Molecular Genetic Analysis and Growth Hormone Treatment in a Three-Generation Chinese Family with Tricho-Rhino-Phalangeal Syndrome I.

INTRODUCTION: Tricho-rhino-phalangeal syndrome (TRPS) is a rare genetic disorder characterized by craniofacial and skeletal abnormalities, which is caused by variants in the TRPS1 gene. METHODS: Clinical information and follow-up data were collected. Whole-exome sequencing (WES) was performed for variants and validated by Sanger sequencing. Bioinformatic analysis was performed to predict the pathogenicity of the identified variant. Moreover, wild-type and mutated TRPS1 vectors were constructed and transfected into human embryonic kidney (HEK) 293T cells. Immunofluorescence experiments were performed to assess the localization and expression of the mutated protein. Western blot analysis and RT-qPCR were used to detect the expression of downstream genes. RESULTS: The affected family members had typical craniofacial phenotype including sparse lateral eyebrows, pear-shaped nasal tip, and large prominent ears, plus skeletal abnormalities including short stature and brachydactyly. WES and Sanger sequencing identified the TRPS1 c.880_882delAAG variant in affected family members. In vitro functional studies showed that the TRPS1 variant did not affect the cellular localization and the expression of TRPS1, but the transcriptional repression effect of the TRPS1 on the RUNX2 and STAT3 was disturbed. The proband and his brother have been treated with growth hormone (GH) for 2 years until now, and we have observed the improvement of the linear growth in both. CONCLUSIONS: The variant of c.880_882delAAG in TRPS1 was responsible for the pathogenesis of the Chinese family with TRPS I. The treatment of GH could be beneficial for the height outcome in TRPS I patients, and earlier initiation and longer duration of the therapy in prepubertal or early pubertal stage could be associated with better height outcomes.

FGL2 deficiency alleviates maternal inflammation-induced blood-brain barrier damage by blocking PI3K/NF-κB mediated endothelial oxidative stress.

Introduction: The impairment of blood-brain barrier (BBB) is one of the key contributors to maternal inflammation induced brain damage in offspring. Our previous studies showed Fibrinogen-like protein 2 (FGL2) deficiency alleviated maternal inflammation induced perinatal brain damage. However, its role in BBB remains undefined. Methods: Lipopolysaccharide (LPS) was intraperitoneally injected to dams at Embryonic day 17 to establish maternal inflammation model. FGL2 knockout mice and primary brain microvascular endothelial cells (BMECs) were used for the in-vivo and in-vitro experiments. BBB integrity was assessed by sodium fluorescein extravasation and tight junction (TJ) protein expression. Oxidative stress and the activation of PI3K/NF-κB pathway were evaluated to explore the mechanisms underlying. Results: Upon maternal inflammation, BBB integrity was remarkedly reduced in neonatal mice. Meanwhile, FGL2 expression was consistently increased in BBB-impaired brain as well as in LPS-treated BMECs. Moreover, FGL2 deficiency attenuated the hyperpermeability of BBB, prevented the decline of TJ proteins, and reduced the cytokine expressions in LPS-exposed pups. Mechanistically, the indicators of oxidative stress, as well as the activation of PI3K/NF-κB pathway, were upregulated after LPS exposure in vivo and in vitro. FGL2 deletion decreased the generation of ROS and NO, reduced the endothelial iNOS and NOX2 expressions, and suppressed the PI3K/NF-κB pathway activation. Besides, inhibition of PI3K by LY294002 decreased the oxidative stress in LPS-treated wild-type BMECs. While, overexpression of PI3K by lentivirus reemerged the induction of NOX2 and iNOS as well as NF-κB activation in FGL2-deleted BMECs. Conclusion: Our findings indicate that FGL2 deficiency alleviates the maternal inflammation-induced BBB disruption by inhibiting PI3K/NF-κB mediated oxidative stress in BMECs. Targeting FGL2 may provide a new therapy for prenatal brain damage of offspring.

Maternal obesity inhibits placental angiogenesis by down-regulating the SIRT1/PGC-1α pathway.

