Stress-induced TDP-43 nuclear condensation causes splicing loss of function and STMN2 depletion.

TDP-43 protein is dysregulated in several neurodegenerative diseases, which often have a multifactorial nature and may have extrinsic stressors as a "second hit." TDP-43 undergoes reversible nuclear condensation in stressed cells including neurons. Here, we demonstrate that stress-inducible nuclear TDP-43 condensates are RNA-depleted, non-liquid assemblies distinct from the known nuclear bodies. Their formation requires TDP-43 oligomerization and ATP and is inhibited by RNA. Using a confocal nanoscanning assay, we find that amyotrophic lateral sclerosis (ALS)-linked mutations alter stress-induced TDP-43 condensation by changing its affinity to liquid-like ribonucleoprotein assemblies. Stress-induced nuclear condensation transiently inactivates TDP-43, leading to loss of interaction with its protein binding partners and loss of function in splicing. Splicing changes are especially prominent and persisting for STMN2 RNA, and STMN2 protein becomes rapidly depleted early during stress. Our results point to early pathological changes to TDP-43 in the nucleus and support therapeutic modulation of stress response in ALS.

Plumbagin induces the apoptosis of drug-resistant oral cancer in vitro and in vivo through ROS-mediated endoplasmic reticulum stress and mitochondrial dysfunction.

BACKGROUND: Oral cancer is one of the leading causes of cancer-related deaths worldwide. Chemotherapy is widely used in the treatment of oral cancer, but its clinical efficacy is limited by drug resistance. Hence, novel compounds capable of overcoming drug-resistance are urgently needed. PURPOSE: Plumbagin (PG), a natural compound isolated from Plumbago zeylanica L, has been used to treat various cancers. In this study, we investigated the anticancer effects of PG on drug-resistant oral cancer (CR-SAS) cells, as well as the underlying mechanism. METHODS: MTT assays were used to evaluate the effect of PG on the viability of CR-SAS cells. Apoptosis and reactive oxygen species (ROS) production by the cells were determined using flow cytometry. Protein expression levels were detected by western blotting. RESULTS: The results show that PG reduces the viability and causes the apoptosis of CR-SAS cells. PG is able to induce intracellular and mitochondrial ROS generation that leads to mitochondrial dysfunction. Furthermore, endoplasmic reticulum (ER) stress was triggered in PG-treated CR-SAS cells. The inhibition of ROS using N-acetylcysteine (NAC) abrogated the PG-induced ER stress and apoptosis, as well as the reduction in cell viability. Meanwhile, similar results were observed both in zebrafish and in murine models of drug-resistant oral cancer. CONCLUSION: Our results indicate that PG induces the apoptosis of CR-SAS cells via the ROS-mediated ER stress pathway and mitochondrial dysfunction. It will be interesting to develop the natural compound PG for the treatment of drug-resistant oral cancer.

Preparation of amidated pectins through enzymatic method: Structures, hydrogel properties and its application potential in fat substitutes.

In this paper, α-alanine and ß-alanine were used as modifiers to prepare α-alanine amidated pectin (α-AP) and ß-alanine amidated pectin (ß-AP) through enzymatic method. The effects of alanine and its isomer on the amidation degree and physicochemical properties of pectin were studied. Fourier transform infrared spectrum, proton nuclear magnetic resonance analysis, X-ray photoelectron spectrum and elemental analysis indicated that the amino groups from α-C and ß-C could be aminated with the carboxyl group of pectin to form the corresponding aminated pectin. The alanine grafting ratio of α-AP and ß-AP were 21.99% and 18.92%, respectively. The results showed that the dynamic viscosity of ß-AP was significantly higher than that of α-AP due to the influence of amino acid side chain. However, due to the higher alanine grafting ratio of α-AP, the strength of hydrogel prepared by α-AP was higher than that of ß-AP, and it also has the highest elastic modulus and swelling capacity. In addition, pectin, as a carbohydrate-based fat substitute, has been widely used in the field of food to simulate the smooth and delicate taste of fat. Compared with High methoxy pectin (HMP) and ß-AP, α-AP had better colloid stability and smaller hydrogel particles in the composite system. The results provide references for the application of amidated pectin in low-fat food.

