups. A wide scope is reported, including examples with bioactive molecules. Insights on the structure of hydrazinium salts were provided by X‐ray analysis.
Chemotherapy-induced peripheral neuropathy (CIPN) and hypersensitivity reactions (HSRs) are among the most frequent and impairing side effects of the antineoplastic agent paclitaxel. Here, we ...demonstrated that paclitaxel can bind and activate complement component 5a receptor 1 (C5aR1) and that this binding is crucial in the etiology of paclitaxel-induced CIPN and anaphylaxis. Starting from our previous data demonstrating the role of interleukin (IL)-8 in paclitaxel-induced neuronal toxicity, we searched for proteins that activate IL-8 expression and, by using the Exscalate platform for molecular docking simulations, we predicted the high affinity of C5aR1 with paclitaxel. By in vitro studies, we confirmed the specific and competitive nature of the C5aR1-paclitaxel binding and found that it triggers intracellularly the NFkB/P38 pathway and c-Fos. In F11 neuronal cells and rat dorsal root ganglia, C5aR1 inhibition protected from paclitaxel-induced neuropathological effects, while in paclitaxel-treated mice, the absence (knock-out mice) or the inhibition of C5aR1 significantly ameliorated CIPN symptoms-in terms of cold and mechanical allodynia-and reduced the chronic pathological state in the paw. Finally, we found that C5aR1 inhibition can counteract paclitaxel-induced anaphylactic cytokine release in macrophages in vitro, as well as the onset of HSRs in mice. Altogether these data identified C5aR1 as a key mediator and a new potential pharmacological target for the prevention and treatment of CIPN and HSRs induced by paclitaxel.
G-protein coupled receptors 40 and 120 (GPR40 and GPR120) are increasingly emerging as potential therapeutic targets for the treatment of altered glucose homeostasis, and their agonists are under ...evaluation for their glucagon-like peptide-1 (GLP-1)-mediated therapeutic effects on insulin production and sensitivity. Here, we characterized a new dual GPR40 and GPR120 agonist (DFL23916) and demonstrated that it can induce GLP-1 secretion and improve glucose homeostasis.
Resulting from a rational drug design approach aimed at identifying new dual GPR120/40 agonists able to delay receptor internalization, DFL23916 had a good activity and a very high selectivity towards human GPR120 (long and short isoforms) and GPR40, as well as towards their mouse orthologous, by which it induced both Gαq/11-initiated signal transduction pathways with subsequent Ca2+ intracellular spikes and G protein-independent signaling via β-arrestin with the same activity. Compared to the endogenous ligand alpha-linolenic acid (ALA), a selective GPR120 agonist (TUG-891) and a well-known dual GPR40 and GPR120 agonist (GW9508), DFL23916 was the most effective in inducing GLP-1 secretion in human and murine enteroendocrine cells, and this could be due to the delayed internalization of the receptor (up to 3 h) that we observed after treatment with DFL23916. With a good pharmacokinetic/ADME profile, DFL23916 significantly increased GLP-1 portal vein levels in healthy mice, demonstrating that it can efficiently induce GLP-1 secretion in vivo. Contrary to the selective GPR120 agonist (TUG-891), DFL23916 significantly improved also glucose homeostasis in mice undergoing an oral glucose tolerance test (OGTT).
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•DFL23916 is a new dual agonist of human and mouse GPR40 and GPR120.•DFL23916 significantly delayed receptor endocytosis compared to other known GPR120 agonists.•DFL23916 efficiently induced GLP-1 secretion in vitro and in vivo.•DFL23916 significantly improved glucose homeostasis in mice following glucose load.
Abstract
Hearing loss impacts the quality of life and affects communication resulting in social isolation and reduced well-being. Despite its impact on society and economy, no therapies for ...age-related hearing loss are available so far. Loss of mechanosensory hair cells of the cochlea is a common event of hearing loss in humans. Studies performed in birds demonstrating that they can be replaced following the proliferation and transdifferentiation of supporting cells, strongly pointed out on HCs regeneration as the main focus of research aimed at hearing regeneration. Neurotrophins are growth factors involved in neuronal survival, development, differentiation, and plasticity. NGF has been involved in the interplay between auditory receptors and efferent innervation in the cochlea during development. During embryo development, both NGF and its receptors are highly expressed in the inner ears. It has been reported that NGF is implicated in the differentiation of auditory gangliar and hair cells. Thus, it has been proposed that NGF administration can decrease neuronal damage and prevent hearing loss. The main obstacle to the development of hearing impairment therapy is that efficient means of delivery for selected drugs to the cochlea are missing. Herein, in this study NGF was administered by the intranasal route. The first part of the study was focused on a biodistribution study, which showed the effective delivery in the cochlea; while the second part was focused on analyzing the potential therapeutic effect of NGF in senescence-accelerated prone strain 8 mice. Interestingly, intranasal administration of NGF resulted protective in counteracting hearing impairment in SAMP8 mice, ameliorating hearing performances (analyzed by auditory brainstem responses and distortion product otoacoustic emission) and hair cells morphology (analyzed by microscopy analysis). The results obtained were encouraging indicating that the neurotrophin NGF was efficiently delivered to the inner ear and that it was effective in counteracting hearing loss.
