Association of Structural Forms of 17q21.31 with the Risk of Progressive Supranuclear Palsy and MAPT Sub-haplotypes.

Importance: The chromosome 17q21.31 region, containing a 900 Kb inversion that defines H1 and H2 haplotypes, represents the strongest genetic risk locus in progressive supranuclear palsy (PSP). In addition to H1 and H2, various structural forms of 17q21.31, characterized by the copy number of α, ß, and γ duplications, have been identified. However, the specific effect of each structural form on the risk of PSP has never been evaluated in a large cohort study. Objective: To assess the association of different structural forms of 17q.21.31, defined by the copy numbers of α, ß, and γ duplications, with the risk of PSP and MAPT sub-haplotypes. Design setting and participants: Utilizing whole genome sequencing data of 1,684 (1,386 autopsy confirmed) individuals with PSP and 2,392 control subjects, a case-control study was conducted to investigate the association of copy numbers of α, ß, and γ duplications and structural forms of 17q21.31 with the risk of PSP. All study subjects were selected from the Alzheimer's Disease Sequencing Project (ADSP) Umbrella NG00067.v7. Data were analyzed between March 2022 and November 2023. Main outcomes and measures: The main outcomes were the risk (odds ratios [ORs]) for PSP with 95% CIs. Risks for PSP were evaluated by logistic regression models. Results: The copy numbers of α and ß were associated with the risk of PSP only due to their correlation with H1 and H2, while the copy number of γ was independently associated with the increased risk of PSP. Each additional duplication of γ was associated with 1.10 (95% CI, 1.04-1.17; P = 0.0018) fold of increased risk of PSP when conditioning H1 and H2. For the H1 haplotype, addition γ duplications displayed a higher odds ratio for PSP: the odds ratio increases from 1.21 (95%CI 1.10-1.33, P = 5.47 × 10-5) for H1ß1γ1 to 1.29 (95%CI 1.16-1.43, P = 1.35 × 10-6) for H1ß1γ2, 1.45 (95%CI 1.27-1.65, P = 3.94 × 10-8) for H1ß1γ3, and 1.57 (95%CI 1.10-2.26, P = 1.35 × 10-2) for H1ß1γ4. Moreover, H1ß1γ3 is in linkage disequilibrium with H1c (R2 = 0.31), a widely recognized MAPT sub-haplotype associated with increased risk of PSP. The proportion of MAPT sub-haplotypes associated with increased risk of PSP (i.e., H1c, H1d, H1g, H1o, and H1h) increased from 34% in H1ß1γ1 to 77% in H1ß1γ4. Conclusions and relevance: This study revealed that the copy number of γ was associated with the risk of PSP independently from H1 and H2. The H1 haplotype with more γ duplications showed a higher odds ratio for PSP and were associated with MAPT sub-haplotypes with increased risk of PSP. These findings expand our understanding of how the complex structure at 17q21.31 affect the risk of PSP.

Disruption of Cdh23 exon 68 splicing leads to progressive hearing loss in mice by affecting tip-link stability.

Inner ear hair cells are characterized by the F-actin-based stereocilia that are arranged into a staircase-like pattern on the apical surface of each hair cell. The tips of shorter-row stereocilia are connected with the shafts of their neighboring taller-row stereocilia through extracellular links named tip links, which gate mechano-electrical transduction (MET) channels in hair cells. Cadherin 23 (CDH23) forms the upper part of tip links, and its cytoplasmic tail is inserted into the so-called upper tip-link density (UTLD) that contains other proteins such as harmonin. The Cdh23 gene is composed of 69 exons, and we show here that exon 68 is subjected to hair cell-specific alternative splicing. Tip-link formation is not affected in genetically modified mutant mice lacking Cdh23 exon 68. Instead, the stability of tip links is compromised in the mutants, which also suffer from progressive and noise-induced hearing loss. Moreover, we show that the cytoplasmic tail of CDH23(+68) but not CDH23(-68) cooperates with harmonin in phase separation-mediated condensate formation. In conclusion, our work provides evidence that inclusion of Cdh23 exon 68 is critical for the stability of tip links through regulating condensate formation of UTLD components.