Fabrication of phenylalanine amidated pectin using ultra-low temperature enzymatic method and its hydrogel properties in drug sustained release application.

In this study, pectin was modified with phenylalanine by ultra-low temperature enzymatic method to improve its gel properties. The grafting ratio of phenylalanine amidated pectin was studied under different reaction conditions. The highest value (29.21 %) was reached a reaction temperature of -5 °C and time of 12 h. Further analysis indicated that phenylalanine and high methoxyl pectin combined at the solid-liquid two phase interface under the catalysis of papain to form phenylalanine amidated pectin. Moreover, the physicochemical properties of pectin hydrogel and its feasibility as a sustained-release drug carrier were discussed. The results showed that phenylalanine amidated pectin can form hydrogel with a certain strength under acidic conditions, and there is no need to add a lot of soluble solids and divalent cations. Besides, the phenylalanine amidated pectin hydrogel as a sustained release carrier of drugs showed more sustained and complete drug release.

RNA Helicases in Microsatellite Repeat Expansion Disorders and Neurodegeneration.

Short repeated sequences of 3-6 nucleotides are causing a growing number of over 50 microsatellite expansion disorders, which mainly present with neurodegenerative features. Although considered rare diseases in relation to the relatively low number of cases, these primarily adult-onset conditions, often debilitating and fatal in absence of a cure, collectively pose a large burden on healthcare systems in an ageing world population. The pathological mechanisms driving disease onset are complex implicating several non-exclusive mechanisms of neuronal injury linked to RNA and protein toxic gain- and loss- of functions. Adding to the complexity of pathogenesis, microsatellite repeat expansions are polymorphic and found in coding as well as in non-coding regions of genes. They form secondary and tertiary structures involving G-quadruplexes and atypical helices in repeated GC-rich sequences. Unwinding of these structures by RNA helicases plays multiple roles in the expression of genes including repeat-associated non-AUG (RAN) translation of polymeric-repeat proteins with aggregating and cytotoxic properties. Here, we will briefly review the pathogenic mechanisms mediated by microsatellite repeat expansions prior to focus on the RNA helicases eIF4A, DDX3X and DHX36 which act as modifiers of RAN translation in C9ORF72-linked amyotrophic lateral sclerosis/frontotemporal dementia (C9ORF72-ALS/FTD) and Fragile X-associated tremor/ataxia syndrome (FXTAS). We will further review the RNA helicases DDX5/17, DHX9, Dicer and UPF1 which play additional roles in the dysregulation of RNA metabolism in repeat expansion disorders. In addition, we will contrast these with the roles of other RNA helicases such as DDX19/20, senataxin and others which have been associated with neurodegeneration independently of microsatellite repeat expansions. Finally, we will discuss the challenges and potential opportunities that are associated with the targeting of RNA helicases for the development of future therapeutic approaches.

Acupuncture therapy for radiotherapy-induced adverse effect: A systematic review and network meta-analysis.

Objective: To evaluate the efficacy of different acupuncture therapies for radiotherapy-induced adverse effects (RIAEs) and find out the optimal scheme. Methods: Eligible randomized controlled trials (RCTs) were collected from inception to June 2020 from 9 bibliographic databases. The risk of bias evaluation of the analyzed literature was carried out using the Cochrane risk-of-bias tool. Network meta-analysis was mainly performed using STATA 14.2 and OpenBUGS 3.2.3 by figuring out the network diagrams, league figures, and SUCRA values. Results: A total of 41 studies with 3,011 participants reported data suitable for network meta-analysis. There was a low to moderate risk of bias in twenty of the articles. ST36 was the most widely prescribed acupoint. Based on network meta-analysis, four outcome indicators were described, namely, acupuncture + medication ranked first in treating radiation enteritis, moxibustion + medication ranked first in preventing radiotherapy-induced leukopenia, acupuncture + medication ranked first in preventing radioactive oral mucositis, and acupuncture ranked first in improving the stimulated salivary flow rate of radioactive xerostomia. Conclusion: The findings of the network meta-analysis manifested that acupuncture therapy combined with medication has superiority in most RIAEs, both reducing incidence and relieving symptoms. However, high-quality studies are still needed to provide conclusive evidence. Systematic review registration: https://inplasy.com/inplasy-2020-7-0054/, identifier: INPLASY202070054.

