High Contrast Bioimaging of Tumor and Inflammation with a Bicyclic Dioxetane Chemiluminescent Probe.

The link between inflammation and the evolution of cancer is well established. Visualizing and tracking both tumor proliferation and the associated inflammatory response within a living organism are vital for dissecting the nexus between these two processes and for crafting precise treatment modalities. We report the creation and synthesis of an advanced NIR chemiluminescence probe that stands out for its exceptional selectivity, extraordinary sensitivity at nanomolar concentrations, swift detection capabilities, and broad application prospects. Crucially, this probe has been successfully utilized to image endogenous ONOO- across different inflammation models, including abdominal inflammation triggered by LPS, subcutaneous inflammatory conditions, and tumors grafted onto mice. These findings highlight the significant promise of chemiluminescence imaging in enhancing our grasp of the intricate interplay between cancer and inflammation and in steering the development of potent, targeted therapeutic strategies.

Nesterenkonia marinintestina sp. nov., isolated from the fish intestine.

A Gram-positive, aerobic, non-motile, irregular short rod, nonspore-forming actinobacterial strain, designated GX14115T, was isolated from fish intestine in Beihai City, Guangxi, China and subjected to a taxonomic polyphasic investigation. Colonies were yellow‒green, circular, smooth, central bulge, convex, opaque and 2.0-3.0 mm in diameter after growth on 2216E medium at 30 °C for 72 h. Growth occurred at 4-45 °C (optimum 30 °C), at pH 4.5-10.0 (optimum pH 7.5) and in the presence of 0-12% NaCl (w/v) (optimum 3.5%). Chemotaxonomic analysis showed that the main menaquinone of strain GX14115T was MK-7. The major cellular fatty acids were anteiso-C15:0 (44.8%), anteiso-C17:0 (20.5%), and iso-C15:0 (16%). The whole-cell sugars were galactose and xylose. The peptidoglycan type was L-Lys-Gly-D-Asp, and the polar lipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), one unknown phospholipid (UP), and one unknown glycolipid (UG). The DNA G + C content of the type of strain was 69.5 mol%. The 16S rRNA gene sequence analysis revealed that strain GX14115T is affiliated with the genus Nesterenkonia and is closely related to Nesterenkonia sandarakina YIM 70009T (96.5%) and Nesterenkonia lutea YIM 70081T (96.8%). The calculated results indicated that the average nucleotide identity (ANI) values of GX14115T were 74.49-74.78%, to the two aforementioned type strains, and the digital DNA-DNA hybridization (dDDH) values were 20.1-20.7%. Strain GX14115T was proposed as a novel species of the genus Nesterenkonia by the physiological, chemotaxonomic, and phylogenetic data, for whose the name is Nesterenkonia marinintestina sp. nov. The type of strain is GX14115T (= MCCC 1K06658T = KCTC 49495T).

Microbulbifer litoralis sp. nov., Isolated from Seashore of Weizhou Island.

A bacterium designated GXH0434T was isolated from sea shore samples collected from Weizhou Island, Beihai, Guangxi, China. The organism is motile, strictly aerobic, and possesses a rod-coccus cell cycle in association with the growth phase. It can grow at 15-45 °C (optimum 37 °C), at pH 6.0-11.0 (optimum 6.0), and at 0-20% (w/v) NaCl (optimum 5.0-8.0%). The strain is positive for peroxidase and oxidase activity, negative for Voges-Proskauer test, can hydrolyze Tween 20, Tween 60, Tween 80, casein, and is able to produce siderophore and has the function of nitrogen fixation. Molecular phylogenetic analysis based on 16S rRNA gene sequences indicated that GXH0434T was most closely related to Microbulbifer halophilus KCTC 12848T with the similarity of 97.2%, followed by Microbulbifer chitinilyticus JCM 16148T (97.1%) and Microbulbifer taiwanensis LMG 26125T (96.5%). The digital DNA-DNA hybridization and the average nucleotide identity values between GXH0434T and Microbulbifer halophilus KCTC 12848T were 28.90% and 83.38%, respectively, which were below thresholds of species delineation. The genomic DNA G+C content of the strain was 61.9%. The major fatty acids were iso-C15:0, C16:0, iso-C11:0 3-OH, iso-C11:0 and Summed features 8 (C18:0 ω7c and/or C18:0 ω6c). The major polar lipids detected in GXH0434T were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC). The major respiratory quinone was ubiquinone Q-8. Based on the above polyphasic classification indicated strain GXH0434T represents a novel species of the genus Microbulbifer, for which the name Microbulbifer litoralis sp. nov. is proposed. The type strain is GXH0434T (= MCCC 1K07158T = KCTC 92169T).

