Chemerin-9 stimulates migration in rat cardiac fibroblasts in vitro

Since chemerin is an adipocytokine whose concentration in blood increases in the subjects with various cardiac diseases, chemerin may be involved in pathogenesis of cardiac diseases. In the present study, we examined the effects of chemerin-9, an active fragment of chemerin, on functions of cardiac fibroblasts, which are involved in pathophysiology of cardiac diseases. Primary cardiac fibroblasts were enzymatically isolated from adult male Wistar rats. Migration of cardiac fibroblasts was measured by a Boyden chamber assay and a scratch assay. Phosphorylation of Akt and extracellular signal-regulated kinase (ERK) was measured by Western blotting. Reactive oxygen species (ROS) production was measured by 2',7'-dichlorodihydrofluoresein staining. Chemerin-9 significantly stimulated migration in cardiac fibroblasts. Chemerin-9 significantly stimulated phosphorylation of Akt and ERK as well as ROS production. An Akt pathway inhibitor, LY294002, an ERK pathway inhibitor, PD98059, an antagonist of chemokine-like receptor 1 (CMKLR1), 2-(α-Napththoyl) ethyltrimethylammonium iodide, or an antioxidant, N-acetyl-L-cysteine prevented the migration induced by chemerin-9. In summary, we for the first time revealed that chemerin-9 stimulates migration perhaps through the ROS-dependent activation of Akt and ERK via CMKLR1 in cardiac fibroblasts. It is proposed that chemerin plays a role in the pathogenesis of cardiac diseases.

Structural elucidation of spiro cyclohexandienonyl naphthalenes with potential anti-neuroinflammatory activities from Caragana acanthophylla Kom

Four undescribed spiro cyclohexandienonyl naphthalenes (acanthophyllas A-D) and a revised compound were isolated from the roots of Caragana acanthophylla Kom. (Fabaceae). They were identified using extensive spectroscopic data and via chemical methods. Three of them were resolved into their enantiomers, and their absolute configurations were confirmed by comparing the experimental and calculated electronic circular dichroism spectra. Moreover, the anti-inflammatory activities of the compounds were investigated by evaluating their inhibitory effects on nitric oxide production in lipopolysaccharide-stimulated BV-2 cells. Some compounds showed significant inhibitory activities with IC₅₀ values of 8.8-13.4 μM (minocycline, IC₅₀ 7.8 μM), indicating that they might serve as potential therapeutic agents for neurodegenerative diseases.

Dickkopf-1 Inhibition Reactivates Wnt/β-Catenin Signaling in Rhabdomyosarcoma, Induces Myogenic Markers In Vitro and Impairs Tumor Cell Survival In Vivo

The Wnt/β-catenin signaling pathway plays a pivotal role during embryogenesis and its deregulation is a key mechanism in the origin and progression of several tumors. Wnt antagonists have been described as key modulators of Wnt/β-catenin signaling in cancer, with Dickkopf-1 (DKK-1) being the most studied member of the DKK family. Although the therapeutic potential of DKK-1 inhibition has been evaluated in several diseases and malignancies, little is known in pediatric tumors. Only a few works have studied the genetic inhibition and function of DKK-1 in rhabdomyosarcoma. Here, for the first time, we report the analysis of the therapeutic potential of DKK-1 pharmaceutical inhibition in rhabdomyosarcoma, the most common soft tissue sarcoma in children. We performed DKK-1 inhibition via shRNA technology and via the chemical inhibitor WAY-2626211. Its inhibition led to β-catenin activation and the modulation of focal adhesion kinase (FAK), with positive effects on in vitro expression of myogenic markers and a reduction in proliferation and invasion. In addition, WAY-262611 was able to impair survival of tumor cells in vivo. Therefore, DKK-1 could constitute a molecular target, which could lead to novel therapeutic strategies in RMS, especially in those patients with high DKK-1 expression.

Targeting ribosomal G-quadruplexes with naphthalene-diimides as RNA polymerase I inhibitors for colorectal cancer treatment

Guanine quadruplexes (G4s) are non-canonical nucleic acid structures commonly found in regulatory genomic regions. G4 targeting has emerged as a therapeutic approach in cancer. We have screened naphthalene-diimides (NDIs), a class of G4 ligands, in a cellular model of colorectal cancer (CRC). Here, we identify the leading compound T5 with a potent and selective inhibition of cell growth by high-affinity binding to G4s in ribosomal DNA, impairing RNA polymerase I (Pol I) elongation. Consequently, T5 induces a rapid inhibition of Pol I transcription, nucleolus disruption, proteasome-dependent Pol I catalytic subunit A degradation and autophagy. Moreover, we attribute the higher selectivity of carbohydrate-conjugated T5 for tumoral cells to its preferential uptake through the overexpressed glucose transporter 1. Finally, we succinctly demonstrate that T5 could be explored as a therapeutic agent in a patient cohort with CRC. Therefore, we report a mode of action for these NDIs involving ribosomal G4 targeting.

Tryptophan Ameliorates Barrier Integrity and Alleviates the Inflammatory Response to Enterotoxigenic Escherichia coli K88 Through the CaSR/Rac1/PLC-γ1 Signaling Pathway in Porcine Intestinal Epithelial Cells

Background

Impaired intestinal barrier integrity plays a crucial role in the development of many diseases such as obesity, inflammatory bowel disease, and type 2 diabetes. Thus, protecting the intestinal barrier from pathological disruption is of great significance. Tryptophan can increase gut barrier integrity, enhance intestinal absorption, and decrease intestinal inflammation. However, the mechanism of tryptophan in decreasing intestinal barrier damage and inflammatory response remains largely unknown. The objective of this study was to test the hypothesis that tryptophan can enhance intestinal epithelial barrier integrity and decrease inflammatory response mediated by the calcium-sensing receptor (CaSR)/Ras-related C3 botulinum toxin substrate 1 (Rac1)/phospholipase Cγ1 (PLC-γ1) signaling pathway.

Methods

IPEC-J2 cells were treated with or without enterotoxigenic Escherichia coli (ETEC) K88 in the absence or presence of tryptophan, CaSR inhibitor (NPS-2143), wild-type CaSR overexpression (pcDNA3.1-CaSR-WT), Rac1-siRNA, and PLC-γ1-siRNA.

Results

The results showed that ETEC K88 decreased the protein concentration of occludin, zonula occludens-1 (ZO-1), claudin-1, CaSR, total Rac1, Rho family member 1 of porcine GTP-binding protein (GTP-rac1), phosphorylated phospholipase Cγ1 (p-PLC-γ1), and inositol triphosphate (IP3); suppressed the transepithelial electrical resistance (TEER); and enhanced the permeability of FITC-dextran compared with the control group. Compared with the control group, 0.7 mM tryptophan increased the protein concentration of CaSR, total Rac1, GTP-rac1, p-PLC-γ1, ZO-1, claudin-1, occludin, and IP3; elevated the TEER; and decreased the permeability of FITC-dextran and contents of interleukin-8 (IL-8) and TNF-α. However, 0.7 mM tryptophan+ETEC K88 reversed the effects induced by 0.7 mM tryptophan alone. Rac1-siRNA+tryptophan+ETEC K88 or PLC-γ1-siRNA+tryptophan+ETEC K88 reduced the TEER, increased the permeability of FITC-dextran, and improved the contents of IL-8 and TNF-α compared with tryptophan+ETEC K88. NPS2143+tryptophan+ETEC K88 decreased the TEER and the protein concentration of CaSR, total Rac1, GTP-rac1, p-PLC-γ1, ZO-1, claudin-1, occludin, and IP3; increased the permeability of FITC-dextran; and improved the contents of IL-8 and TNF-α compared with tryptophan+ETEC K88. pcDNA3.1-CaSR-WT+Rac1-siRNA+ETEC K88 and pcDNA3.1-CaSR-WT+PLC-γ1-siRNA+ETEC K88 decreased the TEER and enhanced the permeability in porcine intestine epithelial cells compared with pcDNA3.1-CaSR-WT+ETEC K88.

Conclusion

Tryptophan can improve intestinal epithelial barrier integrity and decrease inflammatory response through the CaSR/Rac1/PLC-γ1 signaling pathway.

New Pyridone-Based Derivatives as Cannabinoid Receptor Type 2 Agonists

The activation of the human cannabinoid receptor type II (CB2R) is known to mediate analgesic and anti-inflammatory processes without the central adverse effects related to cannabinoid receptor type I (CB1R). In this work we describe the synthesis and evaluation of a novel series of N-aryl-2-pyridone-3-carboxamide derivatives tested as human cannabinoid receptor type II (CB2R) agonists. Different cycloalkanes linked to the N-aryl pyridone by an amide group displayed CB2R agonist activity as determined by intracellular [cAMP] levels. The most promising compound 8d exhibited a non-toxic profile and similar potency (EC50 = 112 nM) to endogenous agonists Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) providing new information for the development of small molecules activating CB2R. Molecular docking studies showed a binding pose consistent with two structurally different agonists WIN-55212-2 and AM12033 and suggested structural requirements on the pyridone substituents that can satisfy the orthosteric pocket and induce an agonist response. Our results provide additional evidence to support the 2-pyridone ring as a suitable scaffold for the design of CB2R agonists and represent a starting point for further optimization and development of novel compounds for the treatment of pain and inflammation.