Mechanisms of repeat-associated non-AUG translation in neurological microsatellite expansion disorders.

Repeat-associated non-AUG (RAN) translation was discovered in 2011 in spinocerebellar ataxia type 8 (SCA8) and myotonic dystrophy type 1 (DM1). This non-canonical form of translation occurs in all reading frames from both coding and non-coding regions of sense and antisense transcripts carrying expansions of trinucleotide to hexanucleotide repeat sequences. RAN translation has since been reported in 7 of the 53 known microsatellite expansion disorders which mainly present with neurodegenerative features. RAN translation leads to the biosynthesis of low-complexity polymeric repeat proteins with aggregating and cytotoxic properties. However, the molecular mechanisms and protein factors involved in assembling functional ribosomes in absence of canonical AUG start codons remain poorly characterised while secondary repeat RNA structures play key roles in initiating RAN translation. Here, we briefly review the repeat expansion disorders, their complex pathogenesis and the mechanisms of physiological translation initiation together with the known factors involved in RAN translation. Finally, we discuss research challenges surrounding the understanding of pathogenesis and future directions that may provide opportunities for the development of novel therapeutic approaches for this group of incurable neurodegenerative diseases.

Acupuncture therapy for radiotherapy-induced adverse effects: a protocol for systematic review and Bayesian network meta-analysis.

BACKGROUND: Radiotherapy is the cornerstone in cancer treatment, and its adverse effects have been recognized widely nowadays. In response, effective and nontoxic therapies are in demand for patients affected by radiotherapy-induced adverse effects (RIAE). As a multitude of clinical studies have suggested that acupuncture therapies seem to be potential in treating RIAE, this study aims to make a systematic review and Bayesian network meta-analysis (NMA) to evaluate effectiveness and safety of different acupuncture treatments. METHODS: A full-scale search will be performed in the following databases from inception to June, 2020: PubMed/Medline, Cochrane library, Web of Science, Ebsco, Embase, China National Knowledge Infrastructure (CNKI), Wanfang Database, VIP Database and China Biology Medicine disc (CBM). Randomized controlled trials meeting the eligible criteria based on PICOS elements will be included. The primary outcome is the response rate of RIAE or the incidence of RIAE. The secondary outcome is the incidence of adverse events directly related to acupuncture. Cochrane risk-of-bias tool (ROB 2.0) will be employed to evaluate the quality of chosen literatures. Stata, Addis and OpenBUGS will be performed to manage data. DISCUSSION: The results can provide a relatively objective evidence to assess effectiveness and safety of acupuncture therapies for each RIAE, which may be rewarding as a guiding proposal for researchers concerning RIAE. TRIAL REGISTRATION: This study has been registered at INPLASY (https://inplasy.com/) with a registration ID INPLASY202070054.

Acupuncture therapy for preventing the nausea and vomiting following high emetic risk chemotherapy: A protocol for systematic review and Bayesian Network meta-analysis.