First Report of Diaporthe hongkongensis Causing Leaf Blight on Macadamia in China.

Macadamia (Macadamia ternifolia Maiden and Betche) belongs to the Proteaceae family (Li et al. 2022). In the hilly areas of Guangxi (southern China), macadamia trees are an important source of revenue. The planting area in Guangxi has increased in recent years, exceeding 53,333 hectares by the end of 2022, but this increase is also associated with emergency of, macadamia diseases. Leaf blight symptoms were observed in 37/241 macadamia trees (15% incidence) in a plantation in Nanning, Guangxi province in China, during June, 2022. Disease severity on infected trees ranged from 5% to 60%. The disease developed from the tips or margins of leaves, causing the leaves to turn brown, and later gradually withered (Fig. 1 A). Ten leaves with lesions were collected from five macadamia trees (two leaves per tree. Thereafter, small segments (3 to 4 mm²) excised from the margins of ten lesions were surface sterilized in 75% ethanol for 30 s and 1% hypochlorite for 90 s and Page 1 of 6 2 rinsed in sterile water, before plating onto potato dextrose agar (PDA) medium. Plates were incubated under lighting during the daytime, and darkness at night-time for 5 days at 25℃. Twenty-two purified colonies were generated by subculturing hyphal tips, of which eight exhibited similar morphology and were further characterized. The colonies on PDA were gray with a white outer ring and flat lawn on the surface (Fig. 1 B). The pycnidia were superficial to semi-immersed on PDA, solitary to aggregated, globose to sub-globose, brown to black and oozed yellow mucilaginous masses (Fig.1 C). The α-conidia were unicellular, hyaline elliptical or fusiform, and measuring 4-8 × 1.9-4 µm (n=30) ， whereas the ß-conidia were hyaline, long, straight or curved, measuring 20-23 × 0.9-2 µm (n=30) (Fig. 1 D-E). The morphological features were similar to Diaporthe hongkongensis (Dissanayake et al. 2015). The eight morphologically similar isolates were identified as D. hongkongensis using the internal transcribed spacer (ITS) region, but only one isolate, JG11, was selected for further molecular identification. Five target genes, including the ITS region, translation elongation factor 1 alpha (EF1-α), beta-tubulin genes (TUB2), calmodulin (CAL), and histone H3 (HIS) were amplified and sequenced using primers ITS1/ITS4, EF1-728F/EF1-986R, Bt2a/Bt2b, CAL-228F/CAL-737R, and CYLH3F/H3-1b, respectively (Carbone and Kohn 1999). The sequences were deposited in GenBank under accession numbers OQ932790 (ITS) and OR147955-58 for EF1-α, TUB, CAL and HIS genes, respectively. BLAST search of GenBank showed that ITS, EF1-α, TUB, CAL, and HIS sequences of JG11 were similar to Page 2 of 6 3 those of D. hongkongensis NR111848 (99.22% identity), KY433566 (99.72%), MW208603 (99.42%), MW221740 (99.80%), and MW221661 (99.79%), respectively. Phylogenetic analysis of concatenated sequences was performed with IQ-TREE software. JG11 was grouped in the same clade as other Diaporthe hongkongensis isolates (Fig. 2). Pathogenicity experiments were carried out on healthy macadamia trees in a greenhouse. Three macadamia trees were used as negative controls where five uninjured leaves per tree were sprayed with sterile distilled water. Uninjured five leaves per tree of three other macadamia trees were sprayed with conidia suspension of the isolate JG11 at a concentration of 1×106. Each treatment was repeated 3 times independently, with 5 leaves per tree (Liu et al. 2023; Havill et al. 2023; Zhang et al. 2022). Plastic bags were placed over all inoculated leaves. The average daily temperature and relative humidity in the greenhouse were 32°C and 65%, respectively. Two days later, browning appeared on the leaves inoculated with the spore suspension and expanded outward. After 5 days, all macadamia leaves inoculated with the fungal spores began to wither, while controls remained asymptomatic (Fig. 1 H-I). D. hongkongensis was consistently re-isolated and purified from inoculated leaves and the identity was confirmed by morphological identification and molecular analysis, completed Koch's postulates. D. hongkongensis has been reported on peach (Zhang et al. 2021), grapevine trunk (Dissanayake et al. 2015) and Cunninghamia lanceolata (Liao et al. 2022). To our knowledge, this is the first report of D. hongkongensis causing leaf blight on macadamia in China. These findings provide a foundation for future research on the epidemiology and control of this newly emerging disease of macadamia.

