Agonist Compounds Research Articles

Angiotensin AT2 Receptor Stimulation Alleviates Collagen-Induced Arthritis by Upregulation of Regulatory T Cell Numbers.

The angiotensin AT2 receptor (AT2R) is a main receptor of the protective arm of the renin-angiotensin system and exerts for instance anti-inflammatory effects. The impact of AT2R stimulation on autoimmune diseases such as rheumatoid arthritis (RA) is not yet known. We investigated the therapeutic potential of AT2R-stimulation with the selective non-peptide AT2R agonist Compound 21 (C21) in collagen-induced arthritis (CIA), an animal model for inflammatory arthritis. Arthritis was induced by immunization of DBA/1J mice with collagen type II (CII). Prophylactic and therapeutic C21 treatment alleviates arthritis severity and incidence in CIA. Joint histology revealed significantly less infiltrates of IL-1 beta and IL-17A expressing cells and a well-preserved articular cartilage in C21- treated mice. In CIA, the number of CD4+CD25+FoxP3+ regulatory T (Treg) cells significantly increased upon C21 treatment compared to vehicle. T cell differentiation experiments demonstrated increased expression of FoxP3 mRNA, whereas IL-17A, STAT3 and IFN-gamma mRNA expression were reduced upon C21 treatment. In accordance with the mRNA data, C21 upregulated the percentage of CD4+FoxP3+ cells in Treg polarizing cultures compared to medium-treated controls, whereas the percentage of CD4+IL-17A+ and CD4+IFN-gamma+ T cells was suppressed. To conclude, C21 exerts beneficial effects on T cell-mediated experimental arthritis. We found that C21-induced AT2R-stimulation promotes the expansion of CD4+ regulatory T cells and suppresses IL-17A production. Thus, AT2R-stimulation may represent an attractive treatment strategy for arthritis.

Improving Genomic Selection for Heat Tolerance in Dairy Cattle: Current Opportunities and Future Directions.

Heat tolerance is the ability of an animal to maintain production and reproduction levels under hot and humid conditions and is now a trait of economic relevance in dairy systems worldwide because of an escalating warming climate. The Australian dairy population is one of the excellent study models for enhancing our understanding of the biology of heat tolerance because they are predominantly kept outdoors on pastures where they experience direct effects of weather elements (e.g., solar radiation). In this article, we focus on evidence from recent studies in Australia that leveraged large a dataset [∼40,000 animals with phenotypes and 15 million whole-genome sequence variants] to elucidate the genetic basis of thermal stress as a critical part of the strategy to breed cattle adapted to warmer environments. Genotype-by-environment interaction (i.e., G × E) due to temperature and humidity variation is increasing, meaning animals are becoming less adapted (i.e., more sensitive) to changing environments. There are opportunities to reverse this trend and accelerate adaptation to warming climate by 1) selecting robust or heat-resilient animals and 2) including resilience indicators in breeding goals. Candidate causal variants related to the nervous system and metabolic functions are relevant for heat tolerance and, therefore, key for improving this trait. This could include adding these variants in the custom SNP panels used for routine genomic evaluations or as the basis to design specific agonist or antagonist compounds for lowering core body temperature under heat stress conditions. Indeed, it was encouraging to see that adding prioritized functionally relevant variants into the 50k SNP panel (i.e., the industry panel used for genomic evaluation in Australia) increased the prediction accuracy of heat tolerance by up to 10% units. This gain in accuracy is critical because genetic improvement has a linear relationship with prediction accuracy. Overall, while this article used data mainly from Australia, this could benefit other countries that aim to develop breeding values for heat tolerance, considering that the warming climate is becoming a topical issue worldwide.