The Spicy Story of Cannabimimetic Indoles

The Sterling Research Group identified pravadoline as an aminoalkylindole (AAI) non-steroidal anti-inflammatory pain reliever. As drug design progressed, the ability of AAI analogs to block prostaglandin synthesis diminished, and antinociceptive activity was found to result from action at the CB1 cannabinoid receptor, a G-protein-coupled receptor (GPCR) abundant in the brain. Several laboratories applied computational chemistry methods to ultimately conclude that AAI and cannabinoid ligands could overlap within a common binding pocket but that WIN55212-2 primarily utilized steric interactions via aromatic stacking, whereas cannabinoid ligands required some electrostatic interactions, particularly involving the CB1 helix-3 lysine. The Huffman laboratory identified strategies to establish CB2 receptor selectivity among cannabimimetic indoles to avoid their CB1-related adverse effects, thereby stimulating preclinical studies to explore their use as anti-hyperalgesic and anti-allodynic pharmacotherapies. Some AAI analogs activate novel GPCRs referred to as "Alkyl Indole" receptors, and some AAI analogs act at the colchicine-binding site on microtubules. The AAI compounds having the greatest potency to interact with the CB1 receptor have found their way into the market as "Spice" or "K2". The sale of these alleged "herbal products" evades FDA consumer protections for proper labeling and safety as a medicine, as well as DEA scheduling as compounds having no currently accepted medical use and a high potential for abuse. The distribution to the public of potent alkyl indole synthetic cannabimimetic chemicals without regard for consumer safety contrasts with the adherence to regulatory requirements for demonstration of safety that are routinely observed by ethical pharmaceutical companies that market medicines.

Somatostatin receptor 5 is critical for protecting intestinal barrier function in vivo and in vitro

Somatostatin receptor 5 (SSTR5) is involved in intestinal barrier protection during colitis through modulating tight junction (TJ) proteins, but the mechanisms of SSTR5 in TJ regulation are largely unknown. Therefore, the present study was designed to illuminate how SSTR5 modulated intestinal barrier function and TJ proteins. In this study, activation of SSTR5 by its special agonist L817,818 effectively ameliorated impaired intestinal barrier function in TNF-α-pretreated cells and mice with colitis. Restoration of intestinal barrier function was dependent on upregulation of claudin-4 and ZO-1. Suppression of SSTR5 signaling through specific siRNA or the antagonist BIM23056 markedly exacerbated TNF-α-induced claudin-4 and ZO-1 damage. L817,818 treatment markedly suppressed TNF-α-induced NF-κB p65 phosphorylation, myosin light chain kinase (MLCK) upregulation and myosin light chain (MLC) phosphorylation. Exposure to a NF-κB inhibitor (QNZ) or MLCK inhibitor (ML-7) effectively inhibited compromised claudin-4 and ZO-1 induced by BIM23056/TNF-α. These observations indicate that activation of SSTR5 protects intestinal barrier function by upregulating claudin-4 and ZO-1 expression, which is mediated by NF-κB-MLCK-MLC signaling. Taken together, our findings suggest that SSTR5 might represent a promising target for colitis therapy.

Microcystin-LR (MC-LR) Triggers Inflammatory Responses in Macrophages

We were the first to previously report that microcystin-LR (MC-LR) has limited effects within the colons of healthy mice but has toxic effects within colons of mice with pre-existing inflammatory bowel disease. In the current investigation, we aimed to elucidate the mechanism by which MC-LR exacerbates colitis and to identify effective therapeutic targets. Through our current investigation, we report that there is a significantly greater recruitment of macrophages into colonic tissue with pre-existing colitis in the presence of MC-LR than in the absence of MC-LR. This is seen quantitatively through IHC staining and the enumeration of F4/80-positive macrophages and through gene expression analysis for Cd68, Cd11b, and Cd163. Exposure of isolated macrophages to MC-LR was found to directly upregulate macrophage activation markers Tnf and Il1b. Through a high-throughput, unbiased kinase activity profiling strategy, MC-LR-induced phosphorylation events were compared with potential inhibitors, and doramapimod was found to effectively prevent MC-LR-induced inflammatory responses in macrophages.

Analyses of the Mode of Action of an Alpha-Adrenoceptor Blocker in Substantia Gelatinosa Neurons in Rats

To elucidate why naftopidil increases the frequency of spontaneous synaptic currents in only some substantia gelatinosa (SG) neurons, post-hoc analyses were performed. Blind patch-clamp recording was performed using slice preparations of SG neurons from the spinal cords of adult rats. Spontaneous inhibitory and excitatory postsynaptic currents (sIPSCs and sEPSCs, respectively) were recorded. The ratios of the frequency and amplitude of the sIPSCs and sEPSCs following the introduction of naftopidil compared with baseline, and after the application of naftopidil, serotonin (5-HT), and prazosin, compared with noradrenaline (NA) were evaluated. First, the sIPSC analysis indicated that SG neurons reached their full response ratio for NA at 50 μM. Second, they responded to 5-HT (50 μM) with a response ratio similar to that for NA, but prazosin (10 μM) did not change the sEPSCs and sIPSCs. Third, the highest concentration of naftopidil (100 μM) led to two types of response in the SG neurons, which corresponded with the reactions to 5-HT and prazosin. These results indicate that not all neurons were necessarily activated by naftopidil, and that the micturition reflex may be regulated in a sophisticated manner by inhibitory mechanisms in these interneurons.

Modulation by antenatal therapies of cardiovascular and renal programming in male and female offspring of preeclamptic rats

Morbidity and mortality risks are enhanced in preeclamptic (PE) mothers and their offspring. Here, we asked if sexual dimorphism exists in (i) cardiovascular and renal damage evolved in offspring of PE mothers, and (ii) offspring responsiveness to antenatal therapies. PE was induced by administering N^G-nitro-L-arginine methyl ester (L-NAME, 50 mg/kg/day, oral gavage) to pregnant rats for 7 days starting from gestational day 14. Three therapies were co-administered orally with L-NAME, atrasentan (endothelin ETA receptor antagonist), terutroban (thromboxane A2 receptor antagonist, TXA2), or α-methyldopa (α-MD, central sympatholytic drug). Cardiovascular and renal profiles were assessed in 3-month-old offspring. Compared with offspring of non-PE rats, PE offspring exhibited elevated systolic blood pressure and proteinuria and reduced heart rate and creatinine clearance (CrCl). Apart from a greater bradycardia in male offspring, similar PE effects were noted in male and female offspring. While terutroban, atrasentan, or α-MD partially and similarly blunted the PE-evoked changes in CrCl and proteinuria, terutroban was the only drug that virtually abolished PE hypertension. Rises in cardiorenal inflammatory (tumor necrosis factor alpha, TNFα) and oxidative (isoprostane) markers were mostly and equally eliminated by all therapies in the two sexes, except for a greater dampening action of atrasentan, compared with α-MD, on tissue TNFα in female offspring only. Histopathologically, antenatal terutroban or atrasentan was more effective than α-MD in rectifying cardiac structural damage, myofiber separation, and cytoplasmic alterations, in PE offspring. The repair by antenatal terutroban or atrasentan of cardiovascular and renal anomalies in PE offspring is mostly sex-independent and surpasses the protection offered by α-MD, the conventional PE therapy.

Antagonistic Interaction between Histone Deacetylase Inhibitor: Cambinol and Cisplatin-An Isobolographic Analysis in Breast Cancer In Vitro Models

Breast cancer (BC) is the leading cause of death in women all over the world. Currently, combined chemotherapy with two or more agents is considered a promising anti-cancer tool to achieve better therapeutic response and to reduce therapy-related side effects. In our study, we demonstrated an antagonistic effect of cytostatic agent-cisplatin (CDDP) and histone deacetylase inhibitor: cambinol (CAM) for breast cancer cell lines with different phenotypes: estrogen receptor positive (MCF7, T47D) and triple negative (MDA-MB-231, MDA-MB-468). The type of pharmacological interaction was assessed by an isobolographic analysis. Our results showed that both agents used separately induced cell apoptosis; however, applying them in combination ameliorated antiproliferative effect for all BC cell lines indicating antagonistic interaction. Cell cycle analysis showed that CAM abolished cell cycle arrest in S phase, which was induced by CDDP. Additionally, CAM increased cell proliferation compared to CDDP used alone. Our data indicate that CAM and CDDP used in combination produce antagonistic interaction, which could inhibit anti-cancer treatment efficacy, showing importance of preclinical testing.

Memantine Prevents the WIN 55,212-2 Evoked Cross-Priming of Ethanol-Induced Conditioned Place Preference (CPP)

The activation of the endocannabinoid system controls the release of many neurotransmitters involved in the brain reward pathways, including glutamate. Both endocannabinoid and glutamate systems are crucial for alcohol relapse. In the present study, we hypothesize that N-methyl-D-aspartate (NMDA) glutamate receptors regulate the ability of a priming dose of WIN 55,212-2 to cross-reinstate ethanol-induced conditioned place preference (CPP). To test this hypothesis, ethanol-induced (1.0 g/kg, 10% w/v, i.p.) CPP (unbiased method) was established using male adult Wistar rats. After CPP extinction, one group of animals received WIN 55,212-2 (1.0 and 2.0 mg/kg, i.p.), the cannabinoid receptor 1 (CB1) agonist, or ethanol, and the other group received memantine (3.0 or 10 mg/kg, i.p.), the NMDA antagonist and WIN 55,212-2 on the reinstatement day. Our results showed that a priming injection of WIN 55,212-2 (2.0 mg/kg, i.p.) reinstated (cross-reinstated) ethanol-induced CPP with similar efficacy to ethanol. Memantine (3.0 or 10 mg/kg, i.p.) pretreatment blocked this WIN 55,212-2 effect. Furthermore, our experiments indicated that ethanol withdrawal (7 days withdrawal after 10 days ethanol administration) down-regulated the CNR1 (encoding CB1), GRIN1/2A (encoding GluN1 and GluN2A subunit of the NMDA receptor) genes expression in the prefrontal cortex and dorsal striatum, but up-regulated these in the hippocampus, confirming the involvement of these receptors in ethanol rewarding effects. Thus, our results show that the endocannabinoid system is involved in the motivational properties of ethanol, and glutamate may control cannabinoid induced relapse into ethanol seeking behavior.

