leky-latky/cftr-protein/snizuje-cinnost
Arylaminobenzoate
- Act at a number of other cellular sites that can indirectly alter the activity of CFTR or the transepithelial secretion of Cl-
- The nonspecificity of these compounds has complicated the interpretation of results from cellular-based experiments [16]
Benzofuran
- Groups linked to the sulfonyl have been shown to be effective [17]
Chronická aplikace beta-2 mimetik
- Beta-adrenergic bronchodilators (such as albuterol), is nearly universal for airway clearance
- Greater than 60% reduction in both wild-type and modulator-corrected F508del-CFTR activation following chronic exposure to short- and long-acting ß-agonists !!!
- Due to reduced cellular generation of cAMP downstream of the beta-2 adrenergic receptor–G protein complex
- Posttranscriptional reduction in adenylyl cyclase function
- Mechanism of impaired CFTR activation produced by prolonged beta-agonist exposure
- Induced CFTR dysfunction was sufficient to abrogate VX809/VX770 modulation of F508del-CFTR in vitro
- Clinical relevance of observations is critical for CF patients using these drugs !
- Work on subacute and chronic beta2AR activation demonstrated myriad desensitization mechanisms
- Receptor uncoupling from the GP
- Receptor internalization
- PKA-induced downregulation of certain isoforms of AC
- The downstream effects of these changes on CFTR function
- Subgroup analysis of recent phase 3 trials of lumacaftor/ivacaftor in F508del-CFTR homozygous patients revealed
- Almost 3-fold higher improvement in FEV1 in the small subset of subjects who reported not receiving regular beta2AR-agonist therapy
- Chronic beta2AR stimulation in HAECs downregulates cAMP generation by AC
- 72-hour albuterol exposure
- Reduces stimulated apical CFTR activity in F508del-CFTR+ CFBE41o- cells and primary human airway epithelial cells (HAECs) from F508del homozygous donors
- Continuous exposure to albuterol reduces stimulated CFTR activity in a fashion similar to continuous or intermittent dosing with formoterol
- Chronic albuterol exposure does not reduce CFTR expression or maturation in wtCFTR+ or F508del-CFTR+ CFBE41o- cells
- Chronic albuterol exposure reduces cell surface beta2AR, but not CFTR
- Chronic albuterol-induced CFTR impairment is rescued with application of exogenous cAMP
- Chronic PKA stimulation has been reported to downregulate AC5 and AC6
- Albuterol exposure could result in excessive PKA activation through accumulation of beta2AR-stimulated cAMP
- May ultimately downregulate AC6 activity
insight.jci.org/articles/view/93029
CFTR dysfunctions
- Due to environmental toxins,
- Cigarette smoke,
- Cystic fibrosis
- Chronic obstructive pulmonary disease (COPD) [18]
CFTRinh-172
COVID-19
- CFTR dysfunction is likely an early and persistent aspect of the COVID-19 disease progression
- Therefore likely to be present at the time of diagnosis.
- If safety and efficacy criteria are adequately met, treating COVID-19 patients who do not require hospitalization,
- Especially those who are at high risk (e.g., older individuals or those with pre-existing conditions, such as diabetes), could be considered.