Whole-Genome Sequencing Analysis Reveals New Susceptibility Loci and Structural Variants Associated with Progressive Supranuclear Palsy.

Background: Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease characterized by the accumulation of aggregated tau proteins in astrocytes, neurons, and oligodendrocytes. Previous genome-wide association studies for PSP were based on genotype array, therefore, were inadequate for the analysis of rare variants as well as larger mutations, such as small insertions/deletions (indels) and structural variants (SVs). Method: In this study, we performed whole genome sequencing (WGS) and conducted association analysis for single nucleotide variants (SNVs), indels, and SVs, in a cohort of 1,718 cases and 2,944 controls of European ancestry. Of the 1,718 PSP individuals, 1,441 were autopsy-confirmed and 277 were clinically diagnosed. Results: Our analysis of common SNVs and indels confirmed known genetic loci at MAPT, MOBP, STX6, SLCO1A2, DUSP10, and SP1, and further uncovered novel signals in APOE, FCHO1/MAP1S, KIF13A, TRIM24, TNXB, and ELOVL1. Notably, in contrast to Alzheimer's disease (AD), we observed the APOE ε2 allele to be the risk allele in PSP. Analysis of rare SNVs and indels identified significant association in ZNF592 and further gene network analysis identified a module of neuronal genes dysregulated in PSP. Moreover, seven common SVs associated with PSP were observed in the H1/H2 haplotype region (17q21.31) and other loci, including IGH, PCMT1, CYP2A13, and SMCP. In the H1/H2 haplotype region, there is a burden of rare deletions and duplications (P = 6.73×10-3) in PSP. Conclusions: Through WGS, we significantly enhanced our understanding of the genetic basis of PSP, providing new targets for exploring disease mechanisms and therapeutic interventions.

Transcriptional Control of Neocortical Size and Microcephaly.

The mammalian neocortex differs vastly in size and complexity between mammalian species, yet the mechanisms that lead to an increase in brain size during evolution are not known. We show here that two transcription factors coordinate gene expression programs in progenitor cells of the neocortex to regulate their proliferative capacity and neuronal output in order to determine brain size. Comparative studies in mice, ferrets and macaques demonstrate an evolutionary conserved function for these transcription factors to regulate progenitor behaviors across the mammalian clade. Strikingly, the two transcriptional regulators control the expression of large numbers of genes linked to microcephaly suggesting that transcriptional deregulation as an important determinant of the molecular pathogenesis of microcephaly, which is consistent with the finding that genetic manipulation of the two transcription factors leads to severe microcephaly. Summary: The neocortex varies in size and complexity among mammals due to the tremendous variability in the number and diversity of neuronal subtypes across species 1,2 . The increased cellular diversity is paralleled by the expansion of the pool of neocortical progenitors 2-5 and the emergence of indirect neurogenesis 6 during brain evolution. The molecular pathways that control these biological processes and are disrupted in neurological and psychiatric disorders remain largely unknown. Here we show that the transcription factors BRN1 (POU3F3) and BRN2 (POU3F2) act as master regulators of the transcriptional programs in progenitors linked to neuronal specification and neocortex expansion. Using genetically modified lissencephalic and gyrencephalic animals, we found that BRN1/2 establish transcriptional programs in neocortical progenitors that control their proliferative capacity and the switch from direct to indirect neurogenesis. Functional studies in genetically modified mice and ferrets show that BRN1/2 act in concert with NOTCH and primary microcephaly genes to regulate progenitor behavior. Analysis of transcriptomics data from genetically modified macaques provides evidence that these molecular pathways are conserved in non-human primates. Our findings thus establish a mechanistic link between BRN1/2 and genes linked to microcephaly and demonstrate that BRN1/2 are central regulators of gene expression programs in neocortical progenitors critical to determine brain size during evolution.

Shared Decision Making, Diagnostic Evaluation, and Pharmacotherapy in Type 2 Diabetes.

