scholarly journals Kynurenic Acid Accelerates Healing of Corneal Epithelium In Vitro and In Vivo

2021 ◽  
Vol 14 (8) ◽  
pp. 753
Author(s):  
Anna Matysik-Woźniak ◽  
Waldemar A. Turski ◽  
Monika Turska ◽  
Roman Paduch ◽  
Mirosław Łańcut ◽  
...  

Kynurenic acid (KYNA) is an endogenous compound with a multidirectional effect. It possesses antiapoptotic, anti-inflammatory, and antioxidative properties that may be beneficial in the treatment of corneal injuries. Moreover, KYNA has been used successfully to improve the healing outcome of skin wounds. The aim of the present study is to evaluate the effects of KYNA on corneal and conjunctival cells in vitro and the re-epithelization of corneal erosion in rabbits in vivo. Normal human corneal epithelial cell (10.014 pRSV-T) and conjunctival epithelial cell (HC0597) lines were used. Cellular metabolism, cell viability, transwell migration, and the secretion of IL-1β, IL-6, and IL-10 were determined. In rabbits, after corneal de-epithelization, eye drops containing 0.002% and 1% KYNA were applied five times a day until full recovery. KYNA decreased metabolism but did not affect the proliferation of the corneal epithelium. It decreased both the metabolism and proliferation of conjunctival epithelium. KYNA enhanced the migration of corneal but not conjunctival epithelial cells. KYNA reduced the secretion of IL-1β and IL-6 from the corneal epithelium, leaving IL-10 secretion unaffected. The release of all studied cytokines from the conjunctival epithelium exposed to KYNA was unchanged. KYNA at higher concentration accelerated the healing of the corneal epithelium. These favorable properties of KYNA suggest that KYNA containing topical pharmaceutical products can be used in the treatment of ocular surface diseases.

1995 ◽  
Vol 43 (4) ◽  
pp. 353-362 ◽  
Author(s):  
M A Stepp ◽  
L Zhu ◽  
D Sheppard ◽  
R L Cranfill

A recently characterized integrin alpha-chain, alpha 9, forms heterodimers with the integrin beta 1-chain and is present in the skin with a distribution similar to that of alpha 2 and alpha 3, other beta 1 integrins. To determine whether alpha 9 is expressed in the stratified squamous epithelium of the cornea, we used immunohistochemical techniques to compare the distribution of alpha 9 in the adult mouse cornea with that of alpha 3. Abundant alpha 9 was expressed in the lateral and basal membranes of the basal cells of the conjunctiva and corneal limbus, but very little alpha 9 was present in the basal cells of the central corneal epithelium. In contrast, alpha 3 was present in the membranes of basal cells of the conjunctiva, limbus, and central cornea. To determine when during postnatal maturation of the corneal epithelium alpha 9 becomes restricted to the limbus, we looked at the distribution of alpha 9 and alpha 3 in the developing mouse eye from birth to eyelid opening. At birth, the basal cells of the cornea and developing limbal region did not express alpha 9, but there was abundant alpha 9 expressed in suprabasal cells between the fused lids and in the basal cells of the skin and conjunctiva. In contrast, alpha 3, integrin was expressed uniformly in the basal cells across the surface of the conjunctiva, limbus, and cornea and was present only in the basal cells of the epithelium between the fused eyelids. In the central cornea, alpha 9 expression increased in basal cells up until Day 10 after birth. After Day 10, alpha 9 expression in the central cornea began to decrease; after the lids were open, alpha 9 expression in the central cornea became restricted to the limbus. In the basal and suprabasal cells between the fused eyelids expression of alpha 9 became increasingly restricted over time to the basal cells. Recent data suggest that alpha 9 beta 1 can interact with tenascin. Our dual labeling confocal microscopy studies indicate that localization of alpha 9 and tenascin are not coordinated in the developing mouse cornea. Many recent studies have shown an important role for beta 1 integrins in mediating epithelial cell differentiation in vitro; in vivo, changes in integrin expression have been found in wound healing, psoriasis, and in basal and squamous cell carcinomas.(ABSTRACT TRUNCATED AT 400 WORDS)


2016 ◽  
Vol 2016 ◽  
pp. 1-23 ◽  
Author(s):  
Joseph W. Sassani ◽  
Patricia J. Mc Laughlin ◽  
Ian S. Zagon

The Opioid Growth Regulatory System consists of opioid growth factor (OGF), [Met5]-enkephalin, and its unique receptor (OGFr). OGF inhibits cell division when bound to OGFr. Conversely, blockade of the interaction of OGF and OGFr, using the potent, long-acting opioid receptor antagonist, naltrexone (NTX), results in increased DNA synthesis and cell division. The authors have demonstrated bothin vitroandin vivothat the addition of exogenous OGF or an increase in available OGFr decreases corneal epithelial cell division and wound healing. Conversely, blockade of the OGF-OGFr interaction by NTX or a decrease in the production of the OGFr increases corneal epithelial cell division and facilitates corneal epithelial wound healing. The authors also have demonstrated that depressed corneal and cutaneous wound healing, dry eye, and abnormal corneal sensitivity in type 1 and type 2 diabetes in animals can be reversed by OGF-OGFr blockade by NTX. Thus, the function of the Opioid Growth Regulatory System appears to be disordered in diabetic animals, and its function can be restored with NTX treatment. These studies suggest a fundamental role for the Opioid Growth Regulatory System in the pathobiology of diabetic complications and a need for studies to elucidate this role further.


