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Physiological Reports Apr 2023Development of autosomal dominant polycystic kidney disease (ADPKD) involves renal epithelial cell abnormalities. Cystic fluid contains a high level of ATP that, among...
Development of autosomal dominant polycystic kidney disease (ADPKD) involves renal epithelial cell abnormalities. Cystic fluid contains a high level of ATP that, among other effects, leads to a reduced reabsorption of electrolytes in cyst-lining cells, and thus results in cystic fluid accumulation. Earlier, we demonstrated that Pkd1 mice, a hypomorphic model of ADPKD, exhibit increased expression of pannexin-1, a membrane channel capable of ATP release. In the current study, we found that human ADPKD cystic epithelia have higher pannexin-1 abundance than normal collecting ducts. We hypothesized that inhibition of pannexin-1 function with probenecid can be used to attenuate ADPKD development. Renal function in male and female Pkd1 and control mice was monitored between 9 and 20 months of age. To test the therapeutic effects of probenecid (a uricosuric agent and a pannexin-1 blocker), osmotic minipumps were implanted in male and female Pkd1 mice, and probenecid or vehicle was administered for 42 days until 1 year of age. Probenecid treatment improved glomerular filtration rates and slowed renal cyst formation in male mice (as shown in histopathology). The mechanistic effects of probenecid on sodium reabsorption and fluid transport were tested on polarized mpkCCD cells subjected to short-circuit current measurements, and in 3D cysts grown in Matrigel. In the mpkCCD epithelial cell line, probenecid elicited higher ENaC currents and attenuated in vitro cyst formation, indicating lower sodium and less fluid retention in the cysts. Our studies open new avenues of research into targeting pannexin-1 in ADPKD pathology.
Topics: Mice; Male; Female; Humans; Animals; Polycystic Kidney, Autosomal Dominant; Probenecid; Disease Models, Animal; Kidney; Disease Progression; Adenosine Triphosphate; Cysts; TRPP Cation Channels
PubMed: 37024297
DOI: 10.14814/phy2.15652 -
Viruses Jul 2023Probenecid is an orally bioavailable, uricosuric agent that was first approved in 1951 for the treatment of gout, but was later found to have potent, broad-spectrum... (Randomized Controlled Trial)
Randomized Controlled Trial
Probenecid is an orally bioavailable, uricosuric agent that was first approved in 1951 for the treatment of gout, but was later found to have potent, broad-spectrum antiviral activity against several respiratory viruses including SARS-CoV-2. We conducted a phase 2 randomized, placebo-controlled, single-blind, dose-range finding study in non-hospitalized patients with symptomatic, mild-to-moderate COVID-19. Patients were randomly assigned in a 1:1:1 ratio to receive either 500 mg of probenecid, 1000 mg of probenecid, or a matching placebo every 12 h for five days. The patients' COVID-19 viral load hospitalization, or death from any cause through day 28, as well as safety, were evaluated. COVID-19-related symptoms were assessed at baseline, and on days 3, 5, 10, 15, and 28. The primary endpoints of the study were time to first negative SARS-CoV-2 viral test (or viral clearance) and the proportion of patients that were symptom-free at day 5. A total of 75 patients were randomized, with 25 patients in each group. All of the patients completed the study as planned with no hospitalizations or deaths being reported. The median time to viral clearance was significantly shorter for the probenecid 1000 mg group than for placebo (7 days vs. 11 days, respectively; < 0.0001), and for the probenecid 500 mg group versus placebo (9 days vs. 11 days, respectively; < 0.0001). In addition, the median time to viral clearance was significantly shorter for the probenecid 1000 mg group than for the probenecid 500 mg group (7 days vs. 9 days, respectively; < 0.0001). All patients reported at least one COVID-19-related symptom on days 3 and 5; however, on day 10, a significantly greater proportion of patients receiving probenecid 1000 mg reported the complete resolution of symptoms versus placebo (68% vs. 20%, respectively; = 0.0006), as well as for those receiving probenecid 500 mg versus placebo (56% vs. 20%, respectively, = 0.0087). The incidence of adverse events during treatment was similar across all groups for any adverse event, and was 12%. All events were mild with no serious adverse events reported and no discontinuations due to an adverse event. The treatment of patients with symptomatic, mild-to-moderate COVID-19 with probenecid resulted in a significant, dose-dependent decrease in the time to viral clearance and a significantly higher proportion of patients reporting complete symptom resolution by day 10. (Supported by TrippBio; ClinicalTrials.gov number, NCT05442983 and Clinical Trials Registry India number CTRI/2022/07/043726).