BACKGROUND: Type 2 diabetes is one of the most important widespread diseases worldwide. In Germany, nearly one in five persons over age 65 has type 2 diabetes. The German National Disease Management Guideline for Type 2 Diabetes (NDMG; in German: Nationale Versorgungsleitlinie, NVL) contains updated recommendations for the diagnostic evaluation and pharmacotherapy of this disease as well as information about specific groups of people for whom early detection may be useful. METHODS: The guideline has been updated, chapter by chapter, since 2018. Its recommendations are based on systematically searched and evaluated scientific evidence, the clinical expertise of a multidisciplinary panel of experts, and patient perspectives. RESULTS: The new chapter on shared decision making includes a description of a structured approach that can be used when individual treatment goals have not been achieved. The diagnosis of diabetes newly requires at least two abnormally elevated laboratory values: e.g., fasting plasma glucose ≥ 126 mg/dL (≥ 7.0 mmol/L), HbA1c ≥ 6.5 % (≥ 48 mmol/mol) and/or casual plasma glucose ≥ 200 mg/dL (≥ 11.1 mmol/L). Cardiovascular and renal risks are to be considered in the choice of drug. Studies have shown that, in persons with cardiovascular disease, treatment with GLP-1 receptor agonists (GLP-1, glucagon-like peptide-1) or SGLT2 inhibitors (SGLT2, sodium-glucose co-transporter-2) was less likely than the comparison intervention to lead to certain patient-relevant endpoints, including all-cause mortality (OR = 0.88 and 0.84, respectively), hospitalization for heart failure (SGLT2 inhibitors: OR = 0.65), and worsening of renal function (OR = 0.61 and 0.59, respectively). CONCLUSION: Current evidence continues to support the recommendations on pharmacotherapy of the 2021 guideline. The Guideline Group did not find evidence of adequate certainty to inform recommendations about the screening of persons at risk, HbA1c target values, or screening for sequelae and comorbidities. Better evidence on these matters would be desirable.

Peptide conjugates with polyaromatic hydrocarbons can benefit the activity of catalytic RNAs.

Early stages of life likely employed catalytic RNAs (ribozymes) in many functions that are today filled by proteins. However, the earliest life forms must have emerged from heterogenous chemical mixtures, which included amino acids, short peptides, and many other compounds. Here we explored whether the presence of short peptides can help the emergence of catalytic RNAs. To do this, we conducted an in vitro selection for catalytic RNAs from randomized sequence in the presence of ten different peptides with a prebiotically plausible length of eight amino acids. This in vitro selection generated dozens of ribozymes, one of them with ∼900-fold higher activity in the presence of one specific peptide. Unexpectedly, the beneficial peptide had retained its N-terminal Fmoc protection group, and this group was required to benefit ribozyme activity. The same, or higher benefit resulted from peptide conjugates with prebiotically plausible polyaromatic hydrocarbons (PAHs) such as fluorene and naphthalene. This shows that PAH-peptide conjugates can act as potent cofactors to enhance ribozyme activity. The results are discussed in the context of the origin of life.

Molecular signatures define subtypes of auditory afferents with distinct peripheral projection patterns and physiological properties.

Type I spiral ganglion neurons (SGNs) are the auditory afferents that transmit sound information from cochlear inner hair cells (IHCs) to the brainstem. These afferents consist of physiological subtypes that differ in their spontaneous firing rate (SR), activation threshold, and dynamic range and have been described as low, medium, and high SR fibers. Lately, single-cell RNA sequencing experiments have revealed three molecularly defined type I SGN subtypes. The extent to which physiological type I SGN subtypes correspond to molecularly defined subtypes is unclear. To address this question, we have generated mouse lines expressing CreERT2 in SGN subtypes that allow for a physiological assessment of molecular subtypes. We show that Lypd1-CreERT2 expressing SGNs represent a well-defined group of neurons that preferentially innervate the IHC modiolar side and exhibit a narrow range of low SRs. In contrast, Calb2-CreERT2 expressing SGNs preferentially innervate the IHC pillar side and exhibit a wider range of SRs, thus suggesting that a strict stratification of all SGNs into three molecular subclasses is not obvious, at least not with the CreERT2 tools used here. Genetically marked neuronal subtypes refine their innervation specificity onto IHCs postnatally during the time when activity is required to refine their molecular phenotype. Type I SGNs thus consist of genetically defined subtypes with distinct physiological properties and innervation patterns. The molecular subtype-specific lines characterized here will provide important tools for investigating the role of the physiologically distinct type I SGNs in encoding sound signals.