www.frontiersin.org/articles/10.3389/fphys.2020.583862/full
Chinese wild grapevine (Vitis amurensis Rupr)
- Inhibited CFTR conductance
- Mass spectrometry (MS) and nuclear magnetic resonance (NMR) studies determined the two active compounds as
- Trans-epsilon-viniferin (TV)
- R-2-viniferin (RV)
- Dose-dependently blocked CFTR-mediated iodide influx with IC50 around 20 nicroM
- Excised inside-out patch-clamp indicated
- TV and RV inhibited CFTR-mediated short-circuit Cl- currents in isolated rat colonic mucosa in a dose-dependent manner
- Intraluminal applications of TV (2.5 µg) and RV (4.5 µg) significantly reduced cholera toxin-induced intestinal fluid secretion
- The present study identified two resveratrol oligomers as new CFTR inhibitors [13]
Chřipka
- Component of the influenza virus pathology, CFTR may be targeted for rapid degradation (Londino et al., 2013, 2015; Brand et al., 2018)
- CFTR therapeutic lumacaftor
- Can stabilize CFTR against degradation (Okiyoneda et al., 2013; Lidington et al., 2019)
- Use in experimental settings restores airway cell function following in vitro influenza infection (Brand et al., 2018)
- Foundation for clinical testing
- Potential application has yet to be tested in the clinical arena
www.frontiersin.org/articles/10.3389/fphys.2020.583862/full
Cigarette smoke
- Is a negative regulator of CFTR (reviewed in Rab et al., 2013)
- CFTR inhibition by cigarette smoke are incompletely defined
www.frontiersin.org/articles/10.3389/fchem.2016.00001/full
Získaná porucha CFTR kouřením
- Both acquired and inherited expression defects of CFTR result in
- Periciliary liquid layer depletion
- Acidification
- Mucus dehydration
- Increased bacterial adhesion
- Decreased mucociliary clearance (MCC)
- Recurrent infections
- Sustained inflammation with progressive deterioration of the lung tissue
- Compelling evidence indicates that subacute (2–24 h) and chronic (>24 h) cigarette smoke (CS) exposure
- Compromises CFTR activity at the protein and mRNA level in a variety of cell types
- Including human nasal
- Bronchial epithelia
www.nature.com/articles/s41598-019-48971-y
Crofelemer
- Anti-diarrhoea drug
- Inhibited CFTR channel
en.wikipedia.org/wiki/Cystic_fibrosis_transmembrane_conductance_regulator
Diazoxide
- Compounds that open SUR/Kir6.2 (dělají hyperglykemii)
- Caused a reduction in CFTR-dependent Cl- conductance [17]
Disulfonic stilbenes
- Act at a number of other cellular sites that can indirectly alter the activity of CFTR or the transepithelial secretion of Cl-
- The nonspecificity of these compounds has complicated the interpretation of results from cellular-based experiments [16]
Genistein
- Could regulate basal diabetic jejunum Cl- secretion in ob/ob female mice by reduce CFTR expression [18]
Glucose in a concentration-dependent manner
- CFTR protein and mRNA expression were reduced
www.spandidos-publications.com/10.3892/ijmm.2018.3547
Gluten/gliadin-derived peptide (P31–43)
- Inhibits CFTR in mouse intestinal epithelial cells [25]
- Causing a local stress response [25]
- P31–43-induced CFTR inhibition elicits an epithelial stress response perturbing proteostasis
- Triggers TGM2 activation, BECN1 sequestration
- Results in molecular crosslinking of CFTR and P31-43 by TGM2
- Stimulation of CFTR function with a pharmacological potentiator (Ivacaftor)
- Could attenuate the autophagy-inhibition and pro-inflammatory effects of gliadin in preclinical models [25]
Glycine hydrazides
- Block the extracellular CFTR pore
faseb.onlinelibrary.wiley.com/doi/full/10.1096/fj.201600891R
IFN gamma
Ibuprofen
- Gave promising results in children and adolescents with CF
www.sciencedirect.com/science/article/pii/S1569199309000356
- Aspirin, ibuprofen, and indomethacin
pubmed.ncbi.nlm.nih.gov/10704076/
Indanyl
- Groups linked to the sulfonyl have been shown to be effective [17]
Inhibice adenylát cyklázy
- Gi alpha
- calcium
- calcium-calmodulin complexes
- Variety of protein kinases