Topics: Humans; Adult; COVID-19; SARS-CoV-2; Probenecid; Single-Blind Method; Antiviral Agents
PubMed: 37515194
DOI: 10.3390/v15071508 -
Frontiers in Cell and Developmental... 2022An exaggerated inflammatory response is the hallmark of a plethora of disorders. ATP is a central signaling molecule that orchestrates the initiation and resolution of... (Review)
Review
An exaggerated inflammatory response is the hallmark of a plethora of disorders. ATP is a central signaling molecule that orchestrates the initiation and resolution of the inflammatory response by enhancing activation of the inflammasome, leukocyte recruitment and activation of T cells. ATP can be released from cells through pannexin (Panx) channels, a family of glycoproteins consisting of three members, Panx1, Panx2, and Panx3. Panx1 is ubiquitously expressed and forms heptameric channels in the plasma membrane mediating paracrine and autocrine signaling. Besides their involvement in the inflammatory response, Panx1 channels have been shown to contribute to different modes of cell death (i.e., pyroptosis, necrosis and apoptosis). Both genetic ablation and pharmacological inhibition of Panx1 channels decrease inflammation and contribute to a better outcome in several animal models of inflammatory disease involving various organs, including the brain, lung, kidney and heart. Up to date, several molecules have been identified to inhibit Panx1 channels, for instance probenecid (Pbn), mefloquine (Mfq), flufenamic acid (FFA), carbenoxolone (Cbx) or mimetic peptides like Panx1. Unfortunately, the vast majority of these compounds lack specificity and/or serum stability, which limits their application. The recent availability of detailed structural information on the Panx1 channel from cryo-electron microscopy studies may open up innovative approaches to acquire new classes of synthetic Panx1 channel blockers with high target specificity. Selective inhibition of Panx1 channels may not only limit acute inflammatory responses but may also prove useful in chronic inflammatory diseases, thereby improving human health. Here, we reviewed the current knowledge on the role of Panx1 in the initiation and resolution of the inflammatory response, we summarized the effects of Panx1 inhibition in inflammatory pathologies and recapitulate current Panx1 channel pharmacology with an outlook towards future approaches.
PubMed: 36438559
DOI: 10.3389/fcell.2022.1020826 -
British Journal of Pharmacology Mar 2022Ca influx via TRPV4 channels triggers Ca release from the IP -sensitive internal store to generate repetitive oscillations. Although mitochondria are acknowledged...
BACKGROUND AND PURPOSE
Ca influx via TRPV4 channels triggers Ca release from the IP -sensitive internal store to generate repetitive oscillations. Although mitochondria are acknowledged regulators of IP -mediated Ca release, how TRPV4-mediated Ca signals are regulated by mitochondria is unknown. We show that depolarised mitochondria switch TRPV4 signalling from relying on Ca -induced Ca release at IP receptors to being independent of Ca influx and instead mediated by ATP release via pannexins.
EXPERIMENTAL APPROACH
TRPV4-evoked Ca signals were individually examined in hundreds of cells in the endothelium of rat mesenteric resistance arteries using the indicator Cal520.
KEY RESULTS
TRPV4 activation with GSK1016790A (GSK) generated repetitive Ca oscillations that required Ca influx. However, when the mitochondrial membrane potential was depolarised, by the uncoupler CCCP or complex I inhibitor rotenone, TRPV4 activation generated large propagating, multicellular, Ca waves in the absence of external Ca . The ATP synthase inhibitor oligomycin did not potentiate TRPV4-mediated Ca signals. GSK-evoked Ca waves, when mitochondria were depolarised, were blocked by the TRPV4 channel blocker HC067047, the SERCA inhibitor cyclopiazonic acid, the PLC blocker U73122 and the inositol trisphosphate receptor blocker caffeine. The Ca waves were also inhibited by the extracellular ATP blockers suramin and apyrase and the pannexin blocker probenecid.
CONCLUSION AND IMPLICATIONS
These results highlight a previously unknown role of mitochondria in shaping TRPV4-mediated Ca signalling by facilitating ATP release. When mitochondria are depolarised, TRPV4-mediated release of ATP via pannexin channels activates plasma membrane purinergic receptors to trigger IP -evoked Ca release.
Topics: Adenosine Triphosphate; Animals; Calcium; Calcium Signaling; Mitochondria; Rats; TRPV Cation Channels
PubMed: 34605007
DOI: 10.1111/bph.15687 -
Viruses Apr 2022RNA viruses like SARS-CoV-2, influenza virus, and respiratory syncytial virus (RSV) are dependent on host genes for replication. We investigated if probenecid, an...
