The alteration of H4-K16ac and H3-K27met influences the differentiation of neural stem cells.

The neural stem cell therapy provides a promising future for patients with central nerve system damage, thus an insight into its differentiation mechanism is urgently needed. Herein, we aimed to identify various histone modifications and reveal their impact on the differentiation of neural stem cells (NSCs) toward neurons. Firstly, we labeled primary NSCs using the stable isotope labeling with amino acids in cell culture (SILAC) technique. Then we induced these NSCs to differentiate by all-trans retinoic acid (atRA) or SB216763. Next, we identified the alteration of histone modifications in early-differentiated NSCs by mass spectrometry and verified them by Western blot. Interestingly, these modification alterations and phenotype changes were found similar in NSCs induced by the two different drugs. More interestingly, during the differentiation process H3-K27met was significantly up-regulated while H4-K16ac was not altered at the global level but down-regulated in some low-abundance combinatorial codes. We inhibited the methyltransferase of H3-K27 and deacetylase of H4-K16 simultaneously and found the differentiation procedure was obviously delayed. The function of H4-K16ac and H3-K27met in NSCs differentiation would be useful to reveal the differentiation mechanism and valuable for further neural stem cell therapy.

Activated cyclin-dependent kinase 5 promotes microglial phagocytosis of fibrillar ß-amyloid by up-regulating lipoprotein lipase expression.

Amyloid plaques are crucial for the pathogenesis of Alzheimer disease (AD). Phagocytosis of fibrillar ß-amyloid (Aß) by activated microglia is essential for Aß clearance in Alzheimer disease. However, the mechanism underlying Aß clearance in the microglia remains unclear. In this study, we performed stable isotope labeling of amino acids in cultured cells for quantitative proteomics analysis to determine the changes in protein expression in BV2 microglia treated with or without Aß. Among 2742 proteins identified, six were significantly up-regulated and seven were down-regulated by Aß treatment. Bioinformatic analysis revealed strong over-representation of membrane proteins, including lipoprotein lipase (LPL), among proteins regulated by the Aß stimulus. We verified that LPL expression increased at both mRNA and protein levels in response to Aß treatment in BV2 microglia and primary microglial cells. Silencing of LPL reduced microglial phagocytosis of Aß, but did not affect degradation of internalized Aß. Importantly, we found that enhanced cyclin-dependent kinase 5 (CDK5) activity by increasing p35-to-p25 conversion contributed to LPL up-regulation and promoted Aß phagocytosis in microglia, whereas inhibition of CDK5 reduced LPL expression and Aß internalization. Furthermore, Aß plaques was increased with reducing p25 and LPL level in APP/PS1 mouse brains, suggesting that CDK5/p25 signaling plays a crucial role in microglial phagocytosis of Aß. In summary, our findings reveal a potential role of the CDK5/p25-LPL signaling pathway in Aß phagocytosis by microglia and provide a new insight into the molecular pathogenesis of Alzheimer disease.

A fixed nitrous oxide/oxygen mixture as an analgesic for trauma patients in emergency department: study protocol for a randomized, controlled trial.

BACKGROUND: Acute pain is always the most common complaint in Emergency Department admissions and options for analgesia are limited. Nitrous oxide/oxygen possess many properties showing it may be an ideal analgesic method for the Emergency Department; it is quick-acting, well-tolerated, and does not mask signs and symptoms. The aim of this study is to evaluate the safety and analgesic effect of the fixed nitrous oxide/oxygen mixture for trauma patients in a busy emergency environment. METHODS: The randomized, double-blind, prospective, placebo-controlled study will be carried out in the Emergency Department of General Hospital of Ningxia Medical University. The target research objects are trauma patients who present to the Emergency Department and report moderate to severe intensities of acute pain. A total of 90 patients will be recruited and randomly assigned into the treatment and control group. The treatment group will receive conventional pain treatment plus nitrous oxide/oxygen mixture and the control group will receive conventional pain treatment plus oxygen. Neither patients, nor investigators, nor data collectors will know the nature of the gas mixture in each cylinder and the randomization list. Outcomes will be monitored at baseline(T0), 5 min (T1), and 15 min (T2) after the beginning of intervention and at 5 min post intervention (T3) for each group. The primary outcome is the level of pain relief after the initial administering of the intervention at T1, T2, and T3. Secondary outcomes include adverse events, physiological parameters, total time of the gas administration, satisfaction from both patients and healthcare professionals, and the acceptance of patients. DISCUSSION: Our previous studies suggested that a fixed nitrous oxide/oxygen mixture was an efficacious analgesic for the management of burning dressing pain and breakthrough cancer pain. The results of this study will provide a more in-depth understanding of the effect of this gas. If this treatment proves successful, it could help to generate preliminary guidelines and be implemented widely in trauma patients with pain in Emergency Departments. TRIAL REGISTRATION: Chinese Clinical Trial Register, ChiCTR-INR-16007807 . Registered on 21 January 2016.