Identifying SARS-CoV-2 antiviral compounds by screening for small molecule inhibitors of Nsp3 papain-like protease

The COVID-19 pandemic has emerged as the biggest life-threatening disease of this century. Whilst vaccination should provide a long-term solution, this is pitted against the constant threat of mutations in the virus rendering the current vaccines less effective. Consequently, small molecule antiviral agents would be extremely useful to complement the vaccination program. The causative agent of COVID-19 is a novel coronavirus, SARS-CoV-2, which encodes at least nine enzymatic activities that all have drug targeting potential. The papain-like protease (PLpro) contained in the nsp3 protein generates viral non-structural proteins from a polyprotein precursor, and cleaves ubiquitin and ISG protein conjugates. Here we describe the expression and purification of PLpro. We developed a protease assay that was used to screen a custom compound library from which we identified dihydrotanshinone I and Ro 08-2750 as compounds that inhibit PLpro in protease and isopeptidase assays and also inhibit viral replication in cell culture-based assays.

Growth differentiation factor 11 attenuates cardiac ischemia reperfusion injury via enhancing mitochondrial biogenesis and telomerase activity

It has been reported that growth differentiation factor 11 (GDF11) protects against myocardial ischemia/reperfusion (IR) injury, but the underlying mechanisms have not been fully clarified. Considering that GDF11 plays a role in the aging/rejuvenation process and that aging is associated with telomere shortening and cardiac dysfunction, we hypothesized that GDF11 might protect against IR injury by activating telomerase. Human plasma GDF11 levels were significantly lower in acute coronary syndrome patients than in chronic coronary syndrome patients. IR mice with myocardial overexpression GDF11 (oe-GDF11) exhibited a significantly smaller myocardial infarct size, less cardiac remodeling and dysfunction, fewer apoptotic cardiomyocytes, higher telomerase activity, longer telomeres, and higher ATP generation than IR mice treated with an adenovirus carrying a negative control plasmid. Furthermore, mitochondrial biogenesis-related proteins and some antiapoptotic proteins were significantly upregulated by oe-GDF11. These cardioprotective effects of oe-GDF11 were significantly antagonized by BIBR1532, a specific telomerase inhibitor. Similar effects of oe-GDF11 on apoptosis and mitochondrial energy biogenesis were observed in cultured neonatal rat cardiomyocytes, whereas GDF11 silencing elicited the opposite effects to oe-GDF11 in mice. We concluded that telomerase activation by GDF11 contributes to the alleviation of myocardial IR injury through enhancing mitochondrial biogenesis and suppressing cardiomyocyte apoptosis.

Effect of Postoperative Analgesic Exposure to the Cannabinoid Receptor Agonist WIN55 on Osteogenic Differentiation and Spinal Fusion in Rats

BACKGROUND

After spinal surgery and other orthopaedic procedures, most patients receive opioids for pain, leading to potential complications such as pseudarthrosis and opioid abuse associated with long-term use. As an alternative, the endocannabinoid system has been shown to have antinociceptive activity, while contributing to bone homeostasis via the CB1 and CB2 cannabinoid receptors. This study evaluates the impact of the cannabinoid receptor agonist WIN55,212-2 (WIN55) on osteogenic differentiation in vitro as well as bone regeneration and spinal fusion in a preclinical rat model.

METHODS

Primary rat bone marrow stromal cells were cultured in standard or osteogenic media and exposed to vehicle alone or WIN55. Runx2 and Alkaline phosphatase (Alpl) were quantified via qPCR (quantitative real-time polymerase chain reaction), followed by assessment of ALP activity and matrix mineralization. For in vivo evaluation, 45 female Sprague Dawley rats (n = 15 per group) underwent L4-L5 posterolateral spinal fusion with bilateral placement of collagen scaffolds preloaded with low-dose rhBMP-2 (recombinant human bone morphogenetic protein-2; 0.5 μg/implant). Postoperatively, rats received the vehicle alone or 0.5 or 2.5 mg/kg WIN55 via daily intraperitoneal injections for 5 days. Bone regeneration and spinal fusion were assessed using radiography, manual palpation-based fusion scoring, microcomputed tomography imaging, and histology.

RESULTS

mRNA expression levels of Runx2 and Alp were similar among cells treated with vehicle alone and WIN55. Likewise, exposure to WIN55 did not inhibit ALP activity or bone matrix mineralization. In this animal model, no significant differences were found among groups with regard to mean fusion score, fusion rate, or new bone volume.

CONCLUSIONS

WIN55 showed no adverse impact on osteogenic differentiation, bone regeneration, and spinal fusion. This supports that cannabinoid receptor agonists should be further investigated as a potential alternative approach for postoperative analgesia following spinal fusion and other orthopaedic procedures requiring bone-healing.

CLINICAL RELEVANCE

The identification of alternative treatments for postoperative pain following orthopaedic surgical procedures is crucial in combating the ongoing opioid abuse crisis. The endocannabinoid system may represent a viable alternative target for addressing orthopaedic postoperative pain.

Optical Redox Imaging of Treatment Responses to Nampt Inhibition and Combination Therapy in Triple-Negative Breast Cancer Cells

We evaluated the utility of optical redox imaging (ORI) to identify the therapeutic response of triple-negative breast cancers (TNBC) under various drug treatments. Cultured HCC1806 and MDA-MB-231 cells treated with FK866 (nicotinamide phosphoribosyltransferase (Nampt) inhibitor), FX11 (lactate dehydrogenase A inhibitor), paclitaxel, and their combinations were subjected to ORI, followed by imaging fluorescently labeled reactive oxygen species (ROS). Cell growth inhibition was measured by a cell viability assay. We found that both cell lines experienced significant NADH decrease and redox ratio (Fp/(NADH+Fp)) increase due to FK866 treatment; however, HCC1806 was much more responsive than MDA-MB-231. We further studied HCC1806 with the main findings: (i) nicotinamide riboside (NR) partially restored NADH in FK866-treated cells; (ii) FX11 induced an over 3-fold NADH increase in FK866 or FK866+NR pretreated cells; (iii) FK866 combined with paclitaxel caused synergistic increases in both Fp and the redox ratio; (iv) FK866 sensitized cells to paclitaxel treatments, which agrees with the redox changes detected by ORI; (v) Fp and the redox ratio positively correlated with cell growth inhibition; and (vi) Fp and NADH positively correlated with ROS level. Our study supports the utility of ORI for detecting the treatment responses of TNBC to Nampt inhibition and the sensitization effects on standard chemotherapeutics.

Solidagenone acts on promastigotes of L. amazonensis by inducing apoptosis-like processes on intracellular amastigotes by IL-12p70/ROS/NO pathway activation

BACKGROUND

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the Leishmania genus. Currently, the treatment has limited effectiveness and high toxicity, is expensive, requires long-term treatment, induces significant side effects, and promotes drug resistance. Thus, new therapeutic strategies must be developed to find alternative compounds with high efficiency and low cost. Solidagenone (SOL), one of the main constituents of Solidago chilensis, has shown gastroprotective, anti-inflammatory and immunomodulatory effects.

PURPOSE

This study assessed the in vitro effect of SOL on promastigotes and Leishmania amazonensis-infected macrophages, as well its microbicide and immunomodulatory mechanisms.

METHODS

SOL was isolated from the roots of S. chilensis, 98% purity, and identified by chromatographic methods, and the effect of SOL on leishmanicidal activity against promastigotes in vitro, SOL-induced cytotoxicity in THP-1, J774 cells, sheep erythrocytes, and L. amazonensis-infected J774 macrophages, and the mechanisms of death involved in this action were evaluated.

RESULTS

In silico predictions showed good drug-likeness potential for SOL with high oral bioavailability and intestinal absorption. SOL treatment (10-160 μM) inhibited promastigote proliferation 24, 48, and 72 h after treatment. After 24 h of treatment, SOL at the IC₅₀ (34.5 μM) and 2 × the IC₅₀ (69 μM) induced several morphological and ultrastructural changes in promastigotes, altered the cell cycle and cellular volume, increased phosphatidylserine exposure on the cell surface, induced the loss of plasma membrane integrity, increased the reactive oxygen species (ROS) level, induced loss of mitochondrial integrity (characterized by an apoptosis-like process), and increased the number of lipid droplets and autophagic vacuoles. Additionally, SOL induced low cytotoxicity in J774 murine macrophages (CC₅₀ of 1587 μM), THP-1 human monocytes (CC₅₀ of 1321 μM), and sheep erythrocytes. SOL treatment reduced the percentage of L. amazonensis-infected macrophages and the number of amastigotes per macrophage (IC₅₀ 9.5 μM), reduced TNF-α production and increased IL-12p70, ROS and nitric oxide (NO) levels.

CONCLUSION

SOL showed in vitro leishmanicidal effects against the promastigotes by apoptosis-like mechanism and amastigotes by reducing TNF-α and increasing IL-12p70, ROS, and NO levels, suggesting their potential as a candidate for use in further studies on the design of antileishmanial drugs.

