Persistent DNA damage associated with ATM kinase deficiency promotes microglial dysfunction.

The autosomal recessive genome instability disorder Ataxia-telangiectasia, caused by mutations in ATM kinase, is characterized by the progressive loss of cerebellar neurons. We find that DNA damage associated with ATM loss results in dysfunctional behaviour of human microglia, immune cells of the central nervous system. Microglial dysfunction is mediated by the pro-inflammatory RELB/p52 non-canonical NF-κB transcriptional pathway and leads to excessive phagocytic clearance of neuronal material. Activation of the RELB/p52 pathway in ATM-deficient microglia is driven by persistent DNA damage and is dependent on the NIK kinase. Activation of non-canonical NF-κB signalling is also observed in cerebellar microglia of individuals with Ataxia-telangiectasia. These results provide insights into the underlying mechanisms of aberrant microglial behaviour in ATM deficiency, potentially contributing to neurodegeneration in Ataxia-telangiectasia.

Heteromeric channels formed by TRPC1, TRPC4 and TRPC5 define hippocampal synaptic transmission and working memory.

Canonical transient receptor potential (TRPC) channels influence various neuronal functions. Using quantitative high-resolution mass spectrometry, we demonstrate that TRPC1, TRPC4, and TRPC5 assemble into heteromultimers with each other, but not with other TRP family members in the mouse brain and hippocampus. In hippocampal neurons from Trpc1/Trpc4/Trpc5-triple-knockout (Trpc1/4/5-/-) mice, lacking any TRPC1-, TRPC4-, or TRPC5-containing channels, action potential-triggered excitatory postsynaptic currents (EPSCs) were significantly reduced, whereas frequency, amplitude, and kinetics of quantal miniature EPSC signaling remained unchanged. Likewise, evoked postsynaptic responses in hippocampal slice recordings and transient potentiation after tetanic stimulation were decreased. In vivo, Trpc1/4/5-/- mice displayed impaired cross-frequency coupling in hippocampal networks and deficits in spatial working memory, while spatial reference memory was unaltered. Trpc1/4/5-/- animals also exhibited deficiencies in adapting to a new challenge in a relearning task. Our results indicate the contribution of heteromultimeric channels from TRPC1, TRPC4, and TRPC5 subunits to the regulation of mechanisms underlying spatial working memory and flexible relearning by facilitating proper synaptic transmission in hippocampal neurons.

Disruption of RFX family transcription factors causes autism, attention-deficit/hyperactivity disorder, intellectual disability, and dysregulated behavior.

PURPOSE: We describe a novel neurobehavioral phenotype of autism spectrum disorder (ASD), intellectual disability, and/or attention-deficit/hyperactivity disorder (ADHD) associated with de novo or inherited deleterious variants in members of the RFX family of genes. RFX genes are evolutionarily conserved transcription factors that act as master regulators of central nervous system development and ciliogenesis. METHODS: We assembled a cohort of 38 individuals (from 33 unrelated families) with de novo variants in RFX3, RFX4, and RFX7. We describe their common clinical phenotypes and present bioinformatic analyses of expression patterns and downstream targets of these genes as they relate to other neurodevelopmental risk genes. RESULTS: These individuals share neurobehavioral features including ASD, intellectual disability, and/or ADHD; other frequent features include hypersensitivity to sensory stimuli and sleep problems. RFX3, RFX4, and RFX7 are strongly expressed in developing and adult human brain, and X-box binding motifs as well as RFX ChIP-seq peaks are enriched in the cis-regulatory regions of known ASD risk genes. CONCLUSION: These results establish a likely role of deleterious variation in RFX3, RFX4, and RFX7 in cases of monogenic intellectual disability, ADHD and ASD, and position these genes as potentially critical transcriptional regulators of neurobiological pathways associated with neurodevelopmental disease pathogenesis.

Comparative cardiovascular risk in users versus non-users of xanthine oxidase inhibitors and febuxostat versus allopurinol users.

