Supplementation with autologous adipose stem cell-derived mitochondria can be a safe and promising strategy for improving oocyte quality.

PURPOSE: In our previous study, we confirmed that the supplementation of vitrified-warmed murine oocytes with autologous adipose stem cell (ASC)-derived mitochondria during intracytoplasmic sperm injection enhances post-fertilization developmental competence in mice. To ensure the safety of this technology, we conducted a thorough study in mice to investigate the potential presence of specific malformations in offspring developed from this approach. METHODS: A transgenerational comparative analysis was conducted on founder mice from embryos that developed after mitochondrial supplementation, and two subsequent generations. Reproductive performance, body growth rate, histopathological parameters, hematological parameters, daily activity patterns, and daily body temperature changes in male and female mice across these three generations were assessed in comparison to wild-type mice of the same age. RESULTS: Both male and female animals in all three generations showed comparable reproductive performance to the control group. Additionally, body growth rate by the age of 8 weeks were found to be comparable to controls across all three generations. Notably, no significant histopathological abnormalities were detected in vital organs, including the brain, heart, liver, kidneys, lungs, ovaries, and testes, in any individuals from the studied cohorts. The blood parameters were consistent with the control data. The continuous monitoring of activity and body temperature changes (both day and night) over a 1-week period revealed a pattern closely resembling that observed in the control animals. CONCLUSION: Injection of ASC-mitochondria into oocytes may be a promising technique to support developmental potential without causing adverse epigenetic events in the offspring in mice. However, before considering clinical application, additional safety screening using larger animals or non-human primates is essential.

Exploring the Impact of Endometrioma Aspiration and Dienogest Combination Therapy on Cyst Size, Inflammatory Cytokines in Follicular Fluid and Fertility Outcomes.

Endometriomas (chocolate cysts) are cystic lesions that can develop on ovaries, and are characterized by the presence of ectopic endometrial tissue or similar tissue. Such lesions can cause a decline in the number and quality of oocytes, and lead to implantation failure. In this study, we retrospectively assessed the efficacy of repeated endometrioma aspiration and dienogest combination therapy in patients suffering endometriosis-associated infertility with endometriomas. A comparison was made between a treated group that underwent combination therapy followed by controlled ovarian hyperstimulation (COH) (n = 30) and a control group that did not undergo treatment (n = 40), at the IVF Osaka Clinic from September 2019 to September 2021. There were no differences in patient background between the two groups. A reduction in endometrioma size continued for 12 months after treatment. The numbers of follicles that developed to 15 mm or greater in size following COH and mature oocytes were significantly lower in the treated group compared to those in the control group. The levels of inflammatory cytokines in the follicular fluid significantly decreased in the treated group (p < 0.05). In patients in the treated group who underwent a second ova retrieval, the results were compared between those in the first ova retrieval (immediately after the end of treatment) and those in the second ova retrieval (four months after the first retrieval). The numbers of follicles following COH, retrieved, mature and fertilized ova were significantly increased in the second ova retrieval.

Mitochondrial Transfer into Human Oocytes Improved Embryo Quality and Clinical Outcomes in Recurrent Pregnancy Failure Cases.

One of the most critical issues to be solved in reproductive medicine is the treatment of patients with multiple failures of assisted reproductive treatment caused by low-quality embryos. This study investigated whether mitochondrial transfer to human oocytes improves embryo quality and provides subsequent acceptable clinical results and normality to children born due to the use of this technology. We transferred autologous mitochondria extracted from oogonia stem cells to mature oocytes with sperm at the time of intracytoplasmic sperm injection in 52 patients with recurrent failures (average 5.3 times). We assessed embryo quality using the following three methods: good-quality embryo rates, transferable embryo rates, and a novel embryo-scoring system (embryo quality score; EQS) in 33 patients who meet the preset inclusion criteria for analysis. We also evaluated the clinical outcomes of the in vitro fertilization and development of children born using this technology and compared the mtDNA sequences of the children and their mothers. The good-quality embryo rates, transferable embryo rates, and EQS significantly increased after mitochondrial transfer and resulted in 13 babies born in normal conditions. The mtDNA sequences were almost identical to the respective maternal sequences at the 83 major sites examined. Mitochondrial transfer into human oocytes is an effective clinical option to enhance embryo quality in recurrent in vitro fertilization-failure cases.