Cannabis sativa terpenes are cannabimimetic and selectively enhance cannabinoid activity

Limited evidence has suggested that terpenes found in Cannabis sativa are analgesic, and could produce an "entourage effect" whereby they modulate cannabinoids to result in improved outcomes. However this hypothesis is controversial, with limited evidence. We thus investigated Cannabis sativa terpenes alone and with the cannabinoid agonist WIN55,212 using in vitro and in vivo approaches. We found that the terpenes α-humulene, geraniol, linalool, and β-pinene produced cannabinoid tetrad behaviors in mice, suggesting cannabimimetic activity. Some behaviors could be blocked by cannabinoid or adenosine receptor antagonists, suggesting a mixed mechanism of action. These behavioral effects were selectively additive with WIN55,212, suggesting terpenes can boost cannabinoid activity. In vitro experiments showed that all terpenes activated the CB1R, while some activated other targets. Our findings suggest that these Cannabis terpenes are multifunctional cannabimimetic ligands that provide conceptual support for the entourage effect hypothesis and could be used to enhance the therapeutic properties of cannabinoids.

A novel p53 regulator, C16ORF72/TAPR1, buffers against telomerase inhibition

Telomere erosion in cells with insufficient levels of the telomerase reverse transcriptase (TERT), contributes to age-associated tissue dysfunction and senescence, and p53 plays a crucial role in this response. We undertook a genome-wide CRISPR screen to identify gene deletions that sensitized p53-positive human cells to telomerase inhibition. We uncovered a previously unannotated gene, C16ORF72, which we term Telomere Attrition and p53 Response 1 (TAPR1), that exhibited a synthetic-sick relationship with TERT loss. A subsequent genome-wide CRISPR screen in TAPR1-disrupted cells reciprocally identified TERT as a sensitizing gene deletion. Cells lacking TAPR1 or TERT possessed elevated p53 levels and transcriptional signatures consistent with p53 upregulation. The elevated p53 response in TERT- or TAPR1-deficient cells was exacerbated by treatment with the MDM2 inhibitor and p53 stabilizer nutlin-3a and coincided with a further reduction in cell fitness. Importantly, the sensitivity to treatment with nutlin-3a in TERT- or TAPR1-deficient cells was rescued by loss of p53. These data suggest that TAPR1 buffers against the deleterious consequences of telomere erosion or DNA damage by constraining p53. These findings identify C16ORF72/TAPR1 as new regulator at the nexus of telomere integrity and p53 regulation.

IRE1α Is a Therapeutic Target for Cystic Fibrosis Airway Inflammation

New anti-inflammatory treatments are needed for CF airway disease. Studies have implicated the endoplasmic reticulum stress transducer inositol requiring enzyme 1α (IRE1α) in CF airway inflammation. The activation of IRE1α promotes activation of its cytoplasmic kinase and RNase, resulting in mRNA splicing of X-box binding protein-1 (XBP-1s), a transcription factor required for cytokine production. We tested whether IRE1α kinase and RNase inhibition decreases cytokine production induced by the exposure of primary cultures of homozygous F508del CF human bronchial epithelia (HBE) to supernatant of mucopurulent material (SMM) from CF airways. We evaluated whether IRE1α expression is increased in freshly isolated and native CF HBE, and couples with increased XBP-1s levels. A FRET assay confirmed binding of the IRE1α kinase and RNase inhibitor, KIRA6, to the IRE1α kinase. F508del HBE cultures were exposed to SMM with or without KIRA6, and we evaluated the mRNA levels of XBP-1s, IL-6, and IL-8, and the secretion of IL-6 and IL-8. IRE1α mRNA levels were up-regulated in freshly isolated CF vs. normal HBE and coupled to increased XBP-1s mRNA levels. SMM increased XBP-1s, IL-6, and IL-8 mRNA levels and up-regulated IL-6 and IL-8 secretion, and KIRA6 blunted these responses in a dose-dependent manner. Moreover, a triple combination of CFTR modulators currently used in the clinic had no effect on SMM-increased XBP-1s levels coupled with increased cytokine production in presence or absence of KIRA6. These findings indicate that IRE1α mediates cytokine production in CF airways. Small molecule IRE1α kinase inhibitors that allosterically reduce RNase-dependent XBP-1s may represent a new therapeutic strategy for CF airway inflammation.

A semi-mechanistic exposure-response model to assess the effects of verinurad, a potent URAT1 inhibitor, on serum and urine uric acid in patients with hyperuricemia-associated diseases

Verinurad, a uric acid transporter 1 (URAT1) inhibitor, lowers serum uric acid by promoting its urinary excretion. Co-administration with a xanthine oxidase inhibitor (XOI) to simultaneously reduce uric acid production rate reduces the potential for renal tubular precipitation of uric acid, which can lead to acute kidney injury. The combination is currently in development for chronic kidney disease and heart failure. The aim of this work was to apply and extend a previously developed semi-mechanistic exposure–response model for uric acid kinetics to include between-subject variability to verinurad and its combinations with XOIs, and to provide predictions to support future treatment strategies. The model was developed using data from 12 clinical studies from a total of 434 individuals, including healthy volunteers, patients with hyperuricemia, and renally impaired subjects. The model described the data well, taking into account the impact of various patient characteristics such as renal function, baseline fractional excretion of uric acid, and race. The potencies (EC50s) of verinurad (reducing uric acid reuptake), febuxostat (reducing uric acid production), and oxypurinol (reducing uric acid production) were: 29, 128, and 13,030 ng/mL, respectively. For verinurad, symptomatic hyperuricemic (gout) subjects showed a higher EC50 compared with healthy volunteers (37 ng/mL versus 29 ng/mL); while no significant difference was found for asymptomatic hyperuricemic patients. Simulations based on the uric acid model were performed to assess dose–response of verinurad in combination with XOI, and to investigate the impact of covariates. The simulations demonstrated application of the model to support dose selection for verinurad.

RNA-seq Characterization of Melanoma Phenotype Switch in 3D Collagen after p38 MAPK Inhibitor Treatment

Melanoma phenotype plasticity underlies tumour dissemination and resistance to therapy, yet its regulation is incompletely understood. In vivo switching between a more differentiated, proliferative phenotype and a dedifferentiated, invasive phenotype is directed by the tumour microenvironment. We found that treatment of partially dedifferentiated, invasive A375M2 cells with two structurally unrelated p38 MAPK inhibitors, SB2021920 and BIRB796, induces a phenotype switch in 3D collagen, as documented by increased expression of melanocyte differentiation markers and a loss of invasive phenotype markers. The phenotype is accompanied by morphological change corresponding to amoeboid–mesenchymal transition. We performed RNA sequencing with an Illumina HiSeq platform to fully characterise transcriptome changes underlying the switch. Gene expression results obtained with RNA-seq were validated by comparing them with RT-qPCR. Transcriptomic data generated in the study will extend the present understanding of phenotype plasticity in melanoma and its contribution to invasion and metastasis.

Alleviation of extensive visual pathway dysfunction by a remyelinating drug in a chronic mouse model of multiple sclerosis

Visual deficits are among the most prevalent symptoms in patients with multiple sclerosis (MS). To understand deficits in the visual pathway during MS and potential treatment effects, we used experimental autoimmune encephalomyelitis (EAE), the most commonly used animal model of MS. The afferent visual pathway was assessed in vivo using optical coherence tomography (OCT), electroretinography (ERG), and visually evoked cortical potentials (VEPs). Inflammation, demyelination, and neurodegeneration were examined by immunohistochemistry ex vivo. In addition, an immunomodulatory, remyelinating agent, the estrogen receptor β ligand chloroindazole (IndCl), was tested for its therapeutic potential in the visual pathway. EAE produced functional deficits in visual system electrophysiology, including suppression of ERG and VEP waveform amplitudes and increased signal latencies. Therapeutic IndCl rescued overall visual system latency by VEP but had little impact on amplitude or ERG findings relative to vehicle. Faster VEP conduction in IndCl-treated mice was associated with enhanced myelin basic protein signal in all visual system structures examined. IndCl preserved retinal ganglion cells (RGCs) and oligodendrocyte density in the prechiasmatic white matter, but similar retinal nerve fiber layer thinning by OCT was noted in vehicle and IndCl-treated mice. Although IndCl differentially attenuated leukocyte and astrocyte staining signal throughout the structures analyzed, axolemmal varicosities were observed in all visual fiber tracts of mice with EAE irrespective of treatment, suggesting impaired axonal energy homeostasis. These data support incomplete functional recovery of VEP amplitude with IndCl, as fiber tracts displayed persistent axon pathology despite remyelination-induced decreases in latencies, evidenced by reduced optic nerve g-ratio in IndCl-treated mice. Although additional studies are required, these findings demonstrate the dynamics of visual pathway dysfunction and disability during EAE, along with the importance of early treatment to mitigate EAE-induced axon damage.

Discovery of Survivin Inhibitors Part 1: Screening the Harbor Branch Pure Compound Library

Survivin is a 16.5 KDa protein whose functions include promoting cellular mitosis, angiogenesis, and senescence as well as inhibiting apoptosis. Higher survivin expression is found in cancer tissues than normal tissues, and this expression correlates with disease progression and aggressiveness. Survivin has been validated as a clinical target for cancer. Small molecules are important antagonists of survivin levels in cancer cells. A structurally diverse library of genetically encoded small molecules (natural products) derived from marine plants, invertebrates, and microbes was screened for their ability to reduce expression levels of survivin in the DLD-1 colon adenocarcinoma and the A549 nonsmall cell lung carcinoma cell lines. This led to the identification of this novel activity for the known compounds eryloside E, ilicicolin H, tanzawaic acid A, and p-hydroxyphenopyrrozin. Both eryloside E and ilicicolin H showed the ability to reduce survivin expression in the low micromolar range against both cell lines.

