Simulated microgravity attenuates myogenesis and contractile function of 3D engineered skeletal muscle tissues.

While the effects of microgravity on inducing skeletal muscle atrophy have been extensively studied, the impacts of microgravity on myogenesis and its mechanisms remain unclear. In this study, we developed a microphysiological system of engineered muscle tissue (EMT) fabricated using a collagen / Matrigel composite hydrogel and murine skeletal myoblasts. This 3D EMT model allows non-invasive quantitative assessment of contractile function. After applying a 7-day differentiation protocol to induce myotube formation, the EMTs clearly exhibited sarcomerogenesis, myofilament formation, and synchronous twitch and tetanic contractions with electrical stimuli. Using this 3D EMT system, we investigated the effects of simulated microgravity at 10-3 G on myogenesis and contractile function utilizing a random positioning machine. EMTs cultured for 5 days in simulated microgravity exhibited significantly reduced contractile forces, myofiber size, and differential expression of muscle contractile, myogenesis regulatory, and mitochondrial biogenesis-related proteins. These results indicate simulated microgravity attenuates myogenesis, resulting in impaired muscle function.

Influence of presurgical nasoalveolar molding (PNAM) treatment in maxillary dental arch width and nasolabial symmetry in patients with unilateral complete cleft lip and palate.

Unilateral complete cleft lip and palate (UCCLP) is one of the most severe clinical subphenotypes among nonsyndromic cleft lip and/or palate (NSCL/P), that complicates surgical repair operations. Presurgical nasoalveolar molding (PNAM) is a technique used to reshape the nose, lip and alveolar bone of infants with UCCLP before surgery (the modified Mohler rotation advancement cheiloplasty and two flap palatoplasty), with the potential to facilitate surgical repair. However, the effectiveness of PNAM treatment is still a matter of debate. In this paper, the 3Shape scanning system and 3dMD stereophotography were used to assess the short-term and long-term effects of PNAM treatment on the dental arch morphology and nasolabial features of patients with UCCLP, respectively. The findings indicated that PNAM treatment negatively affects both short-term and long-term dental arch shape compared to the treatment without PNAM, particularly in terms of limiting the transverse width of the maxillary canine-to-midline. Regarding the nasal and labial symmetry, PNAM improves the symmetry of the nasal alae in patients over 7 years old and the symmetry of the lip in patients under 7 years old. Moreover, UCCLP patients who received PNAM treatment exhibited a shorter and wider shape of the nostril on the cleft side compared to those without PNAM treatment. In clinical practice, the multidisciplinary team should carefully consider the advantages and disadvantages of the outcomes of PNAM treatment when treating infants with cleft lip and palate.

Establishment of a novel classification system for alveolar morphology in infants with unilateral complete cleft lip and palate.

OBJECTIVES: Unilateral complete cleft lip and palate (UCCLP) is one of the most severe clinical subtypes among cleft lip and palate (CLP), making repair surgery and subsequent orthodontic treatment particularly challenging. Presurgical nasoalveolar molding (PNAM) has shown conflicting and heterogeneous results in the treatment of UCCLP patients, raising questions about whether the diversity in alveolar anatomical morphology among these patients plays a role in the effectiveness of PNAM treatment. MATERIALS AND METHODS: We collected 90 digital maxillary models of infants with UCCLP and performed mathematical clustering analysis, including principal component analysis (PCA), decision tree modeling, and area under the ROC Curve (AUC) analysis, to classify alveolar morphology and identify key measurements. We also conducted clinical evaluations to assess the association between the alveolar morphology and CLP treatment outcomes. RESULTS: Using mathematical clustering analysis, we classified the alveolar morphology into three distinct types: average form, horizontal form, and longitudinal form. The decision tree model, AUC analysis, and comparison analysis revealed that four measurements (Trans ACG-ACL, ML length, MG length and Inc length) were essential for clustering the alveolar morphology of infants with UCCLP. Furthermore, the blinded clinical evaluation indicated that UCCLP patients with alveolar segments of horizontal form had the lowest treatment outcomes. CONCLUSION: Overall, our findings establish a novel quantitative classification system for the morphology of alveolar bone in infants with UCCLP and suggest that this classification may be associated with the outcomes of CLP treatment. CLINICAL RELEVANCE: The multidisciplinary CLP team should thoroughly evaluate and classify the specific alveolar morphology when administering PNAM to infants with UCCLP.