Identification and analysis of toxins in novel Bacillus thuringiensis strain Bt S3076-1 against Spodoptera frugiperda and Helicoverpa armigera (Lep.: Noctuidae).

Despite the successful application of toxins from Bacillus thuringiensis as biological control agents against pests, pests are showing resistance against an increasing number of Bacillus thuringiensis toxins due to evolution; thus, new toxins with higher toxicity and broad-spectrum activity against insects are being increasingly identified. To find new toxins, whole genome sequencing of the novel B. thuringiensis strain Bt S3076-1 was performed, and ten predicted toxic genes were identified in this study, including six cry genes, two tpp genes, one cyt gene and one vip gene, among which six were novel toxins. Subsequently, SDS‒PAGE analysis showed that the major proteins at the spore maturation stage were approximately 120 kDa, 70 kDa, 67 kDa, 60 kDa and 40 kDa, while active proteins after trypsin digestion (approximately 70 kDa and 40 kDa) exhibited LC50 values of 149.64 µg/g and 441.47 µg/g against Spodoptera frugiperda and Helicoverpa armigera larvae, respectively. Furthermore, pathological observation results showed that the peritrophic membrane of Spodoptera frugiperda and Helicoverpa armigera larvae was degraded. These findings will provide an experimental reference for further research on the insecticidal activity, toxicity spectrum and synergism of these toxins in Bt S3076-1.

The value of preoperative positron emission tomography/computed tomography in differentiating the invasive degree of hypometabolic lung adenocarcinoma.

OBJECTIVES: To investigate the value of preoperative positron emission tomography/computed tomography (PET/CT) in differentiating the invasive degree of hypometabolic lung adenocarcinoma. METHODS: We retrospectively analyzed the data of patients who underwent PET/CT examination, high-resolution computed tomography, and surgical resection for low-metabolism lung adenocarcinoma in our hospital between June 2016 and December 2021. We also investigated the relationship between the preoperative PET/CT findings and the pathological subtype of hypometabolic lung adenocarcinoma. RESULTS: A total of 128 lesions were found in 113 patients who underwent resection for lung adenocarcinoma, including 20 minimally invasive adenocarcinomas (MIA) and 108 invasive adenocarcinomas (IAC), whose preoperative PET/CT showed low metabolism. There were significant differences in the largest diameter (Dmax), lesion type, maximum standard uptake value (SUVmax), SUVindex (the ratio of SUVmax of lesion to SUVmax of contralateral normal lung paranchyma), fasting blood glucose, lobulation, spiculation, and pleura indentation between the MIA and IAC groups (p < 0.05). Multivariate logistic regression analysis showed that the Dmax (odds ratio (OR) = 1.413, 95% confidence interval (CI: 1.155-1.729, p = 0.001)) and SUVmax (OR = 12.137, 95% CI: 1.068-137.900, p = 0.044) were independent risk factors for predicting the hypometabolic IAC (p < 0.05). Receiver operating characteristic (ROC) curve analysis showed that the Dmax ≥ 10.5 mm and SUVmax ≥ 0.85 were the cut-off values for differentiating MIA from IAC, with high sensitivity (84.3% and 75.9%, respectively) and specificity (84.5% and 85.0%, respectively), the Combined Diagnosis showed higher sensitivity (91.7%) and specificity (85.0%). CONCLUSIONS: The PET/CT findings correlated with the subtype of hypometabolic lung adenocarcinoma. The parameters Dmax and SUVmax were independent risk factors for predicting IAC, and the sensitivity of Combined Diagnosis prediction is better.