Nerve growth factor (NGF) is the best characterized neurotrophin, and it is known to play an important role in ocular homeostasis. Here, we demonstrated the expression of NGF receptors in adult ...zebrafish retina and optimized a light-induced retina degeneration (LID) zebrafish model that mimics human cone-rod disorders, demonstrating that intravitreal (IV) administration of rhNGF can boost zebrafish retinal regeneration in this model. Adult zebrafish retinae exposed to 60 h of light irradiation (60 h LID) displayed evident reduction of outer nuclear layer (ONL) thickness and cell number with presence of apoptotic cells. Retinal histologic evaluation at different time points showed that IV therapeutic injection of rhNGF resulted in an increase of ONL thickness and cell number at late time points after damage (14 and 21 days post injury), ultimately accelerating retinal tissue recovery by driving retinal cell proliferation. At a molecular level, rhNGF activated the ERK1/2 pathway and enhanced the regenerative potential of Müller glia
and
expressing cells by stimulating at early time points the expression of the photoreceptor regeneration factor Drgal1-L2. Our results demonstrate the highly conserved nature of NGF canonical pathway in zebrafish and thus support the use of zebrafish models for testing new compounds with potential retinal regenerative properties. Moreover, the pro-regenerative effects of IV-injected NGF that we observed pave the way to further studies aimed at evaluating its effects also in mammals, in order to expedite the development of novel rhNGF-based therapeutic approaches for ophthalmological disorders.
In age-related sarcopenia, the gradual loss of skeletal muscle mass, function and strength is underpinned by an imbalanced rate of protein synthesis/breakdown. Hence, an adequate protein intake is ...considered a valuable strategy to mitigate sarcopenia. Here, we investigated the effects of a 12-week oral supplementation with branched-chain amino acids (BCAAs: leucine, isoleucine, and valine) with recognized anabolic properties, in 17-month-old (AGED) C57BL/6J male mice. BCAAs (2:1:1) were formulated in drinking water, alone or plus two L-Alanine equivalents (2ALA) or dipeptide L-Alanyl-L-Alanine (Di-ALA) to boost BCAAs bioavailability. Outcomes were evaluated on in/ex vivo readouts vs. 6-month-old (ADULT) mice. In vivo hind limb plantar flexor torque was improved in AGED mice treated with BCAAs + Di-ALA or 2ALA (recovery score, R.S., towards ADULT: ≥20%), and all mixtures significantly increased hind limb volume. Ex vivo, myofiber cross-sectional areas were higher in gastrocnemius (GC) and soleus (SOL) muscles from treated mice (R.S. ≥ 69%). Contractile indices of isolated muscles were improved by the mixtures, especially in SOL muscle (R.S. ≥ 20%). The latter displayed higher mTOR protein levels in mice supplemented with 2ALA/Di-ALA-enriched mixtures (R.S. ≥ 65%). Overall, these findings support the usefulness of BCAAs-based supplements in sarcopenia, particularly as innovative formulations potentiating BCAAs bioavailability and effects.
Chronic pain is an enormous public health concern, and its treatment is still an unmet medical need. Starting from data highlighting the promising effects of some nonsteroidal anti-inflammatory drugs ...in combination with gabapentin in pain treatment, we sought to combine ketoprofen lysine salt (KLS) and gabapentin to obtain an effective multimodal therapeutic approach for chronic pain. Using relevant in vitro models, we first demonstrated that KLS and gabapentin have supra-additive effects in modulating key pathways in neuropathic pain and gastric mucosal damage. To leverage these supra-additive effects, we then chemically combined the two drugs via co-crystallization to yield a new compound, a ternary drug-drug co-crystal of ketoprofen, lysine and gabapentin (KLS-GABA co-crystal). Physicochemical, biodistribution and pharmacokinetic studies showed that within the co-crystal, ketoprofen reaches an increased gastrointestinal solubility and permeability, as well as a higher systemic exposure in vivo compared to KLS alone or in combination with gabapentin, while both the constituent drugs have increased central nervous system permeation. These unique characteristics led to striking, synergistic anti-nociceptive and anti-inflammatory effects of KLS-GABA co-crystal, as well as significantly reduced spinal neuroinflammation, in translational inflammatory and neuropathic pain rat models, suggesting that the synergistic therapeutic effects of the constituent drugs are further boosted by the co-crystallization. Notably, while strengthening the therapeutic effects of ketoprofen, KLS-GABA co-crystal showed remarkable gastrointestinal tolerability in both inflammatory and chronic neuropathic pain rat models. In conclusion, these results allow us to propose KLS-GABA co-crystal as a new drug candidate with high potential clinical benefit–to–risk ratio for chronic pain treatment.