Biomanufacturing of 3D Tissue Constructs in Microgravity and their Applications in Human Pathophysiological Studies.

The growing interest in bioengineering in-vivo-like 3D functional tissues has led to novel approaches to the biomanufacturing process as well as expanded applications for these unique tissue constructs. Microgravity, as seen in spaceflight, is a unique environment that may be beneficial to the tissue-engineering process but cannot be completely replicated on Earth. Additionally, the expense and practical challenges of conducting human and animal research in space make bioengineered microphysiological systems an attractive research model. In this review, published research that exploits real and simulated microgravity to improve the biomanufacturing of a wide range of tissue types as well as those studies that use microphysiological systems, such as organ/tissue chips and multicellular organoids, for modeling human diseases in space are summarized. This review discusses real and simulated microgravity platforms and applications in tissue-engineered microphysiological systems across three topics: 1) application of microgravity to improve the biomanufacturing of tissue constructs, 2) use of tissue constructs fabricated in microgravity as models for human diseases on Earth, and 3) investigating the effects of microgravity on human tissues using biofabricated in vitro models. These current achievements represent important progress in understanding the physiological effects of microgravity and exploiting their advantages for tissue biomanufacturing.

Retrospective study on primary rhinoplasty for unilateral complete cleft lip nasal deformity.

OBJECTIVES: A retrospective study was conducted on the effect of primary rhinoplasty on infants with unilateral complete cleft lip nasal deformity. METHODS: Infants with unilateral complete cleft lip in the Department of Cleft Lip and Palate Surgery, College of Stomatology, Xi'an Jiaotong University were selected. All infants underwent cheiloplasty and primary rhinoplasty. We reconstructed the nasal base and corrected the nasal septum and alar deformity at the same time. The nasal splint was worn 1 week after the surgery. The nasal morphology before surgery as well as 1 week and 1 year after surgery were analyzed. RESULTS: Significant differences were found on symmetry ratios including nasal base width, nostril height, alar angle and columella deviation angle between before and after operation (P<0.05). There were statistically significant differences in the symmetry ratio of nostril height and columella deviation angle between 1 year after surgery and 1 week after surgery (P<0.05). CONCLUSIONS: Infants with unilateral complete cleft lip nasal deformity can achieve satisfactory nasal morphology by primary rhinoplasty. Despite few cases of recurrence of nasal deformity, the nasal morphology can be well improved and maintained.

Case report: Identification of three novel compound heterozygous SGLT2 variants in three Chinese pediatric patients with familial renal glucosuria.

Familial renal glucosuria (FRG) is a rare genetic condition featured by isolated glucosuria without hyperglycemia or other kidney diseases. It is caused by pathogenic mutations of the SGLT2 (Sodium-Glucose Cotransporter 2) gene, whose protein product is responsible for reabsorbing the majority of glucose in the early proximal convoluted tubule. Hitherto, quite an array of variants of SGLT2 have been identified in patients of FRG. In this study, we performed whole exome sequencing on three Chinese pediatric patients with FRG and uncovered three compound heterozygous variants of SGLT2: c.1333C > T (p.Q445X) and c.1130-5 C > G; c.1438G > T (p.V480F) and c.346G > A (p.V116M); c.1175C > G (p.S392C) and c.1333C > T (p.Q445X). Among the total of five variants, c.1333C > T (p.Q445X), c.1438G > T (p.V480F) and c.1175C > G (p.S392C) represented novel variants that had not been reported in any genetic databases. All five variants had extremely low allele frequencies and the amino acids loci affected by missense variants were highly conserved in vertebrate species. Bioinformatic tools predicted that all five variants might disrupt the function of SGLT2, which were likely to be causal for FRG in these patients. Our findings expand the variant spectrum of SGLT2 associated with FRG and provide novel insights into mechanism of action of this transporter, which will aid in the development of novel SGLT2 inhibitors for treatment of type 2 diabetes and cardiovascular diseases.

