The integrity and thus the function of blood–brain barrier (BBB) TJs play a crucial role in the pathomechanism of neuroinflammatory and neurodegenerative diseases. Previously, it has been suggested that targeting different elements of the zonulin pathway, including actin filaments, TJs, or NF-κB, have potential therapeutic effects on CNS diseases. Indeed, encouraging results are accumulating from a recent preclinical study, using myosin light chain kinase (MLCK) inhibitor ML-7, which attenuates BBB disruption by preventing the disintegration of actin cytoskeletal microfilaments. Similarly, blocking the cleavage of TJ proteins by matrix metalloproteases (MMP) inhibitors, using either direct (broad-spectrum or selective MMP-2 and MMP-9) or indirect inhibitors (COX) has been shown to protect BBB. Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists, such as rosiglitazone, pioglitazone, or D-allose, also prevented BBB integrity by inhibiting NF-κB activation. Therefore, the use of zonulin inhibitors seems to be justified in the treatment of CNS diseases.
Condition | Results | Study (Enrollment) |
Clinical Trials Identifier | Ref. |
---|---|---|---|---|
Healthy | good tolerability | Phase I (24) |
NCT00386490 | [3] |
Celiac disease, gluten-free diet |
good tolerability | Phase Ib (21) |
NCT00386165 | [4] |
Celiac disease, | ||||
gluten-free diet | (terminated based on interim analysis) | Phase III (307) |
NCT03569007 | [15][16] |
Model | Species | Administration | Daily Dose | Results | Ref. | ||||
---|---|---|---|---|---|---|---|---|---|
celiac disease | gliadin-sensitized HLA-HCD4/DQ8 transgenic mouse | p.o. gavage |
0.25 mg | reduced intestinal permeability and macrophage infiltration | [21] | ||||
p.o. gavage |
0.3 mg | reduced intestinal permeability | [22] | ||||||
Celiac disease, gluten challenge | improvement in GI symptoms, | ||||||||
intestinal permeability | good tolerability |
Phase IIa (80) |
NCT00362856 | [ | Il10−/− mouse | 5 | p.o. gavage][6][7][ |
5 mg8] | |
reduced intestinal permeability and inflammation | [ | 23 | ] | Celiac disease, gluten challenge | improvement in histological scores, good tolerability |
Phase IIb (105) |
NCT00620451 | ||
spontaneous colitis | p.o. in drinking water | [ | 9 | ][10] | |||||
0.1 or 1 mg/mL | reduced intestinal permeability and inflammation | [ | 24 | ] | Celiac disease, gluten challenge | improvement in GI symptoms, decreased level of anti-tTG IgA | Phase IIb (171) |
NCT00492960 | [11][12] |
Celiac disease, persistent symptoms with gluten-free diet | improvement in GI and extra-GI symptoms, |
Target | Type | Compound | Cell Line | Effect on TJs and/or Transcellular Permeability |
Ref. | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
PAR2 | peptidic antagonist | FSLLRY-NH2 | pHNECs | harmful | [46] | ||||||
SLIGRL-NH2 | |||||||||||
non-peptidic full agonist | AC-55541 | hBMECs | protective | [50] | |||||||
small molecule antagonist | GB88 | A549 | [48] | ||||||||
DSS induced colitis | zonulin transgenic mouse | p.o. in drinking water |
1 mg/mL | reduced intestinal permeability | [25] | ||||||
hECs | [49] | good tolerability | Phase IIb (342) |
NCT01396213 | [13][14] | ||||||
COVID19—MIS-C | improvement in clinical symptoms, decreased level of inflammatory markers and SARS-CoV-2 nucleocapsid (N) protein | ||||||||||
radiation-induced enteropathy | mouse | i.p. | 0.25 mg | improved clinical state and histological scores, inhibited bacterial translocation, elevated TJ protein levels | [26] | ||||||
GB83 | Caco2 | harmful | [47] | healthy (pharmacokinetics) |
pig | p.o. capsule |
0.05 mg/kg | ||||
EGFR | tyrosine kinase inhibitor | AG1478 | hCMEC/D3case report (1) |
[17] | |||||||
determining pharmacokinetics of larazotide acetate in the small intestine | [ | 27 | ] | ||||||||
protective | [ | 51 | ] | Ruminococcus blautia gnavus colonization | germ-free mouse | p.o. in drinking water |
0.15 mg/mL | reduced intestinal permeability | [28] | COVID19—MIS-C | improvement in GI symptoms, decreased level of SARS-CoV-2 Spike (S) protein |
Calu-3 | [52] | case series | |||||||||
spontaneous T1D | (4) | BB diabetic-prone rat | p.o. [18] |
||||||||
in drinking water | 0.01 mg/mL | COVID19—MIS-C | (not completed) | Phase IIa (20) |
NCT05022303 | [19] |
inhibited development of diabetes | ||||||
[ | ||||||
29 | ||||||
] | ||||||
HSC-3 | ||||||
[ | 53] | |||||
rheumatoid arthritis | mouse | p.o. in drinking water |
0.15 mg/mL | attenuated arthritis | [30] | |
erlotinib | IEC-6 | Il10ra−/− mouse, Cldn8−/− mouse |
p.o. gavage |
2 × 0.05 mg | reduced intestinal permeability, inflammation, and joint swelling | [31] |
vasculitis | mouse | i.p. | 0.5 mg | reduced intestinal permeability and LPS translocation, prevented cardiovascular lesions | [32] | |
LPS-induced acute lung injury | i.t. | 0.05 mg | reduced severity, decreased inflammatory markers | [33] | ||
i.v. | 0.01 or 0.025 or 0.05 mg | |||||
harmful | influenza | i.v. | 0.15 mg | reduced severity of acute lung injury | [34] | |
salivary gland fibrosis | i.p. | 5 mg/kg | improved epithelial barrier function, ameliorated fibrosis | [35] | ||
NAFLD | p.o. in drinking water |
0.1 or 1 mg/mL | reduced intestinal permeability | [36] | ||
p.o. gavage |
2 × 0.03 or 2 × 0.3 mg | |||||
acute liver failure | rat | p.o. in drinking water |
0.01 mg/mL | decreased intestinal damage | [37] | |
p.o. gavage |
2 × 0.03 mg |
[ | ||
54 | ||
] | ||
gefitinib | ||
[ | ||
55 | ||
] | ||
icotinib | ||
dacomitinib | T84 | [57] |
lapatinib | HBCCs | [58] |
vandetanib | Calu-6 | [59] |