miRNA dosage control in development and human disease.

In mammals, miRNAs recognize target mRNAs via base pairing, which leads to a complex 'multiple-to-multiple' regulatory network. Previous studies have focused on the regulatory mechanisms and functions of individual miRNAs, but alterations of many individual miRNAs do not strongly disturb the miRNA regulatory network. Recent studies revealed the important roles of global miRNA dosage control events in physiological processes and pathogenesis, suggesting that miRNAs can be considered as a 'cellular buffer' that controls cell fate. Here, we review the current state of research on how global miRNA dosage is tightly controlled to regulate development, tumorigenesis, neurophysiology, and immunity. We propose that methods of controlling global miRNA dosage may serve as effective therapeutic tools to cure human diseases.

C/EBPß Coupled with E2F2 Promoted the Proliferation of hESC-Derived Hepatocytes through Direct Binding to the Promoter Regions of Cell-Cycle-Related Genes.

Human embryonic stem cells (hESCs) hold the potential to solve the problem of the shortage of functional hepatocytes in clinical applications and drug development. However, a large number of usable hepatocytes derived from hESCs cannot be effectively obtained due to the limited proliferation capacity. In this study, we found that enhancement of liver transcription factor C/EBPß during hepatic differentiation could not only significantly promote the expression of hepatic genes, such as albumin, alpha fetoprotein, and alpha-1 antitrypsin, but also dramatically reinforce proliferation-related phenotypes, including increasing the expression of proliferative genes, such as CDC25C, CDC45L, and PCNA, and the activation of cell cycle and DNA replication pathways. In addition, the analysis of CUT&Tag sequencing further revealed that C/EBPß is directly bound to the promoter region of proliferating genes to promote cell proliferation; this interaction between C/EBPß and DNA sequences of the promoters was verified by luciferase assay. On the contrary, the knockdown of C/EBPß could significantly inhibit the expression of the aforementioned proliferative genes. RNA transcriptome analysis and GSEA enrichment indicated that the E2F family was enriched, and the expression of E2F2 was changed with the overexpression or knockdown of C/EBPß. Moreover, the results of CUT&Tag sequencing showed that C/EBPß also directly bound the promoter of E2F2, regulating E2F2 expression. Interestingly, Co-IP analysis exhibited a direct binding between C/EBPß and E2F2 proteins, and this interaction between these two proteins was also verified in the LO2 cell line, a hepatic progenitor cell line. Thus, our results demonstrated that C/EBPß first initiated E2F2 expression and then coupled with E2F2 to regulate the expression of proliferative genes in hepatocytes during the differentiation of hESCs. Therefore, our findings open a new avenue to provide an in vitro efficient approach to generate proliferative hepatocytes to potentially meet the demands for use in cell-based therapeutics as well as for pharmaceutical and toxicological studies.

Resveratrol rescues cutaneous radiation-induced DNA damage via a novel AMPK/SIRT7/HMGB1 regulatory axis.

Cutaneous radiation injury (CRI) interrupts the scheduled process of radiotherapy and even compromises the life quality of patients. However, the current clinical options for alleviating CRI are relatively limited. Resveratrol (RSV) has been shown to be a promising protective agent against CRI; yet the mechanisms of RSV enhancing radioresistance were not fully elucidated and limited its clinical application. In this study, we demonstrate RSV promotes cutaneous radioresistance mainly through SIRT7. During ionizing radiation (IR) treatment, RSV indirectly phosphorylates and activates SIRT7 through AMPK, which is critical for maintaining the genome stability of keratinocytes. Immunoprecipitation and mass spectrometry identified HMGB1 to be the key interacting partner of SIRT7 to mediate the radioprotective function of RSV. Mechanistic study elucidated that SIRT7 interacts with and deacetylates HMGB1 to redistribute it into nucleus and "switch on" its function for DNA damage repair. Our findings establish a novel AMPK/SIRT7/HMGB1 regulatory axis that mediates the radioprotective function of RSV to alleviate IR-induced cutaneous DNA injury, providing an efficiently-curative option for patients with CRI during radiotherapy.

Chondroitin Sulfate/Polycaprolactone/Gelatin Electrospun Nanofibers with Antithrombogenicity and Enhanced Endothelial Cell Affinity as a Potential Scaffold for Blood Vessel Tissue Engineering.

Electrospun polymer nanofibers have gained much attention in blood vessel tissue engineering. However, conventional nanofiber materials with the deficiencies of slow endothelialization and thrombosis are not effective in promoting blood vessel tissue repair and regeneration. Herein, biomimetic gelatin (Gt)/polycaprolactone (PCL) composite nanofibers incorporating a different amount of chondroitin sulfate (CS) were developed via electrospinning technology to investigate their effects on antithrombogenicity and endothelial cell affinity. Varying CS concentrations in PG nanofibers affects fiber morphology and diameter. The CS/Gt/PCL nanofibers have suitable porosity (~ 80%) and PBS solution absorption (up to 650%). The introduction of CS in Gt/PCL nanofibers greatly enhances their anticoagulant properties, prolongs their coagulation time, and facilitates cell responses. Particularly, 10%CS/Gt/PCL nanofibers display favorable cell attachment, elongation, and proliferation. Thus, the Gt/PCL nanofibers containing a certain amount of CS could be excellent candidates as a promising tissue-engineering scaffold in blood vessel repair and regeneration.

Inhibition of prostaglandin E2 protects abdominal aortic aneurysm from expansion through regulating miR-29b-mediated fibrotic ECM expression.