COMPOUND 21 STIMULATES THE ACTIVATION OF AKT AND ERK1/2 IN MOUSE ADIPOSE TISSUE IN VIVO

Objective: To analyze signaling events triggered by in vivo stimulation of the AT2 receptor. Design and method: Male B57Bl/6 mice were used as model at the age of 3 month. Mice were subjected to a bolus in vivo intravenous injection (cava vein) of saline buffer containing either the AT2 agonist compound 21 (0.25 mg/Kg), a mixture of C21 (0.25 mg/Kg) and the AT2 antagonist PD123319 (2.5 mg/Kg) or saline for baseline assesment under anesthesia. A group of animals that received insulin (0.25 mg/Kg) were used as positive control. The heart and the inguinal adipose tissue were removed after 1 and 3 min respectively, flash-frozen and kept at -70 C until analysis. Proteins from heart and adipose tissue were solubilized in a buffer containing 1% Triton together withprotease and phosphatase inhibitors. Protein content was measured by the BCA method and homogenates were subjected to Western Blotting using specific anti-phospho Akt or anti-phospho ERK1/2 antibodies. The content of Akt and ERK content was detected through incubation with either anti-Akt or anti-ERK1/2 antibodies. Specific bands were detected by chemiluminescence. Protein loading control was checked by coomassie blue staining of every PVDF membrane employed. Results: Injection of C21 resulted in the activation of both Akt and ERK1/2 in mouse adipose tissue. The extent of activation of Akt and ERK1/2 attained was equivalent to approximately 30–40% of the levels of activation of these enzymes obtained after an injection of a dose of insulin known to generate maximum activation of these signaling components. Co-infusion of C21 and PD123319 abolished the in vivo activation of Akt and ERK1/2, indicating that these events were mediated by the AT2 receptor. Conclusions: In vivo administration of the AT2 receptor agonist C21 resulted in the stimulation of the phosphorylation of both Akt and ERK1/2 at stimulatory sites indicative of activation of these enzymes. Co-infusion of C21 with the specific AT2 receptor antangonist blunted this effect. It is concluded that the AT2 receptor is capable of recruiting both Akt as ERK1/2 as signaling molecules in mouse adipose tissue in vivo.

Raman enhancement effect of different silver nanoparticles on salbutamol

Salbutamol is a β-adrenergic receptor agonist compound which has been abused as an animal growth promoter to improve carcass lean meat percentage. At present, the detection of salbutamol by SERS mostly uses gold colloid as substrate, which is expensive and has a high detection limit. In this report, Raman enhancement signal of salbutamol was compared with concentrated gold and silver colloids. The results show that the concentrated silver colloid prepared by reducing silver nitrate with hydroxylamine hydrochloride had superior performance. Three silver colloids with different particle sizes were synthesized by the same reducing agent and used as substrates for spectra acquisition of salbutamol to explore the enhancement performance of different silver nanoparticles sizes on salbutamol. The results showed that silver nanoparticles with larger particle sizes were more conducive to the adsorption of salbutamol. Finally, under the optimal conditions (Silver colloid A as enhanced substrate, 0.2 mol/L NaOH aqueous solution as aggregating compound), a better linear relationship between the concentration of salbutamol (ranged from 0.2 to 1 mg/L) and SERS intensity. The linear equation between SERS intensity and salbutamol concentration was C = 0.0023∙I-0.079 (mg/L) with a good linearity (R2 =0.994) and lower root mean square error (RMSEc = 0.022 mg/L), where C (mg/L) was the concentration of salbutamol solution and I was the SERS intensity of salbutamol solution. Validation set correlation coefficient was 0.988 and prediction root mean square error was 0.029 mg/L. This method provides a new idea for further reducing the detection limit of salbutamol. This study is helpful to further develop a simple and low-cost SERS detection method of salbutamol based on silver colloid.

Angiotensin II type-2-receptor stimulation ameliorates focal and segmental glomerulosclerosis in mice.

Podocyte damage and loss are the early event in the development of focal segmental glomerulosclerosis (FSGS). Podocytes express angiotensin II type-2-receptor (AT2R), which may play a key role in maintaining kidney integrity and function. Here, we examined the effects of AT2R deletion and AT2R agonist compound 21 (C21) on the evolution of FSGS. FSGS was induced by adriamycin (ADR) injection in both male wild-type (WT) and AT2R knockout (KO) mice. C21 was administered to WT-FSGS mice either one day before or 7 days after ADR (Pre-C21 or Post-C21), using two doses of C21 at either 0.3 (low dose, LD) or 1.0 (high dose, HD) mg/kg/day. ADR-induced FSGS was more severe in AT2RKO mice compared with WT-FSGS mice, and included profound podocyte loss, glomerular fibrosis, and albuminuria. Glomerular cathepsin L expression increased more in AT2RKO-FSGS than in WT-FSGS mice. C21 treatment ameliorated podocyte injury, most significantly in the Pre C21-HD group, and inhibited glomerular cathepsin L expression. In vitro, Agtr2 knock-down in mouse podocyte cell line given ADR confirmed the in vivo data. Mechanistically, C21 inhibited cathepsin L expression, which protected synaptopodin from destruction and stabilized actin cytoskeleton. C21 also prevented podocyte apoptosis. In conclusion, AT2R activation by C21 ameliorated ADR-induced podocyte injury in mice by the inhibition of glomerular cathepsin L leading to the maintenance of podocyte integrity and prevention of podocyte apoptosis.