BACKGROUND: Nausea and vomiting are the most common complications after chemotherapy, which cannot be completely controlled even with commonly prescribed antiemetic drugs, particularly in patients receiving highly emetogenic chemotherapy Acupuncture therapy is an effective replacement method for chemotherapy-induced nausea and vomiting (CINV), which effectiveness and safety have been observed by many clinicians. However, different acupuncture treatments have various effectiveness. Based on enough clinical researches, the study aims to uses Bayesian network meta-analysis (NMA) to evaluate the effectiveness of different acupuncture therapies used for preventing CINV. METHODS: Authors will search PubMed/Medline, Cochrane library, Web of Science, Ebsco, Ovid/Embase, China National Knowledge Infrastructure, Wanfang Database, VIP Database, and China Biology Medicine from setup time to July 2020. All randomized control trails meet the standard will be included. Quality evaluation of included studies will be implemented with Cochrane risk-of-bias tool. STATA 14.0 will be used to perform pairwise meta-analysis. Addis 1.16.8 (University Medical Center Groningen (UMCG), Groningen, NL) and OpenBUGS 3.2.3 (Medical Research Council (MRC), London, UK) will be used to conduct NMA. RESULTS: The results of this review will generate a comprehensive review of current evidence and be published on a peer-reviewed journal. CONCLUSION: The result of this systematic review and Bayesian NMA may offer better options for patients in relieving CINV.Systematic review registration number: INPLASY202070070.

The Validity of the Montreal Cognitive Assessment for Moderate to Severe Traumatic Brain Injury Patients: A Pilot Study.

OBJECTIVE: The aim of the study was to pilot the use of Montreal Cognitive Assessment as a quick clinical screen for cognitive assessment in traumatic brain injury patients. DESIGN: The study recruited 61 participants with moderate to severe traumatic brain injury presenting to a tertiary rehabilitation center under the Brain Injury Program. A Montreal Cognitive Assessment questionnaire and neuropsychological battery (Repeatable Battery for the Assessment of Neuropsychological Status and Color Trails Test) were administered to participants who had completed inpatient rehabilitation. RESULTS: Receiver operating characteristic analysis for the Montreal Cognitive Assessment revealed an optimal balance of sensitivity and specificity at 24/25 to discriminate participants who were classified as less than 5th centile on the Total Scale Index on the Repeatable Battery for the Assessment of Neuropsychological Status. This achieved a sensitivity, specificity, PPV, and NPV of 73.9%, 86.5%, 77.3%, and 84.2%, respectively. Receiver operating characteristic analysis for the trail making subtest of the Montreal Cognitive Assessment achieved a sensitivity, specificity, PPV, and NPV of 79.4%, 74.1%, 79.4%, and 74.1% in identifying patients classified as less than 5th centile on Color Trail Test part 2. CONCLUSIONS: The use of Montreal Cognitive Assessment displayed good validity in identifying patients with clinically significant impairment on a standard neuropsychological assessment battery in the study population. However, it may lack sensitivity for estimating mild levels of impairment.

mRNA-Mediated Duplexes Play Dual Roles in the Regulation of Bidirectional Ribosomal Frameshifting.

In contrast to -1 programmed ribosomal frameshifting (PRF) stimulation by an RNA pseudoknot downstream of frameshifting sites, a refolding upstream RNA hairpin juxtaposing the frameshifting sites attenuates -1 PRF in human cells and stimulates +1 frameshifting in yeast. This eukaryotic functional mimicry of the internal Shine-Dalgarno (SD) sequence-mediated duplex was confirmed directly in the 70S translation system, indicating that both frameshifting regulation activities of upstream hairpin are conserved between 70S and 80S ribosomes. Unexpectedly, a downstream pseudoknot also possessed two opposing hungry codon-mediated frameshifting regulation activities: attenuation of +1 frameshifting and stimulation of a non-canonical -1 frameshifting within the +1 frameshift-prone CUUUGA frameshifting site in the absence of release factor 2 (RF2) in vitro. However, the -1 frameshifting activity of the downstream pseudoknot is not coupled with its +1 frameshifting attenuation ability. Similarly, the +1 frameshifting activity of the upstream hairpin is not required for its -1 frameshifting attenuation function Thus, each of the mRNA duplexes flanking the two ends of a ribosomal mRNA-binding channel possesses two functions in bi-directional ribosomal frameshifting regulation: frameshifting stimulation and counteracting the frameshifting activity of each other.