insight.jci.org/articles/view/93029
Intracelulární ADP
- ADP snižuje the open probability [17]
- Tedy málo ATP - málo energie - což může infekce virem/chlamídií aj. snadno způsobit, když ho buňce bude spotřebovávat nebo jí poškodí
Kinases
- Inhibit AMP-dependent protein kinase (AMPK) (Hallows et al., 2000) by activation of:
www.frontiersin.org/articles/10.3389/fchem.2016.00001/full
Increased activity of LMTK2 at the apical PM
- Proposed to inhibit CFTR-mediated Cl- secretion
- At least in part by attenuating the PM abundance of CFTR channels (Luz et al., 2014)
- Mutations in the LMTK2 gene have also been associated with lung adenocarcinoma in smokers (Seo et al., 2012)
www.frontiersin.org/articles/10.3389/fchem.2016.00001/full
Minoxidil
- Compounds that open SUR/Kir6.2 (dělají hyperglykemii)
- Caused a reduction in CFTR-dependent Cl- conductance [17]
NEDD4L
- Ubiquitinates membrane proteins
- Including ion channels
- Leading to increased internalization and degradation of its target proteins [19]
Nocodazole
- A microtubule disrupting agent, prevented the forskolin-induced rise in CFTR fluorescence at the apical surface
- [Apical recruitment of CFTR in T-84 cells is dependent on cAMP and microtubules but not Ca2+ or microfilaments; Albert Tousson1]
Nonspecific Cl- channel blockers
- Phenylanthranilic acid,
- 9-anthracene carboxylic acid,
- 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB)
- DIDS
Porucha funkce pendrinu - možná
Pendred syndrome
- Autosomal recessive disorder caused by mutations in the PDS/SLC26A4 gene
- Sensorineural hearing loss with malformations of the inner ear (enlarged vestibular system)
- Variable degrees of goiter and hypothyroidism
- Partial iodine organification defect
- ijpeonline.biomedcentral.com/articles/10.1186/1687-9856-2014-8
Phorbol 12 - myristate 12 - acetate (PMA)
- Mobilizuje intrac. Ca2+ a TNF alfa
- Downregulace CFTR
Phosphatases
Alkaline phosphatase or PP2A
- CFTR channels expressed in cell lines (CHO and NIH 3T3) can be inactivated by exposure to specific phosphatases
- Results do not indicate that these phosphatases regulate CFTR activity in vivo and especially in cells or tissues that normally express CFTR [17]
PP2C alpha
- Present in colonic and airway epithelial cells
- Was capable of dephosphorylating CFTR in vitro
- Reduced transepithelial Cl- currents when over expressed
- Inactivated CFTR in excised membrane patches
- Might have a physiological role in CFTR regulation [17]
Protein phosphatase type 2A (PP2A)
- Interact with, and dephosphorylate, CFTR (Hwanget al.1994; Luoet al.1998; Thelinet al.2005)
- Is strongly inhibited when phosphorylated by Src atresidue Y307 (Chenet al.1992) [20]
R domain
- In particular—S737 and S768 have a phospho-dependent inhibitory effect on the CFTR channel function (Wilkinson et al., 1997)
- Phosphorylation of these inhibitory sites by AMPK inhibits CFTR mediated Cl- secretion
- By maintaining the channel in a closed state (Kongsuphol et al., 2009)
www.frontiersin.org/articles/10.3389/fchem.2016.00001/full
Rab 5
- Snižuje začlenění endozomu s CFTR do apikální membrány
Resveratrol
- F508del-CFTR homozygous (CF) - resveratrol
- Two hours after intraperitoneal administration of resveratrol (50 mg/kg) dissolved in DMSO
- Compound was detected in salivary glands
- In CF mice, resveratrol rescued the response to isoprenaline
- Eliciting a 2.5-fold increase of ß-adrenergic-stimulated secretion
- Inhibition by atropine (basal ß-adrenergic-dependent component)
- Immunolabelling of CFTR in human bronchial epithelial cells suggests
- That the effect is associated with increased CFTR protein expression
- Support the view that resveratrol is beneficial for treating CF
- Sinižoval sicel CFTR aktivitu po stimulaci isoprenalinem, ale zato stimuloval sekreci cestou beta-adrenergní stimulace [14]
Rhein, aloe-emodin and 1,8-dihydroxyanthraquinone (DHAN)
- Stimulated I(-) influx through CFTR chloride channel