MO1019: Sigma-1 Receptor Agonists are Protective in a Rat Model of Kidney Transplantation

Abstract BACKGROUND AND AIMS End-stage renal disease affects nearly 2 million people worldwide. The disease is associated with an irreversible deterioration in renal function and can only be treated by dialysis or kidney transplantation (KTx). KTx is associated with better long-term outcomes and quality of life compared with dialysis, but the shortage of donor organs is a serious and unsolved problem. Graft survival is highly dependent on the extent of cold and warm ischemic injury during Tx. We recently described the renoprotective effects of Sigma-1 receptor (S1R) agonist treatment in IRI. Thus, our aim was to develop a novel preservation solution that, with the addition of S1R agonist compounds, minimizes ischemic damage in order to improve the condition of grafts and so increase the number of organs suitable for Tx. METHOD Kidneys of male Wistar rats were perfused and placed in ice cold (i) custodiol preservation solution; custodiol containing S1R agonists, (ii) fluvoxamine or (iii) SA-4503 for 2 h, then autotransplanted and sacrificed 24 h after reperfusion. Sham-operated rats served as controls. In a second experiment, kidneys of wild-type and S1R knockout mice were perfused and placed in an ice-cold preservation solution containing an original, selective S1R agonist compound (VCC) for 24 h of cold ischemia and tissue samples were collected. Renal function parameters were determined. Renal expression of tubular injury markers (Kim-1, Ngal) and inflammatory cytokines (Il-1α, Il-6, Tnf-α, Mcp-1) were measured. Periodic acid-Schiff staining was performed on kidney tissue sections to evaluate structural changes. CD45 immunostaining was performed on kidney sections to determine the extent of leukocyte infiltration. DNA fragmentation resulted by apoptotic events in the kidney was evaluated by TUNEL-assay. RESULTS S1R agonists mitigated renal functional impairment and tubular dilatation following Tx. Expression of early and sensitive tubular injury markers was markedly less elevated in S1R agonist-treated kidneys. S1R agonists alleviated renal apoptosis as shown on TUNEL-stained kidney sections. Decreased numbers of CD45 + leukocytes and decreased inflammatory cytokine expressions confirmed the anti-inflammatory effect of S1R agonists. The S1R agonist VCC compound mitigated cold ischemic structural kidney damage in wild-type but not in S1R KO mice, which confirms the protective role of the receptor. CONCLUSION The addition of S1R agonists to the preservation solution during Tx improves graft function and alleviates structural damage, thus improving long-term outcomes. S1R agonists reduce graft injury during cold storage, therefore the number of transplantable donor organs can be increased. FUNDING OTKA PD-131 637; FK-124 491; 2020–4.1.1.-TKP2020-6 183 069 269; 2020–4.1.1.-TKP2020-6 183 169 273; KDP-2020/1 019 145.

Angiotensin AT2 Receptor Activation during Ischemic Injury Protects against High Salt‐Induced Hypertension and Proteinuria in the Long‐term: Role of IL‐17A Cells

Short time renal ischemia/reperfusion (I/R) causes reversible acute kidney injury (AKI) that often recovers within 5‐7 days. However, a single event of AKI predisposes and makes kidneys susceptible to develop chronic kidney disease (CKD) in conditions such as obesity and hypertension. Recently we have shown that angiotensin type 2 receptor (AT2R) activation by the agonist compound C21 (C21) protects against I/R‐induced AKI in the early injury phase in terms of suppressing pro‐inflammatory cytokines and improving functional injury markers such as reducing proteinuria and blood urea nitrogen (BUN). The late recovery phase (day 5) in the I/R and I/R treated with C21 remained same i.e., the C21 treated and un‐treated animals fully recovered functionally to the same extent but with higher anti‐inflammatory IL‐10 producing and protective Treg cell (FoxP3+) in I/R+C21 compared I/R groups. However, the long‐term protective effect of the AT2R agonist C21 on these recovered kidneys against chronic injury is unknown. To address this question, male Sprague‐Dawley (SD) rats were administered C21 (0.3 mg/kg, i.p.) prior to 30‐minute bilateral renal ischemia and allowed to recover for 5 days, with daily C21 treatment (I/R+ C21), without treatment (I/R) and sham control. On 7th day, all the three groups were placed on high salt (1% NaCl) in drinking water for two weeks but without C21 treatment. On day 6 (prior to initiating high salt treatment), week 1 and 2 of the high salt treatment, renal function parameters (proteinuria), and T cells were quantitated in the blood and kidney (only at 2 weeks). On 6th day, all the three groups showed similar level of proteinuria, suggesting same renal function. However, at week 1 and 2, I/R group had significantly greater proteinuria, suggesting a function injury. Similarly, I/R group showed higher mean arterial blood pressure at two weeks compared with the I/R+C21 and sham control. Consistent to the higher proteinuria and blood pressure in I/R group, there were higher infiltrating proinflammatory (IL‐17A) cells in the kidney in I/R group compared with sham control and I/R+C21 groups. Also, kidney infiltrating CD45 cells, T cells and CD4 T cells were found to be similar among all the groups. Overall, the data indicate that I/R pre‐disposes the kidneys to high salt‐induced chronic injury which is completely prevented by AT2R agonist treatment during AKI phase. Moreover, AT2R’s protective effect could be related to preventing the T cell modulation into proinflammatory IL‐17A cells.

