Gut lumen formation defect can cause intestinal atresia: evidence from histological studies of human embryos and intestinal atresia septum.

Intestinal atresia (IA), a common cause of neonatal intestinal obstruction, is a developmental defect, which disrupts the luminal continuity of the intestine. Here, we investigated (i) the process of lumen formation in human embryos; and (ii) how a defective lumen formation led to IA. We performed histological and histochemical study on 6-10 gestation week human embryos and on IA septal regions. To investigate the topology of embryonic intestine development, we conducted 3D reconstruction. We showed that a 6-7th gestation week embryonic gut has no lumen, but filled with mesenchyme cells and vacuoles of a monolayer of epithelial cells. A narrow gut lumen was formed by gestation week-9, the gut was filled with numerous vacuoles of different sizes, some vacuoles were merging with the developing embryonic gut wall. At gestation week-10, a prominent lumen was developed, only few vacuoles were present and were merging with the intestine wall. At IA septal regions, vacuoles were located in the submucous layer, covered by a single layer of epithelium without glandular structure, and surrounded with fibrous tissue. The mucosal epithelium was developed with lamina propria and basement membrane, but the submucosa and the longitudinal smooth muscle layers were not properly developed. Hence, the vacuoles in IA septum could represent a remnant of vacuoles of embryonic gut. In conclusion, the fusion of vacuoles with the developing intestine wall associates with the disappearance of vacuoles and gut lumen formation in human embryos, and perturbation of these developmental events could lead to IA.

The Allantois and Urachus: Histological Study Using Human Embryo and Fetuses.

Relatively little is known about allantois and urachal development in early humans.Serial sagittal histological sections from eight human embryos and fetuses were examined to determine allantois development.At gestational age 6-7 weeks, the primitive allantois consists of an enlarged tube located between the umbilical cord and abdominal cavity, whereas the urachus is not yet developed. At 8 weeks, the allantois gradually withdraws from the distal to the proximal end of the umbilical cord, and both the proximal allantois and the rectum (hindgut) start to develop into the cloaca. At 10 weeks, the allantois was located mostly in the abdominal cavity.The urachus forms from the distal end of the allantois and develops into a closed fibrous cord between the base of the urinary bladder and the umbilicus. The urogenital sinus forms from the proximal end of the allantois.

Delayed development of vacuoles and recanalization in the duodenum: a study in human fetuses to understand susceptibility to duodenal atresia/stenosis.

ObjectiveWe compared the cross-sectional areas of the duodenum to the distal small intestine during early gestation to determine if there is a difference in age for recanalization.MethodsSerial sagittal sections of six fetuses of gestational age (GA) 8-10 weeks were examined morphologically to compare the degree of recanalization of the duodenum with to the more distal small intestine.ResultsAt GA 8-9 weeks, the duodenum had more epithelial plugs and vacuoles with no or narrower spaces compared to the distal small bowel. Quantitative assessment at GA 10 weeks showed that the cross-sectional area of the duodenal cavity was significantly less than the distal small bowel.ConclusionThe development and recanalization of vacuoles in the duodenum occurs later than the jejunum and ileum may be involved in the more frequent development of atresia/stenosis of the duodenum compared to more distal gastrointestinal tract.

A Stereological Study of Mouse Ovary Tissues for 3D Bioprinting Application.

INTRODUCTION: The use of 3D-bioprinted ovaries has been proven to be a promising technique for preserving fertility. Stereology is an accurate method to obtain quantitative 3D information and the stereological data is the basis for 3D bioprinting ovaries. METHODS: In this study, six female mice were used to acquire the ovarian tissues. One of the two paraffin-embedded ovaries of each mouse was cut into 5 µm sections, and the other was cut into 15 µm sections and then subjected to haematoxylin and eosin staining and anti-follicle stimulating hormone receptor antibody immunohistochemistry. The volume and volume fractions of ovaries were measured by the Cavalieri method. Then, the numerical densities and total numbers of ovarian granulosa cells (OGCs) and primordial, preantral and antral follicles in serial sections were estimated using design-based stereology. RESULTS: The ovarian volume was 2.50 ± 0.32 mm3. The volume fractions of the cortex, medulla, follicles and OGCs were 86.80% ± 2.82, 13.20% ± 2.82%, 5.60% ± 0.25% and 81.19% ± 2.57%, respectively. The numerical densities of OGCs, the primordial, preantral and antral follicles were 2.11 (± 0.28) × 106/mm3, 719.57 ± 18.04/mm3, 71.84 ± 3.93/mm3 and 17.29 ± 3.54/mm3, respectively. The total number of OGCs and follicles per paraffin-embedded ovary were 5.26 (± 0.09) × 106 and 2013.66 ± 8.16. CONCLUSIONS: The study had obtained the stereological data of the mice ovaries, which contribute to a deeper understanding of the structure of the ovaries. Meanwhile, the data will supply information for 3D bioprinting ovaries.