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•KLS-GABA co-crystal showed a high gastric solubility and systemic exposure of ketoprofen in vivo.•KLS-GABA co-crystal most effectively counteracted neuroinflammation in vivo.•KLS-GABA co-crystal had the greatest therapeutic efficacy in neuropathic pain in vivo.•KLS-GABA co-crystal has a high gastrointestinal tolerability.•KLS-GABA co-crystal is a new multimodal potential therapeutic approach for chronic
Due to the widespread use of non-steroidal anti-inflammatory drugs (NSAIDs), the incidence of NSAID-associated adverse events has increased exponentially over the past decades. Ketoprofen (ketoprofen ...acid, KA) is a widely used NSAID and, like with other NSAIDs, its use can be associated with adverse effects that especially involve the gastrointestinal tract and the kidney. The salification of KA with L-lysine has led to the synthesis of ketoprofen lysine salt (KLS), which is characterized by higher solubility and a more rapid gastrointestinal absorption compared to KA. Previous studies have reported that KLS has also an increased gastric tolerance in vitro, and this is due to the inhibition of lipid peroxidation and reactive oxygen species scavenging effects of L-lysine. Here, we report in vivo tolerability/toxicity studies that were conducted prior seeking KLS marketing authorization, in which we compared KLS and KA safety profile, focusing in particular on the evaluation of the gastrointestinal and renal tolerability of the drugs administered orally to dogs. Our results demonstrate that KLS has an increased in vivo gastrointestinal tolerability compared to KA and show, for the first time, that KLS has also increased in vivo renal tolerability compared to KA, thus supporting the concept that L-lysine may counteract NSAID-induced oxidative stress-mediated gastrointestinal and renal injury.
•Ketoprofen L-lysine salt (KLS) has an increased in vivo gastrointestinal tolerability compared to ketoprofen acid (KA).•KLS has also increased in vivo renal tolerability compared to KA.•L-lysine may counteract gastrointestinal and renal non-steroidal anti-inflammatory drug (NSAID)-induced oxidative stress.
Significance Persistent pain in inflammatory and neuropathic conditions is often refractory to conventional analgesic therapy, with most patients suffering with unrelieved pain and serious ...treatment-related side effects. There is still a tremendous need to identify novel therapeutics for pain control with innovative biological mechanisms and minimal side effects. In this paper we challenge the hypothesis that a conserved structural motif across the G protein-coupled receptor family plays a regulatory role in the negative modulation of receptor activation and use a multidisciplinary approach to the rational drug design and characterization of a novel potent allosteric inhibitor of the C5a anaphylatoxin receptor (C5aR), thus providing a new promising avenue for the improvement of pharmacotherapy of chronic pain.
Chronic pain resulting from inflammatory and neuropathic disorders causes considerable economic and social burden. Pharmacological therapies currently available for certain types of pain are only partially effective and may cause severe adverse side effects. The C5a anaphylatoxin acting on its cognate G protein-coupled receptor (GPCR), C5aR, is a potent pronociceptive mediator in several models of inflammatory and neuropathic pain. Although there has long been interest in the identification of C5aR inhibitors, their development has been complicated, as for many peptidomimetic drugs, mostly by poor drug-like properties. Herein, we report the de novo design of a potent and selective C5aR noncompetitive allosteric inhibitor, DF2593A, guided by the hypothesis that an allosteric site, the “minor pocket,” previously characterized in CXC chemokine receptors-1 and -2, is functionally conserved in the GPCR class. In vitro, DF2593A potently inhibited C5a-induced migration of human and rodent neutrophils. In vivo, oral administration of DF2593A effectively reduced mechanical hyperalgesia in several models of acute and chronic inflammatory and neuropathic pain, without any apparent side effects. Mechanical hyperalgesia after spared nerve injury was also reduced in C5aR ⁻/⁻ mice compared with WT mice. Furthermore, treatment of C5aR ⁻/⁻ mice with DF2593A did not produce any further antinociceptive effect compared with C5aR ⁻/⁻ mice treated with vehicle. The successful medicinal chemistry strategy confirms that a conserved minor pocket is amenable for the rational design of selective inhibitors and the pharmacological results support that the allosteric blockade of the C5aR represents a highly promising therapeutic approach to control chronic inflammatory and neuropathic pain.
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