AFF4 globally affects the release of paused RNA polymerase II in HEL cells.

P-TEFb, a heterodimer of the kinase CDK9 and Cyclin T1, is a critical regulator of promoter-proximal pause release of Pol II in metazoans. It is capable of forming three larger complexes, including the super elongation complex (SEC), the BRD4/P-TEFb complex and the 7SK snRNP. In the SEC or the BRD4/P-TEFb complex, P-TEFb is enzymatically active, while in the 7SK snRNP, its activity is inhibited. The SEC consists of AFF1 or 4, ENL or AF9, ELL1, 2 or 3 and EAF1 or 2 in addition to P-TEFb, the only subunit with catalytic activity, and the noncatalytic subunits have been found to be able to regulate pause release through P-TEFb. We and others recently found that AFF1, ENL and AF9 are capable of regulating transcriptional initiation, but it is unknown yet whether AFF4 is also capable of doing so. With respect to the gene regulation selectivity of the SEC and the BRD4/P-TEFb complex, one recent study showed that in human DLD-1 cells, the SEC only regulates pause release of heat shock (HS) genes, whereas the BRD4/P-TEFb complex regulates pause release of the rest of the genes. However, it is unclear whether those mechanisms are general. In this study for the purpose of further understanding the role of AFF4 in transcriptional regulation, we found that AFF4 knockdown by RNA interference in human HEL cells decreased not only cellular level but also global chromatin occupancy of CTD serine 2 phosphorylated Pol II. Direct target genes of AFF4 were identified by RNA-seq and CUT&Tag. Notably, we found by ChIP-seq and PRO-seq that AFF4 loss also increased promoter-proximal pause of Pol II on several hundred HS and thousands of non-HS genes. Mechanistically, AFF4 promotes pause release likely by facilitating the binding of P-TEFb to Pol II. These results suggest that extent of the impact of AFF4 on pause release is likely to be context-dependent or cell-type dependent.

Renormalization of Thalamic Sub-Regional Functional Connectivity Contributes to Improvement of Cognitive Function after Liver Transplantation in Cirrhotic Patients with Overt Hepatic Encephalopathy

Objective@#The role of preoperative overt hepatic encephalopathy (OHE) in the neurophysiological mechanism of cognitive improvement after liver transplantation (LT) remains elusive. This study aimed to explore changes in sub-regional thalamic functional connectivity (FC) after LT and their relationship with neuropsychological improvement using resting-state functional MRI (rs-fMRI) data in cirrhotic patients with and without a history of OHE. @*Materials and Methods@#A total of 51 cirrhotic patients, divided into the OHE group (n = 21) and no-OHE group (n = 30), and 30 healthy controls were enrolled in this prospective study. Each patient underwent rs-fMRI before and 1 month after LT. Using 16 bilateral thalamic subregions as seeds, we conducted a seed-to-voxel FC analysis to compare the thalamic FC alterations before and after LT between the OHE and no-OHE groups, as well as differences in FC between the two groups of cirrhotic patients and the control group. Correction for multiple comparisons was conducted using the false discovery rate (p < 0.05). @*Results@#We found abnormally increased FC between the thalamic sub-region and prefrontal cortex, as well as an abnormally decreased FC between the bilateral thalamus in both OHE and no-OHE cirrhotic patients before LT, which returned to normal levels after LT. Compared with the no-OHE group, the OHE group exhibited more extensive abnormalities prior to LT, and the increased FC between the right thalamic subregions and right inferior parietal lobe was markedly reduced to normal levels after LT. @*Conclusion@#The renormalization of FC in the cortico-thalamic loop might be a neuro-substrate for the recovery of cognitive function after LT in cirrhotic patients. In addition, hyperconnectivity between thalamic subregions and the inferior parietal lobe might be an important feature of OHE. Changes in FC in the thalamus might be used as potential biomarkers for recovery of cognitive function after LT in cirrhotic patients.

Study on anti-atherosclerotic mechanisms of divided functional recipes of dahuang zhechong pill in rabbits / 中国中药杂志

<p><b>OBJECTIVE</b>To study anti-atherosclerotic mechanisms of divided functional recipes of Dahuang Zhechong pill (DHZCP) in rabbits.</p><p><b>METHOD</b>The atherosclerotic rabbit model was established by high fat feeding combined with immune endothelial injury. Male New Zealand rabbits were divided into 9 groups: normal control group, model control group, Danshen positive control group, and 6 DHZCP-divided groups including divided functional recipes No. 1, 2, 3 with low and high doses for each divided recipe. After intragastric administration for 60 days, blood lipids and serum MDA and NO levels and SOD activity and plasma ET concentration, and contents of hydroxyproline and proteins in the vascular wall were determined.</p><p><b>RESULT</b>Compared with the model group, the level of blood lipids did not significantly change, serum MDA and ET levels, and the contents of hydroxyproline and proteins in the vascular wall significantly decreased (P < 0.05), and SOD activity and NO level increased in the divided functional recipes (all P < 0.05).</p><p><b>CONCLUSION</b>The divided functional recipes of DHZCP can inhibit development of atherosclerosis via a non-lowering lipid mechanisms, including anti-peroxidation of lipids, protection of endothelial function, and decrease of formation of extracellular matrix by reducing synthesis of collage and protein on the vascular wall. Among them, the divided functional recipe No. 1 exhibits the most obvious effect.</p>

Effect of the disassembled recipes of dahuang zhechong pill on proliferation and apoptosis of vascular smooth muscle cells in atherosclerotic rabbits / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effects of the disassembled recipes of Dahuang Zhechong Pill (DRDZP) on proliferation and apoptosis of vascular smooth muscle cell (VSMC) of thoracic aorta in atherosclerotic rabbits.</p><p><b>METHODS</b>The atherosclerotic rabbit model was induced by high-cholesterol diet and immune injury of endothelium. Expression of proliferating cell nuclear antigen (PCNA) in VSMC was detected by SP immunohistochemical technique, and VSMC apoptosis was observed with TUNEL technique.</p><p><b>RESULTS</b>Compared with the model control, PCNA expression in VSMC decreased, while apoptotic cells increased significantly in all the groups treated by DR-DZP (P < 0.01).</p><p><b>CONCLUSION</b>All the DR-DZP could inhibit VSMC proliferation and promote its apoptosis to modulate the balance between cell proliferation and apoptosis, so as to exert antiatherosclerotic action, among which the disassembled-recipe I is the main composition to contribute to antiatherosclerotic action of Dahuang Zhechong Pill.</p>