İsmail Öğülür

Suppressive effect of compact bone-derived mesenchymal stem cells on chronic airway remodeling in murine model of asthma

New therapeutic strategies are needed in the treatment of asthma besides vaccines and pharmacotherapies. For the development of novel therapies, the use of mesenchymal stem cells (MSCs) is a promising approach in regenerative medicine. Delivery of compact bone (CB) derived MSCs to the injured lungs is an alternative treatment strategy for chronic asthma. In this study, we aimed to isolate highly enriched population of MSCs from mouse CB with regenerative capacity, and to investigate the impact of these cells in airway remodeling and inflammation in experimental ovalbumin-induced mouse model of chronic asthma. mCB-MSCs were isolated, characterized, labeled with GFP and then transferred into mice with chronic asthma developed by ovalbumin (OVA) provocation. Histopathological changes including basement membrane, epithelium, subepithelial smooth thickness and goblet cell hyperplasia, and MSCs migration to lung tissues were evaluated. These histopathological alterations were increased in ovalbumin-treated mice compared to PBS group (P<0.001). Intravenous administration of mCB-MSC significantly reduced these histopathological changes in both distal and proximal airways (P<0.001). We showed that GFP-labeled MSCs were located in the lungs of OVA group 2weeks after intravenous induction. mCB-MSCs also significantly promoted Treg response in ovalbumin-treated mice (OVA+MSC group) (P<0.037). Our studies revealed that mCB-MSCs migrated to lung tissue and suppressed histopathological changes in murine model of asthma. The results reported here provided evidence that mCB-MSCs may be an alternative strategy for the treatment of remodeling and inflammation associated with chronic asthma.

CD55 Deficiency, Early-Onset Protein-Losing Enteropathy, and Thrombosis

Background Studies of monogenic gastrointestinal diseases have revealed molecular pathways critical to gut homeostasis and enabled the development of targeted therapies. Methods We studied 11 patients with abdominal pain and diarrhea caused by early‐onset protein‐losing enteropathy with primary intestinal lymphangiectasia, edema due to hypoproteinemia, malabsorption, and less frequently, bowel inflammation, recurrent infections, and angiopathic thromboembolic disease; the disorder followed an autosomal recessive pattern of inheritance. Whole‐exome sequencing was performed to identify gene variants. We evaluated the function of CD55 in patients’ cells, which we confirmed by means of exogenous induction of expression of CD55. Results We identified homozygous loss‐of‐function mutations in the gene encoding CD55 (decay‐accelerating factor), which lead to loss of protein expression. Patients’ T lymphocytes showed increased complement activation causing surface deposition of complement and the generation of soluble C5a. Costimulatory function and cytokine modulation by CD55 were defective. Genetic reconstitution of CD55 or treatment with a complement‐inhibitory therapeutic antibody reversed abnormal complement activation. Conclusions CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and protein‐losing enteropathy (the CHAPLE syndrome) is caused by abnormal complement activation due to biallelic loss‐of‐function mutations in CD55. (Funded by the National Institute of Allergy and Infectious Diseases and others.)

Potentially Beneficial Effect of Hydroxychloroquine in a Patient with a Novel Mutation in Protein Kinase Cδ Deficiency

Protein kinase C delta (PRKCD) has essential functions in controlling B-cell proliferation and apoptosis, development of B-cell tolerance and NK-cell cytolitic activity. Human PRKCD deficiency was recently identified to be causative for an autoimmune lymphoproliferative syndrome like disorder with significant B-cell proliferation particularly of immature B cells. Here we report a child with a novel mutation in PRKCD gene who presented with CMV infection and an early onset SLE-like disorder which was successfully treated with hydroxychloroquine.

Biochemistry, genetics and regulation of bacilysin biosynthesis and its significance more than an antibiotic

Bacillus subtilis has the capacity to produce more than two dozen bioactive compounds with an amazing variety of chemical structures. Among them, bacilysin is a non-ribosomally synthesized dipeptide antibiotic consisting of l-alanine residue at the N terminus and a non-proteinogenic amino acid, l-anticapsin, at the C terminus. In spite of its simple structure, it is active against a wide range of bacteria and fungi. As a potent antimicrobial agent, we briefly review the biochemistry and genetics as well as the regulation of bacilysin biosynthesis within the frame of peptide pheromones-based control of secondary activities. Biological functions of bacilysin in the producer B. subtilis beyond its antimicrobial activity as well as potential biotechnological use of the biosynthetic enzyme l-amino acid ligase (Lal) are also discussed.

Global regulatory systems operating in Bacilysin biosynthesis in Bacillus subtilis.