Relation between semen oxidative reduction potential in initial semen examination and IVF outcomes.

Purpose: The MiOXSYS system is a new technique to analyze the semen oxidative reduction potential (ORP) that may use to classify the level of sperm DNA integrity. It does not clearly explain how the semen ORP values could help to change the IVF outcomes. We have analyzed correlations between semen ORP value and the IVF results. Methods: Four hundred and thirty couples were enrolled. The male counterparts were divided into two groups according to their semen ORP values and compared the fertilization rate, cell cleavage rate, and embryo quality, following the IVF procedures. The relations between ORP values and the clinical pregnancy, live birth, and abortion rates were analyzed. Results: The ORP values show negative and positive correlations with some conventional semen parameters. The fertilization and the cleavage rate did not show any differences in those two groups, but the transferable embryo rate was significantly high in patients with high semen ORP. However, the patients with high ORP show a tendency to lower clinical pregnancy with a low abortion rate compared to the low ORP group. Conclusion: The main purpose of measuring the ORP value in semen is still questionable and shows controversial results.

Prevention of intrauterine fetal growth restriction by administrating C1q/TNF-related protein 6, a specific inhibitor of the alternative complement pathway.

PURPOSE: The latest treatments do not sufficiently prevent miscarriage and fetal growth restriction (FGR) in pregnant women. Here, we assessed the effects of a human protein, CTRP6, that specifically inhibits the activation of the alternative complement pathway on miscarriage, fetal and placental development. METHODS: Pregnant CBA/J mice mated with DBA/2 male mice as a model of spontaneous abortion and FGR were randomly divided into the control and CTRP6 groups. In the CTRP6 group, the mice were intravenously administered CTRP6 on days 4.5 and 6.5 post-conception (dpc). The abortion rate and fetal and placental weights on 14.5 dpc were examined. Remodeling of the spiral artery was also assessed. RESULTS: The abortion rate in the CTRP6 group (13%) was reduced compared to the control group (21%), but there was no statistical difference. The placental and fetal weights in the CTRP6 group were also heavier than those in the control (P < 0.05). Moreover, the thickness of the blood vessel wall in the CTRP6 group was significantly thinner than that in the control (P < 0.05) and comparable to that in the non-abortion model (CBA/J x BALB). The ratio of the inner-per-the-outer diameter of the spiral artery increased more in the CTRP6 group than that in the control (P < 0.05). As well, the Th1/Th2 cytokine ratio was significantly reduced by CTRP6 treatment. CONCLUSIONS: Taken together, the supplementation with a protein that regulates the alternative complement pathway in vivo improves FGR and promotes spiral artery remodeling in a mouse model of miscarriage and FGR.

Influence of climatic conditions in the mesothermal climate area on pregnancies following elective fresh single blastocyst transfer.

PURPOSE: To investigate the effect of climatic parameters in the mesothermal climate area on clinical pregnancy and live birth following fresh single blastocyst transfer. METHODS: This study investigated clinical pregnancies and live births that resulted from 555 ovarian stimulation cycles followed by fresh single blastocyst transfer. The samples were stratified according to climatic conditions (low T, temperature < 12.9 °C; middle T, 12.9 °C ≤ temperature < 22.6 °C; high T, temperature ≥ 22.6 °C; low H, relative humidity < 62.1%; middle H, 62.1% ≤ relative humidity < 66.5%; high H, relative humidity ≥ 66.5%; short S, sunlight duration < 5.2 h; middle S, 5.2 h ≤ sunlight duration < 6.7 h; long S, sunlight duration ≥ 6.7 h). Clinical pregnancy and live birth rates among three groups from each climatic parameter were compared. Multivariable analyses were performed to investigate the effects of climatic conditions on blastocyst development, endometrial thickness, clinical pregnancy, and live birth. RESULTS: A statistically significant difference was found in pregnancy rates among low T (48.8%), middle T (37.3%), and high T (36.6%) groups. Multivariable analyses revealed that temperature was associated with clinical pregnancy and live birth rates with adjustment for patient age, BMI, type of ovarian stimulation, endometrial thickness, and expansion grade of the transferred blastocyst. The association between climatic parameters and blastocyst development and endometrial thickness was not confirmed. CONCLUSIONS: This study suggests that lower temperatures in the mesothermal climate area could favorably affect the rates of clinical pregnancy and live birth achieved by fresh single blastocyst transfer.