A new 6,9'-cyclolignan from Syringa pinnatifolia.

A new lignan, 4,4'-dihydroxy-3,3'-dimethoxy-6,9'-cycloligna-7,8'-dien-9'-al, was isolated from the stem of Syringa pinnatifolia Hems1. var. alashanensis MA. et S.Q. Zhou (S. pinnatifolia). This is the first report on the structure elucidation of a new compound based on spectroscopic methods including UV, IR, ESI-MS, 1D NMR and 2D NMR techniques.

Structure elucidation and NMR assignments of a new 6,9-cyclotetrahydrofuranlignan from Syringa pinnatifolia.

A new 6,9-cyclotetrahydrofuranlignan, 3,3'-dimethoxy-4,4'-dihydroxy-8ß,9ß,8'α-6,9-cyclotetrahydrofuranlignan, was isolated from the stem of Syringa pinnatifolia Hems1.var. alashanensis MA. et S. Q. ZHOU. Its structures were elucidated on the basis of spectroscopic methods including UV, IR, ESI-MS, 1D NMR and 2D NMR.

PGC-1α/ERRα-Sirt3 Pathway Regulates DAergic Neuronal Death by Directly Deacetylating SOD2 and ATP Synthase ß.

AIMS: Parkinson's disease (PD) heavily affects humans and little is known about its cause and pathogenesis. Sirtuin 3 (Sirt3) plays a key role in regulating mitochondrial dysfunction, which is the main cause of DAergic neuronal loss in PD. We investigated the mechanisms of neuroprotective role of Sirt3 in DAergic neuronal survival. RESULTS: Sirt3 was reduced in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP)-treated neurons with its overexpression being neuroprotective. We identified that Sirt3 interacted with manganese superoxide dismutase (SOD2) and adenosine triphosphate (ATP) synthase ß and modulated their activities by deacetylating SOD2 (K130) and ATP synthase ß (K485) to prevent reactive oxygen species accumulation and ATP depletion, and to alleviate DAergic neuronal death upon MPTP treatment. Peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) interacted with estrogen-related receptor alpha (ERRα) that bound to the Sirt3 promoter as its transcription factor to regulate Sirt3 expression and DAergic neuronal death. In the mouse midbrain, MPTP administration led to the loss of PGC-1α and Sirt3, high acetylation level of SOD2 and ATP synthase ß, and the specific loss of DAergic neurons, while Sirt3 overexpression could protect against DAergic neuronal loss. Sirt3 knockout mice exhibited more sensitive and more DAergic neuronal loss to MPTP treatment. INNOVATION: The study provides new insights into a critical PGC-1α/ERRα-Sirt3 pathway, linking regulation of mitochondrial protein acetylation and DAergic neuronal death in PD pathogenesis, which provide a potential therapeutic strategy and target in PD treatment. CONCLUSION: These results provide a vital PGC-1α/ERRα-Sirt3 pathway that protects against DAergic neuronal death by directly deacetylating SOD2 (K130) and ATP synthase ß (K485) in PD.

Deacetylation of TFEB promotes fibrillar Aß degradation by upregulating lysosomal biogenesis in microglia.

Microglia play a pivotal role in clearance of Aß by degrading them in lysosomes, countering amyloid plaque pathogenesis in Alzheimer's disease (AD). Recent evidence suggests that lysosomal dysfunction leads to insufficient elimination of toxic protein aggregates. We tested whether enhancing lysosomal function with transcription factor EB (TFEB), an essential regulator modulating lysosomal pathways, would promote Aß clearance in microglia. Here we show that microglial expression of TFEB facilitates fibrillar Aß (fAß) degradation and reduces deposited amyloid plaques, which are further enhanced by deacetylation of TFEB. Using mass spectrometry analysis, we firstly confirmed acetylation as a previously unreported modification of TFEB and found that SIRT1 directly interacted with and deacetylated TFEB at lysine residue 116. Subsequently, SIRT1 overexpression enhanced lysosomal function and fAß degradation by upregulating transcriptional levels of TFEB downstream targets, which could be inhibited when TFEB was knocked down. Furthermore, overexpression of deacetylated TFEB at K116R mutant in microglia accelerated intracellular fAß degradation by stimulating lysosomal biogenesis and greatly reduced the deposited amyloid plaques in the brain slices of APP/PS1 transgenic mice. Our findings reveal that deacetylation of TFEB could regulate lysosomal biogenesis and fAß degradation, making microglial activation of TFEB a possible strategy for attenuating amyloid plaque deposition in AD.

The isolation and antimicrobial activities of three monocylic sesquiterpenes from Syringa pinnatifolia.

We report the isolation of a new sesquiterpene, named as syripinol (1), and two known compounds from the volatile oil of the stems of Syringa pinnatifolia, for the first time. The structures of the isolated compounds were elucidated on the basis of spectroscopic methods including UV, IR, ESI-MS, 1D and 2D NMR techniques. The antibacterial activities of the compounds were also evaluated against various bacteria which showed good results.