RNA viruses like SARS-CoV-2, influenza virus, and respiratory syncytial virus (RSV) are dependent on host genes for replication. We investigated if probenecid, an FDA-approved and safe urate-lowering drug that inhibits organic anion transporters (OATs) has prophylactic or therapeutic efficacy to inhibit RSV replication in three epithelial cell lines used in RSV studies, i.e., Vero E6 cells, HEp-2 cells, and in primary normal human bronchoepithelial (NHBE) cells, and in BALB/c mice. The studies showed that nanomolar concentrations of all probenecid regimens prevent RSV strain A and B replication in vitro and RSV strain A in vivo, representing a potential prophylactic and chemotherapeutic for RSV.
Topics: Animals; COVID-19; Mice; Probenecid; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; SARS-CoV-2; Virus Replication
PubMed: 35632652
DOI: 10.3390/v14050912 -
Biomedicines May 2023Probenecid is an old uricosuric agent used in clinics to treat gout and reduce the renal excretion of antibiotics. In recent years, probenecid has gained attention due... (Review)
Review
Probenecid is an old uricosuric agent used in clinics to treat gout and reduce the renal excretion of antibiotics. In recent years, probenecid has gained attention due to its ability to interact with membrane proteins such as TRPV2 channels, organic anion transporters, and pannexin 1 hemichannels, which suggests new potential therapeutic utilities in medicine. Some current functions of probenecid include their use as an adjuvant to increase the bioavailability of several drugs in the Central Nervous System (CNS). Numerous studies also suggest that this drug has important neuroprotective, antiepileptic, and anti-inflammatory properties, as evidenced by their effect against neurological and neurodegenerative diseases. In these studies, the use of probenecid as a Panx1 hemichannel blocker to reduce neuroinflammation is highlighted since neuroinflammation is a major trigger for diverse CNS alterations. Although the clinical use of probenecid has declined over the years, advances in its use in preclinical research indicate that it may be useful to improve conventional therapies in the psychiatric field where the drugs used have a low bioavailability, either because of a deficient passage through the blood-brain barrier or a high efflux from the CNS or also a high urinary clearance. This review summarizes the history, pharmacological properties, and recent research uses of probenecid and discusses its future projections as a potential pharmacological strategy to intervene in neurodegeneration as an outcome of neuroinflammation.
PubMed: 37371611
DOI: 10.3390/biomedicines11061516 -
Pharmacology Research & Perspectives Apr 2017Uric acid, generated from the metabolism of purines, has both proven and emerging roles in human disease. Serum uric acid in humans is determined by production and by...
Uric acid, generated from the metabolism of purines, has both proven and emerging roles in human disease. Serum uric acid in humans is determined by production and by the net balance of reabsorption and secretion in kidney and intestine. In the human kidney, epithelial reabsorption dominates over secretion, such that in normal subjects there is at least 90% net reabsorption of filtered urate resulting in a fractional excretion of <10%. Tranilast, an anti-inflammatory drug with pleiotropic effects has a marked hypouricemic, uricosuric effect in humans. We report here that tranilast is a potent inhibitor of [C]-urate transport mediated by the major reabsorptive urate transporters (URAT1, GLUT9, OAT4, and OAT10) in oocytes; this provides an unequivocal molecular mechanism for the drug's uricosuric effect. Tranilast was found to inhibit urate transport mediated by URAT1 and GLUT9 in a fully reversible and noncompetitive (mixed) manner. In addition, tranilast inhibits the secretory urate transporters NPT1, OAT1, and OAT3 without affecting the secretory efflux pump ABCG2. Notably, while benzbromarone and probenecid inhibited urate as well as nicotinate transport, tranilast inhibited the urate transport function of URAT1, GLUT9, OAT4, OAT10, and NPT1, without significantly affecting nicotinate transport mediated by SMCT1 (IC ~1.1 mmol/L), SMCT2 (IC ~1.0 mmol/L), and URAT1 (IC ~178 mol/L). In summary, tranilast causes uricosuria by inhibiting all the major reabsorptive urate transporters, selectively affecting urate over nicotinate transport. These data have implications for the treatment of hyperuricemia and gout, the pharmacology of tranilast, and the structure-function analysis of urate transport.