Protective Role of Angiotensin II type 2 receptor (AT2R) in High Salt Diet‐Induced Low Molecular Weight Proteinuria and Loss of Megalin in the Kidney

Proteinuria is a cause and a risk factor for tubulointerstitial injury with the progression of end‐stage kidney disease. Proteinuria is a function of the glomerular filtration of protein and the reabsorption of protein from the post‐glomerular filtrate by the endocytic receptors, megalin and cubilin, localized in the renal proximal tubules. We have shown that treatment with the angiotensin‐II type 2 receptor (AT2R) agonist compound 21 (C21) for 2 weeks reduces proteinuria in obese Zucker rats (OZR) fed with high salt diet (HSD). OZR is a salt‐sensitive model but has no effect on blood pressure in the first 3 days of HSD treatment. However, the early cellular and molecular mechanism of proteinuria in response to HSD and the protective effect of AT2R activation is unknown. Therefore, the present study is designed to determine the molecular/cellular mechanism of AT2R‐mediated protection against HSD‐induced proteinuria, independent of glomerular injury in obesity. We hypothesize that AT2R activation prevents the loss of megalin in proximal tubule epithelial cells and thereby decreases the urinary excretion of low molecular weight (LMW) proteins in HSD fed obese rats. Male OZR (11–14 weeks of age) were fed on normal salt diet (NSD) (0.4%) or HSD (4%) for 2 days with and without treatment with C21. The animals were placed in metabolic cages for collecting urine at various time intervals namely 6, 12, 24 and 48 hours. We observed that HSD caused proteinuria at 24 hrs. and was prevented by C21 treatment. Further analysis by gel electrophoresis revealed that proteinuria was based on LMW protein (<60 kDa) excretion in the urine. This observation was confirmed by no change in albuminuria by HSD and C21. Dot blot analysis and confocal immunofluorescence microscopy revealed that megalin and not cubilin, was significantly decreased in HSD treatment group and the remaining megalin was mostly present in the cytosolic compartment with negligible expression on plasma membrane, suggesting megalin recycling impairment. The C21 treatment restored megalin back to the plasma membrane. FcRn is an exclusive receptor for albumin transport, which remained unaltered by HSD and C21. Western blot of nephrin and podocin, indices of glomerular filtration apparatus, remained unchanged suggesting structural integrity of the glomerular filtration assembly. Consistent to this notion, GFR measured by creatinine clearance method remained same in all the three groups. HSD caused a significant increase in the urinary sodium excretion, which was not affected by C21 treatment and the plasma sodium concentration in all the groups remained the same. Overall, the data suggest that acute feeding of HSD causes LMW proteinuria due to reduction as well as cytosolic expression of megalin in proximal tubule and not due to the change in the glomerular filtration. AT2R activation restores megalin expression and prevents proteinuria with a potential of long‐term protection against tubule‐interstitial injury and kidney disease.

Chemogenetic Modulation of the Posterior Insular Cortex Alters Both Affective and Sensory Pain-related Behavior

The insula is a multimodal cortical area involved in interoception, and somatic and autonomic control. Human imaging studies have consistently shown that the insula is activated during noxious somatosensory stimulation. However, the distinct function of the insula in processing noxious stimuli is poorly understood. The purpose of this study is to investigate how bidirectional chemogenetic modulation of the insula influences sensory and affective behaviors. Selective targeting of the posterior insula (PIC) was determined by anatomical labeling from the sensory thalamus. Modulation of the PIC was performed using excitatory and inhibitory designer receptors exclusively activated by designer drugs (DREADDs), with the agonists compound 21 or clozapine-N-oxide for transient activation. Affective behaviors were evaluated through conditioned place aversion (CPA), thermal preference assay, and hot plate test. Sensory threshold tests performed were Hargreaves and von Frey. The PIC, not the anterior insula, receives direct projections from the thalamic posterior triangular nucleus (PoT), a target of an ascending somatosensory tract. Activating the PIC produced a place aversion in naive mice and a heightened aversion to warmth without altering thermal or mechanical threshold. Conversely, inhibiting the PIC in naive mice increased hot plate latency. Interestingly, activating only the PoT to PIC projections produced thermal hyperalgesia. Our results show that the PIC is an important region for both affective and sensory processing of somatosensory stimuli. Activation of the PIC alone produced negative valence in CPA and an aversion to warmth without altering sensory threshold, while activating the PoT to PIC circuit produced a decrease in thermal threshold. These results suggest that the PIC could be involved in a separate circuit to generate negative affect. Overall, the PIC contributes to the multidimensional experience of pain and thus therapeutics aimed at reducing PIC activity could be effective in alleviating the suffering associated with pain. Grant support from R01 NS107356.