Neuroprotective effect of the somatostatin receptor 5 agonist L-817,818 on retinal ganglion cells in experimental glaucoma

Somatostatin plays important roles in modulating neuronal functions by activating the five specific G-protein coupled receptors (sst1-sst5). Previous studies have demonstrated that sst5 were expressed in retinal ganglion cells (RGCs) and sst5 agonist attenuated the α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid-induced retinal neurotoxicity. In this study, we investigated effects and underlying mechanisms of the sst5 agonist L-817,818 on RGC injury induced by elevated intraocular pressure (COH) in experimental glaucoma. Our results showed that intraperitoneal administration of L-817,818 significantly reduced RGC loss and decreased the number of terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL)-positive RGCs in COH retinas, suggesting that L-817,818 may attenuate RGC apoptosis. Consistently, in COH retinas with L-817,818 administration, both the down-regulated mRNA and protein levels of anti-apoptotic Bcl-2 and the up-regulated mRNA and protein levels of pro-apoptotic Bax were partially reversed. L-817,818 administration downregulated the expression of apoptosis-related proteins caspase-9 and caspase-3 in COH retinas. In addition, L-817,818 administration reduced the concentrations of reactive oxygen species/reactive nitrogen species and malondialdehyde, and ameliorated the functions of mitochondrial respiratory chain complex (MRCC). Our results imply that administration of the sst5 agonist L-817,818 reduces RGC loss in COH rats through decreasing RGC apoptosis, which is mediated by regulating Bcl-2/Bax balance, reducing oxidative stress and rescuing activities of MRCC. Activation of sst5 may provide neuroprotective roles for RGCs in glaucoma.

α-Cyperone inhibitory effects on tumor-derived DNA trigger microglia by STING pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cyperus rotundus L. (Cyperaceae) is a widespread herbal in China and widely used in Traditional Chinese Medicine for multiple effects such as anti-arthritic, anti-genotoxic, anti-mutagenic, anti-bacterial effects, and analgesic. α-Cyperone is an active compound in Cyperus rotundus and has analgesic effects, but the exact molecular mechanisms require further investigations.

MATERIALS AND METHODS

Tumor-derived DNA isolated from Lewis cell lines was transfected into microglia, and analyzed for stimulator of interferon genes (STING) effects. The downstream protein, such as interferon regulatory factor 3 (IRF3) and p65 nuclear factor-κB (NF-κB) were treated with STING siRNA and 5,6-dimethyllxanthenone-4-acetic acid (DMXAA) in microglia. The α-Cyperone effect on microglia was also investigated.

RESULTS

Tumor-derived DNA activate microglia by upregulation of STING and downstream proteins. STING siRNA was reduced to its downstream expression and neuroinflammation inhibition was caused by tumor-derived DNA. However, DMXAA reversed the STING siRNA effect and increased neuroinflammation. α-Cyperone takes inhibitory effects on tumor-derived DNA that trigger microglia by STING pathway.

CONCLUSIONS

α-Cyperone inhibition by tumor-derived DNA activated microglial to neuroinflammation in STING signaling pathway.

Chronic cannabinoid exposure produces tolerance to the dopamine releasing effects of WIN 55,212-2 and heroin in adult male rats

Synthetic cannabinoids were introduced into recreational drug culture in 2008 and quickly became one of the most commonly abused drugs in the United States. The neurobiological consequences resulting from synthetic cannabinoid repeated exposure remain poorly understood. It is possible that a blunted dopamine (DA) response may lead drug users to consume larger quantities to compensate for this form of neurochemical tolerance. Because the endogenous cannabinoid and opioid systems exhibit considerable cross-talk and cross-tolerance frequently develops following repeated exposure to either opioids or cannabinoids, there is interest in investigating whether a history of synthetic cannabinoid exposure influences the ability of heroin to increase DA release. To test the effects of chronic cannabinoid exposure on cannabinoid- and heroin-evoked DA release, male adult rats were treated with either vehicle or a synthetic cannabinoid (WIN55-212-2; WIN) using an intravenous (IV) dose escalation regimen (0.2-0.8 mg/kg IV over 9 treatments). As predicted, WIN-treated rats showed a rightward shift in the dose-response relationship across all behavioral/physiological measures when compared to vehicle-treated controls. Then, using fast-scan cyclic voltammetry to measure changes in the frequency of transient DA events in the nucleus accumbens shell of awake and freely-moving rats, it was observed that the DA releasing effects of both WIN and heroin were significantly reduced in male rats with a pharmacological history of cannabinoid exposure. These results demonstrate that repeated exposure to the synthetic cannabinoid WIN can produce tolerance to its DA releasing effects and cross-tolerance to the DA releasing effects of heroin.

Hatsusamides A and B: Two New Metabolites Produced by the Deep-Sea-Derived Fungal Strain Penicillium steckii FKJ-0213

Two new nitrogen-containing metabolites, designated hatsusamide A (1) and B (2), were isolated from a culture broth of Penicilliumsteckii FKJ-0213 together with the known compounds tanzawaic acid B (3) and trichodermamide C (4) by physicochemical (PC) screening. The structures of 1 and 2 were determined as a tanzawaic acid B-trichodermamide C hybrid structure and a new analog of aspergillazines, respectively. The absolute configuration of 1 was determined by comparing the values of tanzawaic acid B and trichodermamide C in the literatures, such as 1H-nuclear magnetic resonance (1H-NMR) data and optical rotation, after hydrolysis of 1. Compounds 1-4 were evaluated for cytotoxicity and anti-malarial activities. Compounds 1 and 3 exhibited weak anti-malarial activity at half-maximal inhibitory concentration (IC50) values of 27.2 and 78.5 µM against the K1 strain, and 27.9 and 79.2 µM against the FCR3 strain of Plasmodium falciparum, respectively. Furthermore, 1 exhibited cytotoxicity against HeLa S3, A549, Panc1, HT29 and H1299 cells, with IC50 values of 15.0, 13.7, 12.9, 6.8, and 18.7 μM, respectively.

Novel 2'-alkoxymethyl substituted klavuzon derivatives as inhibitors of Topo I and CRM1

In this work, 2'-alkoxymethyl substituted klavuzon derivatives were prepared starting from 2-methyl-1-naphthoic acid in eight steps. Anticancer potencies of the synthesized compounds were evaluated by performing MTT cell viability test over cancerous and healthy pancreatic cell lines, along with CRM1 inhibitory properties in HeLa cells by immunostaining and Topo I inhibition properties by supercoiled DNA relaxation assay. Their cytotoxic activities were also presented in hepatocellular carcinoma cells (HuH-7) derived 3D spheroids. Among the tested klavuzon derivatives, isobutoxymethyl substituted klavuzon showed the highest selectivity of cytotoxic activity against pancreatic cancer cell line. They showed potent Topo I inhibition while their CRM1 inhibitory properties somehow diminished compared to 4'-alkylsubstituted klavuzons. The most cytotoxic 2'-methoxymethyl derivative inhibited the growth of the spheroids derived from HuH-7 cell lines and PI staining exhibited time and concentration dependent cell death in 3D spheroids.

The voltage-gated T-type Ca2+ channel is key to the sperm motility of Atlantic salmon (Salmo salar)

Ca²⁺ is a key element in the sperm activation process of Salmo salar. However, the molecular mechanisms by which this ion enters the sperm cell have been poorly studied. In this study, we examined, for the first time, the role of the voltage-gated T-type Ca²⁺ channel in the activation of sperm motility of Salmo salar. Using an in vitro inhibition assay, a significant decrease in total and progressive motility (P < 0.0001) was observed in Salmo salar sperm when they were treated with NNC-55-0396, a highly selective blocker. The in silico analysis showed that this blocker is docked with a strong affinity for the pore of the voltage-gated T-type calcium channel suggesting the blocking of Ca²⁺ ions. The results show that the T-type voltage-gated Ca²⁺ channel is key to sperm motility in Salmo salar.

Evocalcet in patients with primary hyperparathyroidism: an open-label, single-arm, multicenter, 52-week, dose-titration phase III study

INTRODUCTION

Primary hyperparathyroidism (PHPT) is caused by parathyroid adenoma, primary parathyroid hyperplasia, or parathyroid carcinoma. For some patients with PHPT controlling serum calcium levels is critical.

MATERIALS AND METHODS

We conducted an open-label, single-arm, 52-week, phase III study in Japanese patients with hypercalcemia due to PHPT to demonstrate efficacy and safety of evocalcet, a new calcimimetic. Patients with intractable PHPT (n = 13), postsurgical recurrence (n = 2), and parathyroid carcinoma (n = 3) were enrolled. Evocalcet administration started at a dose of 2 mg once or twice daily and was titrated to achieve the target serum corrected calcium (cCa) concentration (≤ 10.3 mg/dL) for two consecutive weeks (maximal dose 24 mg/day).

RESULTS

Fourteen patients achieved the target (77.8%; 95% confidence interval [CI] 52.4-93.6). The lower limit of 95% CI exceeded the predetermined reference limit (11%), and thus, efficacy was confirmed. Of 18 patients, 12 (66.7%; 95% CI 41.0-86.7) showed decreased serum cCa of ≥ 1.0 mg/dL from the baseline for two consecutive weeks during the titration phase. Sixteen patients entered the maintenance phase, and 15 patients completed the study. Treatment-emergent adverse events (TEAEs) were recorded in 18/18 patients (100%) and drug-related TEAEs in 8/18 (44.4%). The most commonly observed drug-related TEAE was nausea (2/18 patients). No unexpected drug-related TEAEs were observed. All drug-related TEAEs were mild in severity. No patient discontinued the study because of drug-related TEAEs.