In Bacillus subtilis, bacilysin is a nonribosomally synthesized dipeptide antibiotic composed of L-alanine and L-anticapsin. The biosynthesis of bacilysin depends on the bacABCDEywfG operon (bac operon)and the adjacent ywfH gene. To elucidate the effects of global regulatory genes on the expression of bac operon, we used the combination of lacZ fusion analysis and the gel mobility shift assays. The cell density-dependent transition state induction of the bac operon was clearly shown. The basal expression level of the bac operon as well as transition state induction of bac is directly ComA dependent. Three Phr peptides, PhrC, PhrF and PhrK, are required for full-level expression of ComA-dependent bac operon expression, but the most important role seemed to be played by PhrC in stimulating bac expression through a RapC-independent manner. Spo0A is another positive regulator which participates in the transition state induction of bac both directly by interacting with the bac promoter and indirectly by repressing abrB expression. AbrB and CodY proteins do not only directly repress the bac promoter, but they also mutually stimulate the transition state induction of bac indirectly, most likely by antagonizing their repressive effects without preventing each other’s binding since both proteins can bind to the bac promoter simultaneously.

Allogeneic pluripotent stem cells suppress airway inflammation in murine model of acute asthma.

New strategies are needed to suppress airway inflammation and prevent or reverse airway remodeling in asthma. Reprogramming induced pluripotent stem cells (iPSCs) have the potential of embryonic stem cells (ESCs) and provide a resource for stem cell-based utility. The aim of this study was to evaluate the histopathological and immunomodulatory effects of ESCs and iPSCs for potential allogenic application in a murine model of acute asthma. BALB/c mice were sensitized with alum-absorbed ovalbumin (OVA) and then challenged with 1% aerosolized OVA. 5×10(5) ESCs and iPSCs were administrated intranasally on the last day of nebulization. Mice were sacrificed after 24 h, and serum allergen specific antibody level, airway remodeling, cytokine levels in lung supernatants, and eosinophilic infiltration in BAL fluid were examined. As a result, more ESCs and iPSCs integrated into the lungs of mice in OVA groups than those of the controls. Epithelial, smooth muscle and basal membrane thicknesses as well as goblet cell hyperplasia occurring in airway remodeling were significantly suppressed by pluripotent stem cells in both distal and proximal airways. Percentage of eosinophils decreased significantly in BAL fluid as well as serum allergen-specific IgE and IL-4 levels in lung supernatants. On the contrary, regulatory cytokine - IL-10 level - was enhanced. Application of especially ESCs significantly increased the percentage of Treg subsets. Our comparative results showed that i.n. delivery of miRNA-based reprogrammed iPSCs is beneficial in attenuating airway inflammation in a murine model of acute asthma, and that cells also have similar immunomodulatory effects in mice.

G6PC3 Deficiency: Primary Immune Deficiency Beyond Just Neutropenia.

Glucose-6-phosphatase catalytic subunit 3 (G6PC3) deficiency was recently defined as a new severe congenital neutropenia subgroup remarkable with congenital heart defects, urogenital malformations, endocrine abnormalities, and prominent superficial veins. Here, we report 3 patients with G6PC3 deficiency presenting with recurrent diarrhea, failure to thrive, and sinopulmonary infections leading to bronchiectasis. In patient I and II, a combined immune deficiency was suspected due to early-onset disease with lymphopenia, neutropenia, and thrombocytopenia, along with variable reductions in lymphocyte subpopulations and favorable response to intravenous γ-globulin therapy. Apart from neutropenia, all 3 patients had intermittent thrombocytopenia, anemia, and lymphopenia. All patients had failure to thrive and some of the classic syndromic features of G6PC3 deficiency, including cardiac abnormalities and visibility of superficial veins in all, endocrinologic problems in PI and PIII, and urogenital abnormalities in PII. Our experience suggests that a diagnosis of congenital neutropenia due to G6PC3 may not be as straightforward in such patients with combined lymphopenia and thrombocytopenia. A high index of suspicion and the other syndromic features of G6PC3 were clues to diagnosis. Screening of all combined immune deficiencies with neutropenia may help to uncover the whole spectra of G6PC3 deficiency.

JAGN1 Deficient Severe Congenital Neutropenia: Two Cases from the Same Family

Recently autosomal recessively inherited mutations in the gene encoding Jagunal homolog 1 (JAGN1) was described as a novel disease-causing gene of severe congenital neutropenia (SCN) JAGN1-mutant neutrophils were characterized by abnormality in endoplasmic reticulum structure, absence of granules, abnormal N-glycosylation of proteins and susceptibility to apoptosis. These findings imply the role of JAGN1 in neutrophil survival. Here, we report two siblings with a homozygous mutation in JAGN1 gene, exhibiting multisystemic involvement.