Differential Regulation of Inflammatory Responses Following 5‐HT2 Receptor Activation in Pulmonary Tissues

IntroductionThe concept of functional selectivity and psychedelics is often regarded as the ability of different 5‐HT2A receptor agonist compounds to exert varying degrees of psychoactivity in the central nervous system. However, the distribution and expression of the 5‐HT2A receptor, the primary pharmacological target for psychedelics, in peripheral and immune‐related tissue suggests selective signaling may occur here as well. Using an ovalbumin (OVA)‐induced model of rodent acute asthma, our lab has previously shown that subtle changes to the 2,5‐dimethoxy‐phenethylamine pharmacophore structure can profoundly impact the ability of these compounds to prevent asthmatic exacerbations. Here, through both in vitroand in vivoassays, we interrogate elements of functional selectivity in peripheral tissues following exposure to the 5‐HT2 receptor selective agonists (R)‐2,5‐dimethoxy‐4‐iodoamphetamine [(R)‐DOI] and 2,5‐dimethoxy‐4‐trifluoromethylamphetamine (DOTFM). (R)‐DOI is a full and potent anti‐inflammatory compound, whereas DOTFM has no measurable anti‐inflammatory activity. We find that elements of selective signaling combined with modulation to overall chromatin structure and downstream protein expression provide mechanistic clues regarding how psychedelics may elicit their long‐lasting, therapeutic effects.ObjectiveTo elucidate mechanistic variations between anti‐inflammatory and non‐anti‐inflammatory 5‐HT2 receptor agonists.MethodsWe utilized fluorescence recovery after photobleaching (FRAP) to probe the kinetics of the linker histone H1c transiently transfected into a HEK293 cell line stably expressing the human 5‐HT2A receptor, and calcium mobilization assays in the same cell line to determine differences in signaling between (R)‐DOI and DOTFM. For in vivoassays we measured enhanced pause (PenH) values for BALB/c mice challenged with OVA and treated with either (R)‐DOI or DOTFM, using PenH values as a proxy measure for pulmonary inflammation. Lungs were removed en bloc,processed, and analyzed by qPCR and quantitative proteomics using tandem tag mass spectrometry (TMT).ResultsIn vitro assays indicate modest differences irrespective of phenethylamine compound, whereas whole‐body plethysmography (WBP), qPRC, and proteomic analysis reveal significant differential regulation of proteins relevant for both asthmatic initiation and chromatin compaction dependent upon 5‐HT2A agonist.ConclusionAs 5‐HT2‐mediated expression of asthma‐relevant proteins are differentially regulated by either (R)‐DOI and DOTFM, the downregulation of inflammatory pathways via activation of the 5‐HT2 receptor likely requires an accessible, non‐sterically hindered subunit at the 4‐position of the standard 2,5‐dimethoxy‐ampetamine structure to maximally induce anti‐inflammatory effects. Changes to both linker histone mobility and the expression of proteins relevant to chromatin architecture suggest that modulation to the overall chromatin structure combined with downstream epigenetic regulation is a potential mechanism by which certain 5‐HT2A agonists can exert their therapeutic effects.

MRGPRX2-Mediated Degranulation of Human Skin Mast Cells Requires the Operation of Gαi, Gαq, Ca++ Channels, ERK1/2 and PI3K-Interconnection between Early and Late Signaling.

The recent discovery of MRGPRX2 explains mast cell (MC)-dependent symptoms independently of FcεRI-activation. Because of its novelty, signaling cascades triggered by MRGPRX2 are rudimentarily understood, especially in cutaneous MCs, by which MRGPRX2 is chiefly expressed. Here, MCs purified from human skin were used following preculture or ex vivo and stimulated by FcεRI-aggregation or MRGPRX2 agonists (compound 48/80, Substance P) in the presence/absence of inhibitors. Degranulation was assessed by β-hexosaminidase or histamine release. Phosphorylation events were studied by immunoblotting. As a G protein-coupled receptor, MRGPRX2 signals by activating G proteins; however, their nature has remained controversial. In skin MCs, Gαi and Gαq were required for degranulation, but Gαi was clearly more relevant. Ca++ channels were likewise crucial. Downstream, PI3K was essential for granule discharge initiated by MRGPRX2 or FcεRI. ERK1/2 and JNK were additional participants, especially in the allergic route. Addressing possible points of intersection between early and later events, pERK1/2 and pAKT were found to depend on Gαi, further highlighting its significance. Gαq and Ca++ channels made some contributions to the phosphorylation of ERK. Ca++ differentially affected PI3K activation in FcεRI- vis-à-vis MRGPRX2-signaling, as channel inhibition increased pAKT only when triggered via FcεRI. Collectively, our study significantly extends our understanding of the molecular framework behind granule secretion from skin MCs.

