Mitochondrion-processed TERC regulates senescence without affecting telomerase activities

Mitochondrial dysfunctions play major roles in ageing. How mitochondrial stresses invoke downstream responses and how specificity of the signaling is achieved, however, remains unclear. We have previously discovered that the RNA component of Telomerase TERC is imported into mitochondria, processed to a shorter form TERC-53, and then exported back to the cytosol. Cytosolic TERC-53 levels respond to mitochondrial functions, but have no direct effect on these functions, suggesting that cytosolic TERC-53 functions downstream of mitochondria as a signal of mitochondrial functions. Here, we show that cytosolic TERC-53 plays a regulatory role on cellular senescence and is involved in cognition decline in 10 months old mice, independent of its telomerase function. Manipulation of cytosolic TERC-53 levels affects cellular senescence and cognition decline in 10 months old mouse hippocampi without affecting telomerase activity, and most importantly, affects cellular senescence in terc cells. These findings uncover a senescence-related regulatory pathway with a non-coding RNA as the signal in mammals.

Mammalian mitochondrial RNAs are degraded in the mitochondrial intermembrane space by RNASET2

Mammalian mitochondrial genome encodes a small set of tRNAs, rRNAs, and mRNAs. The RNA synthesis process has been well characterized. How the RNAs are degraded, however, is poorly understood. It was long assumed that the degradation happens in the matrix where transcription and translation machineries reside. Here we show that contrary to the assumption, mammalian mitochondrial RNA degradation occurs in the mitochondrial intermembrane space (IMS) and the IMS-localized RNASET2 is the enzyme that degrades the RNAs. This provides a new paradigm for understanding mitochondrial RNA metabolism and transport.

Measurement of fibular rotation angle：Intraoperative judgment of the success rate of inferior tibiofibular syndesmosis reduction / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.26.016

Preventive effects of rivaroxaban on the deep vein thrombosis after orthopedic surgery / 国际外科学杂志

The morbidity of deep vein thrombosis (DVT) after total hip replacement,total knee replacement or hip fractures surgery is high,and there is no effect way to prevent.Rivaroxaban is an oral,direct factor Xa inhibitor.The prevention effect of rivaroxaban to DVT after orthopedic surgery is stronger than enoxaparin.The view summarizes the mechanism,pharmacokinetics,interaction of drugs and the antithrombotic effect after orthopedic surgery.