DEAD-Box RNA Helicase 42 Plays a Critical Role in Pre-mRNA Splicing under Cold Stress.

Low temperature is an important environmental stress that adversely affects rice (Oryza sativa) growth and productivity. Splicing of pre-mRNA is a crucial posttranscriptional regulatory step in gene expression in plants and is sensitive to temperature. DEAD-box RNA helicases belong to an RNA helicase family involved in the rearrangement of ribonucleoprotein complexes and the modification of RNA structure and are therefore involved in all aspects of RNA metabolism. In this study, we demonstrate that the rate of pre-mRNA splicing is reduced in rice at low temperatures and that the DEAD-box RNA Helicase42 (OsRH42) is necessary to support effective splicing of pre-mRNA during mRNA maturation at low temperatures. OsRH42 expression is tightly coupled to temperature fluctuation, and OsRH42 is localized in the splicing speckles and interacts directly with U2 small nuclear RNA. Retarded pre-mRNA splicing and plant growth defects were exhibited by OsRH42-knockdown transgenic lines at low temperatures, thus indicating that OsRH42 performs an essential role in ensuring accurate pre-mRNA splicing and normal plant growth under low ambient temperature. Unexpectedly, our results show that OsRH42 overexpression significantly disrupts the pre-mRNA splicing pathway, causing retarded plant growth and reducing plant cold tolerance. Combined, these results indicate that accurate control of OsRH42 homeostasis is essential for rice plants to respond to changes in ambient temperature. In addition, our study presents the molecular mechanism of DEAD-box RNA helicase function in pre-mRNA splicing, which is required for adaptation to cold stress in rice.

A natural product, resveratrol, protects against high-glucose-induced developmental damage in chicken embryo.

Resveratrol, a famous plant-derived polyphenolic phytoalexin, has been considered to play physiological roles such as antioxidative, neuroprotective, and anticancer effects in adults. However, its antioxidative activity and neuroprotective effect were seldom discussed in the embryonic system. In this study, the effect of resveratrol on chicken embryo development under high glucose and its underlying mechanism of resveratrol were investigated. High glucose administrated to chicken embryo at embryonic Day 1 induced stillbirth, growth retardation, and impaired blood vessel development on yolk sac. However, resveratrol supplementation before glucose exposure showed significant effect on decreasing the death rate, developmental damage, and vessel injury. In addition, oxidative stress was caused by high-glucose exposure, and resveratrol could rescue this high-glucose-induced oxidative stress. Moreover, the neural developmental marker paired box 3 was significantly decreased by high glucose and recovered by resveratrol. Cell cycle-regulated gene expression was also intervened by resveratrol. This study had found an association between resveratrol and hyperglycemia-induced embryonic damage, which suggested a potential protective effect of resveratrol on gestational diabetes.

Massive Hepatocellular Carcinoma Combined With Giant Uterine Fibroid on 18F-FDG PET/CT.

ABSTRACT: A 50-year-old woman was admitted due to a liver mass discovered by ultrasound in routine physical examination. MRI demonstrated a large hepatocellular carcinoma. It also discovered an abdominal mass simultaneously. 18F-FDG PET/CT was performed for staging. PET/CT showed mixed and mild metabolism of the hepatic lesion and giant abdominopelvic mass, respectively. Hepatocellular carcinoma combined with a benign mass in abdominopelvic cavity from uterine was considered and finally proved pathologically. We present a rare case of woman with large liver cancer accompanied by giant uterine fibroid where 18F-FDG PET/CT helped in making the right diagnosis.