OncoTherad® (MRB-CFI-1) nano-immunotherapy reduced tumoral progression in non-muscle invasive bladder cancer through activation of Toll-like signaling pathway

The new modalities for treating patients with high-grade non-muscle invasive bladder cancer (HGNMIBC) for whom Bacillus Calmette-Guerin (BCG) has failed or is contraindicated are recently increasing due to the development of new drugs. Since NMIBC is sensitive to immunotherapy, Toll-like receptors (TLRs) agonist compounds may represent a potential antitumor therapeutic approach. Our research group developed a synthetic compound, with antitumor and immunological properties, called OncoTherad® (MRB-CFI-1). To evaluate the effects of OncoTherad® (MRB-CFI-1) and its compounds (P14−16 and CFI-1), thirty-six female C57Bl/6 J mice were divided into six groups (n = 6): Control, Cancer, Cancer + BCG (40 mg), Cancer + OncoTherad® (20 mg/mL), Cancer + P14−16 (20 mg/mL) and Cancer + CFI-1 (20 mg/mL). NMIBC was chemically induced (N-ethyl-N-nitrosourea 50 mg/mL) and the treatments were followed for six weeks. The bladder was collected and routinely processed for immunohistochemical analyses of the Toll-Like receptors signaling pathway (TLR2, TLR4, MyD88, IRF-3, IKK-α, NF-kB, TNF-α, TRIF, IFN-γ, IL-6). The results obtained showed that the tumor progression was 100 % reduced on OncoTherad® (MRB-CFI-1) treated animals. Immunohistochemical analysis demonstrated that while the conventional BCG treatment stimulated the canonic pathway, OncoTherad® (MRB-CFI-1) stimulated the non-canonical pathway (increasing expression of TLR4, TRIF, IRF, and IFNγ). OncoTherad® (MRB-CFI-1) could be considered a promising therapy in the treatment of NMIBC.

Study of the effect of the VEGF receptor blockade on the antiischemic activity of the compound GK-2 in a rat hind limb ischemia model

Earlier, in experiments in vitro and in vivo, it was shown that the TrkA receptor agonist compound GK-2, which was a low molecular weight NGF mimetic, had pronounced angiogenic and antiischemic activity. However, it remained unclear whether this activity was associated with the activation of VEGF-A, since, on the one hand, there are reports that NGF-mediated angiogenesis can be initiated by activating NGF of the vascular endothelial growth factor VEGF-A, and on the other hand, it is shown that a selective antagonist of Flk1 receptors specific for VEGF-A, compound SU-5416 does not affect the angiogenic effect of NGF. Purpose of the investigation. Study of the selective VEGF blockade effect on the antiischemic activity of the TrkA receptor agonist GK-2. Methods. Evaluation of the compound GK-2 antiischemic activity was assessed in model experiments simulating hind limb ischemia in rats. Results. It has been shown that against the background of blockade of VEGF-A binding with specific for it (VEGFR1 / Flt-1 / and VEGFR2 / KDR /) receptors, bevacizumab (2.5 mg / kg, i.p., every 3 days for 14 days) compound GK-2 (1 mg / kg, i.p., daily, for 14 days) realizes its antiischemic activity. Conclusion. The results of these experiments indicate that the selective blockade of VEGF does not significantly affect the anti-ischemic activity of the dipeptide NGF mimetic compound GK-2, which has the properties of a TrkA receptor agonist.

Synthesis and SAR Studies of Isoquinoline and Tetrahydroisoquinoline Derivatives as Melatonin Receptor Ligands.

In our constant search for new successors of agomelatine, we report herein a new series of compounds resulting from bioisosteric modulation of the naphthalene ring. The isoquinoline and tetrahydroisoquinoline derivatives were synthesized and pharmacologically evaluated. This isosteric replacement of the naphthalene group of agomelatine has led to potent agonist and partial agonist compounds with nanomolar melatonergic binding affinities. Overall, the presence of a nitrogen atom was accompanied with a decrease in the binding affinity toward both MT1 and MT2 and the loss of 5HT2C response, especially for tetrahydroisoquinoline in comparison with the parent compound. Interestingly, due to the presence of this nitrogen atom, a notable improvement in the pharmacokinetic properties was observed for all compounds.