Novel Bi-Specific Immuno-Modulatory Tribodies Potentiate T Cell Activation and Increase Anti-Tumor Efficacy.

Cancer immunotherapy has already shown significant improvements by combining different antibodies specific for distinct immune checkpoints, such as Ipilimumab and Nivolumab. Here, we tested combinatorial treatments of immunomodulatory antibodies, previously generated in our laboratory, for their effects on hPBMC activation, either upon stimulation with SEB or in co-cultures with tumor cells by cytokine secretion assays. We found that some of them showed additive or synergistic effects, and on the basis of these observations, we constructed, for the first time, four novel bispecific tribodies (TR), made up of a Fab derived from one anti-IC mAb and two scFvs derived from another mAb targeting a different IC. All four TRs cotargeting either programmed cell death protein 1 (PD-1) and Lymphocyte Activating 3 (LAG-3) or programmed death-ligand 1 (PD-L1) and LAG-3 retained binding affinity for their targets and the antagonistic effects of their parental mAbs, but some of them also showed an increased ability to induce lymphocyte activation and increased in vitro cytotoxicity against tumor cells compared to parental antibodies used either alone or in combinatorial treatments. Furthermore, none of the tribodies showed significant increased cytotoxicity on human cardiomyocytes. Considering that the tribody format reduces production costs (as only one construct provides the inhibitory effects of two antibodies), has an intermediate molecular size (100 kDa) which is well suited for both tumor penetration and an acceptable half-life, we think that these novel immunomodulatory TRBs have the potential to become precious tools for therapeutic applications, particularly in monotherapy-resistant cancer patients.

Mitochondrial function of human embryo: Decline in their quality with maternal aging.

Background: Female fertility declines with age, due to increased chromosomal aneuploidy and possible reduced mitochondrial function in the embryo. Methods: This review outlines how mitochondrial function in human embryos, as predicted from oxygen consumption rate (OCR) measurements, changes in preimplantation stage, and what factors, particularly maternal age, affect mitochondrial function in embryos. Main findings: The structure of the mitochondrial inner membrane and its respiratory function developed with embryo development, while the copy number of mitochondrial DNA per specimen was transiently reduced compared with that of the oocyte. The undifferentiated state of the inner cell mass cells appears to be associated with a low OCR. In contrast, the copy number of mitochondrial DNA increased in trophoblast cells and mitochondrial aerobic metabolism increased.The OCRs at morulae stage decreased with maternal age, but there was no relationship between maternal age and the copy number of mitochondrial DNA at any stages. The higher oxygen spent at the morula stage; the shorter time was needed for development to the mid-stage blastocyst. Conclusions: The mitochondrial respiratory function of human embryos developed along with embryonic growth. Mitochondrial function at morula stage declined with their maternal age and reduced mitochondrial function decreased the rate of development from morula to blastocyst.

High serum free IL-18 is associated with decreased omalizumab efficacy: findings from a 2-year omalizumab treatment study.