The risk of rupture, the most feared clinical consequence of abdominal aortic aneurysm, increases with the enlargement of aorta. MicroRNA-29b (miR-29b) has emerged as a key modulator of extracellular matrix (ECM) homeostasis and thereby is proposed to play a crucial role in vascular remodeling. However, agents that alter miR-29b expression are relatively inefficient in the aorta, likely due to inferior uptake. Herein we found that miR-29b was upregulated in aortic smooth muscle cells upon prostaglandin E2 (PGE2) stimulation whereas indomethacin treatment downregulated miR-29b expression. In order to obtain insight into the pathological processes associated with the vascular remodeling that accompanies aortic dilatation, we compared expression profiles of several representative ECM components in aortic walls. Notably, PGE2 induced a dramatic decline in these ECM components, which was rescued by introduction of indomethacin. In addition, COL1A1 was validated as a direct target gene of miR-29b by dual-luciferase reporter assay. In aggregate, our study suggests that PGE2 may accelerate ECM degradation through decreasing miR-29b expression. Thus those anti-inflammatory drugs that inhibit PGE2 synthesis represent an effective means of inducing an augmented profibrotic response in the aortic walls and thereby inhibiting aneurysmal expansion.

Platelet endothelial cell adhesion molecule-1 gene 125C/G polymorphism is associated with deep vein thrombosis.

Deep vein thrombosis (DVT) is a common disorder that is associated with high morbidity and mortality. Genetic factors have been suggested to influence the predisposition towards thrombosis and the incidence of DVT. Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a key adhesion molecule that is involved in platelet function and maintenance of endothelial cell junctions. To date, no studies have examined the association between polymorphisms in PECAM-1 and DVT. The present study analyzed the single nucleotide polymorphisms (SNPs) of PECAM-1, namely Leu125Val (C373G), Asn563Ser (T1688C) and Gly670Arg (C2008T), in Chinese patients with DVT and age-and gender-matched controls, using polymerase chain reaction-restriction fragment length polymorphism analysis. Furthermore, plasma soluble PECAM-1 (sPECAM-1) levels were quantified by ELISA. The results of the present study demonstrated significantly higher genotype and allele frequencies of the Leu125Val polymorphism in PECAM-1 in the DVT group as compared with those in the control group (P<0.05). The plasma levels of sPECAM-1 in the DVT group (83.4 ± 23.5 ng/ml) were also significantly higher as compared with those in the control group (60.4 ± 19.4 ng/ml, P<0.01). In the patients with DVT, plasma levels of sPECAM-1 were significantly higher in those with the Leu/Val and Val/Val genotypes as compared with those possessing the Leu/Leu genotype (P<0.05). The PECAM-1 Leu125Val polymorphism was shown to be associated with an increased risk of DVT and PECAM-1 protein expression levels in venous vessels. In patients with DVT, the PECAM-1 Leu/Val and Val/Val genotypes were associated with delayed thrombus resolution, as determined by thrombus scoring, as compared with that in patients possessing the Leu/Val genotype. In conclusion, the present study indicated that PECAM-1 Leu125Val polymorphism and sPECAM-1 levels may be associated with DVT.

Leiomyoma of the femoral vein: a case report and review of the literature.

Leiomyomas are benign smooth muscle tumors. A leiomyoma originating from the vein is rare. We describe a primary femoral vein tumor that was diagnosed as an unusual leiomyoma in a 50-year-old woman. It was the first reported leiomyoma in the femoral vein in English studies. We have reviewed the studies on leiomyoma from the blood vessel and summarized their characteristics, therapies, and prognosis.

Catheter-directed thrombolysis with a continuous infusion of low-dose urokinase for non-acute deep venous thrombosis of the lower extremity.

OBJECTIVE: We wanted to evaluate the feasibility of catheter-directed thrombolysis with a continuous infusion of low-dose urokinase for treating non-acute (less than 14 days) deep venous thrombosis of the lower extremity. MATERIALS AND METHODS: The clinical data of 110 patients who were treated by catheter-directed thrombolysis with a continuous infusion of low-dose urokinase for lower extremity deep venous thrombosis was analysed. Adjunctive angioplasty or/and stenting was performed for the residual stenosis. Venous recanalization was graded by pre- and post-treatment venography. Follow-up was performed by clinical evaluation and Doppler ultrasound. RESULTS: A total of 112 limbs with deep venous thrombosis with a mean symptom duration of 22.7 days (range: 15-38 days) were treated with a urokinase infusion (mean: 3.5 million IU) for a mean of 196 hours. After thrombolysis, stent placement was performed in 25 iliac vein lesions and percutaneous angioplasty (PTA) alone was done in five iliac veins. Clinically significant recanalization was achieved in 81% (90 of 112) of the treated limbs; complete recanalization was achieved in 28% (31 of 112) and partial recanalization was achieved in 53% (59 of 112). Minor bleeding occurred in 14 (13%) patients, but none of the patients suffered from major bleeding or symptomatic pulmonary embolism. During follow-up (mean: 15.2 months, range: 3-24 months), the veins were patent in 74 (67%) limbs. Thirty seven limbs (32%) showed progression of the stenosis with luminal narrowing more than 50%, including three with rethrombosis, while one revealed an asymptomatic iliac vein occlusion; 25 limbs (22%) developed mild post-thrombotic syndrome, and none had severe post-thrombotic syndrome. Valvular reflux occurred in 24 (21%) limbs. CONCLUSION: Catheter-directed thrombolysis with a continuous infusion of low-dose urokinase combined with adjunctive iliac vein stenting is safe and effective for removal of the clot burden and for restoration of the venous flow in patients with non-acute lower extremity deep venous thrombosis.