CONCLUSION

Evocalcet demonstrated long-term effectiveness in reducing serum cCa concentrations and safety without any unexpected drug-related TEAEs in PHPT patients.

Identification of novel and selective agonists for ABA receptor PYL3

Abscisic acid (ABA) although complicated and expensive to produce, plays an important role in signalling responsible for regulation of developmental manifestations such as seed maturation and surviving through stress conditions. Hence, development of cost effective molecules with minimal side effects that mimic the functions of ABA is the need of the hour. In this agreement, we screened a series of 27 in-house synthesized 3-methyleneisoindolin-1-one molecules over three ABA receptors (PYR1, PYL1, and PYL3). The commercial ABA agonist Pyrabactin was taken as a standard ligand in this study. The top three molecules for each receptor were selected and further evaluated to estimate the dynamical contribution and complex stability via Molecular Mechanics-Poisson Boltzmann surface area calculations. Two molecules (Mol26 and Mol25) showed higher binding free energy and stable complex conformation for PYL3 in comparison to Pyrabactin. This study revealed the structural basis of the binding mechanism of 3-methyleneisoindolin-1-one molecules with ABA receptors. Mol26 and Mol25 were identified for the development of specific PYL3 agonists with a vast potential in agriculture to accentuate the ABA like action in plants.

Characterization and Noncovalent Inhibition of the Deubiquitinase and deISGylase Activity of SARS-CoV-2 Papain-Like Protease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for COVID-19, is a novel human betacoronavirus that is rapidly spreading worldwide. The outbreak currently includes over 3.7 million cases and 260,000 fatalities. As a betacoronavirus, SARS-CoV-2 encodes for a papain-like protease (PLpro) that is likely responsible for cleavage of the coronavirus (CoV) viral polypeptide. The PLpro is also responsible for suppression of host innate immune responses by virtue of its ability to reverse host ubiquitination and ISGylation events. Here, the biochemical activity of SARS-CoV-2 PLpro against ubiquitin (Ub) and interferon-stimulated gene product 15 (ISG15) substrates is evaluated, revealing that the protease has a marked reduction in its ability to process K48 linked Ub substrates compared to its counterpart in SARS-CoV. Additionally, its substrate activity more closely mirrors that of the PLpro from the Middle East respiratory syndrome coronavirus and prefers ISG15s from certain species including humans. Additionally, naphthalene based PLpro inhibitors are shown to be effective at halting SARS-CoV-2 PLpro activity as well as SARS-CoV-2 replication.

A G-quadruplex-binding compound shows potent activity in human gemcitabine-resistant pancreatic cancer cells

Gemcitabine is a drug of choice in the treatment of human pancreatic cancer. Chemo-resistance to this drug is common and has been attributed to a variety of distinct mechanisms, involving > 100 genes. A recently developed small-molecule G-quadruplex ligand, the trisubstituted naphthalene diimide compound CM03, has previously been shown to have equivalent potency to gemcitabine in the pancreatic cancer cell line MIA PaCa-2. We report here on cell lines of increased resistance to gemcitabine that have been generated from this line, with the most resistant having 1,000-fold reduced sensitivity to gemcitabine. These resistant lines retain nM sensitivity to CM03. The molecular basis for the retention of potency by this G-quadruplex ligand has been examined using whole transcriptome data analysis with RNA-seq. This has revealed that the pattern of pathways down regulated by CM03 in the parental MIA PaCa-2 cell line is largely unaffected in the gemcitabine-resistant line. The analysis has also shown that the expression patterns of numerous genes involved in gemcitabine sensitivity are down regulated in the resistant line upon CM03 treatment. These results are supportive of the concept that G-quadruplex small molecules such as CM03 have potential for clinical use in the treatment of gemcitabine-resistant human pancreatic cancer.

Prescription Opioids induce Gut Dysbiosis and Exacerbate Colitis in a Murine Model of Inflammatory Bowel Disease

BACKGROUND AND AIMS

Opioids are the most prescribed analgesics for pain in inflammatory bowel diseases [IBD]; however, the consequences of opioid use on IBD severity are not well defined. This is the first study investigating consequences of hydromorphone in both dextran sodium sulphate [DSS]-induced colitis and spontaneous colitis (IL-10 knockout [IL-10-/-]) mouse models of IBD.

METHODS

To determine the consequences of opioids on IBD pathogenesis, wild-type [WT] mice were treated with clinically relevant doses of hydromorphone and colitis was induced via 3% DSS in drinking water for 5 days. In parallel we also determined the consequences of opioids in a spontaneous colitis model.

RESULTS

Hydromorphone and DSS independently induced barrier dysfunction, bacterial translocation, disruption of tight junction organisation and increased intestinal and systemic inflammation, which were exacerbated in mice receiving hydromorphone in combination with DSS. Hydromorphone + DSS-treated mice exhibited significant microbial dysbiosis. Predictive metagenomic analysis of the gut microbiota revealed high abundance in the bacterial communities associated with virulence, antibiotic resistance, toxin production, and inflammatory properties. Hydromorphone modulates tight junction organisation in a myosin light chain kinase [MLCK]-dependent manner. Treatment with MLCK inhibitor ML-7 ameliorates the detrimental effects of hydromorphone on DSS-induced colitis and thus decreases severity of IBD. Similarly, we demonstrated that hydromorphone treatment in IL-10-/- mice resulted in accelerated clinical manifestations of colitis compared with control mice.

CONCLUSIONS

Opioids used for pain management in IBD accelerate IBD progression by dysregulation of the gut microbiota, leading to expansion of pathogenic bacteria, translocation of bacteria, immune deregulation and sustained inflammation.

Molecular docking-based virtual drug screening revealing an oxofluorenyl benzamide and a bromonaphthalene sulfonamido hydroxybenzoic acid as HDAC6 inhibitors with cytotoxicity against leukemia cells

HDAC6 is a crucial epigenetic modifier that plays a vital role in tumor progression and carcinogenesis due to its multiple biological functions. It is a unique member of class-II HDAC enzymes. It possesses two catalytic domains, which function independently of the overall enzyme activity. Up to date, there are only a few selective HDAC6 inhibitors with anti-cancer activity. In this study, 175,204 ligands obtained from the ZINC15 and OTAVAchemical databases were used for virtual drug screening against HDAC6. Molecular docking studies were performed for 100 selected compounds. Furthermore, the top 10 compounds obtained from docking were tested for their efficacy to inhibit the function of HDAC6. Five compounds (N-(9-oxo-9H-fluoren-3-yl)benzamide, 2-hydroxy-5-[(5-oxo-6-phenyl-4,5-dihydro-1,2,4-triazin-3-yl)amino]benzoic acid, 5-(4-bromonaphthalene-1-sulfonamido)-2-hydroxybenzoic acid, 2-(naphthalen-2-yl)-N-(1H-1,2,3,4-tetrazol-5-yl)cyclopropane-1-carboxamide, and 4-oxa-5,6 diazapentacyclo[10.7.1.0³,⁷.0⁸,²⁰.0¹⁴,¹⁹]icosa-1,3(7),5,8(20),9,11,14,16,18-nonaen-13-one) inhibited enzymatic activity by more than 50 % compared to DMSO as the control. Two candidates, (N-(9-oxo-9H-fluoren-3-yl)benzamide and 5-(4-bromonaphthalene-1-sulfonamido)-2-hydroxybenzoic acid), were identified with considerable cytotoxicity towards drug-sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. Microscale thermophoresis revealed the binding of N-(9-oxo-9H-fluoren-3-yl)benzamide and 5-(4-bromonaphthalene-1-sulfonamido)-2-hydroxybenzoic acid to purified HDAC6 protein. Both compounds induced apoptosis in a dose-dependent manner as analyzed by flow cytometry. In conclusion, we demonstrate for the first time that these two compounds bind to HDAC6, inhibit its function, and exert cytotoxic activity by apoptosis induction.

CaSR Antagonist (Calcilytic) NPS 2143 Hinders the Release of Neuroinflammatory IL-6, Soluble ICAM-1, RANTES, and MCP-2 from Aβ-Exposed Human Cortical Astrocytes

Available evidence shows that human cortical neurons’ and astrocytes’ calcium-sensing receptors (CaSRs) bind Amyloid-beta (Aβ) oligomers triggering the overproduction/oversecretion of several Alzheimer’s disease (AD) neurotoxins—effects calcilytics suppress. We asked whether Aβ•CaSR signaling might also play a direct pro-neuroinflammatory role in AD. Cortical nontumorigenic adult human astrocytes (NAHAs) in vitro were untreated (controls) or treated with Aβ_25–35 ± NPS 2143 (a calcilytic) and any proinflammatory agent in their protein lysates and growth media assayed via antibody arrays, enzyme-linked immunosorbent assays (ELISAs), and immunoblots. Results show Aβ•CaSR signaling upregulated the synthesis and release/shedding of proinflammatory interleukin (IL)-6, intercellular adhesion molecule-1 (ICAM-1) (holoprotein and soluble [s] fragment), Regulated upon Activation, normal T cell Expressed and presumably Secreted (RANTES), and monocyte chemotactic protein (MCP)-2. Adding NPS 2143 (i) totally suppressed IL-6′s oversecretion while remarkably reducing the other agents’ over-release; and (ii) more effectively than Aβ alone increased over controls the four agents’ distinctive intracellular accumulation. Conversely, NPS 2143 did not alter Aβ-induced surges in IL-1β, IL-3, IL-8, and IL-16 secretion, consequently revealing their Aβ•CaSR signaling-independence. Finally, Aβ_25–35 ± NPS 2143 treatments left unchanged MCP-1′s and TIMP-2′s basal expression. Thus, NAHAs Aβ•CaSR signaling drove four proinflammatory agents’ over-release that NPS 2143 curtailed. Therefore, calcilytics would also abate NAHAs’ Aβ•CaSR signaling direct impact on AD’s neuroinflammation.