OBJECTIVE: Omalizumab is more effective in severe allergic patients with eosinophilic asthma than those with non-eosinophilic asthma. IL-18, a unique cytokine involved in allergic but non-eosinophilic inflammation, might be associated with the latter condition. We aimed to clarify the roles of IL-18 related pathways in insufficient response to omalizumab treatment. METHODS: Patients with severe allergic asthma who completed 2-year omalizumab treatments at Kyoto University Hospital were included in this study (UMIN000002389). Associations between pretreatment levels of serum free IL-18 in addition to other mediators and asthma phenotypes including responses to omalizumab treatment were analyzed. Changes in serum free IL-18, periostin and total IgE levels during the treatment were also examined. RESULTS: Twenty-seven patients (19 females, average age of 55.7 years) were examined. Fifteen incomplete responders who experienced exacerbations in the second year, were significantly and more frequently obese and showed significantly earlier asthma onset, lower blood eosinophils and more exacerbations before omalizumab treatment than complete responders. Significantly more patients showed high baseline serum free IL-18 levels (≥141 pg/mL, a threshold for the highest tertile) among the incomplete responders than complete responders. Patients with high serum free IL-18 levels shared similar characteristics with incomplete responders, showing significant reductions in serum total IgE levels during omalizumab treatment. Finally, serum free IL-18 levels negatively correlated with serum periostin levels at baseline and in change ratios. CONCLUSIONS: High baseline serum free IL-18 levels may predict reduced omalizumab efficacy in severe allergic patients with type-2 low asthma, regarding reduction of exacerbations.

Mural granulosa cells support to maintain the viability of growing porcine oocytes and its developmental competence after insemination.

PURPOSE: To enhance the in vitro growth of porcine oocytes, we studied the effect of mural granulosa cells (MGCs) on the viability of oocytes attached to granulosa cells (oocyte-granulosa cell complexes, OGCs) that were obtained from early antral follicles. METHODS AND RESULTS: When OGCs were cultured with MGCs for 12 days, there were significant improvement (P < 0.05) in the robustness of gap junctional communication between the oocyte and the granulosa cells (82% vs. 59%), the survival rate of oocytes (57% vs. 39%), and the diameter of survived oocytes (118 µm vs. 112 µm). The rate of oocyte release of OGCs cultured with MGCs on the 12th day (1.9%) was significantly lower than that of OGCs cultured without MGCs (26%). Complete meiotic arrest was maintained in the group with MGCs (100%), while partial resumption of spontaneous meiosis was noticed in the absence of MGCs (10-19%). Furthermore, the presence of MGCs increased the oocyte maturation rate after maturation culture in both 12- and 14-day culture groups (P < 0.05, 85-88%) compared to OGCs cultured without MGCs (48-60%). MGCs also significantly improved the blastocyst formation rate (day 7) after ICSI (P < 0.05). CONCLUSIONS: The data of this study thus shows that the presence of MGCs during in vitro oocyte growth plays a crucial role in supporting the developmental competence of growing porcine oocytes attached to the granulosa cells via enhancement of their viability.

Effect of X-ray exposure during hysterosalpingography on capabilities of female germ cells.

PURPOSE: To elucidate the effect of X-ray exposure during hysterosalpingography (HSG) on subsequent laboratory outcomes in in vitro fertilization (IVF). METHODS: A total of 1458 oocytes, consisting of 990 oocytes retrieved from 70 women (89 cycles) who underwent HSG prior to IVF and 468 oocytes from 45 women (57 cycles) who underwent IVF without HSG, were evaluated for their retrieval number, maturity, fertilization, and development post fertilization. X-ray exposure during HSG was recorded as reference air kerma (RAK) (mGy). Subjects were stratified according to the amount of RAK (Nil: IVF without HSG, L-RAK: RAK < 16.23, mH-RAK: RAK ≥ 16.23). The number of oocytes retrieved, oocyte maturation, fertilization, and embryo development was compared among 3 groups. Further, multivariate analyses were performed to investigate the effect of X-ray exposure on laboratory outcomes in IVF. RESULTS: There was a statistically significant difference in the fertilization rate among 3 groups (Nil: 71.6%, L-RAK: 80.5%, mH-RAK: 78.3%). The good-quality blastocyst rate in mH-RAK (46.2%) was significantly higher than L-RAK (35.3%) and Nil (32.4%). Multivariate analyses revealed that X-ray exposure was associated with higher fertilization, higher blastocyst development, and higher good-quality blastocyst development rates with adjustment for patient age, BMI, ovarian stimulation types, and fertilization methods. Association between X-ray exposure and the number of oocytes retrieved, and oocyte maturation was not confirmed. CONCLUSIONS: The present study suggests that X-ray exposure of the female reproductive organs during HSG could enhance the potential of oocytes rather than adversely.