The Impact of Time-Integrating Active or Passive Sampling Methods on Bioanalytical Water Quality Risk Assessment

Since traditional chemical analytical methods only consider a minor fraction of substances present in the water cycle, biological effect monitoring (BEM) is required for a more reliable assessment of the chemical status. BEM integrates the effects of all micropollutants that may trigger adverse outcome pathways. For reliable risk assessment it is important that substances are efficiently recovered from the water matrix by the environmental sampling and extraction methods. The present study compares the performance of five time-integrated sampling and extraction methods for large effluent volumes at three wastewater treatment plants (WWTPs). Both chemical and bioassay data are evaluated to select the best suited method for bioanalytical monitoring. Large volumes of WWTP effluents, collected for three weeks by flow-proportional active sampling, were extracted with XAD resins and large-volume solid-phase extraction (SPE). Simultaneously, three types of passive samplers (silicon rubber, POCIS and Speedisk) were deployed in the effluent channels. Clear differences were observed between both chemical and bioanalytical profiles for the five time-integrated sampling/extraction methods. Higher levels of extracted chemicals did not always lead to higher responses in the bioassays. If the total amount of extracted substances reflects the overall bioactivity, this may be since both agonistic and antagonistic compounds are extracted more efficiently. The best of the investigated active sampling methods seems to be SPE, that concentrated more compounds and at higher concentrations than XAD. The results obtained with passive samplers are highly dependent on estimations of average extracted water volumes, which are difficult to predict for complex environmental mixtures. POCIS seems to be the most efficient passive sampler for concentration of polar organic micropollutants. The preference between SPE and POCIS depends on the application. Since differences in sampling and extraction will affect the assessments of environmental risks, effect-based trigger values need to be adjusted for each method.

Discovery of 2-(Ortho-Substituted Benzyl)-Indole Derivatives as Potent and Orally Bioavailable RORγ Agonists with Antitumor Activity.

RORγ is a dual-functional drug target, which involves not only induction of inflammation but also promotion of cancer immunity. The development of agonists of RORγ promoting Th17 cell differentiation could provide a novel mechanism of action (MOA) as an immune-activating anticancer agent. Herein, we describe new 2-(ortho-substituted benzyl)-indole derivatives as RORγ agonists by scaffold hopping based on clinical RORγ antagonist VTP-43742. Interestingly, subtle structural differences of the compounds led to the opposite biological MOA. After rational optimization for structure-activity relationship and pharmacokinetic profile, we identified a potent RORγ agonist compound 17 that was able to induce the production of IL-17 and IFNγ in tumor tissues and elicit antitumor efficacy in MC38 syngeneic mouse colorectal tumor model. This is the first comprehensive work to demonstrate the in vivo antitumor efficacy of an RORγ agonist.

Effect of adjuvant drugs on the analgesic activity of opioid morphine analgesics and compound RU-1205

Introduction: Adjuvant medications can be used to increase the analgesic effect of opioid analgesics, reduce the manifestation of side effects, and also for premedication. This paper provides information on the effect of clonidine, haloperidol, metocloparmide, diazepam, midazolam on opioid analgesics: - morphine and the selective kappa-opioid agonist compound RU-1205.
 Materials and methods: A probable interaction between RU-1205, morphine and adjuvant drugs in pain behaviors was carried out on the model of somatogenic pain. 95 male mice received either RU-1205 (5 mg/kg, i.p.) and morphine (1 mg/kg, i.p.) separately or in combination with haloperidol (0.45 mg/kg, i.p.); midazolam (0.3 mg/kg, i.p.); diazepam (1 mg/kg, i.p.); metoclopramide (5 mg/kg, i.p.), and clonidine (1 mg/kg, i.p.). The analgesic effect was assessed by tail flick test. Registration of the latent period of the reaction was carried out 30, 60 and 90 minutes after the adjuvant drug administration.
 Results: When studying the interaction with morphine, it was found that clonidine, haloperidol and metoclopramide enhanced the effects; diazepam offset them, and midazolam had no affect on the analgesic properties. In the course of the studies, RU-1205 showed an increase in analgesic activity when combined with clonidine, a slight increase with midazolam, and a decrease when co-administered with diazepam. Haloperidol had no influence on the effect of RU-1205, while metoclopramide both potentiated and reduced the analgesic effect.
 Discussion: Pharmacodynamic and pharmacokinetic interactions of RU-1205 with an α2AR agonist, benzodiazepine receptor agonists, D2P antagonist, and σ-receptor blocker were established.
 Conclusion: The presented data make it possible to more accurately formulate ideas about the localization and action mechanism of the kappa-agonist of opioid receptors, the compound RU-1205.