Could Sublingual Immunotherapy Affect Oral Health in Children with Asthma and/or Allergic Rhinitis Sensitized to House Dust Mite?

Background: Sublingual immunotherapy (SLIT) has been successfully employed in IgE-mediated respiratory allergies. However, it is not known whether the modulation of immune responses in the sublingual area during SLIT has any deleterious effect on oral health. We sought to determine the oral health prospectively in children receiving SLIT for house dust mite allergy. Material and Methods: Eighteen children with allergic asthma and/or rhinitis and 31 age-matched healthy controls (HC) were included in an open-labeled trial. Oral health was evaluated by scoring the decayed, missing, and filled teeth for primary (dmft) and permanent (DMFT) dentition, and the plaque and gingival indices. Moreover, cariogenic food intake and teeth-brushing habits were also noted at baseline and at 19 months. Results: The mean age of the SLIT participants was 9.5 ± 3.1 years and that of the HC was 9.2 ± 3.7 years. The mean duration of SLIT was 19.13 ± 3.81 months. At baseline, the total dmft and DMFT indices were similar in the SLIT and HC groups (p > 0.05), which demonstrated poor hygiene overall. In the within-group comparisons at the examination at 19 months, the SLIT group had a lower number of carious primary teeth and a higher number of filled primary teeth compared to the count at baseline (p = 0.027 and p = 0.058, respectively). Conclusion: Our study showed no detrimental effect of SLIT on oral health during a period of 19 months of follow-up. Parents should be motivated to use dental health services to prevent new caries formation since our cohort had overall poor oral hygiene at the baseline.

Hiper-IgE sendromunda Th17 farklılaşması; IL-17 salınımı ve ROR?t gösterimi

Amaç: Hiper-IgE sendromu (HIES), enfeksiyona duyarlılık ve düşük sayıdaki Th17 hücreleri ile karakterize edilir. Th17 hücreleri fungal ve hücre dışı bakteriyel enfeksiyonların eliminasyonunda önemli rol oynarlar. Bu çalışmada amacımız, HIES hastaları ve sağlıklı kontroller arasında interlökin 17 (IL-17) salgılanması ve RAR-bağımlı orphan reseptör gama t (RORγt) ekspresyonunun ölçülmesi ile Th17 hücrelerinin farklılaşmasını araştırmaktır. Yöntem: Çalışmaya 3 adet HIES tanısı almış çocuk ve 4 adet sağlıklı kontrol alındı. HIES skorları değerlendirildi ve hastaların klinik verileri hastane kayıtlarından toplandı. Th17 farklılaşması, ELİSA yöntemi ile IL-17 üretiminin ve gerçek zamanlı PZR yöntemi ile ROR-γt ekpresyonunun ölçülmesiyle değerlendirildi. Bulgular: HIES hastalarında, peripheral kan mononükleer hücreler (PKMH) ve CD45+RA naif T hücreler Th17 farklılaştırma koşullarında kültüre edildiğinde, IL-17 sitokin seviyesinde sağlıklı bireylere göre önemli derecede azalma gözlendi. Buna ek olarak, sağlıklı kontrollerin IL-17 seviyeleri forbol 12-miristat 13-asetat (FMA) ve iyonomisin uyarımlı durumda uyarımsız duruma göre daha yüksek bulundu. Ayrıca PKMH kültürlerinde IL-17 seviyesi FMA ve iyonomisin uyarımlı durumda, HIES hastaları ve sağlıklı kontroller için uyarımsız koşullarla karşılaştırıldığı zaman önemli derecede yüksek gözlendi. HIES hastasında uyarılmış PKMH’lerdeki RORγt ekspresyon seviyesi, sağlıklı kontrolün yarı düzeyinde olarak tespit edildi. Sonuç: IL-17 salgılanması ve ROR-γt ifadesinin değerlendirilmesi mutasyon analizleri için aday olan hastaları belirlemek için yapılmalıdır. Ülkemizde bu adımların uygulanması ve bilinen mutasyonları olmayan HIES hastalarının seçimi, yeni genetik bozuklukların keşfedilmesine ve böylece yeni tedavi yaklaşımlarına olanak sağlayacaktır. Anahtar sözcükler: Th17, interlökin 17 (IL-17), RAR-bağımlı orphan reseptör gama t (ROR-γt), Hiper-IgE sendromu (HIES) ABS TRACT Th17 Differentiation in Hyper-IgE Syndrome; IL-17 Secretion and RORγt Expression