OBJECTIVES: The aim of this study is to determine major adverse cardiovascular events (MACE) and all-cause mortality comparing between xanthine oxidase inhibitors (XOIs) and non-XOI users, and between allopurinol and febuxostat. METHODS: This is a retrospective cohort study of gout patients prescribed anti-hyperuricemic medications between 2013 and 2017 using a territory-wide administrative database. XOI users were matched 1:1 to XOI non-users using propensity scores. Febuxostat users were matched 1:3 to allopurinol users. Subgroup analyses were conducted based on colchicine use. RESULTS: Of the 13 997 eligible participants, 3607 (25.8%) were XOI users and 10 390 (74.2%) were XOI non-users. After propensity score matching, compared with non-users (n = 3607), XOI users (n = 3607) showed similar incidence of MACE (hazard ratio [HR]: 0.997, 95% CI, 0.879, 1.131; P>0.05) and all-cause mortality (HR = 0.972, 95% CI 0.886, 1.065, P=0.539). Febuxostat (n = 276) users showed a similar risk of MACE compared with allopurinol users (n = 828; HR: 0.672, 95% CI, 0.416, 1.085; P=0.104) with a tendency towards a lower risk of heart failure-related hospitalizations (HR = 0.529, 95% CI 0.272, 1.029; P=0.061). Concurrent colchicine use reduced the risk for all-cause mortality amongst XOI users (HR = 0.671, 95% 0.586, 0.768; P<0.001). CONCLUSION: In gout patients, XOI users showed similar risk of MACE and all-cause mortality compared with non-users. Compared with allopurinol users, febuxostat users showed similar MACE and all-cause mortality risks but lower heart failure-related hospitalizations.

ATM-deficiency-induced microglial activation promotes neurodegeneration in ataxia-telangiectasia.

While ATM loss of function has long been identified as the genetic cause of ataxia-telangiectasia (A-T), how it leads to selective and progressive degeneration of cerebellar Purkinje and granule neurons remains unclear. ATM expression is enriched in microglia throughout cerebellar development and adulthood. Here, we find evidence of microglial inflammation in the cerebellum of patients with A-T using single-nucleus RNA sequencing. Pseudotime analysis revealed that activation of A-T microglia preceded upregulation of apoptosis-related genes in granule and Purkinje neurons and that microglia exhibited increased neurotoxic cytokine signaling to granule and Purkinje neurons in A-T. To confirm these findings experimentally, we performed transcriptomic profiling of A-T induced pluripotent stem cell (iPSC)-derived microglia, which revealed cell-intrinsic microglial activation of cytokine production and innate immune response pathways compared to controls. Furthermore, A-T microglia co-culture with either control or A-T iPSC-derived neurons was sufficient to induce cytotoxicity. Taken together, these studies reveal that cell-intrinsic microglial activation may promote neurodegeneration in A-T.

A Video Decision Aid for Advance Care Planning Among Community-Dwelling Older Chinese Adults: A Cluster Randomized Controlled Trial.

Background: Health literacy is the foundation for discussing and reaching decisions regarding future care in advance care planning (ACP). Objectives: This cluster randomized controlled trial compared the effects of a video decision aid with those of verbal narratives accompanied by photos in preparing community-dwelling Chinese adults for ACP. Setting and Subjects: Adults aged 60 years or older who were capable of communicating and decision making (n = 182). Methods: The study was conducted in eight community centers in Hong Kong from April to December 2018. The primary outcome was readiness for ACP. Secondary outcomes included knowledge of and decisional conflict regarding end-of-life care. Results: In both groups, significant improvements were noted in the readiness to discuss (ß = 0.52, 95% confidence interval [CI] = 0.18 to 0.87, p = 0.003) and document (ß = 0.52, 95% CI = 0.13 to 0.90, p = 0.008) end-of-life care preferences and knowledge (ß = 0.85, 95% CI = 0.50 to 1.21, p < 0.001); in addition, decisional conflicts significantly decreased (ß = 0.87, 95% CI = 0.49 to 1.25, p < 0.001). The video group demonstrated a greater improvement than the verbal group only in the knowledge score (ß = 0.55, 95% CI = 0.08 to 1.02, p = 0.023). Conclusions: The findings showed that both video decision aids and verbal narratives accompanied by photos are effective ways to prepare older Chinese adults for ACP, although the video format was more effective for knowledge transfer. More work is needed to evaluate the sustained effects of these education interventions. Clinical Trial: This trial was registered at ISRCTN14628950.

Both microsatellite length and sequence context determine frameshift mutation rates in defective DNA mismatch repair.