Background: To explore whether maternal obesity inhibits placental angiogenesis through down-regulation of Sirtuin 1/Peroxisome proliferator-activated receptor-γ coactivator-1α (SIRT1/PGC-1α) signaling pathway. Methods: In a rat model of pre-pregnancy obesity, rats were sacrificed at embryonic day (E)18.5. Maternal characteristics were measured. Placentas were collected to observe the pathological changes and angiogenesis using hematoxylin-eosin (HE) staining and platelet endothelial cell adhesion molecule-1 [PECAM-1/CD31 (CD31)] immunohistochemical (IHC) staining, and the expression of the SIRT1/PGC-1α signaling pathway was also analyzed using western blotting and quantitative real-time polymerase chain reaction (qPCR). In in vitro experiments, human umbilical vein endothelial cells (HUVECs) were incubated under high fat conditions. We activated and inhibited the SIRT1/PGC-1α signaling pathway to determine the proliferation, angiogenic tube formation, and migration capacity of endothelial cells. Cell counting kit-8 (CCK-8) assays, tubule formation assays, and scratch wound-healing migration assays were also performed. Results: In vivo results showed that compared with the control group, the high-fat diet (HFD) group were heavier and their plasma triglyceride and total cholesterol contents were higher. The ratio of fetal weight to placental weight was reduced in the HFD group compared to the control group. In the HFD group, placental angiogenesis was decreased, and the SIRT1/PGC-1α signaling pathway was down-regulated compared with that in the control group. The results of in vitro experiments showed that SRT1720 reduced SIRT1/PGC-1α and vascular endothelial growth factor (VEGFA) expression inhibition induced by high fat stress, while EX-527 increased SIRT1/PGC-1α and VEGFA expression inhibition. Compared with the control group, maternal obesity impaired placental angiogenesis and reduced the proliferation and migration of HUVECs. Conclusions: The results suggest that maternal obesity impairs placental angiogenesis. They also provide experimental evidence that activation of the SIRT1/PGC-1α signaling pathway improves angiogenesis in vitro.

Clinical and Functional Characterization of a Novel Mutation in AVPR2 Causing Nephrogenic Diabetes Insipidus in a Four-Generation Chinese Family.

Background: Congenital nephrogenic diabetes insipidus (CNDI) is a rare inherited disease that is caused by mutations in arginine vasopressin receptor 2 (AVPR2) or aquaporin 2 (AQP2). Functional analysis of the mutated receptor is necessary to verify the impact of the mutation on receptor function and suggest some possible therapeutic strategies for specific functional defects. Methods: Family history and clinical information were collected. Whole-exome sequencing and sanger sequencing were performed to determine the potential genetic cause of diabetes insipidus. The identified variant was classified according to the American College of Medical Genetics (ACMG) criteria. Bioinformatic analysis was performed to predict the function of the identified variation. Moreover, wild-type and mutated AVPR2 vectors were constructed and transfection to HEK-293T cells. Immunofluorescence experiments were performed to investigate the expression and localization of the mutated protein and cAMP parameter assays were used to measure its activity in response to AVP. Results: The heights of the adult members affected with polyuria and polydipsia were normal, but all affected children had growth retardation. Next-generation sequencing identified a novel mutation in AVPR2 gene (c.530T > A) in this family. Bioinformatic analysis indicated that the mutation in AVPR2 changed the hydropathic characteristic of the protein and was probably deleterious. Although immunofluorescence showed that the mutated AVPR2 was normally expressed in the cell surface, the intracellular cAMP concentration stimulated by AVP was significantly lower in cells transfected with mutated AVPR2 than cells transfected with wild-type AVPR2. Based on the ACMG criteria, the novel c.530T > A variant of the AVPR2 gene was likely pathogenic and the affected family members were diagnosed as CNDI. After the confirmation of the diagnosis, the proband was treated with compound amiloride hydrochloride and rhGH, the symptoms of polyuria, polydipsia and growth retardation were all improved. Conclusion: These findings suggested that the novel mutation in AVPR2 (c.530T > A) was a true disease-causing variant with mild effects, which could be classified as a type III mutant receptor. Moreover, investigations of the function of growth hormone axis could be important for the pediatric CNDI patients with extreme short stature, and rhGH treatment might improve the final adult heights in these patients.