Blocking D2/D3 dopamine receptors in male participants increases volatility of beliefs when learning to trust others.

The ability to learn about other people is crucial for human social functioning. Dopamine has been proposed to regulate the precision of beliefs, but direct behavioural evidence of this is lacking. In this study, we investigate how a high dose of the D2/D3 dopamine receptor antagonist sulpiride impacts learning about other people's prosocial attitudes in a repeated Trust game. Using a Bayesian model of belief updating, we show that in a sample of 76 male participants sulpiride increases the volatility of beliefs, which leads to higher precision weights on prediction errors. This effect is driven by participants with genetically conferred higher dopamine availability (Taq1a polymorphism) and remains even after controlling for working memory performance. Higher precision weights are reflected in higher reciprocal behaviour in the repeated Trust game but not in single-round Trust games. Our data provide evidence that the D2 receptors are pivotal in regulating prediction error-driven belief updating in a social context.

A ribozyme that uses lanthanides as cofactor.

To explore how an early, RNA-based life form could have functioned, in vitro selection experiments have been used to develop catalytic RNAs (ribozymes) with relevant functions. We previously identified ribozymes that use the prebiotically plausible energy source cyclic trimetaphosphate (cTmp) to convert their 5'-hydroxyl group to a 5'-triphosphate. While these ribozymes were developed in the presence of Mg2+, we tested here whether lanthanides could also serve as catalytic cofactors because lanthanides are ideal catalytic cations for this reaction. After an in vitro selection in the presence of Yb3+, several active sequences were isolated, and the most active RNA was analyzed in more detail. This ribozyme required lanthanides for activity, with highest activity at a 10:1 molar ratio of cTmp : Yb3+. Only the four heaviest lanthanides gave detectable signals, indicating a high sensitivity of ribozyme catalysis to the lanthanide ion radius. Potassium and Magnesium did not facilitate catalysis alone but they increased the lanthanide-mediated kOBS by at least 100-fold, with both K+ and Mg2+ modulating the ribozyme's secondary structure. Together, these findings show that RNA is able to use the unique properties of lanthanides as catalytic cofactor. The results are discussed in the context of early life forms.

Characterisation of thermally treated beech and birch by means of quasi-static tests and ultrasonic waves.

Wood, being renewable and highly abundant material, with excellent high specific strength and stiffness, has received increasing attention to be used in high performance applications such as the structural element of a battery case in an electric vehicle. For a successful implementation of wood in the automotive sector, it is, therefore, crucial to understand the behaviour of wood during and after temperature exposure and in the event of fire with the presence/absence of oxygen. In this study, the mechanical properties of thermally modified and unmodified European beech and birch in air and nitrogen environments at six different treatment intensities were characterised using compression tests, tensile tests, shear tests and Poisson's ratio tests. Further, the elastic properties of these wood species were quantified using the ultrasound measurements. The obtained strength and stiffness exhibited mild improvement upon moderate temperature treatment (200 °C), followed by a decrease at elevated temperature levels. This improvement was somewhat more pronounced under nitrogen treatment than under air treatment conditions. Nevertheless, a more noticeable decrease in the material performance was observed in beech compared to birch, occurring at earlier stages of modifications. This study confirms the tension-compression asymmetry of beech and birch where higher Young's moduli were obtained from tensile than from compression tests for reference and thermally treated beech and birch. The shear moduli obtained from ultrasound for birch were comparable to those obtained from quasi-static tests, whereas there was an overestimation of approximately 11-59% for the shear modulus of beech compared to quasi-static tests. Poisson's ratios from ultrasound tests corresponded well with those from quasi-static tests for untreated beech and birch, but not for thermally modified samples. The Saint-Venant model can satisfactorily predict the shear moduli of untreated and treated beech wood.

Mechanoelectrical transduction-related genetic forms of hearing loss.