It is generally accepted that longer microsatellites mutate more frequently in defective DNA mismatch repair (MMR) than shorter microsatellites. Indeed, we have previously observed that the A10 microsatellite of transforming growth factor beta type II receptor (TGFBR2) frameshifts -1 bp at a faster rate than the A8 microsatellite of activin type II receptor (ACVR2), although both genes become frameshift-mutated in >80% of MMR-defective colorectal cancers. To experimentally determine the effect of microsatellite length upon frameshift mutation in gene-specific sequence contexts, we altered the microsatellite length within TGFBR2 exon 3 and ACVR2 exon 10, generating A7, A10 and A13 constructs. These constructs were cloned 1 bp out of frame of EGFP, allowing a -1 bp frameshift to drive EGFP expression, and stably transfected into MMR-deficient cells. Subsequent non-fluorescent cells were sorted, cultured for 7-35 days and harvested for EGFP analysis and DNA sequencing. Longer microsatellites within TGFBR2 and ACVR2 showed significantly higher mutation rates than shorter ones, with TGFBR2 A13, A10 and A7 frameshifts measured at 22.38x10(-4), 2.17x10(-4) and 0.13x10(-4), respectively. Surprisingly, shorter ACVR2 constructs showed three times higher mutation rates at A7 and A10 lengths than identical length TGFBR2 constructs but comparably lower at the A13 length, suggesting influences from both microsatellite length as well as the sequence context. Furthermore, the TGFBR2 A13 construct mutated into 33% A11 sequences (-2 bp) in addition to expected A12 (-1 bp), indicating that this construct undergoes continual subsequent frameshift mutation. These data demonstrate experimentally that both the length of a mononucleotide microsatellite and its sequence context influence mutation rate in defective DNA MMR.

Flanking nucleotide specificity for DNA mismatch repair-deficient frameshifts within activin receptor 2 (ACVR2).

We previously demonstrated that exonic selectivity for frameshift mutation (exon 10 over exon 3) of ACVR2 in mismatch repair (MMR)-deficient cells is partially determined by 6 nucleotides flanking 5' and 3' of each microsatellite. Substitution of flanking nucleotides surrounding the exon 10 microsatellite with those surrounding the exon 3 microsatellite greatly diminished heteroduplex (A(7)/T(8)) and full (A(7)/T(7)) mutation, while substitution of flanking nucleotides from exon 3 with those from exon 10 enhanced frameshift mutation. We hypothesized that specific individual nucleotide(s) within these flanking sequences control ACVR2 frameshift mutation rates. Only the 3rd nucleotide 5' of the microsatellite, and 3rd, 4th, and 5th nucleotides 3' of the microsatellite were altered from the native flanking sequences and these locations were individually altered (sites A, B, C, and D, respectively). Constructs were cloned +1bp out-of-frame of EGFP, allowing a -1bp frameshift to express EGFP. Plasmids were stably transfected into MMR-deficient cells. Non-fluorescent cells were sorted, cultured for 35 days, and harvested for flow cytometry and DNA-sequencing. Site A (C to T) and B (G to C) in ACVR2 exon 10 decreased both heteroduplex and full mutant as much as the construct containing all 4 alterations. For ACVR2 exon 3, site A (T to C), C (A to G), and D (G to C) are responsible for increased heteroduplex formation, whereas site D is responsible for full mutant formation by ACVR2 exon 10 flanking sequences. Exonic selectivity for frameshift mutation within ACVR2's sequence context is specifically controlled by individual nucleotides flanking each microsatellite.

Will You Protect Me or Make the Situation Worse?: Teachers' Responses to School Violence Against Students With Disabilities.

School violence is a global public health epidemic, with students with disabilities at a significantly greater risk than their non-disabled peers. Students with disabilities are more vulnerable to school violence from peers, teachers, and school staff due to stereotypes and prejudice. Teachers are pivotal in preventing violence and intervening, but literature on the role that teachers play in responding to disability-based violence is limited. Guided by the social-ecological framework of bullying, this qualitative study explored educators' responses to school violence against students with disabilities in Zambia. Data generation included document review, interviews, and focus groups with 33 teachers and 12 parents, and child-friendly methods with 90 students with disabilities. Findings illuminated that students with disabilities are less safe in schools. Teachers are not responding to violence seen or heard about due to stigmatizing beliefs and cultural norms surrounding disability and violence, with students with disabilities blamed for the violence and the response being their burden. Students with disabilities felt protected by special education teachers; however, disability-based stigma did not end with the student. By association, special education teachers were experiencing stigma from other teachers and were discouraged to respond. This stigma undermined the support special education teachers could provide to decrease school violence. Findings provide direction so teachers can respond to school violence in prosocial ways that create an environment where students with disabilities feel safe.

Prevalence and mechanisms of somatic deletions in single human neurons during normal aging and in DNA repair disorders.

