In vitro up‐regulation of HLA‐G using dexamethasone and hydrocortisone in first‐trimester trophoblast cells of women experiencing recurrent miscarriage

Abstract

The trophoblast cells at the maternal-fetal interface express an unusual combination of human leukocyte antigen (HLA)-C, HLA-E and HLA-G. Altered expression of HLA-G on the extravillous cytotrophoblast has been implicated in the etiology of recurrent miscarriages (RMs). We have assessed HLA-G expression in extravillous cytotrophoblast in cell cultures prepared from RM patients and compared with those of first-trimester voluntarily terminated normal pregnancies (control). Glucocorticoids, dexamethasone and hydrocortisone were examined for their role in modulation of the HLA-G expression. HLA-G promoter and 3'UTR variants were investigated for their effect on the transcription of HLA-G. Cultured cytotrophoblast cells from the first-trimester RM patients were treated with dexamethasone and hydrocortisone (dose concentration 0-1000 ng/ml). HLA-G gene transcription was determined by semiquantitative and quantitative real-time polymerase chain reaction (RT-PCR), while protein expression was determined by a specific enzyme-linked immunosorbent assay (ELISA), flow cytometry and western blot analyses. HLA-G polymorphisms were detected by PCR and/or sequence-based typing. Low level of HLA-G was observed in untreated trophoblast cells obtained from RM patients as compared with controls. Upon treatment with glucocorticoids, the expression of HLA-G in these cells was up-regulated in a dose-dependent manner (P < 0.05), with no change in cellular proliferation and viability. There was no significant association between HLA-G polymorphism in RM patients and controls. HLA-G is minimally expressed in cultured trophoblast cells of RM patients. It can be up-regulated upon exposure with both dexamethasone and hydrocortisone. Glucocorticoids have the potential to modulate HLA-G expression in vitro, and can be further examined for their therapeutic applicability in RM.

Soluble Human Leukocyte Antigen G Molecule Expression in Allogeneic Hematopoietic Stem Cell Transplantation: Good Predictor of Acute Graft-versus-Host Disease

“…HLA-G has a strong immunosuppressive function and a restricted expression in trophoblast cells [26], adult thymic medulla [27], cornea [28], pancreatic islets [29], erythroblasts [30] and endothelial cell precursors [31] under ‘physiological conditions'. An alternative splicing of its primary transcript generates 7 different isoforms including 4 membrane-bound (HLA-G1 to HLA-G4) and 3 soluble (HLA-G5 to HLA-G7) proteins [32,33].…”

Relationship between HLA-G polymorphism and susceptibility to recurrent miscarriage: A meta-analysis of non-family-based studies

“…Among these, 4 studies were excluded due to duplicate publications [32][33][34][35], three had incomplete data on allele and genotype frequency which we failed to get by emails to the corresponding authors [36][37][38], and an additional one was excluded due to the absence of a control group [39]. Consequently, the remaining 17 case-control studies which examined the association between the HLA-G 14-bp polymorphism and RM were finally included [12,17,[25][26][27][40][41][42][43][44][45][46][47][48][49][50][51] (Fig. 1).…”

“…Association between RM and HLA-G 14-bp insertion/deletion polymorphism allele Sixteen studies were included in assessing the association between HLA-G 14-bp insertion/deletion polymorphism allele and RM [12,17,[25][26][27][40][41][42][43][44][45][46][47][48][49][50]. As shown in Fig.…”

“…When there were multiple publications from the same study group, the most informative and recent study was included for review [24]. Moreover, three studies of Akhter A et al 2012 [25], Kano T et al 2007[26] and Liu YD et al 2008[27] which reported the association of HLA-G 14-bp polymorphism and RM susceptibility did not be included in the meta-analysis article of Wang et al,(2013) . Therefore it was necessary to reevaluate the association of HLA-G 14-bp polymorphism and RM susceptibility, by excluding the study of and including the studies of Akhter A et al 2012, Kano T et al 2007 andLiu YD et al 2008.…”

Genetic regulation of recurrent spontaneous abortion in humans

“…Immunotolerogenic treatments applied to the cells (dexamethasone, hydrocortisone) were able to modulate HLA-G expression positively, but the basal level of HLA-G was systematically lower in RSA patients. [93] Since HLA is a relatively small chromosome region (<3 Mbp), LD between Class I and Class II can be expected and was indeed shown, for instance, in the locus encompassing the three Class II DRB1*03-DQA1*05-DQB1*02, on the one hand and the Class I G*01010 2 in the other hand G*010102 is the HLA-G haplotype that encompasses the 14-bp sequence variant. [94] This result could put forward the idea that only one of these genes is actually modulating implantation success, according to the alleles displayed by the patient.…”