- A dose-dependent manner
- In the presence of physiological concentration of cAMP
- Rhein also enhanced Cl(-) current in freshly isolated rat colonic mucosa with a similar potency
- Effects were completely reversed by the CFTR selective blocker CFTR(inh)-172
- In in vivo closed loop experiments
- Rhein 2 mmol/L stimulated colonic fluid accumulation that was largely blocked by CFTR(inh)-172
- Anthraquinone compounds did not elevate cAMP level in cultured FRT cells and rat colonic mucosa
- Suggesting a direct effect on CFTR activity [15]
Rhodiola kirilowii (Regel) Maxim
- Treatment of secretory diarrhea
- Identify CFTR inhibitors from Rhodiola kirilowii (Regel) Maxim that inhibited CFTR Cl- channel activity
- Identification of:
- 5 commercially available EGCG analogs including
- (+)-catechins (C)
- (-)-epicatechin (EC)
- (-)-epigallocatechin (EGC)
- (-)-epicatechin-3-gallate (ECG)
- EGCG
- Revealed that ECG also had CFTR inhibitory activity
- EGCG dose-dependently and reversibly inhibited CFTR Cl- channel activity
- IC50 value around 100 microM
- EGCG and ECG inhibited CFTR-mediated short-circuit currents in isolated rat colonic mucosa in a dose-dependent manner
- EGCG (10 mcg) and ECG (10 mcg)
- Significantly reduced cholera toxin-induced intestinal fluid secretion
www.researchgate.net/publication/273326061_Bioactivity-Guided_Fractionation_of_an_Antidiarrheal_Chinese_Herb_Rhodiola_kirilowii_Regel_Maxim_Reveals_--Epicatechin-3-Gallate_and_--Epigallocatechin-3-Gallate_as_Inhibitors_of_Cystic_Fibrosis_Trans
S737 site
- Recent in vitro work demonstrated as preferred substrate for Lemur Tyrosine kinase (LMTK2; Wang and Brautigan, 2006)
www.frontiersin.org/articles/10.3389/fchem.2016.00001/full
Sphingomyelinases (SMase) bakteriální
- SMase cleaves sphingomyelin into
- From human respiratory pathogens strongly inhibit CFTR function-
- Hydrolysis of sphingomyelin by SMase
- Makes it more difficult to activate CFTR by phosphorylation of its regulatory domain
- By inhibiting CFTR currents, SMase-producing respiratory tract bacteria
- Aggravate pulmonary infection in some CF patients
- Elicit a condition, analogous to CFTR deficiency, in non-CF patients suffering from bacterial lung infection
- Infection with bacteria that produce SMase activity would further suppress CFTR activity
SMase C
- Bacillus anthracis
- Produce little SMase C
- Partly because of a deletion in the gene encoding a key pleiotropic regulator
- Staphylococcus aureus, encodes SMase C
- SMase C of S. aureus was originally called beta-hemolysin for its hemolytic effect on a sheep blood agar culture
- Bc SMase C (from Bacillus cereus)
- Inhibitory effect required the presence of Mg2+
- Hydrolysis products phosphocholine or ceramide caused no significant current inhibition
Sphingomyelinase (SMase) D
- From the Brown spider venom
- Suppresses the Cl- current that flows through the activated CFTR
- Bound Mg2+ is essential for lipase activity
- Corynebacterium pseudotuberculosis produces Cp SMase D
- Arcanobacterium haemolyticum also produces SMase D
- SMase D inhibition is reversible and can be overcome by high cAMP concentration
- Forskolin not only restored the current but also boosted it to about twice the original level
- SMase D causes severe tissue necrosis
Phospholipase (termed PLC-H)
- Pseudomonas aeruginosa permanently colonizes the airways of virtually all late-stage CF patients
- Secretes a phospholipase (termed PLC-H) that can hydrolyze sphingomyelin
Sulfonylureas
- Act at a number of other cellular sites that can indirectly alter the activity of CFTR or the transepithelial secretion of Cl-
- The nonspecificity of these compounds has complicated the interpretation of results from cellular-based experiments [16]
Antidiabetic sulfonylureas - pharmacologically characterize SUR/Kir6.2
- Reduced whole cell Cl- currents in NIH 3T3 cells expressing CFTR
- Blocker concentrations in excess of 1,000-fold greater than those reported to inhibit SUR/Kir6.2