Hair cells of the mammalian cochlea are specialized mechanosensory cells that convert mechanical stimuli into electrical signals to initiate the neuronal responses that lead to the perception of sound. The mechanoelectrical transduction (MET) machinery of cochlear hair cells is a multimeric protein complex that consists of the pore forming subunits of the MET channel and several essential accessory subunits that are crucial to regulate channel function and render the channel mechanically sensitive. Mutations have been discovered in the genes that encode all known components of the MET machinery. These mutations cause hearing loss with or without vestibular dysfunction. Some mutations also affect other tissues such as the retina. In this brief review, we will summarize gene mutations that affect the MET machinery of hair cells and how the study of the affected genes has illuminated our understanding of the physiological role of the encoded proteins.

Atmospheric CO2 forcing on Mediterranean biomes during the past 500 kyrs.

There is growing concern on the survival of Mediterranean forests under the projected near-future droughts as a result of anthropogenic climate change. Here we determine the resilience of Mediterranean forests across the entire range of climatic boundary conditions realized during the past 500 kyrs based on continuous pollen and geochemical records of (sub)centennial-scale resolution from drillcores from Tenaghi Philippon, Greece. Using convergent cross-mapping we provide empirical confirmation that global atmospheric carbon dioxide (CO2) may affect Mediterranean vegetation through forcing on moisture availability. Our analysis documents two stable vegetation regimes across the wide range of CO2 and moisture levels realized during the past four glacial-interglacial cycles, with abrupt shifts from forest to steppe biomes occurring when a threshold in precipitation is crossed. Our approach highlights that a CO2-driven moisture decrease in the near future may bear an impending risk for abrupt vegetation regime shifts prompting forest loss in the Mediterranean region.

The tetraspan LHFPL5 is critical to establish maximal force sensitivity of the mechanotransduction channel of cochlear hair cells.

The mechanoelectrical transduction (MET) channel of cochlear hair cells is gated by the tip link, but the mechanisms that establish the exquisite force sensitivity of this MET channel are not known. Here, we show that the tetraspan lipoma HMGIC fusion partner-like 5 (LHFPL5) directly couples the tip link to the MET channel. Disruption of these interactions severely perturbs MET. Notably, the N-terminal cytoplasmic domain of LHFPL5 binds to an amphipathic helix in TMC1, a critical gating domain conserved between different MET channels. Mutations in the amphipathic helix of TMC1 or in the N-terminus of LHFPL5 that perturb interactions of LHFPL5 with the amphipathic helix affect channel responses to mechanical force. We conclude that LHFPL5 couples the tip link to the MET channel and that channel gating depends on a structural element in TMC1 that is evolutionarily conserved between MET channels. Overall, our findings support a tether model for transduction channel gating by the tip link.

The Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitor Empagliflozin Reverses Hyperglycemia-Induced Monocyte and Endothelial Dysfunction Primarily through Glucose Transport-Independent but Redox-Dependent Mechanisms.