Factors mediating spaceflight-induced skeletal muscle atrophy.

Skeletal muscle atrophy is a well-known consequence of spaceflight. Because of the potential significant impact of muscle atrophy and muscle dysfunction on astronauts and their mission, a thorough understanding of the mechanisms of this atrophy and the development of effective countermeasures is critical. Spaceflight-induced muscle atrophy is similar to atrophy seen in many terrestrial conditions, and therefore our understanding of this form of atrophy may also contribute to the treatment of atrophy in humans on Earth. The unique environmental features humans encounter in space include the weightlessness of microgravity, space radiation, and the distinctive aspects of living in a spacecraft. The disuse and unloading of muscles in microgravity are likely the most significant factors that mediate spaceflight-induced muscle atrophy and have been extensively studied and reviewed. However, there are numerous other direct and indirect effects on skeletal muscle that may be contributing factors to the muscle atrophy and dysfunction seen as a result of spaceflight. This review offers a novel perspective on the issue of muscle atrophy in space by providing a comprehensive overview of the unique aspects of the spaceflight environment and the various ways in which they can lead to muscle atrophy. We systematically review the potential contributions of these different mechanisms of spaceflight-induced atrophy and include findings from both actual spaceflight and ground-based models of spaceflight in humans, animals, and in vitro studies.

Haplogroup Structure and Genetic Variation Analyses of 60 Mitochondrial DNA Markers in Southern Shaanxi Han Population.

Mitochondrial DNA (mtDNA) has been widely employed as one tool for the studies of human migration and phylogenetic evolution owing to the characteristics of its lack of recombination and matrilineal inheritance. In this study, we analyze genetic distributions of 60 mtDNA markers in 126 unrelated individuals of Southern Shaanxi Han population and classify their haplogroups. Genetic distribution comparisons between Southern Shaanxi Han and other populations from different continents are conducted based on the same mtDNA markers. The majority of 60 mtDNA markers are polymorphic in Southern Shaanxi Han population. The most common haplogroups observed in Southern Shaanxi Han population are B5, followed by D5, A, D4e, and N9a1'3. Obtained matching probability for these 60 mtDNA markers indicates that the panel could be used as a valuable tool in forensic caseworks. Results of genetic distances (Fst) and multidimensional scaling analysis show that Southern Shaanxi Han population has relatively close genetic relationships with other Han populations in different regions. In conclusion, the panel comprising 60 mtDNA markers could be utilized for forensic applications in Southern Shaanxi Han population.

Effects of CCN3 on fibroblast proliferation, apoptosis and extracellular matrix production.

CCN2 and CCN3 belong to the CCN family of proteins, which show a high level of structural similarity.Previous studies have shown that CCN2 mediates the ability of transforming growth factor (TGF)­ß to stimulate collagen synthesis, leading to keloid formation. CCN2 and CCN3 are opposing factors in regulating the promoter activity and secretion of this extracellular matrix (ECM) protein. Thus, we hypothesize that CCN3 possesses an anti­scarring effect. However, the exact mechanism of CCN3 in this anti­scarring effect remains unclear. The aim of this study was to investigate the mechanism of CCN3 in reducing scar formation. Palatal fibroblasts were obtained from the explants of the oral palatal mucosa of 8­week­old male Sprague­Dawley rats. CCN3 overexpression vector was constructed and then transfected into cells. The inhibitory effects of CCN3 on cell growth were detected via the 3­(4,5­dimethylthiazol­2­yl)­2,5­diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured using an Annexin V­fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis detection kit and flow cytometry. The expression levels of collagen I, collagen III and α­smooth muscle actin (α­SMA) were determined by western blot analysis and RT­PCR. Following treatment with TGF­ß1, we detected the expression of CCN3 and Smad1 in the fibroblasts. CCN3 significantly inhibited the growth and induction of apoptosis of fibroblasts. The expression of collagen I, collagen III and α­SMA was lower in the CCN3­transfected group as compared to the control and vector groups. TGF­ß1 stimulation efficiently suppressed the expression of CCN3 at the mRNA and protein levels, and CCN3 was required for TGF­ß1­induced Smad1 phosphorylation. Results of this study demonstrated that CCN3 is involved in the proliferation and apoptosis of fibroblasts and the synthesis of ECM proteins. Therefore, CCN3 may play an important role in the development of scar tissue, and may represent a novel therapeutic target for reducing scar formation.