PCAT-1 facilitates breast cancer progression via binding to RACK1 and enhancing oxygen-independent stability of HIF-1α.

Hypoxia induces a series of cellular adaptive responses that enable promotion of inflammation and cancer development. Hypoxia-inducible factor-1α (HIF-1α) is involved in the hypoxia response and cancer promotion, and it accumulates in hypoxia and is degraded under normoxic conditions. Here we identify prostate cancer associated transcript-1 (PCAT-1) as a hypoxia-inducible long non-coding RNA (lncRNA) that regulates HIF-1α stability, crucial for cancer progression. Extensive analyses of clinical data indicate that PCAT-1 is elevated in breast cancer patients and is associated with pathological grade, tumor size, and poor clinical outcomes. Through gain- and loss-of-function experiments, we find that PCAT-1 promotes hypoxia-associated breast cancer progression including growth, migration, invasion, colony formation, and metabolic regulation. Mechanistically, PCAT-1 directly interacts with the receptor of activated protein C kinase-1 (RACK1) protein and prevents RACK1 from binding to HIF-1α, thus protecting HIF-1α from RACK1-induced oxygen-independent degradation. These findings provide new insight into lncRNA-mediated mechanisms for HIF-1α stability and suggest a novel role of PCAT-1 as a potential therapeutic target for breast cancer.

Quantification of the CM-Dil-labeled human umbilical cord mesenchymal stem cells migrated to the dual injured uterus in SD rat.

BACKGROUND: Human umbilical cord mesenchymal stem cell (hUC-MSC) therapy is considered as a promising approach in the treatment of intrauterine adhesions (IUAs). Considerable researches have already detected hUC-MSCs by diverse methods. This paper aims at exploring the quantitative distribution of CM-Dil-labeled hUC-MSCs in different regions of the uterus tissue of the dual injury-induced IUAs in rats and the underlying mechanism of restoration of fertility after implantation of hUC-MSCs in the IUA model. METHODS: In this study, we investigated the quantification of the CM-Dil-labeled hUC-MSCs migrated to the dual injured uterus in Sprague Dawley rats. Additionally, we investigated the differentiation of CM-Dil-labeled hUC-MSCs. The differentiation potential of epithelial cells, vascular endothelial cells, and estrogen receptor (ER) cells were assessed by an immunofluorescence method using CK7, CD31, and ERα. The therapeutic impact of hUC-MSCs in the IUA model was assessed by hematoxylin and eosin, Masson, immunohistochemistry staining, and reproductive function test. Finally, the expression of TGF-ß1/Smad3 pathway in uterine tissues was determined by qRT-PCR and Western blotting. RESULTS: The CM-Dil-labeled cells in the stroma region were significantly higher than those in the superficial myometrium (SM) (71.67 ± 7.98 vs. 60.92 ± 3.96, p = 0.005), in the seroma (71.67 ± 7.98 vs. 23.67 ± 8.08, p = 0.000) and in the epithelium (71.67 ± 7.98 vs. 4.17 ± 1.19, p = 0.000). From the 2nd week of treatment, hUC-MSCs began to differentiate into epithelial cells, vascular endothelial cells, and ER cells. The therapeutic group treated with hUC-MSCs exhibited a significant decrease in fibrosis (TGF-ß1/Smad3) as well as a significant increase in vascularization (CD31) compared with the untreated rats. CONCLUSION: Our findings suggested that the distribution of the migrated hUC-MSCs in different regions of the uterine tissue was unequal. Most cells were in the stroma and less were in the epithelium of endometrium and gland. Injected hUC-MSCs had a capacity to differentiate into epithelial cells, vascular endothelial cells, and ER cells; increase blood supply; inhibit fibration; and then restore the fertility of the IUA model.