PURPOSE: Hyperglycaemia-induced oxidative stress and inflammation contribute to vascular cell dysfunction and subsequent cardiovascular events in T2DM. Selective sodium-glucose co-transporter-2 (SGLT-2) inhibitor empagliflozin significantly improves cardiovascular mortality in T2DM patients (EMPA-REG trial). Since SGLT-2 is known to be expressed on cells other than the kidney cells, we investigated the potential ability of empagliflozin to regulate glucose transport and alleviate hyperglycaemia-induced dysfunction of these cells. METHODS: Primary human monocytes were isolated from the peripheral blood of T2DM patients and healthy individuals. Primary human umbilical vein endothelial cells (HUVECs) and primary human coronary artery endothelial cells (HCAECs), and fetoplacental endothelial cells (HPECs) were used as the EC model cells. Cells were exposed to hyperglycaemic conditions in vitro in 40 ng/mL or 100 ng/mL empagliflozin. The expression levels of the relevant molecules were analysed by RT-qPCR and confirmed by FACS. Glucose uptake assays were carried out with a fluorescent derivative of glucose, 2-NBDG. Reactive oxygen species (ROS) accumulation was measured using the H2DFFDA method. Monocyte and endothelial cell chemotaxis were measured using modified Boyden chamber assays. RESULTS: Both primary human monocytes and endothelial cells express SGLT-2. Hyperglycaemic conditions did not significantly alter the SGLT-2 levels in monocytes and ECs in vitro or in T2DM conditions. Glucose uptake assays carried out in the presence of GLUT inhibitors revealed that SGLT-2 inhibition very mildly, but not significantly, suppressed glucose uptake by monocytes and endothelial cells. However, we detected the significant suppression of hyperglycaemia-induced ROS accumulation in monocytes and ECs when empagliflozin was used to inhibit SGLT-2 function. Hyperglycaemic monocytes and endothelial cells readily exhibited impaired chemotaxis behaviour. The co-treatment with empagliflozin reversed the PlGF-1 resistance phenotype of hyperglycaemic monocytes. Similarly, the blunted VEGF-A responses of hyperglycaemic ECs were also restored by empagliflozin, which could be attributed to the restoration of the VEGFR-2 receptor levels on the EC surface. The induction of oxidative stress completely recapitulated most of the aberrant phenotypes exhibited by hyperglycaemic monocytes and endothelial cells, and a general antioxidant N-acetyl-L-cysteine (NAC) was able to mimic the effects of empagliflozin. CONCLUSIONS: This study provides data indicating the beneficial role of empagliflozin in reversing hyperglycaemia-induced vascular cell dysfunction. Even though both monocytes and endothelial cells express functional SGLT-2, SGLT-2 is not the primary glucose transporter in these cells. Therefore, it seems likely that empagliflozin does not directly prevent hyperglycaemia-mediated enhanced glucotoxicity in these cells by inhibiting glucose uptake. We identified the reduction of oxidative stress by empagliflozin as a primary reason for the improved function of monocytes and endothelial cells in hyperglycaemic conditions. In conclusion, empagliflozin reverses vascular cell dysfunction independent of glucose transport but could partially contribute to its beneficial cardiovascular effects.

Mechanosensation and joint deformities.

Dysfunction of a mechanosensor in sensory neurons causes joint contracture.

Autophagy proteins are essential for aminoglycoside-induced hearing loss.

Aminoglycosides (AGs) are widely used to treat severe infections. However, systemically administered AGs preferentially kill cochlear hair cells, resulting in irreversible hearing loss. Recently, we found that AGs bind to RIPOR2 and trigger its rapid translocation in cochlear hair cells. Reducing RIPOR2 expression entirely prevents AG-induced hair cell death and subsequent hearing loss in mice. Next using yeast two-hybrid screening, we found that RIPOR2 interacts with GABARAP, a key macroautophagy/autophagy pathway protein. Following AG treatment, RIPOR2 colocalizes with GABARAP and regulates the activation of autophagy. Remarkably, reducing the expression of GABARAP, or another key autophagy protein MAP1LC3B/LC3B, entirely prevents AG-induced hair cell death and subsequent hearing loss in mice. Furthermore, we found that AGs activate the autophagy pathway specific to mitochondria. Reducing the expression of PINK1 or PRKN/parkin, two key mitophagy proteins, protects hair cells against AG toxicity. Thus, our findings demonstrated that RIPOR2-mediated autophagic dysfunction is essential for AG-induced hearing loss and provided potential therapeutic strategies for preventing AG toxicity.

State anxiety by itself does not change political attitudes: A threat of shock experiment.

Previous research suggests that state anxiety may sway political attitudes. However, previous experimental procedures induced anxiety using political contexts (e.g., social or economic threat). In a pre-registered laboratory experiment, we set out to examine if anxiety that is unrelated to political contexts can influence political attitudes. We induced anxiety with a threat of shock paradigm, void of any political connotation. All participants were instructed that they might receive an electric stimulus during specified threat periods and none during safety periods. Participants were randomly assigned to one of two conditions: Political attitudes (implicit and explicit) were assessed under safety in one condition and under threat in the other. Psychometric, as well as physiological data (skin conductance, heart rate), confirmed that anxiety was induced successfully. However, this emotional state did not alter political attitudes. In a Bayesian analytical approach, we confirmed the absence of an effect. Our results suggest that state anxiety by itself does not sway political attitudes. Previously observed effects that were attributed to anxiety may be conditional on a political context of threat.