RNA-based detection of genetically modified plants via current-voltage characteristic measurement.

The widespread adoption of genetically modified (GM) crops has escalated concerns about their safety and ethical implications, underscoring the need for efficient GM crop detection methods. Conventional detection methods, such as polymerase chain reaction, can be costly, lab-bound, and time-consuming. To overcome these challenges, we have developed RapiSense, a cost-effective, portable, and sensitive biosensor platform. This sensor generates a measurable voltage shift (0.1-1 V) in the system's current-voltage characteristics, triggered by an increase in membrane's negative charge upon hybridization of DNA/RNA targets with a specific DNA probe. Probes designed to identify the herbicide resistance gene hygromycin phosphotransferase show a detection range from ∼1 nM to ∼10 µM and can discriminate between complementary, non-specific, and mismatched nucleotide targets. The incorporation of a small membrane sensor to detect fragmented RNA samples substantially improve the platform's sensitivity. In this study, RapiSense has been effectively used to detect specific DNA and fragmented RNA in transgenic variants of Arabidopsis, sweet potato, and rice, showcasing its potential for rapid, on-site GM crop screening.

Prenatal hormone stress triggers embryonic cardiac hypertrophy outcome by ubiquitin-dependent degradation of mitochondrial mitofusin 2.

Prenatal stress has been extensively documented as a contributing factor to adverse cardiac development and function in fetuses and infants. The release of glucocorticoids (GCs), identified as a significant stressor, may be a potential factor inducing cardiac hypertrophy. However, the underlying mechanism remains largely unknown. Herein, we discovered that corticosterone (CORT) overload induced cardiac hypertrophy in embryonic chicks and fetal mice in vivo, as well as enlarged cardiomyocytes in vitro. The impaired mitochondria dynamics were observed in CORT-exposed cardiomyocytes, accompanied by dysfunction in oxidative phosphorylation and ATP production. This phenomenon was found to be linked to decreased mitochondrial fusion protein mitofusin 2 (MFN2). Subsequently, we found that CORT facilitated the ubiquitin-proteasome-system-dependent degradation of MFN2 with an enhanced binding of appoptosin to MFN2, serving as the underlying cause. Collectively, our findings provide a comprehensive understanding of the mechanisms by which exposure to stress hormones induces cardiac hypertrophy in fetuses.

18 F-FDG PET/CT of a Rare Sternal Osteoblastoma in a Man With History of Lymphoma.

ABSTRACT: A 27-year-old man, with a history of non-Hodgkin lymphoma 8 years ago, was admitted due to 9 months of persistent sternal pain. Chest CT revealed a mass in the sternum. 18 F-FDG PET/CT was performed, demonstrating a radioactive accumulation mass in the sternum, accompanied by massive osteogenesis and osteolysis. Histological and immunohistochemical analysis of ultrasound-guided fine-needle aspiration biopsy samples confirmed the diagnosis of aggressive osteoblastoma. We present a rare case of aggressive sternal osteoblastoma, instead of lymphoma recurrence, on 18 F-FDG PET/CT in an adult with history of lymphoma.

Jejunal Cavernous Hemangioma Mimicking Malignancy With Increased Activity on 18 F-FDG PET/CT.

ABSTRACT: A 50-year-old woman underwent 18 F-FDG PET/CT to evaluate possible abdominal malignancy, which was revealed by CT. The images showed a large cystic-solid lesion with peripherally increased FDG activity in the left mid-abdomen. Histopathology of the excised lesion confirmed a jejunal cavernous hemangioma. We reported a rare case of jejunal cavernous hemangioma with FDG accumulation on PET/CT, mimicking malignancy.

A Teenager Physical Fitness Evaluation Model Based on 1D-CNN with LSTM and Wearable Running PPG Recordings.