In vitro and in vivo pharmacological evaluation of the synthetic cannabinoid receptor agonist EG-018

Synthetic cannabinoid receptor agonists (SCRAs) possess high abuse liability and complex toxicological profiles, making them serious threats to public health. EG-018 is a SCRA that has been detected in both illicit products and human samples, but it has received little attention to date. The current studies investigated EG-018 at human CB₁ and CB₂ receptors expressed in HEK293 cells in [³H]CP55,940 competition binding, [³⁵S]GTPγS binding and forskolin-stimulated cAMP production. EG-018 was also tested in vivo for its ability to produce cannabimimetic and abuse-related effects in the cannabinoid tetrad and THC drug discrimination, respectively. EG-018 exhibited high affinity at CB₁ (21 nM) and at CB₂ (7 nM), but in contrast to typical SCRAs, behaved as a weak partial agonist in [³⁵S]GTPγS binding, exhibiting lower efficacy but greater potency, than that of THC at CB₁ and similar potency and efficacy at CB₂. EG-018 inhibited forskolin-stimulated cAMP with similar efficacy but lower potency, compared to THC, which was likely due to high receptor density facilitating saturation of this signaling pathway. In mice, EG-018 (100 mg/kg, 30 min) administered intraperitoneally (i.p.) did not produce effects in the tetrad or drug discrimination nor did it shift THC's ED₅₀ value in drug discrimination when administered before THC, suggesting EG-018 has negligible occupancy of brain CB₁ receptors following i.p. administration. Following intravenous (i.v.) administration, EG-018 (56 mg/kg) produced hypomotility, catalepsy, and hypothermia, but only catalepsy was blocked by the selective CB₁ antagonist rimonabant (3 mg/kg, i.v.). Additional studies of EG-018 and its structural analogues could provide further insight into how cannabinoids exert efficacy through the cannabinoid receptors.

Differential activation of G protein-mediated signaling by synthetic cannabinoid receptor agonists

Synthetic cannabinoid receptor agonists (SCRAs) are new psychoactive substances associated with acute intoxication and even death. However, the molecular mechanisms through which SCRAs may exert their toxic effects remain unclear-including the potential differential activation of G protein subtypes by cannabinoid receptor type 1 (CB1), a major target of SCRA. We measured CB1-mediated activation of Gαs and Gαi/o proteins by SCRAs by examining stimulation (pertussis toxin, PTX treated) as well as inhibition (non-PTX treated) of forskolin (FSK)-induced cyclic adenosine monophosphate (cAMP) accumulation in human embryonic kidney (HEK) cells stably expressing CB1. Real-time measurements of stimulation and inhibition of cAMP levels were made using a BRET biosensor. We found that the maximum concentration of SCRAs tested (10 µmol L-1 ), increased cAMP levels 12%-45% above that produced by FSK alone, while the phytocannabinoid THC did not significantly alter cAMP levels in PTX-treated HEK-CB1 cells. All SCRAs had greater potency to inhibit FSK-induced cAMP levels than to stimulate cAMP levels. The rank order of potencies for SCRA stimulation of cAMP (Gαs ) was PB-22 > 5F-MDMB-PICA > JWH-018 ≈ AB-FUBINACA > XLR-11. By contrast, the potency of SCRAs for inhibition of cAMP (Gαi/o ) was 5F-MDMB-PICA > AB-FUBINACA > PB-22 > JWH-018 > XLR-11. The different rank order of potency and EMax  of the SCRAs to stimulate Gαs -like signaling compared to Gαi/o signaling suggests differences in G protein preference between SCRAs. Understanding the apparent differences among these drugs may contribute to unravelling their complex effects in humans.

FX11 limits Mycobacterium tuberculosis growth and potentiates bactericidal activity of isoniazid through host-directed activity

Lactate dehydrogenase A (LDHA) mediates interconversion of pyruvate and lactate, and increased lactate turnover is exhibited by malignant and infected immune cells. Hypoxic lung granuloma in Mycobacterium tuberculosis-infected animals present elevated levels of Ldha and lactate. Such alterations in the metabolic milieu could influence the outcome of host-M. tuberculosis interactions. Given the central role of LDHA for tumorigenicity, targeting lactate metabolism is a promising approach for cancer therapy. Here, we sought to determine the importance of LDHA for tuberculosis (TB) disease progression and its potential as a target for host-directed therapy. To this end, we orally administered FX11, a known small-molecule NADH-competitive LDHA inhibitor, to M. tuberculosis-infected C57BL/6J mice and Nos2-/- mice with hypoxic necrotizing lung TB lesions. FX11 did not inhibit M. tuberculosis growth in aerobic/hypoxic liquid culture, but modestly reduced the pulmonary bacterial burden in C57BL/6J mice. Intriguingly, FX11 administration limited M. tuberculosis replication and onset of necrotic lung lesions in Nos2-/- mice. In this model, isoniazid (INH) monotherapy has been known to exhibit biphasic killing kinetics owing to the probable selection of an INH-tolerant bacterial subpopulation. However, adjunct FX11 treatment corrected this adverse effect and resulted in sustained bactericidal activity of INH against M. tuberculosis As a limitation, LDHA inhibition as an underlying cause of FX11-mediated effect could not be established as the on-target effect of FX11 in vivo was unconfirmed. Nevertheless, this proof-of-concept study encourages further investigation on the underlying mechanisms of LDHA inhibition and its significance in TB pathogenesis.

Evaluation of the effect of afoxalaner with milbemycin 1 oxime in the treatment of rabbits naturally infected with Psoroptes cuniculi

Rabbits (Oryctolagus cuniculi) are very popular as pets. However, problems of otitits caused by Psoroptes cuniculi are one of the main reasons to visit the veterinarian. Isoxazolines are an alternative treatment to treat this mite, and therefore, an evaluation of the effectiveness of oral afoxalaner with milbemycin oxime in rabbits infected with P. cuniculi was carried out. Nineteen rabbits, of New Zealand breed, with otitis due to an infection with P. cuniculi, were treated, whereas six rabbits were left untreated and formed the control group. The ear canals of each individual were examined, through the collection of otic exudate samples with cotton swabs. These were visualized under the microscope to identify the ectoparasite. Each animal was treated with a single oral dose of 2.50 mg / kg of afoxolaner, and 0.50 mg / kg of milbemycin oxime. Clinical signs and lesions associated with the infection, such as the presence of detritus, cerumen and / or scabs, and erythema, were evaluated. After receiving the treatment, all the lesions were classified as: mild, moderate and intense, with a visual analog scale. A week after providing medication, there was a decrease in the lesions of the group treated with Nexgard Spectra®, without further topical or systemic treatment. The decrease was gradual in the treated group and no recurrence was detected of P. cuniculi infection in both ears. Thus, the administration of a single oral dose of afoxolaner with milbemycin oxime was effective for the treatment of P. cuniculi infection in rabbits.

Structure-activity relationships and mechanism of action of tetragomycin derivatives as inhibitors of Staphylococcus aureus staphyloxanthin biosynthesis

Despite the main strategy to overcome bacterial resistance has focused on the development of more potent antimicrobial agents, the evolutionary pressure caused by such drugs makes this strategy limited. Molecules that interfere with virulence factors appear as a promising alternative though, as they cause reduced selective pressure. As a matter of fact, staphyloxanthin biosynthesis inhibition (STXBI) has been pursued as promising strategy to reduce S. aureus virulence. Herein, we report the inhibitory profile of 27 tetrangomycin derivatives over staphyloxanthin production. The experimental result showed that naphthoquinone dehydro-α-lapachone (25 - EC₅₀ = 57.29 ± 1.15 μM) and 2-Isopropylnaphtho[2,3-b]furan-4,9-dione (26 EC₅₀ = 82.10 ± 1.09 μM) are the most potent compounds and suggest that hydrogen acceptor groups and lipophilic moieties decorating the naphthoquinone ring are crucial for STXBI. In addition, we present an in situ analysis, through RAMAN spectroscopy, that is inexpensive and might be employed to probe the mechanism of action of staphyloxanthin biosynthesis inhibitors. Therefore, our molecular simplification strategies afforded promising lead compounds for the development of drugs that modulate S. aureus staphyloxanthin biosynthesis.