Treatment with Laevo (L)-carnitine reverses the mitochondrial function of human embryos.

PURPOSE: Laevo (l)-carnitine plays important roles in reducing the cytotoxic effects of free fatty acids by forming acyl-carnitine and promoting beta-oxidation, leading to alleviation of cell damage. Recently, the mitochondrial functions in morula has been shown to decrease with the maternal age. Here, we assessed the effect of l-carnitine on mitochondrial function in human embryos and embryo development. METHODS: To examine the effect of L-carnitine on mitochondrial function in morulae, 38 vitrified-thawed embryos at the 6-11-cell stage on day 3 after ICSI were donated from 19 couples. Each couple donated two embryos. Two siblings from each couple were divided randomly into two groups and were cultured in medium with or without 1 mM L-carnitine. The oxygen consumption rates (OCRs) were measured at morula stage. The development of 1029 zygotes cultured in medium with or without L-carnitine was prospectively analyzed. RESULTS: Addition of L-carnitine to the culture medium significantly increased the OCRs of morulae and improved the morphologically-good blastocyst formation rate per zygote compared with sibling embryos. Twenty healthy babies were born from embryos cultured in L-carnitine-supplemented medium after single embryo transfers. CONCLUSION(S): L-carnitine is a promising culture medium supplement that might be able to counteract the decreased mitochondrial function in human morula stage embryos.

A novel embryo quality scoring system to compare groups of embryos at different developmental stages.

PURPOSE: To construct a new embryonic quality scoring system to compare groups of embryos at different developmental stages. METHODS: Based on a hypothesis that the implantation potential of any embryo in an ovum pickup (OPU) cycle remains the same at any stage of development, be it day 2, 3, or 5, a new embryo quality scoring (EQS) system was designed. It was based on the analysis of the clinical results of 1610 single embryo transfers. We validated this scoring system in the comparison of embryonic quality between groups by evaluating the mean scores calculated at day 2, day 3, and day 5 for 957 embryos (150 cycles) from 3 different groups. We then compared EQSs of patients with pregnancy favorable factors (group A) such as young age and high AMH levels, with the patients with contra features (group B). RESULTS: We confirmed that each mean EQS assessed at different stages of embryonic development within the same group was similar. The mean EQSs on day 3 and day 5 in group A were significantly higher than the mean EQSs on days 2, 3, and 5 in group B. CONCLUSION: The novel EQS system proposed by us enables embryonic quality comparison between groups of embryos at different developmental stages.

Mitochondrial oxygen consumption rate of human embryos declines with maternal age.

PURPOSE: The fertility of women decreases with age because of factors such as an increased incidence of aneuploidies and-possibly-decreased mitochondrial activity in oocytes. However, the relationship between maternal aging and mitochondrial function of their embryos remains unknown. Here, we assessed the relationship between maternal age and mitochondrial functions in their oocytes and embryos METHODS: The relationships between maternal age and oxygen consumption rates (OCRs), mitochondrial DNA (mtDNA) copy numbers, or blastocyst development was investigated using 81 embryos donated from 63 infertility couples. The developmental rates from morulae to blastocysts were retrospectively analyzed using data of 105 patients. RESULTS: The OCRs of morulae decreased with maternal age (r2 = 0.48, P < 0.05) although there were no relationships between maternal age and mtDNA copy number in any stages. The more oxygen consumed at the morula stage, the shorter time was required for embryo development to the mid-stage blastocyst (r2 = 0.236, P < 0.05). According to the clinical data analysis, the developmental rate from morulae to blastocysts decreased with maternal age (P < 0.05, < 37 years, 81.1%, vs. ≥ 37 years, 64.1%). CONCLUSIONS: The data of the present study revealed that mitochondrial function at the morula stage of human embryos decreased with their maternal age and a decrease of mitochondrial function led to slow-paced development and impaired developmental rate from morulae to blastocysts.