People attach greater importance to the physical health of teenagers because adolescence is a critical period for the healthy development of the human body. With the progress of biosensing technologies and artificial intelligence, it is feasible to apply wearable devices to continuously record teenagers' physiological signals and make analyses based on modern advanced methods. To solve the challenge that traditional methods of monitoring teenagers' physical fitness lack accurate computational models and in-depth data analyses, we propose a novel evaluation model for predicting the physical fitness of teenagers. First, we collected 1024 teenagers' PPGs under the guidance of the proposed three-stage running paradigm. Next, we applied the median filter and wavelet transform to denoise the original signals and obtain HR and SpO2. Then, we used the Pearson correlation coefficient method to finalize the feature set, based on the extracted nine physical features. Finally, we built a 1D-CNN with LSTM model to classify teenagers' physical fitness condition into four levels: excellent, good, medium, and poor, with an accuracy of 98.27% for boys' physical fitness prediction, and 99.26% for girls' physical fitness prediction. The experimental results provide evidence supporting the feasibility of predicting teenagers' physical fitness levels by their running PPG recordings.

FDG PET/CT Imaging of Pancreatic Plasmacytoma.

A 56-year-old man underwent F-FDG PET/CT to evaluate possible pancreatic cancer, which was revealed by CT. The images showed a solid lesion with peripherally increased FDG activity in the tail of the pancreas, as well as hypermetabolic lesions in the lumbar spine and rib. Pathological examination following lumbar biopsy demonstrated multiple myeloma. Five months after chemotherapy, follow-up FDG PET/CT showed cystic change in the pancreatic lesion without elevated metabolism.

An aptamer-based, fluorescent and radionuclide dual-modality probe.

Aptamers which are promising and effective molecular probes, can deliver either fluorescent materials or radionuclides to tumors. This study aimed to develop a novel both fluorescent and radionuclide dual-modality probe based on a truncated aptamer and evaluate its stability and binding affinities in vitro. The aptamer JHIT2 with binding specifically to HepG2 cells was previously generated by Cell-SELEX. Using mfold and RNAstructure software to predict the secondary structure folded by a middle random sequence to truncate the primer sequences at both ends of the aptamer JHIT2 to yield the aptamer JHIT2e, with a similar secondary structure to JHIT2 and the same specificity and affinity as JHIT2. Attaching carboxyfluorescein (FAM) readily to the aptamer JHIT2e and then attaching iodine-131 to the FAM moiety which has multiple sites for iodine labeling to develop a novel both fluorescent and radionuclide dual-modality probe, termed 131I-FAM-JHIT2e. Cell uptake and fluorescence imaging assays in vitro confirmed that 131I-FAM-JHIT2e had both FAM fluorescence signal and radio-activity signal and maintained specific binding ability to the human hepatoma cell line HepG2. This work formed a basis for aptamer-based, dual-modality imaging probe that contains both fluorescent and radionuclide tags, which also is potential for theranostics.

Novel Homogeneous Anion Exchange Membranes for Reproducible and Sensitive Nucleic Acid Detection via Current-Voltage Characteristic Measurement.

One-pot synthesis of novel hydrogel-based anion exchange membranes (AEMs), with only a single-phase monomer mixture, was used to eliminate surface heterogeneity and generate reproducible electroconvective microvortices in the over-limiting region of the current-voltage characteristic (CVC) curves. Diallyldimethylammonium chloride (DDA) was used as the main component to provide the cation charge groups, and 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethyl acrylate (EGDMA) were used as the auxiliary structure monomers. The uniform membrane structure allowed reproducible and sensitive DNA detection and quantification, as probe-target surface complexes can gate the ion flux and produce large voltage shifts in the over-limiting region. Suppressed membrane curvature due to controlled swelling is a crucial part to avoid the reduction of depletion region for maintaining the influence of target gene hybridization. Fourier-transform infrared (FTIR) spectroscopy verified the synthesized membrane structure, with a residual vinyl group that allows easy carboxylation via additional photografting reaction. Consequently, a significantly higher DNA probe functionalization efficiency is obtained on the homogeneous AEMs, evidenced by the increasing nitrogen element content and bonding via X-ray photoelectron spectroscopy (XPS). The DDA content was optimized to provide a sufficient coulomb force between AEM and nucleic acid backbone to promote the specific binding efficiency but without high dimensional swelling which might change the surface geometry and restrict the voltage shifting for sensing in the over-limiting region, and the optimal DDA/HEMA ratio was found to be 4/10. The synthesized AEM sensor for recombinant 35S promoter sequence identification exhibited a reproducible calibration standard curve with dynamic range between 30 fM and 1 µM and high selectivity with only 0.01 V shift for 1 µM nontarget oligo.