Analysis of the Screening Results for Congenital Adrenal Hyperplasia Involving 7.85 Million Newborns in China: A Systematic Review and Meta-Analysis.

Background: Congenital adrenal hyperplasia (CAH) is a group of congenital genetic diseases caused by defective steroidogenesis. Our study aims to systematically analyze the screening results for CAH in Chinese newborns. Methods: Studies were searched from PubMed, Web of Science, Cochrane library and some Chinese databases up to September, 2020. Meta-analysis was performed after quality assessment and data extraction. Results: After a review of 2 694 articles, we included 41 studies enrolling 7 853 756 newborns. In our study, we found that the incidence of CAH in China was 0.43‱ [95% confidence intervals(CI), (0.39‱, 0.48‱)], or 1/23 024 [95%CI, (1/25 757,1/20 815)]. 27 studies were included for analysis of the screening positive rate, which gave a rate of 0.66% [95%CI, (0.54%, 0.78%)]. As for the recall rate of positive cases, 17 studies were included and showed that the recall rate reached 86.17% [95%CI, (82.70%, 89.64%)]. Among the CAH patients, the ratio of males to females was 1.92:1 (119:62), and the ratio of salt wasting (SW) to simple virilization (SV) type was 3.25:1 (104:32). The average 17-hydroxyprogesterone (17-OHP) value of CAH was 393.40 ± 291.85 nmol/L (Range 33-1 300 nmol/L); there was no significant difference between male and female patients (437.17 ± 297.27 nmol/L v.s. 322.25 ± 293.04 nmol/L, P=0.16), but a significant difference was found between SW and SV patients (483.29 ± 330.07 nmol/L v.s. 73.80 ± 7.83nmol/L, P=0.04). Conclusion: We systematically analyzed the current situation of neonatal CAH screening in China, which will deepen our understanding for future CAH screening and early diagnosis.

Intrauterine inflammation induced white matter injury protection by fibrinogen-like protein 2 deficiency in perinatal mice.

BACKGROUND: White matter injury (WMI) induced by intrauterine inflammation can cause adverse neurological outcomes. Fibrinogen-like protein 2 (FGL2)/fibroleukin is an important trigger of inflammatory responses and is involved in some cerebral diseases. However, the role of FGL2 in intrauterine inflammation-induced WMI remains unclear. METHODS: Lipopolysaccharide (LPS) was intraperitoneally injected into wild-type and FGL2 knockout mice to induce intrauterine inflammation. Body weight and brain weight of offspring were monitored. Major basic protein (MBP) expression was evaluated to demonstrate the myelination of offspring. To investigate the regulatory mechanism of FGL2, cytokine expression, microglial polarization, and the activation of mitogen-activated protein kinase (MAPK) signaling pathway in the offspring were analyzed. RESULTS: Upon LPS exposure, FGL2 knockout offspring showed a significant increase in body weight loss. MBP reduction induced by LPS was prevented in FGL2 knockout offspring. Expression levels of proinflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α, and M1 marker CD86 were suppressed, while the expression levels of anti-inflammatory cytokines IL-10 and M2 marker CD206 were increased. FGL2 deficiency significantly inhibited the phosphorylation of p38MAPK and c-Jun N-terminal kinase (JNK) protein. CONCLUSIONS: FGL2 deficiency can ameliorate WMI induced by intrauterine inflammation, reducing inflammatory cascade and improving hypomyelination, through the regulation of microglial polarization and MAPK signaling pathways. IMPACT: Intrauterine inflammation induces WMI leading to severe neurological sequelae. FGL2 plays an important role in the progression of WMI induced by intrauterine inflammation. FGL2 deficiency can protect against WMI by inhibiting p38 MAPK and JNK phosphorylation, regulating microglia polarization, and reducing inflammation response. FGL2 could be a novel molecular target for protecting against WMI induced by intrauterine inflammation.