[Presurgical nasoalveolar molding in infants with cleft lip and palate: analysis of 29 cases].

PURPOSE: The objective of this study was to treat the cleft lip and alveolus, nasal deformity with presurgical nasoalveolar molding (PNAM), to elucidate the problems and treatment methods, which may be helpful for the use of PNAM in clinic. METHODS: Twenty nine infants with cleft lip and palate (CLP) were treated with PNAM in our center. There were 19 unilateral and 10 bilateral CLP patients. The initial visit time was 3 to 150 days after birth. Treatment time ranged from 2.5 to 3 months. The appliance was modified at 2-week interval. RESULTS: According to the evaluation standards, 17 infants were treated successfully with the closure of cleft lip and alveolar processes, reposition of the deformed nasal cartilages, and increased length of columella. The lip and nasal deformities of 9 infants were corrected partly, which were helpful for surgery. There were 3 infants giving up PNAM. CONCLUSIONS: There were five important facts for the successful treatment, including initial visit time, impression of the intraoral cleft defect, modification of the plate and the nasal stent, and use of nasal splints. Orthodontics and plastic surgeons should have the same views for PNAM in infants, which will advance the treatment level for cleft lip and palate.

[Expression and significance of APC, beta-catenin, C-myc, and Cyclin D1 proteins in colorectal carcinoma].

BACKGROUND & OBJECTIVE: The abnormal oncogenes and antioncogenes in Wnt signaling transduction pathway activate downstream specific target genes, and may play important roles in tumorigenesis and tumor progression. This study was to examine the expression of adenomatous polyposis coli (APC), beta-catenin, C-myc, and Cyclin D1 in different colorectal tissues, and investigate their possible roles in the carcinogenesis of colorectal carcinoma. METHODS: The expression of APC, beta-catenin, C-myc, and Cyclin D1 in 30 specimens of normal colorectal mucosa, 30 specimens of colorectal adenoma, 10 specimens of colorectal adenoma with malignancy, and 50 specimens of colorectal carcinoma was examined by immunohistochemistry. The expression of beta-catenin on cell membrane was regarded as normal, and its expression in cytoplasm and nuclei was defined as ectopic expression. RESULTS: The positive rate of APC was significantly lower in colorectal carcinoma and colorectal adenoma with malignancy than in colorectal adenoma and normal colorectal mucosa (44.0% and 40.0% vs. 86.7% and 100.0%, P<0.01). The ectopic expression rate of beta-catenin was significantly higher in colorectal carcinoma, colorectal adenoma with malignancy, and colorectal adenoma than in normal colorectal mucosa (62.0%, 50.0%, and 30.0% vs. 0%, P<0.01), and significantly higher in colorectal carcinoma than in colorectal adenoma (P<0.01). The positive rate of C-myc was significantly higher in colorectal carcinoma, colorectal adenoma with malignancy, and colorectal adenoma than in normal colorectal mucosa (56.0%, 60.0%, and 46.7% vs. 0%, P<0.01). The positive rate of Cyclin D1 was significantly higher in colorectal carcinoma, colorectal adenoma with malignancy, and colorectal adenoma than in normal colorectal mucosa (66.0%, 60.0%, and 30.0% vs. 0%,P<0.01), and significantly higher in colorectal carcinoma than in colorectal adenoma (P<0.01). The ectopic expression of beta-catenin was positively correlated to the expression of C-myc and Cyclin D1 (r=0.63,P<0.01; r=0.57, P<0.01), and negatively correlated to the expression of APC (r=-0.39, P<0.05). CONCLUSION: The reduced expression of APC, ectopic expression of beta-catenin, overexpression of C-myc and Cyclin D1 exist in colorectal carcinoma, which may play important roles in the carcinogenesis of colorectal carcinoma.