FDG PET/CT Findings of Unsuspected Pulmonary Epithelioid Angiosarcoma Manifested as a Brain Metastasis.

A 42-year-old man presented paroxysmal sharp pain in the right side of the head. Head CT showed a lesion in the right frontal lobe. MRI of the head suggested the possibility of metastasis. FDG PET/CT showed increased uptake corresponding to lesions in the right frontal lobe of the brain, the left upper lobe of lung, and the left adrenal gland, respectively. Cerebral and pulmonary lesions were both resected. Histopathology confirmed that both lesions are primary epithelioid angiosarcomas.

Abnormal O-GlcNAcylation of Pax3 Occurring from Hyperglycemia-Induced Neural Tube Defects Is Ameliorated by Carnosine But Not Folic Acid in Chicken Embryos.

Neural tube defects (NTDs) are among the most common of the embryonic abnormalities associated with hyperglycemic gestation. In this study, the molecular mechanisms of embryonic neurogenesis influenced by hyperglycemia was investigated using chicken embryo models. High-concentration glucose was administered into chicken eggs and resulted in increased plasma and brain tissue glucose, and suppressed expression of glucose transporters (GLUTs). The rate of NTD positively correlated with hyperglycemia. Furthermore, abnormally increased O-GlcNAcylation, a nutritionally responsive modification, of the key neural tube marker Pax3 protein led to the loss of this protein. This loss was not observed in a folate-deficiency NTD induced by methotrexate. Carnosine, an endogenous dipeptide, showed significant recovery effects on neural tube development. In contrast, folic acid, a well-known periconceptional agent, surprisingly showed relatively minimal effect. Higher expression levels of the Pax3 protein were found in the carnosine-treated groups, while lower expression levels were found in folic acid groups. Furthermore, the abnormal O-GlcNAcylation of the Pax3 protein was restored by carnosine. These results suggest new insights into using endogenous nutrients for the protection of embryonic neurodevelopment affected by diabetes gestation. The abnormal excessive O-GlcNAcylation of Pax3 may be responsible for the neural tube defects associated with hyperglycemia.

A new gestational diabetes mellitus model: hyperglycemia-induced eye malformation via inhibition of Pax6 in the chick embryo.

Gestational diabetes mellitus (GDM) is one of the leading causes of fetal malformations. However, few models have been developed to study the underlying mechanisms of GDM-induced fetal eye malformation. In this study, a high concentration of glucose (0.2 mmol per egg) was injected into the air sac of chick embryos on embryo development day (EDD) 1 to develop a hyperglycemia model. Results showed that 47.3% of embryonic eye malformation happened on EDD 5. In this model, the key genes regulating eye development, Pax6, Six3 and Otx2, were downregulated by hyperglycemia. Among these genes, the expression of Pax6 was the most vulnerable to hyperglycemia, being suppressed by 70%. A reduction in Pax6 gene expression induced eye malformation in chick embryos. However, increased expression of Pax6 in chick embryos could rescue hyperglycemia-induced eye malformation. Hyperglycemia stimulated O-linked N-acetylglucosaminylation, which caused oxidative stress in chick embryos. Pax6 was found to be vulnerable to free radicals, but the antioxidant edaravone could restore Pax6 expression and reverse eye malformation. These results illustrated a successful establishment of a new chick embryo model to study the molecular mechanism of hyperglycemia-induced eye malformation. The suppression of the Pax6 gene is probably mediated by oxidative stress and could be a crucial target for the therapy of GDM-induced embryonic eye malformation.