Increased extracellular vesicle miRNA-466 family in the bronchoalveolar lavage fluid as a precipitating factor of ARDS.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a life-threatening disease; however, its treatment has not yet been fully established. The progression of ARDS is considered to be mediated by altered intercellular communication between immune and structural cells in the lung. One of several factors involved in intercellular communication is the extracellular vesicle (EV). They act as carriers of functional content such as RNA molecules, proteins, and lipids and deliver cargo from donor to recipient cells. EVs have been reported to regulate the nucleotide-binding oligomerization like receptor 3 (NLRP3) inflammasome. This has been identified as the cellular machinery responsible for activating inflammatory processes, a key component responsible for the pathogenesis of ARDS. METHODS: Here, we provide comprehensive genetic analysis of microRNAs (miRNAs) in EVs, demonstrating increased expression of the miRNA-466 family in the bronchoalveolar lavage fluid of a mouse ARDS model. RESULTS: Transfection of bone marrow-derived macrophages (BMDMs) with miRNA-466 g and 466 m-5p resulted in increased interleukin-1 beta (IL-1ß) release after LPS and ATP treatment, which is an established in vitro model of NLRP3 inflammasome activation. Moreover, LPS-induced pro-IL-1ß expression was accelerated by miRNA-466 g and 466 m-5p in BMDMs. CONCLUSIONS: These findings imply that miRNA-466 family molecules are secreted via EVs into the airways in an ARDS model, and this exacerbates inflammation through the NLRP3 inflammasome. Our results suggest that the NLRP3 inflammasome pathway, regulated by extracellular vesicle miRNA, could act as a therapeutic target for ARDS.

Oral administration of l-carnitine improves the clinical outcome of fertility in patients with IVF treatment.

Age-dependent decline of mitochondrial function has been proposed to be a main cause of decline of embryo quality. Then, l-carnitine plays important roles in reducing the membranous toxicity of free-fatty acids by forming acyl-carnitine and promoting ß-oxidation, preventing cell damage. Recent research revealed that l-carnitine played important roles in vitro in oocyte growth, oocyte maturation and embryo development. However, such beneficial effects of l-carnitine in vivo have yet to be verified. The effect of oral l-carnitine supplementation on embryo quality and implantation potential was examined. A total of 214 patients were included in this study. They all previously received in vitro fertilization-embryo transfer (IVF-ET) and failed to conceive. Then they were administered l-carnitine for 82 days on average and underwent IVF-ET again. There were no significant differences in the total number of retrieved oocytes, and their maturation and fertilization rates between before and after l-carnitine administration. The quality of embryos on Days 3 and 5 after insemination was improved following l-carnitine administration (p < .05) in cycles after l-carnitine administration compared with previous cycles. Healthy neonates were born after IVF-ET following l-carnitine administration. Our data suggested that oral administration of l-carnitine to fertility patients improved the developmental competence of their oocytes after insemination.

Oocyte retrieval after heterotopic transplantation of ovarian tissue cryopreserved by closed vitrification protocol.

PURPOSE: A device for closed vitrification was designed to reduce the risk of contamination and investigated on its efficacy for ovarian function recovery after cryopreservation and heterotopic transplantation. METHODS: Ovarian tissues from green fluorescence protein transgenic mice (10 GFP mice) were vitrified using the device, and warmed ovarian tissues were transplanted into the ovarian bursa region in wild-type female mice (6 mice). Fresh ovarian tissues were similarly transplanted as a control. After recovery of the estrous cycle, mice were mated with male mice. Ovarian tissues from six cynomolgus monkeys were vitrified and warmed with the device for autologous, heterotopic transplantation. Fresh tissue transplantation was not performed for the control. Ovarian function was examined by recovery of the hormonal cycle. Histological examination was conducted. RESULTS: The number of live pups per recipient mouse was not significantly different after transplantation of fresh or vitrified-warmed ovarian tissue, although the pregnancy rate was reduced with vitrified tissues. The hormonal cycle was restored in 5/6 monkeys after heterotopic transplantation of vitrified-warmed ovarian tissue. Follicles were harvested at eight sites in the omentum and 13 sites in the mesosalpinx. In vitro maturation (IVM)/IVF produced embryo but did not develop. CONCLUSIONS: Resumption of the hormonal cycles, follicle development, and oocyte retrieval from vitrified-warmed ovarian tissue transplants may indicate that the use of vitrification for ovarian tissue in a closed system has a potential of clinical application without the risk of contaminations. More detailed analyses of the effects of vitrification on ovarian tissue, such as gene expression patterns in oocytes and granulosa cells, may be needed for establishing a standard procedure for cryopreservation of ovarian tissues in human.