2011 ◽  
Vol 131 (6) ◽  
pp. 985-991 ◽  
Author(s):  
Noriaki NAGAI ◽  
Takatoshi MURAO ◽  
Kyouhei OE ◽  
Yoshimasa ITO ◽  
Norio OKAMOTO ◽  
...  

2021 ◽  
Author(s):  
Jiapan Gao ◽  
Delu Che ◽  
Xueshan Du ◽  
Yi Zheng ◽  
Huiling Jing ◽  
...  

Abstract Imidazolidinyl urea (IU) is used as an antimicrobial preservative in cosmetic and pharmaceutical products. IU induces allergic contact dermatitis, however, the mechanism has not yet been elucidated. Mas-related G protein-coupled receptor-X2 (MRGPRX2) triggers drug-induced pseudo-allergic reactions. The aims of this study were to determine whether IU activated mast cells through MRGPRX2 to further trigger contact dermatitis. Wild-type (WT) and KitW-sh/HNihrJaeBsmJNju (MUT) mice were treated with IU to observe its effects on local inflammation and mast cells degranulation in vivo. Laboratory of allergic disease 2 cells were used to detect calcium mobilization and release of inflammatory mediators in vitro. WT mice showed a severe local inflammatory response and contact dermatitis, whereas only slight inflammatory infiltration was observed in MUT mice. Thus, MRGPRX2 mediated the IU-induced activation of mast cells. However, histamine, a typical allergen, was not involved in this process. Tryptase expressed by mast cells was the major non-histaminergic inflammatory mediator of contact dermatitis. IU induced anaphylactic reaction via MRGPRX2 and further triggering non-histaminergic contact dermatitis, which explained why antihistamines are clinically ineffective against some chronic dermatitis.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Przemysław Baranowski ◽  
Bożena Karolewicz ◽  
Maciej Gajda ◽  
Janusz Pluta

This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments,in situgels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommendedin vitroandin vivostudies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient’s compliance.


2008 ◽  
Vol 22 (12) ◽  
pp. 2677-2688 ◽  
Author(s):  
Paul G. Tiffen ◽  
Nader Omidvar ◽  
Nuria Marquez-Almuina ◽  
Dawn Croston ◽  
Christine J. Watson ◽  
...  

Abstract Recent studies in breast cancer cell lines have shown that oncostatin M (OSM) not only inhibits proliferation but also promotes cell detachment and enhances cell motility. In this study, we have looked at the role of OSM signaling in nontransformed mouse mammary epithelial cells in vitro using the KIM-2 mammary epithelial cell line and in vivo using OSM receptor (OSMR)-deficient mice. OSM and its receptor were up-regulated approximately 2 d after the onset of postlactational mammary regression, in response to leukemia inhibitory factor (LIF)-induced signal transducer and activator of transcription-3 (STAT3). This resulted in sustained STAT3 activity, increased epithelial apoptosis, and enhanced clearance of epithelial structures during the remodeling phase of mammary involution. Concurrently, OSM signaling precipitated the dephosphorylation of STAT5 and repressed expression of the milk protein genes β-casein and whey acidic protein (WAP). Similarly, during pregnancy, OSM signaling suppressed β-casein and WAP gene expression. In vitro, OSM but not LIF persistently down-regulated phosphorylated (p)-STAT5, even in the continued presence of prolactin. OSM also promoted the expression of metalloproteinases MMP3, MMP12, and MMP14, which, in vitro, were responsible for OSM-specific apoptosis. Thus, the sequential activation of IL-6-related cytokines during mammary involution culminates in an OSM-dependent repression of epithelial-specific gene expression and the potentiation of epithelial cell extinction mediated, at least in part, by the reciprocal regulation of p-STAT5 and p-STAT3.


2021 ◽  
Vol 27 ◽  
Author(s):  
Rishi Paliwal ◽  
Pramod Kumar ◽  
Akash Chaurasiya ◽  
Rameshroo Kenwat ◽  
Sumeet Katke ◽  
...  

Background: Nanopharmaceuticals serve as emerging forms of modern medicines which include nanomedicines, nanosimilars, nanotheranostics, nanodevices and many more. In last two decades, a large number of nano-based products has reached to the market and are being used clinically. Objectives: Unlike, conventional pharmaceutical products, nanopharmaceuticals behave differently both in vitro and in vivo and therefore, development of their generic versions needs special attention to replicate the similar drug release pattern leading to the identical therapeutic outcome. Further, drug-device combinations and 3D products are latest advancements in precise medicine delivery and development. Methods: The regulatory guidelines for these products are being framed at many stages by various regulatory agencies like USFDA/EMA and still are in infancy at the moment if we look at wider prospective and applications of nanomedicine. Results: For a formulation scientist, it is much needed that well-explained and directive guidelines should be available before leading to the development of the generic versions of these nano-cargos. Conclusion: Here, in this review, we have summarized the silent features of the regulatory perspectives related to the nanotechnology based next generation therapeutics and diagnostics.


BioMetals ◽  
2014 ◽  
Vol 27 (5) ◽  
pp. 857-874 ◽  
Author(s):  
Anne Blais ◽  
Cuibai Fan ◽  
Thierry Voisin ◽  
Najat Aattouri ◽  
Michel Dubarry ◽  
...  

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