The pulping industry could become a biorefinery if the lignin and hemicellulose components of the lignocellulose are valorized. Conversion of lignin into well-defined aromatic chemicals is still a major challenge. Lignin depolymerization reactions often occur in parallel with irreversible condensation reactions of the formed fragments. Here, we describe a strategy that markedly suppresses the undesired condensation pathways and allows to selectively transform lignin into a few aromatic compounds. Notably, applying this strategy to woody biomass at organosolv pulping conditions, the hemicellulose, cellulose, and lignin were separated and in parallel the lignin was transformed into aromatic monomers. In addition, we were able to utilize a part of the lignocellulose as an internal source of hydrogen for the reductive lignin transformations. We hope that the presented methodology will inspire researchers in the field of lignin valorization as well as pulp producers to develop more efficient biomass fractionation processes in the future.
IntroductionCritically ill ICU patients commonly develop severe muscle wasting and impaired muscle function, leading to delayed recovery, with subsequent increased morbidity and financial costs, and decreased quality of life for survivors. Critical illness myopathy (CIM) is a frequently observed neuromuscular disorder in ICU patients. Sepsis, systemic corticosteroid hormone treatment and post-synaptic neuromuscular blockade have been forwarded as the dominating triggering factors. Recent experimental results from our group using a unique experimental rat ICU model show that the mechanical silencing associated with CIM is the primary triggering factor. This study aims to unravel the mechanisms underlying CIM, and to evaluate the effects of a specific intervention aiming at reducing mechanical silencing in sedated and mechanically ventilated ICU patients.MethodsMuscle gene/protein expression, post-translational modifications (PTMs), muscle membrane excitability, muscle mass measurements, and contractile properties at the single muscle fiber level were explored in seven deeply sedated and mechanically ventilated ICU patients (not exposed to systemic corticosteroid hormone treatment, post-synaptic neuromuscular blockade or sepsis) subjected to unilateral passive mechanical loading for 10 hours per day (2.5 hours, four times) for 9 ± 1 days.ResultsThese patients developed a phenotype considered pathognomonic of CIM; that is, severe muscle wasting and a preferential myosin loss (P < 0.001). In addition, myosin PTMs specific to the ICU condition were observed in parallel with an increased sarcolemmal expression and cytoplasmic translocation of neuronal nitric oxide synthase. Passive mechanical loading for 9 ± 1 days resulted in a 35% higher specific force (P < 0.001) compared with the unloaded leg, although it was not sufficient to prevent the loss of muscle mass.ConclusionMechanical silencing is suggested to be a primary mechanism underlying CIM; that is, triggering the myosin loss, muscle wasting and myosin PTMs. The higher neuronal nitric oxide synthase expression found in the ICU patients and its cytoplasmic translocation are forwarded as a probable mechanism underlying these modifications. The positive effect of passive loading on muscle fiber function strongly supports the importance of early physical therapy and mobilization in deeply sedated and mechanically ventilated ICU patients.
IntroductionTumor progression in patients and mice is associated with increasing levels of a population of suppressor cells known as myeloidderived suppressor cells (MDSCs). MDSCs suppress antitumor immunity by blocking the activation of CD4 ϩ and CD8 ϩ T cells, 1-3 skewing cytokine production toward a type 2 phenotype, 4 inhibiting natural killer-cell cytotoxicity, 5,6 promoting the accumulation of immune suppressive regulatory T cells, 7,8 and perturbing lymphocyte trafficking. 9 As a result, MDSCs are a significant obstacle to cancer immunotherapies that require activation of the host's immune system.A hallmark of tumor-driven MDSCs is their elevated presence in the BM, spleen, blood, lymph nodes, and primary and metastatic tumor sites. 1,10 Their accumulation is attributed to multiple proinflammatory factors, including IL-1, 11,12 IL-6, 13 prostaglandin E 2 (PGE 2 ), 14,15 S100A8/A9 proteins, 10, 17 and VEGF,18,19 driving their differentiation from hemopoietic progenitor cells. These inflammatory mediators are produced by tumor cells 13,[20][21][22] or host cells 23,24 or both. In persons with cancer, tumor cells are the predominant inducers because removal of tumor causes a rapid decrease in MDSCs. 