Role of airway epithelial barrier dysfunction in pathogenesis of asthma.

Bronchial asthma is characterized by persistent cough, increased sputum, and repeated wheezing. The pathophysiology underlying these symptoms is the hyper-responsiveness of the airway along with chronic airway inflammation. Repeated injury, repair, and regeneration of the airway epithelium following exposure to environmental factors and inflammation results in histological changes and functional abnormalities in the airway mucosal epithelium; such changes are believed to have a significant association with the pathophysiology of asthma. Damage to the barrier functions of the airway epithelium enhances mucosal permeability of foreign substances in the airway epithelium of patients with asthma. Thus, epithelial barrier fragility is closely involved in releasing epithelial cytokines (e.g., TSLP, IL-25, and IL-33) because of the activation of airway epithelial cells, dendritic cells, and innate group 2 innate lymphoid cells (ILC2). Functional abnormalities of the airway epithelial cells along with the activation of dendritic cells, Th2 cells, and ILC2 form a single immunopathological unit that is considered to cause allergic airway inflammation. Here we use the latest published literature to discuss the potential pathological mechanisms regarding the onset and progressive severity of asthma with regard to the disruption of the airway epithelial function.

Asthma and COPD overlap pathophysiology of ACO.

Asthma and COPD appear as a result of different mechanisms triggered by different pathogeneses and although they present different features and symptoms of airway inflammation and airway obstruction, there are also cases that present the features of both asthma and COPD. This type of pathology is known as asthma-COPD overlap syndrome (ACOS). Asthma-COPD overlap is identified in clinical practice by the features that it shares with both asthma and COPD. This is not a definition, but a description for clinical use, as asthma-COPD overlap includes several different clinical phenotypes and there are likely to be several different underlying mechanisms". In this paper, the disease that shares several features of both asthma and COPD will be referred to as asthma-COPD overlap (ACO). In this article, we describe the pathogenesis of ACO for understanding the mechanism in asthma and COPD overlap.

NDRG1 is important to maintain the integrity of airway epithelial barrier through claudin-9 expression.

Impairment of epithelial barrier integrity caused by environmental triggers is associated with the pathogenesis of airway inflammation. Using human airway epithelial cells, we attempted to identify molecule(s) that promote airway epithelial barrier integrity. Microarray analyses were conducted using the Affimetrix human whole genome gene chip, and we identified the N-myc downstream-regulated gene 1 (NDRG1) gene, which was induced during the development of the epithelial cell barrier. Immunohistochemical analysis revealed strong NDRG1 expression in ciliated epithelial cells in nasal tissues sampled from patients with chronic rhinosinusitis (CRS), and the low expression of NDRG1 was observed in goblet cells or damaged epithelial cells. NDRG1 gene knockdown with its specific siRNA decreased the transepithelial electrical resistance and increased the dextran permeability. Immunocytochemistry revealed that NDRG1 knockdown disrupted tight junctions of airway epithelial cells. Next, we analyzed the effects of NDRG1 knockdown on the expression of tight and adhesion junction molecules. NDRG1 knockdown significantly decreased only claudin-9 expression, but did not decrease other claudin family molecules, such as E-cadherin, and ZO-1, -2, or -3. Knockdown of claudin-9 markedly impaired the barrier function in airway epithelial cells. These results suggest that NDRG1 is important for the barrier integrity in airway epithelial cells.