Temperature effects on life history traits of two sympatric branchiopods from an ephemeral wetland.

Temperature effects on organisms are of multiple scientific interests, such as for their life history performance and for the study of evolutionary strategies. We have cultured two sympatric branchiopod species from an ephemeral pond in northern Taiwan, Branchinella kugenumaensis and Eulimnadia braueriana, and compared their hatching rate, maturation time, sex ratio, growth of body length, survivorship, clutch size, net reproductive rate R0, generation time TG, and intrinsic rate of natural increase r in relation to temperature (15, 20, 25 and 30°C). We found that E. braueriana had a significantly higher temperature-dependent fecundity and intrinsic population growth pattern (R0 and r). In contrast, B. kugenumaensis reproduced much slower than E. braueriana with much lower R0 (90-100 folds less) and r (about 10 folds less) at 15, 20 and 25°C and with a double as long TG at 20 and 25°C. In addition, E. braueriana increased its chance of hermaphroditic sexual reproductive mode at higher temperature because of a significantly delayed maturation of males from hermaphrodites. In contrast, B. kugenumaensis showed no significant change in reproductive mode with temperature. This is the first study indicating a significant differentiation in life history parameters of two sympatric branchiopods mediated by temperature.

Establishing the Brief Assessment of Cognition - Short form.

The study aims to identify and validate a parsimonious subset of tests in the commonly used Brief Assessment of Cognition in Schizophrenia (BACS) that allows the evaluation of global cognitive ability. Several permutations of subtests from the BACS were examined to identify the best subset of tests to compose the short form measure. The Brief Assessment of Cognition-Short Form (BAC-SF) was evaluated for convergent validity in healthy and psychiatric samples (N = 3718). Verbal Memory, Digit Sequencing, and Symbol Coding subtests were found to best summarize the variance of composite scores in both Asian and US Norming samples (r = 0.91) indicating that BAC-SF is an appropriate approximation of cognitive deficits. Test re-test reliability of the BAC-SF was adequate (Intraclass Correlation Coefficient (ICC) = 0.73) and showed sufficient separation between healthy controls and schizophrenia (Average Predictive Accuracy = 79.9%; replication = 76.5%). Findings indicate that the BAC-SF an could be used as a cognitive screener for large-scale clinical and epidemiological studies. The short form does not replace the need for comprehensive neuropsychological batteries purposed for detailed neuropsychological and clinical investigation of cognitive function. Further replication of the construct might be necessary in other clinical populations.

Prevalence of Dementia in People Aged 60 Years and Above: Results from the WiSE Study.

BACKGROUND: The challenge of an aging population with its expected attendant problem of an increase in the number of people with dementia is a growing concern across the world. OBJECTIVE: The aims of this study were to establish the prevalence and risk factors of dementia in Singapore among the elderly resident population (aged 60 years and above). METHODS: The WiSE study was a comprehensive single phase, cross-sectional, epidemiological survey that adapted the 10/66 protocol to establish the 10/66 and the Diagnostic and Statistical Manual of mental disorders -fourth edition (DSM-IV) diagnosis of dementia. 10/66 and DSM-IV dementia diagnosis as established by the survey questionnaires was validated by comparing against a gold standard of clinical assessment. RESULTS: A total of 2,565 respondents completed the study giving a response rate of 65.6%. The validity of 10/66 dementia was higher (sensitivity = 95.6%, specificity = 81.8%) than that of DSM-IV dementia (sensitivity = 75.6%, specificity = 88.6%) when compared against the clinical gold standard. The study found that the prevalence of 10/66 dementia was 10% in the older adult population while the prevalence of DSM-IV dementia was 4.6%. Older age (75 years and above); no formal education, or completed primary education (versus higher education); homemaker and retired status (versus employed); and a history of stroke were associated with a higher risk of 10/66 dementia. CONCLUSION: The establishment of accurate data on the number of people with dementia is essential in the planning of services and initiatives.