Replication errors and various genotoxins cause DNA double-strand breaks (DSBs) where error-prone repair creates genomic mutations, most frequently focal deletions, and defective repair may lead to neurodegeneration. Despite its pathophysiological importance, the extent to which faulty DSB repair alters the genome, and the mechanisms by which mutations arise, have not been systematically examined reflecting ineffective methods. Here, we develop PhaseDel, a computational method to detect focal deletions and characterize underlying mechanisms in single-cell whole genome sequences (scWGS). We analyzed high-coverage scWGS of 107 single neurons from 18 neurotypical individuals of various ages, and found that somatic deletions increased with age and in highly expressed genes in human brain. Our analysis of 50 single neurons from DNA repair-deficient diseases with progressive neurodegeneration (Cockayne syndrome, Xeroderma pigmentosum, and Ataxia telangiectasia) reveals elevated somatic deletions compared to age-matched controls. Distinctive mechanistic signatures and transcriptional associations suggest roles for somatic deletions in neurodegeneration.

Stepwise strategy for generating osteoblasts from human pluripotent stem cells under fully defined xeno-free conditions with small-molecule inducers.

Clinically relevant human induced pluripotent stem cell (hiPSC) derivatives require efficient protocols to differentiate hiPSCs into specific lineages. Here we developed a fully defined xeno-free strategy to direct hiPSCs toward osteoblasts within 21 days. The strategy successfully achieved the osteogenic induction of four independently derived hiPSC lines by a sequential use of combinations of small-molecule inducers. The induction first generated mesodermal cells, which subsequently recapitulated the developmental expression pattern of major osteoblast genes and proteins. Importantly, Col2.3-Cherry hiPSCs subjected to this strategy strongly expressed the cherry fluorescence that has been observed in bone-forming osteoblasts in vivo. Moreover, the protocol combined with a three-dimensional (3D) scaffold was suitable for the generation of a xeno-free 3D osteogenic system. Thus, our strategy offers a platform with significant advantages for bone biology studies and it will also contribute to clinical applications of hiPSCs to skeletal regenerative medicine.

Primary Hepatoid Carcinoma of the Pancreas: A Clinicopathological Study of 3 Cases With Review of Additional 31 Cases in the Literature.

Primary pancreatic hepatoid carcinoma (PHC) is very rare. Here, we reported 3 such cases with review of additional 31 cases in the literature. Our 3 patients were male (83, 72, and 54 years old, respectively). Serum α-fetoprotein (AFP) was elevated in 1 patient (case 3, 8338 ng/mL) and not measured in the other two. The PHC in patient 1 (pathological stage pT2N0M0) and patient 2 (pT3N0M0) showed pure hepatocellular carcinoma (HCC)-like morphology, whereas in case 3 it was a PHC with true glandular differentiation (pT4N0M0). The diagnosis of PHC was confirmed with positive immunohistochemical staining in the tumor cells for AFP (2/3), Hep Par 1 (3/3), glypican-3 (2/3), arginase-1 (2/3), and Sal-like protein 4 (1/3). CD10 and polyclonal carcinoembryonic antigen stains show focal canalicular pattern in 2/3 tumors. Patient 1 did not receive further treatment after resection and was alive with no evidence of disease at 107 months. Patient 2 died of postoperative complications, whereas patient 3 received postsurgical chemoradiation and died of disease at 29 months. Our findings and literature review indicate that PHCs can be divided into 4 histological subtypes: with pure HCC-like morphology (n = 22), with neuroendocrine differentiation (n = 8), with true glandular differentiation (n = 3), and with acinar cell differentiation (n = 1). On univariate analysis, pure HCC-like morphology was associated with better disease-specific survival (DSS; P = .04), whereas lymph node and distant metastases were associated with worse DSS ( P = .002 for both). Age, gender, presenting symptoms, serum AFP level, and T stage were not associated with DSS. On multivariate analysis, none of these parameters was significantly associated with DSS.

Calcitonin Gene-Related Peptide Inhibition and Development of Acne and Rosacea.

This cohort study investigates whether calcitonin gene-related peptide inhibition is associated with reduced rates of developing acne or rosacea in patients who experience migraines.

Electrocardiographic conduction and repolarization markers associated with sudden cardiac death: moving along the electrocardiography waveform.