Discovery of Highly Potent Adenosine A1 Receptor Agonists: Targeting Positron Emission Tomography Probes.

Adenosine receptor (AR) radiotracers for positron emission tomography (PET) have provided knowledge on the in vivo biodistribution of ARs in the central nervous system (CNS), which is of therapeutic interest for various neuropsychiatric disorders. Additionally, radioligands that can image changes in endogenous adenosine levels in different physiological and pathological conditions are still lacking. The binding of known antagonist adenosine A1 receptor (A1R) radiotracer, [11C]MDPX, failed to be inhibited by elevated endogenous adenosine in a rodent PET study. Since most of the known AR PET radiotracers were antagonists, we propose that an A1R agonist radioligand may possess higher sensitivity to measure changes in endogenous adenosine concentration. Herein, we report our latest findings toward the development of a full agonist adenosine A1 radioligand for PET. Based on a 3,5-dicyanopyridine template, 16 new derivatives were designed and synthesized to optimize both binding affinity and functional activity, resulting in two full agonists (compounds 27 and 29) with single-digit nanomolar affinities and good subtype selectivity (A1/A2A selectivity of ∼1000-fold for compound 27 and 29-fold for compound 29). Rapid O-[11C]methylation provided [11C]27 and [11C]29 in high radiochemical yields and radiochemical purity. However, subsequent brain PET imaging in rodents showed poor brain permeability for both radioligands. An in vivo PET study using knockout mice for MDR 1a/a, BCRP, and MRP1 indicated that these compounds might be substrates for brain efflux pumps. In addition, in silico evaluation using multiparameter optimization identified high molecular weight and high polar surface area as the main molecular descriptors responsible for low brain penetration. These results will provide further insight toward development of full agonist adenosine A1 radioligands and also highly potent CNS A1AR drugs.

Role of Parasitoids, Conventional Insecticides and Ecdysone Agonists in Regulating Population of Cassida vittata Vill in Egyptian Sugar Beet Fields

This study was carried out at the experimental farm of Sakha Agricultural Station, Kafr El-Sheikh Governorate for three successive seasons (2017/2018, 2018/2019 and 2019/2020). The study aimed to monitor seasonal abundance of Cassida vittata Vill. (Coleoptera: Chrysomelidae) and its hymenopterous parasitoids, Monorthochaeetaa nigra Blood (Trichogrammatidae) and Dinarmus laticeps (Pteromalidae). Further, role of ecdysone agonists compounds in reducing C. vittata numbers and their adverse effect on these parasitoids in comparison with the conventional insecticides. Results proved that population density of C. vittata and its parasitoids gradually increased towards the end of the season resulting in highly positive significant correlations between this insect and its parasitoids. General egg-parasitoid of M. nigra to host ratiowas 1:1.88 and 1:1.96, while it was 1:1.61 and 1:1.44 for larval-pupal parasitoid D. laticeps during 2018/2019 and 2017/2018 seasons, respectively. Lastly, ecdysone agonists were efficient against C. vittata, whereas it were almost safer to parasitoids than conventional insecticides. Thus, C. vittata parasitoids and ecdysone agonists may be used for integrated pest management programs for this serious insect.

Stimulation of angiotensin II receptor 2 preserves cognitive function and is associated with an enhanced cerebral vascular density after stroke

Angiotensin signaling is known to be sexually dimorphic. Although it is a well-studied target for intervention in stroke and cognitive impairment, female studies are rare. With females suffering a disproportionately greater negative impact of stroke and dementia vs. males, effective interventions are of utmost urgency. The aim of the current study was to determine the impact of activation of the angiotensin II type 2 receptor (AT2R) with the agonist compound 21 (C21) on the development of post-stroke cognitive impairment, after experimental ischemic stroke. Ovariectomized (OVX) spontaneously hypertensive rats (SHRs) were subjected to 1 h of middle cerebral artery occlusion (MCAO). At 24 h, rats with a significant neurologic deficit were randomized to receive either saline or C21 (0.03 mg/kg/day) intraperitoneally (IP) for 5 days, then orally (0.12 mg/kg/day) for a total of 6 weeks. Cognitive function, brain structure by MRI and vascular architecture by microCT angiography were measured. C21 preserved cognitive function, specifically spatial memory, and improved vascular density in the ischemic hemisphere at 6 weeks, reflecting both arteriogenesis and angiogenesis. In conclusion, C21 prevented cognitive impairment after stroke, likely through a mechanism involving vascular protection and restoration.