PubMed: 28357121
DOI: 10.1002/prp2.291 -
Angewandte Chemie (International Ed. in... Oct 2019Sulfonimidamides are intriguing new motifs for medicinal and agrochemistry, and provide attractive bioisosteres for sulfonamides. However, there remain few operationally... (Review)
Review
Sulfonimidamides are intriguing new motifs for medicinal and agrochemistry, and provide attractive bioisosteres for sulfonamides. However, there remain few operationally simple methods for their preparation. Here, the synthesis of NH-sulfonimidamides is achieved directly from sulfenamides, themselves readily formed in one step from amines and disulfides. A highly chemoselective and one-pot NH and O transfer is developed, mediated by PhIO in iPrOH, using ammonium carbamate as the NH source, and in the presence of 1 equivalent of acetic acid. A wide range of functional groups are tolerated under the developed reaction conditions, which also enables the functionalization of the antidepressants desipramine and fluoxetine and the preparation of an aza analogue of the drug probenecid. The reaction is shown to proceed via different and concurrent mechanistic pathways, including the formation of novel S≡N sulfanenitrile species as intermediates. Several alkoxy-amino-λ -sulfanenitriles are prepared with different alcohols, and shown to be alkylating agents to a range of nucleophiles.
Topics: Alcohols; Amines; Molecular Structure; Nitriles; Sulfamerazine; Sulfonamides
PubMed: 31390133
DOI: 10.1002/anie.201906001 -
Viruses Mar 2022Viral replication and transmissibility are the principal causes of endemic and pandemic disease threats. There remains a need for broad-spectrum antiviral agents. The... (Review)
Review
Viral replication and transmissibility are the principal causes of endemic and pandemic disease threats. There remains a need for broad-spectrum antiviral agents. The most common respiratory viruses are endemic agents such as coronaviruses, respiratory syncytial viruses, and influenza viruses. Although vaccines are available for SARS-CoV-2 and some influenza viruses, there is a paucity of effective antiviral drugs, while for RSV there is no vaccine available, and therapeutic treatments are very limited. We have previously shown that probenecid is safe and effective in limiting influenza A virus replication and SARS-CoV-2 replication, along with strong evidence showing inhibition of RSV replication in vitro and in vivo. This review article will describe the antiviral activity profile of probenecid against these three viruses.
Topics: Drug Repositioning; Humans; Orthomyxoviridae; Probenecid; Respiratory Syncytial Virus, Human; SARS-CoV-2; COVID-19 Drug Treatment
PubMed: 35337018
DOI: 10.3390/v14030612 -
The Journal of General Physiology Apr 2023Tight control of skeletal muscle contractile activation is secured by the excitation-contraction (EC) coupling protein complex, a molecular machinery allowing the plasma...
Tight control of skeletal muscle contractile activation is secured by the excitation-contraction (EC) coupling protein complex, a molecular machinery allowing the plasma membrane voltage to control the activity of the ryanodine receptor Ca2+ release channel in the sarcoplasmic reticulum (SR) membrane. This machinery has been shown to be intimately linked to the plasma membrane protein pannexin-1 (Panx1). We investigated whether the prescription drug probenecid, a widely used Panx1 blocker, affects Ca2+ signaling, EC coupling, and muscle force. The effect of probenecid was tested on membrane current, resting Ca2+, and SR Ca2+ release in isolated mouse muscle fibers, using a combination of whole-cell voltage-clamp and Ca2+ imaging, and on electrically triggered contraction of isolated muscles. Probenecid (1 mM) induces SR Ca2+ leak at rest and reduces peak voltage-activated SR Ca2+ release and contractile force by 40%. Carbenoxolone, another Panx1 blocker, also reduces Ca2+ release, but neither a Panx1 channel inhibitory peptide nor a purinergic antagonist affected Ca2+ release, suggesting that probenecid and carbenoxolone do not act through inhibition of Panx1-mediated ATP release and consequently altered purinergic signaling. Probenecid may act by altering Panx1 interaction with the EC coupling machinery, yet the implication of another molecular target cannot be excluded. Since probenecid has been used both in the clinic and as a masking agent for doping in sports, these results should encourage evaluation of possible effects on muscle function in treated individuals. In addition, they also raise the question of whether probenecid-induced altered Ca2+ homeostasis may be shared by other tissues.
Topics: Mice; Animals; Probenecid; Calcium; Carbenoxolone; Muscle Fibers, Skeletal; Muscle Contraction; Muscle, Skeletal; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum; Nerve Tissue Proteins; Connexins
PubMed: 36820799
DOI: 10.1085/jgp.202213203