CMKLR1 deficiency attenuates androgen-induced lipid accumulation in mice

Excess androgen-induced obesity has become a public health problem, and its prevalence has increased substantially in recent years. Chemokine-like receptor 1 (CMKLR1), a receptor of chemerin secreted by adipose tissue, is linked to adipocyte differentiation, adipose tissue development, and obesity. However, the effect of CMKLR1 signaling on androgen-mediated adiposity in vivo remains unclear. Using CMKLR1-knockout mice, we constructed an androgen-excess female mouse model through 5α-dihydrotestosterone (DHT) treatment and an androgen-deficient male mouse model by orchidectomy (ORX). For mechanism investigation, we used 2-(α-Naphthoyl) ethyltrimethylammonium iodide (α-NETA), an antagonist of CMKLR1, to suppress CMKLR1 in vivo and wortmannin, a PI3K signaling antagonist, to treat brown adipose tissue (BAT) explant cultures in vitro. Furthermore, we used histological examination and quantitative PCR, as well as Western blot analysis, glucose tolerance tests, and biochemical analysis of serum, to describe the phenotypes and the changes in gene expression. We demonstrated that excess androgen in the female mice resulted in larger cells in the white adipose tissue (WAT) and the BAT, whereas androgen deprivation in the male mice induced a reduction in cell size. Both of these adipocyte size effects could be attenuated in the CMKLR1-knockout mice. CMKLR1 deficiency influenced the effect of androgen treatment on adipose tissue by regulating the mRNA expression of the androgen receptor (AR) and adipocyte markers (such as Fabp4 and Cidea). Moreover, suppression of CMKLR1 by α-NETA could also reduce the extent of the adipocyte cell enlargement caused by DHT. Furthermore, we found that DHT could reduce the levels of phosphorylated ERK (pERK) in the BAT, while CMKLR1 inactivation inhibited this effect, which had been induced by DHT, through the PI3K signaling pathway. These findings reveal an antiobesity role of CMKLR1 deficiency in regulating lipid accumulation, highlighting the scientific importance for the further development of small-molecule CMKLR1 antagonists as fundamental research tools and/or as potential drugs for use in the treatment of adiposity.

CG200745, a Novel HDAC Inhibitor, Attenuates Kidney Fibrosis in a Murine Model of Alport Syndrome

Histone deacetylases have been a target of therapy for organ fibrosis. Here, we report the protective effect of CG200745 (CG), a novel histone deacetylase inhibitor, on tubulointerstitial fibrosis in Col4a3^-/- mice, a murine model of Alport syndrome. Morphological analyses revealed CG treatment markedly alleviated kidney fibrosis in Col4a3^-/- mice at the age of 7 weeks. CG prevented the activation of transforming growth factor β (TGFβ) and its downstream SMAD signaling in the kidney of Col4a3^-/- mice. As critical upstream regulators of TGFβ signaling, immunoblotting of whole kidney lysate of Col4a3^-/- mice reveled that intra-renal renin-angiotensin system (RAS) was activated with concurrent upregulation of inflammation and apoptosis, which were effectively suppressed by CG treatment. CG suppressed both activation of RAS and up-regulation of TGFβ signals in angiotensin II-stimulated HK-2 cells, a human kidney proximal tubular epithelial cell line. CG inhibited activation of TGFβ-driven signals and fibrosis in NRK-49F cells, a rat kidney fibroblast cell line, under angiotensin II-rich conditions. Collectively, CG was found to be effective both in proximal tubular epithelial cells by inhibiting local RAS and TGFβ signaling activation, as well as in fibroblasts by blocking their transition to myofibroblasts, attenuating renal fibrosis in a murine model of Alport syndrome.

Antifungal Activity of an Original Amino-Isocyanonaphthalene (ICAN) Compound Family: Promising Broad Spectrum Antifungals

: Multiple drug resistant fungi pose a serious threat to human health, therefore the development of completely new antimycotics is of paramount importance. The in vitro antifungal activity of the original, 1-amino-5-isocyanonaphthalenes (ICANs) was evaluated against reference strains of clinically important Candida species. Structure-activity studies revealed that the naphthalene core and the isocyano- together with the amino moieties are all necessary to exert antifungal activity. 1,1-N-dimethylamino-5-isocyanonaphthalene (DIMICAN), the most promising candidate, was tested further in vitro against clinical isolates of Candida species, yielding a minimum inhibitory concentration (MIC) of 0.04-1.25 µg/mL. DIMICAN was found to be effective against intrinsically fluconazole resistant Candida krusei isolates, too. In vivo experiments were performed in a severly neutropenic murine model inoculated with a clinical strain of Candida albicans. Daily administration of 5 mg/kg DIMICAN intraperitoneally resulted in 80% survival even at day 13, whereas 100% of the control group died within six days. Based on these results, ICANs may become an effective clinical lead compound family against fungal pathogens.

The Interaction of Cyclic Naphthalene Diimide with G-Quadruplex under Molecular Crowding Condition

G-quadruplex specific targeting molecules, also termed as G4 ligands, are attracting increasing attention for their ability to recognize and stabilize G-quadruplex and high potentiality for biological regulation. However, G4 ligands recognizing G-quadruplex were generally investigated within a dilute condition, which might be interfered with under a cellular crowding environment. Here, we designed and synthesized several new cyclic naphthalene diimide (cNDI) derivatives, and investigated their interaction with G-quadruplex under molecular crowding condition (40% v/v polyethylene glycol (PEG)200) to mimic the cellular condition. The results indicated that, under molecular crowding conditions, cNDI derivatives were still able to recognize and stabilize G-quadruplex structures based on circular dichroism measurement. The binding affinities were slightly decreased but still comparatively high upon determination by isothermal titration calorimetry and UV-vis absorbance spectroscopy. More interestingly, cNDI derivatives were observed with preference to induce a telomere sequence to form a hybrid G-quadruplex under cation-deficient molecular crowding conditions.

Chemical Proteomics and Phenotypic Profiling Identifies the Aryl Hydrocarbon Receptor as a Molecular Target of the Utrophin Modulator Ezutromid

Duchenne muscular dystrophy (DMD) is a fatal muscle-wasting disease arising from mutations in the dystrophin gene. Upregulation of utrophin to compensate for the missing dystrophin offers a potential therapy independent of patient genotype. The first-in-class utrophin modulator ezutromid/SMT C1100 was developed from a phenotypic screen through to a Phase 2 clinical trial. Promising efficacy and evidence of target engagement was observed in DMD patients after 24 weeks of treatment, however trial endpoints were not met after 48 weeks. The objective of this study was to understand the mechanism of action of ezutromid which could explain the lack of sustained efficacy and help development of new generations of utrophin modulators. Using chemical proteomics and phenotypic profiling we show that the aryl hydrocarbon receptor (AhR) is a target of ezutromid. Several lines of evidence demonstrate that ezutromid binds AhR with an apparent KD of 50 nm and behaves as an AhR antagonist. Furthermore, other reported AhR antagonists also upregulate utrophin, showing that this pathway, which is currently being explored in other clinical applications including oncology and rheumatoid arthritis, could also be exploited in future DMD therapies.

Exogenous IGF-1 improves cognitive function in rats with high-fat diet consumption

Insulin-like growth factor-1 (IGF-1) improves cognitive function, but its mechanism has not been elucidated. The aim of the study was to explore whether IGF-1 exerted its protective effect on cognitive function and anxiety behavior through the activation of PI3K/Akt/CREB pathway in high-fat diet rats. Neuronal cells HT22 were treated with nothing, IGF-1, IGF-1 + LY294002 or IGF-1 + 666-15. Expressions of p-PI3K, p-Akt and p-CREB were measured using Western blot analysis. Thirty C57BL/6J rats were used. After feeding with high-fat diet, normal saline, PEG-IGF-1, PEG-IGF-1 + LY294002 or PEG-IGF-1 + 666-15 was treated. Cognitive function and anxiety behavior were assessed by Morris water maze and open field test. Several inflammation and oxidative stress biomarkers were measured using recognized methods. Expressions of p-PI3K and p-CREB were also measured using Western blot analysis. After IGF-1 treatment in cells, expressions of p-PI3K, p-Akt and p-CREB were increased. Furthermore, LY294002 downregulated the expressions of these three proteins, but 666-15 only inhibited the expression of CREB in the cells. Compared with the control rats, we found abnormalities of cognitive function and anxiety behavior, inhibition of PI3K/Akt/CREB pathway and increase of oxidative stress and inflammation in high-fat diet rats. After PEG-IGF-1 treatment, the changes in high-fat diet rats were reversed. Then, we blocked the pathway and found that these blockers attenuated the protective effects of PEG-IGF-1. In conclusion, IGF-1 improved cognitive function and anxiety behavior in high-fat diet rats and inhibited inflammation and oxidative stress in hippocampus tissue through the activation of PI3K/Akt/CREB pathway.

Treatment with Cannabinoids as a Promising Approach for Impairing Fibroblast Activation and Prostate Cancer Progression

Endo-, phyto- and synthetic cannabinoids have been proposed as promising anti-cancer agents able to impair cancer cells’ behavior without affecting their non-transformed counterparts. However, cancer outcome depends not only on cancer cells’ activity, but also on the stromal cells, which coevolve with cancer cells to sustain tumor progression. Here, we show for the first time that cannabinoid treatment impairs the activation and the reactivity of cancer-associated fibroblasts (CAFs), the most represented stromal component of prostate tumor microenvironment. Using prostate cancer-derived CAFs, we demonstrated that WIN 55-212.2 mesylate, a synthetic full agonist of cannabinoid receptors (CBs) 1 and 2, downregulates α-smooth muscle actin and matrix metalloprotease-2 expression, and it inhibits CAF migration, essential features to ensure the activated and reactive CAF phenotype. Furthermore, by impairing stromal reactivity, WIN 55-212.2 mesylate also negatively affects CAF-mediated cancer cells’ invasiveness. Using selective antagonists of CBs, we proved that CAFs response to WIN 55-212.2 mesylate is mainly mediated by CB₂. Finally, we suggest that endocannabinoids self-sustain both prostate tumor cells migration and CAFs phenotype by an autocrine loop. Overall, our data strongly support the use of cannabinoids as anti-tumor agents in prostate cancer, since they are able to simultaneously strike both cancer and stromal cells.