The QT interval along with its heart rate corrected form (QTc) are well-established ECG markers that have been found to be associated with malignant ventricular arrhythmogenesis. However, extensive preclinical and clinical investigations over the years have allowed for novel clinical ECG markers to be generated as predictors of arrhythmogenesis and sudden cardiac death. Repolarization markers include the older QTc, QT dispersion and newer Tpeak - Tend intervals, (Tpeak - Tend) / QT ratios, T-wave alternans (TWA), microvolt TWA and T-wave area dispersion. Meanwhile, conduction markers dissecting the QRS complex, such as QRS dispersion (QRSD) and fragmented QRS, were also found to correlate conduction velocity and unidirectional block with re-entrant substrates in various cardiac conditions. Both repolarization and conduction parameters can be combined into the excitation wavelength (λ). A surrogate marker for λ is the index of Cardiac Electrophysiological Balance (iCEB: QT / QRSd). Other markers based on conduction-repolarization are [QRSD x (Tpeak-Tend) / QRSd] and [QRSD x (Tpeak-Tend) / (QRSd x QT)]. Advancement in technology permitted sophisticated electrophysiological analyses such as principal component analysis and periodic repolarization dynamics to further improve risk stratification. This was closely followed by other novel indices including ventricular ectopic QRS interval, the f99 index and EntropyXQT, which integrates mathematical and physical calculations for determining the risk markers. Though proven to be effective in limited patient cohorts, more clinical studies across different cardiac pathologies are required to confirm their validity. As such, this review seeks to encapsulate the development of old and new ECG markers along with their associated utility and shortcomings in clinical practice.

Synchronous Pancreatic Ductal Adenocarcinoma and Hepatocellular Carcinoma: Report of a Case and Review of the Literature.

Two or more histologically distinct malignancies diagnosed during the same hospital admission are uncommon, but they do exist. Cases with synchronous primary pancreatic ductal adenocarcinoma and hepatocellular carcinoma are rarely seen. This is a case report of a 56 years old Caucasian female with the chief complaint of jaundice over a duration of 10 days. CT imaging findings revealed a 3.5 cm ill-defined pancreatic head mass and a 1.5 cm liver mass in the segment 5. EUS-FNA cytology showed pancreatic head ductal adenocarcinoma (PDAC). Liver biopsy revealed a well differentiated hepatocellular carcinoma (HCC). The patient underwent a pancreaticoduodenectomy and the pathology revealed a pancreatic ductal adenocarcinoma extending into peripancreatic soft tissue, portal vein and vascular groove with perineural invasion. This is a unique and challenging case with the coexistence of a primary PDAC and a primary HCC. To the best of our knowledge, this is the first documented case of synchronous PDAC and HCC in the English literature. The diagnosis and treatment of the two entities are discussed.

Renal Cell Carcinoma, Unclassified with Medullary Phenotype and Synchronous Renal Clear Cell Carcinoma Present in a Patient with No Sickle Cell Trait/Disease: Diagnostic and Therapeutic Challenges.

Renal medullary carcinoma (RMC) is an aggressive high-grade renal cell carcinoma (RCC) associated almost exclusively with sickle cell trait or sickle cell disease. However, RCC with RMC features has rarely been reported in patients with no sickle cell trait or disease. Renal cell carcinoma unclassified with medullary phenotype (RCCU-MP) is a newly-coined term used by an international panel of experts to describe renal cell carcinoma showing morphologic and immunohistochemical features of renal medullary carcinoma in patients without sickle cell trait/disease. So far, only one study in the English literature has described five such cases. Here, we report a case with unique clinical and pathological features in a 76-year-old male patient without sickle cell trait. The patient had a history of colon cancer with liver and lung metastases and was found to have a new renal mass in his right kidney during the follow up. A right nephrectomy was performed and showed two separate masses (tumor 1 and tumor 2). Tumor 1 had histologic features of RMC and the tumor cells were positive for CK7, Pax8, and OCT4 and showed loss of nuclear INI1 expression. Tumor 1 was diagnosed as RCCU-MP (6.3 cm, pT3aNx, WHO/ISUP nuclear grade 3). Tumor 2 showed features of clear cell type of RCC (0.6 cm, pT1aNx, WHO/ISUP grade 2) with intact nuclear INI1 expression. Three-months post-nephrectomy, the patient developed lung metastasis of RCCU-MP. To the best of our knowledge, this was the first documented case with synchronous RCCU-MP and clear cell RCC presenting in a patient without sickle cell trait. Careful histologic assessment with a panel of immunohistochemical biomarkers was helpful to render a correct diagnosis for early aggressive treatment.