- Were required to similarly affect CFTR [17]
Glymenclamid více než tolbutamide
- Structure-dependent and concentration-dependent manner inhibition
- By direct interaction with the channel as recorded in cell-free membrane patches from CFTR [17]
- Compounds reversibly interact exclusively with the open state of CFTR channels to interrupt Cl- conduction [17]
- Sulfonylurea with the open state sequesters CFTR in an activated, albeit nonconducting, state and, in this linear scheme, reduces the likelihood of channel inactivation [17]
- Glibenclamide-CFTR interaction is substantially more stable than the tolbutamide-CFTR interaction [17]
- Glibenclamide-dependent inhibition of anion transport to indicate that CFTR participates in a particular physiological system of interest
- Mouse intestinal crypt secretion, Ref. 400;
- Guinea pig ventricular myocyte Cl- currents, Refs. 388389;
- Rat nephron terminal collecting duct, Ref. 175;
- Human kidney cyst epithelial cells, Ref. 155;
- MIMCD-K2 cells, Ref. 403;
- Shark rectal gland cells, Ref. 90;
- NS004-, NS1619-, 1-EBIO-, and psoralen-stimulated secretion in T84 cells, Refs. 9394;
- protein kinase A (PKA)-stimulated Cl- flux across rat nephron cortical brush-border membranes, Ref. 34;
- Rat fetal lung epithelium, Ref. 377;
- CAMP-stimulated 125I efflux from MDCK cells, Ref. 261]. [17]
- Glibenclamide and tolbutamide
Riziko chyby používání glybenclamidu jako jediného markeru přítomnosti CFTR
- účinky sulfornylure nejsou CFTR specifické !
- Inhibition of a variety of K+ channels (32110)
- The inhibition of numerous enzymes (62) including PKA (275),
- Inhibition of other Cl- channels (255293324438)
- Caution must be exercised in interpreting effects in intact tissues.
- Both nonunity Hill coefficients for concentration-dependent inhibition and the inability to “wash out” the inhibitory effect of glibenclamide
- Might reflect concerted effects on intracellular enzymes including PKA rather than an ongoing bimolecular interaction with CFTR [17]
- Pod 30 microM glibenclamide
- At these concentrations, a significant block of CFTR would not be expected in any situation. [17]
Diarylsulfonylureas
- Provide greater selectivity and slightly higher potency than glibenclamide for the inhibition of CFTR [17]
TNF alpha
- Downregulace CFTR
- TNF signaling has, one intriguing effect is a broad downregulation of cystic fibrosis transmembrane conductance regulator (CFTR) expression in multiple tissues
- Most notably, in the lung and brain (Meissner et al., 2012; Yagi et al., 2015).
www.frontiersin.org/articles/10.3389/fphys.2020.583862/full
Thiazolidinones
- Six CFTR inhibitors of the 2-thioxo-4-thiazolidinone chemical class were identified
- The most potent compound discovered by screening of structural analogs
- Thiazolidinones and quinoxalinediones act at the cytoplasmic surface
CFTRinh-172 - 3-[(3-trifluoromethyl)phenyl]-5-[(4-carboxyphenyl)methylene]-2-thioxo-4-thiazolidinone
- Reversibly inhibited CFTR
- CFTRinh-172 stabilizes the CFTR channel closed-state by binding at or near residue Arg-347
- Significant reductions in plasma insulin concentrations and pancreatic insulin content were also observed in CFTR-inhibited animals.
(R)-benzopyrimido-pyrrolo-oxazine-dione-27 (BPO-27)
- Inhibit bacterial enterotoxin (cholera and Sta toxins) induced diarrhoea
- Prevents BAD and therefore has a role in the treatment of this condition in humans.
- BPO-27 completely inhibits CDCA-induced Cl- secretion in vitro in primary cultures of human colonic epithelial cells and T84 cells
- BPO-27 inhibits CDCA-induced fluid secretion in enclosed murine jejunal and colonic loops by approximately 70%
- Following intraperitoneal administration.
facultyopinions.com/prime/736126318
Zánět
- Even a relatively mild inflammatory setting clearly downregulates wild-type CFTR expression in the lung (Meissner et al., 2012).
www.frontiersin.org/articles/10.3389/fphys.2020.583862/full