Towards Generating Realistic Wrist Pulse Signals Using Enhanced One Dimensional Wasserstein GAN

For the past several years, there has been an increasing focus on deep learning methods applied into computational pulse diagnosis. However, one factor restraining its development lies in the small wrist pulse dataset, due to privacy risks or lengthy experiments cost. In this study, for the first time, we address the challenging by presenting a novel one-dimension generative adversarial networks (GAN) for generating wrist pulse signals, which manages to learn a mapping strategy from a random noise space to the original wrist pulse data distribution automatically. Concretely, Wasserstein GAN with gradient penalty (WGAN-GP) is employed to alleviate the mode collapse problem of vanilla GANs, which could be able to further enhance the performance of the generated pulse data. We compared our proposed model performance with several typical GAN models, including vanilla GAN, deep convolutional GAN (DCGAN) and Wasserstein GAN (WGAN). To verify the feasibility of the proposed algorithm, we trained our model with a dataset of real recorded wrist pulse signals. In conducted experiments, qualitative visual inspection and several quantitative metrics, such as maximum mean deviation (MMD), sliced Wasserstein distance (SWD) and percent root mean square difference (PRD), are examined to measure performance comprehensively. Overall, WGAN-GP achieves the best performance and quantitative results show that the above three metrics can be as low as 0.2325, 0.0112 and 5.8748, respectively. The positive results support that generating wrist pulse data from a small ground truth is possible. Consequently, our proposed WGAN-GP model offers a potential innovative solution to address data scarcity challenge for researchers working with computational pulse diagnosis, which are expected to improve the performance of pulse diagnosis algorithms in the future.

Current diagnosis and potential obstacles for post-neurosurgical bacterial meningitis

Despite the guidance of aseptic technology applied, bacterial meningitis seems to be an unavoidable obstacle in the process of neurosurgery, with high rates of disability and mortality. The diagnosis of post-neurosurgical bacterial meningitis (PNBM) mainly depends both on clinical symptoms and laboratory outcomes. Due to the excessive neuro-inflammatory reactions which are evoked by the primary brain disease or the craniotomy operation, the symptoms derived from the infection and aseptic may not be easily distinguished. On the other hand, the low positive rate and time-consuming character restrict the clinical practical values of bacterial culture. Therefore, it is always difficult to make a definite diagnosis of post-neurosurgical bacterial meningitis. Here, we reviewed the established literature about the diagnostic biomarkers for the PNBM and analyzed the potential obstacles in both clinical and scientific studies. Given the obstacle which has negative impacts on further investigation about the biology of PNBM, we only find relatively small numbers of study on PNBM. In this review, we summarize the established diagnostic methods and biomarkers for PNBM. Meanwhile, we also propose some potential investigation prospects. This review may help to better understand the character of PNBM in both clinical diagnosis and scientific investigations.

Neuronal NLRP3 is a parkin substrate that drives neurodegeneration in Parkinson's disease

Parkinson's disease (PD) is mediated, in part, by intraneuronal accumulation of α-synuclein aggregates andsubsequent death of dopamine (DA) neurons in the substantia nigra pars compacta (SNpc). Microglial hyperactivation of the NOD-like receptor protein 3 (NLRP3) inflammasome has been well-documented in various neurodegenerative diseases, including PD. We show here that loss of parkin activity in mouse and human DA neurons results in spontaneous neuronal NLRP3 inflammasome assembly, leading to DA neuron death. Parkin normally inhibits inflammasome priming by ubiquitinating and targeting NLRP3 for proteasomal degradation. Loss of parkin activity also contributes to the assembly of an active NLRP3 inflammasome complex via mitochondrial-derived reactive oxygen species (mitoROS) generation through the accumulation of another parkin ubiquitination substrate, ZNF746/PARIS. Inhibition of neuronal NLRP3 inflammasome assembly prevents degeneration of DA neurons in familial and sporadic PD models. Strategies aimed at limiting neuronal NLRP3 inflammasome activation hold promise as a disease-modifying therapy for PD.

Sensitive and high-accuracy detection of Salmonella based on CRISPR/Cas12a combined with recombinase polymerase amplification

Salmonella is a crucial food-borne pathogen causing food poisoning, leading to severe public health events. Here, we developed a technique by integrating recombinase polymerase amplification with CRISPR-LbCas12a and employing two targets with engineered crRNA for detection of Salmonella (RPA-LbCas12a-TTECDS). Our findings revealed that this novel method rapidly detects trace Salmonella in food through fluorescence intensity and provides a template for other food-borne pathogen detection methods. Further, crRNA was optimized to increase detection sensitivity. Double targets were used to enhance the detection accuracy, reaching the level of qPCR, which was superior to fluorescent RPA. The RPA-LbCas12a-TTECDS system specifically detected Salmonella levels as low as 50 CFU per ml at 37°C in 1 h. In summary, a simple, rapid, sensitive and high accuracy detection technique based on CRISPR-Cas12a was created for Salmonella detection without complicated equipment.