25,26 In contrast to induction of MDSCs, the factors that regulate MDSC maintenance and turnover are not well understood.Accumulation For personal use only. on May 11, 2018. by guest www.bloodjournal.org From Mass spectrometryMDSCs were obtained from the peripheral blood of tumor-bearing mice 14 (Ͼ 90% Gr1 ϩ CD11b ϩ cells; 5 ϫ 10 6 -10 7 cells/mouse) and lysed at a final concentration of 0.1% Rapigest acid-cleavable detergent (Waters) in 100mM NH 4 HCO 3 , pH 8.4. Cell lysates were digested with sequencing grade-modified trypsin (1:50 trypsin-to-protein ratio; Promega) for 1 hour at 37°C, after which trifluoroacetic acid was added to a final pH of ϳ 3. Lysates were incubated for 1 hour at 37°C, freeze-thawed at Ϫ80°C, and microfuged at 13 200 rpm for 5 minutes (Eppendorf 5415 D), and the trifluoroacetic acid-precipitated material was discarded. 27 Supernatant fluid containing tryptic peptides was collected and brought to pH 7, and peptide concentration was measured by OD 280. Peptides (30 g) were desalted (C18 spin cartridges; Pierce) and analyzed with a LTQ-FT Ultra mass spectrometer (ThermoFischer) interfaced with an Agilent 1100 nanoLC system. Tandem mass spectra were searched against the National Center for Biotechnology Information (NCBI) mouse protein database 28 with the use of MASCOT data analysis software (v2.1; Matrix Science) with the following conditions: peptide mass tolerance at 10 ppm; fragment mass tolerance at 1.5 Da; a maximum of 2 allowed missed cleavages; and methionine oxidation and disulfide as the variable modifications. Proteins identified by Ն 2 peptides with a MASCOT MOWSE (molecular weight search) score Ͼ 30 were considered reliable identifications. 29 Antibodies, flow cytometry, confocal microscopyFluorescently coupled mAbs to Gr1, CD11b, Fas, FasL, CD69, CD3, CD4, DO11.10 TCR (clon...
Spinocerebellar ataxias (SCAs) are dominantly inherited neurodegenerative disorders characterized by progressive cerebellar ataxia and dysarthria. We have identified missense mutations in prodynorphin (PDYN) that cause SCA23 in four Dutch families displaying progressive gait and limb ataxia. PDYN is the precursor protein for the opioid neuropeptides, α-neoendorphin, and dynorphins A and B (Dyn A and B). Dynorphins regulate pain processing and modulate the rewarding effects of addictive substances. Three mutations were located in Dyn A, a peptide with both opioid activities and nonopioid neurodegenerative actions. Two of these mutations resulted in excessive generation of Dyn A in a cellular model system. In addition, two of the mutant Dyn A peptides induced toxicity above that of wild-type Dyn A in cultured striatal neurons. The fourth mutation was located in the nonopioid PDYN domain and was associated with altered expression of components of the opioid and glutamate system, as evident from analysis of SCA23 autopsy tissue. Thus, alterations in Dyn A activities and/or impairment of secretory pathways by mutant PDYN may lead to glutamate neurotoxicity, which underlies Purkinje cell degeneration and ataxia. PDYN mutations are identified in a small subset of ataxia families, indicating that SCA23 is an infrequent SCA type (∼0.5%) in the Netherlands and suggesting further genetic SCA heterogeneity.
Ventilation-induced diaphragm dysfunction (VIDD) is a marked decline in diaphragm function in response to mechanical ventilation, which has negative consequences for individual patients' quality of life and for the health care system, but specific treatment strategies are still lacking. We used an experimental intensive care unit (ICU) model, allowing time-resolved studies of diaphragm structure and function in response to long-term mechanical ventilation and the effects of a pharmacological intervention (the chaperone co-inducer BGP-15). The marked loss of diaphragm muscle fiber function in response to mechanical ventilation was caused by posttranslational modifications (PTMs) of myosin. In a rat model, 10 days of BGP-15 treatment greatly improved diaphragm muscle fiber function (by about 100%), although it did not reverse diaphragm atrophy. The treatment also provided protection from myosin PTMs associated with HSP72 induction and PARP-1 inhibition, resulting in improvement of mitochondrial function and content. Thus, BGP-15 may offer an intervention strategy for reducing VIDD in mechanically ventilated ICU patients.
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