Caco-2细胞模型验证指标的选择与评判

 目的建立Caco-2细胞模型并探讨验证该模型指标的选择与评判。方法在所建立的Caco-2单层细胞模型上,通过测定跨上皮细胞膜电阻(TEER),比较膜两侧碱性磷酸酶(ALP)活性,计算几种公认的标记物在单层模型转运参数等对Caco-2细胞单层可靠性进行评价。结果TEER在细胞单层形成过程中稳定增长,膜两侧培养液中ALP活性差异逐步加大,细胞旁及跨细胞转运标记物均呈现可预见的低或高表观渗透系数(P_app)值,P-gp标准底物非索非那定双侧转运流出率(ER)大于2。结论建立的Caco-2细胞模型在完整性、细胞极性、通透性以及P-gp表达等方面均符合胃肠吸收化合物机制研究的要求。     

Labrasol® and Salts of Medium-Chain Fatty Acids Can Be Combined in Low Concentrations to Increase the Permeability of a Macromolecule Marker Across Isolated Rat Intestinal Mucosae

In addition to their solubilizing properties, excipients used in lipid-based formulations can improve intestinal permeability of macromolecules. We determined whether admixing of medium-chain fatty acid (MCFA) permeation enhancers with a lipoidal excipient (Labrasol^®) could potentiate transepithelial flux of a poorly permeable macromolecule (fluorescein isothiocyanate dextran 4 kDa [FD4]) across rat intestinal mucosae mounted in Ussing chambers. Low concentrations of sodium caprate (C₁₀), sodium undecylenate (C_11:1), or sodium laurate (C₁₂) combined with Labrasol^® increased the apparent permeability coefficient (P_app) of FD4 to values typically seen with higher concentrations of MCFAs or Labrasol^® alone. For example, combination of C_11:1 (0.5 mg/mL) with Labrasol^® (1 mg/mL) increased the P_app of FD4 by 10- and 11-fold over the respective individual agents at the same concentrations where no enhancement was evident. The increased enhancement ratios seen with the combinations were associated with some perturbation in intestinal histology and with attenuation of an epithelial functional measure, carbachol-stimulated inward short-circuit current. In conclusion, combining three MCFAs separately with Labrasol^® increased the P_app of FD4 to values greater than those seen for MCFAs or Labrasol^® alone. Ultimately, this may permit lower concentrations of MCFA to be used in combination with other excipients in oral formulations of poorly permeable molecules.     

Cambios en la selección e impacto potencial de los inhibidores de neprilisina y del receptor de la angiotensina en los pacientes sometidos a reparación mitral percutánea borde a borde

Introduction and objectivesTranscatheter edge-to-edge repair (TEER) should be considered in patients with heart failure and secondary mitral regurgitation (MR). Angiotensin receptor-neprilysin inhibitors (ARNIs) have been demonstrated to improve prognosis in heart failure. We aimed to evaluate the impact ARNIs on patient selection and outcomes.MethodsThe population of the Spanish TEER prospective registry (March 2012 to January 2021) was divided into 2 groups: a) TEER before the ARNI era (n = 450) and b) TEER after the recommendation of ARNIs by European Guidelines (n = 639), with further analysis according to intake (n = 52) or not (n = 587) of ARNIs.ResultsA total of 1089 consecutive patients underwent TEER for secondary MR. In the ARNI era, there was a reduction in left ventricle dilation (82 mL vs 100 mL, P = .025), and better function (35% vs 38%, P = .011). At 2 years of follow-up, mortality (10.6% vs 17.3%, P < .001) and heart failure readmissions (16.6% vs 27.8%, P < .001) were lower in the ARNI era, but not recurrent MR. In the ARNI era, 1- and 2-year mortality were similar irrespective of ARNI intake but patients on ARNIs had a lower risk of readmission + mortality at 2 years (OR, 0.369; 95%CI, 0.137-0.992; P = .048), better NYHA class, and lower recurrence of MR III-IV (1.9% vs 14.3%, P = .011).ConclusionsBetter patient selection for TEER has been achieved in the last few years with a parallel improvement in outcomes. The use of ARNIs was associated with a significant reduction in overall events, better NYHA class, and lower MR recurrence.     

Metabolism and transfer of the mycotoxin zearalenone in human intestinal Caco-2 cells

The mycotoxin zearalenone (ZEA) is found worldwide as contaminant in cereals and grains. It is implicated in reproductive disorders and hyperestrogenic syndromes in animals and humans exposed by food. We investigated metabolism and transfer of ZEA using the human Caco-2 cell line as a model of intestinal epithelial barrier. Cells exposed to 10–200 μM ZEA showed efficacious metabolism of the toxin. α-zearalenol and β-zearalenol were the measured preponderant metabolites (respectively 40.7 ± 3.1% and 31.9 ± 4.9% of total metabolites, after a 3 h exposure to 10 μM ZEA), whereas ZEA-glucuronide and α-zearalenol glucuronide were less produced (respectively 8.2 ± 0.9% and 19.1 ± 1.3% of total metabolites, after a 3 h exposure to 10 μM ZEA). Cell production of reduced metabolites was strongly inhibited by α-and β-hydroxysteroid dehydrogenase inhibitors, and Caco-2 cells exhibited α-hydroxysteroid dehydrogenase type II and β-hydroxysteroid dehydrogenase type I mRNA. After cell apical exposure to ZEA, α-zearalenol was preponderantly found at the basal side, whereas β-zearalenol and both glucuronides were preferentially excreted at the apical side. As α-zearalenol shows the strongest estrogenic activity, the preferential production and basal transfer of this metabolite suggests that intestinal cells may contribute to the manifestation of zearalenone adverse effects.     

Specific permeability modulation of intestinal paracellular pathway by chitosan-poly(isobutylcyanoacrylate) core-shell nanoparticles

This work is focused on the evaluation of the in vitro permeation modulation of chitosan and thiolated chitosan (chitosan-TBA) coated poly(isobutylcyanoacrylate) (PIBCA) nanoparticles as drug carriers for mucosal administration. Core-corona nanoparticles were obtained by radical emulsion polymerisation of isobutylcyanoacrylate (IBCA) with chitosan of different molecular weights and different proportions of chitosan/chitosan-TBA. In this work, the effect of these nanoparticles on the paracellular permeability of intestinal epithelium was investigated using the Ussing chamber technique, by adding nanoparticle suspensions in the mucosal side of rat intestinal mucosa. Results showed that permeation of the tracer [14C]mannitol and the reduction of transepithelial electrical resistance (TEER) in presence of nanoparticles were more pronounced in those formulations prepared with intermediate amounts of thiolated polymer. This effect was explained thanks to the high diffusion capacity of those nanoparticles through the mucus layer that allowed them to reach the tight junctions in higher extent. It was concluded that, although a first contact between nanoparticles and mucus was a mandatory condition for the development of a permeation enhancement effect, the optimal effect depended on the chitosan/chitosan-TBA balance and the conformational structure of the particles shell.