Edaravone activates the GDNF/RET neurotrophic signaling pathway and protects mRNA-induced motor neurons from iPS cells

BACKGROUND

Spinal cord motor neurons (MNs) from human iPS cells (iPSCs) have wide applications in disease modeling and therapeutic development for amyotrophic lateral sclerosis (ALS) and other MN-associated neurodegenerative diseases. We need highly efficient MN differentiation strategies for generating iPSC-derived disease models that closely recapitulate the genetic and phenotypic complexity of ALS. An important application of these models is to understand molecular mechanisms of action of FDA-approved ALS drugs that only show modest clinical efficacy. Novel mechanistic insights will help us design optimal therapeutic strategies together with predictive biomarkers to achieve better efficacy.

METHODS

We induce efficient MN differentiation from iPSCs in 4 days using synthetic mRNAs coding two transcription factors (Ngn2 and Olig2) with phosphosite modification. These MNs after extensive characterization were applied in electrophysiological and neurotoxicity assays as well as transcriptomic analysis, to study the neuroprotective effect and molecular mechanisms of edaravone, an FDA-approved drug for ALS, for improving its clinical efficacy.

RESULTS

We generate highly pure and functional mRNA-induced MNs (miMNs) from control and ALS iPSCs, as well as embryonic stem cells. Edaravone alleviates H2O2-induced neurotoxicity and electrophysiological dysfunction in miMNs, demonstrating its neuroprotective effect that was also found in the glutamate-induced miMN neurotoxicity model. Guided by the transcriptomic analysis, we show a previously unrecognized effect of edaravone to induce the GDNF receptor RET and the GDNF/RET neurotrophic signaling in vitro and in vivo, suggesting a clinically translatable strategy to activate this key neuroprotective signaling. Notably, edaravone can replace required neurotrophic factors (BDNF and GDNF) to support long-term miMN survival and maturation, further supporting the neurotrophic function of edaravone-activated signaling. Furthermore, we show that edaravone and GDNF combined treatment more effectively protects miMNs from H2O2-induced neurotoxicity than single treatment, suggesting a potential combination strategy for ALS treatment.

CONCLUSIONS

This study provides methodology to facilitate iPSC differentiation and disease modeling. Our discoveries will facilitate the development of optimal edaravone-based therapies for ALS and potentially other neurodegenerative diseases.

TRIP12 ubiquitination of glucocerebrosidase contributes to neurodegeneration in Parkinson's disease

Impairment in glucocerebrosidase (GCase) is strongly associated with the development of Parkinson's disease (PD), yet the regulators responsible for its impairment remain elusive. In this paper, we identify the E3 ligase Thyroid Hormone Receptor Interacting Protein 12 (TRIP12) as a key regulator of GCase. TRIP12 interacts with and ubiquitinates GCase at lysine 293 to control its degradation via ubiquitin proteasomal degradation. Ubiquitinated GCase by TRIP12 leads to its functional impairment through premature degradation and subsequent accumulation of α-synuclein. TRIP12 overexpression causes mitochondrial dysfunction, which is ameliorated by GCase overexpression. Further, conditional TRIP12 knockout in vitro and knockdown in vivo promotes the expression of GCase, which blocks α-synuclein preformed fibrils (α-syn PFFs)-provoked dopaminergic neurodegeneration. Moreover, TRIP12 accumulates in human PD brain and α-synuclein-based mouse models. The identification of TRIP12 as a regulator of GCase provides a new perspective on the molecular mechanisms underlying dysfunctional GCase-driven neurodegeneration in PD.

PARIS farnesylation prevents neurodegeneration in models of Parkinson's disease

Accumulation of the parkin-interacting substrate (PARIS; ZNF746), due to inactivation of parkin, contributes to Parkinson's disease (PD) through repression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α; PPARGC1A) activity. Here, we identify farnesol as an inhibitor of PARIS. Farnesol promoted the farnesylation of PARIS, preventing its repression of PGC-1α via decreasing PARIS occupancy on the PPARGC1A promoter. Farnesol prevented dopaminergic neuronal loss and behavioral deficits via farnesylation of PARIS in PARIS transgenic mice, ventral midbrain transduction of AAV-PARIS, adult conditional parkin KO mice, and the α-synuclein preformed fibril model of sporadic PD. PARIS farnesylation is decreased in the substantia nigra of patients with PD, suggesting that reduced farnesylation of PARIS may play a role in PD. Thus, farnesol may be beneficial in the treatment of PD by enhancing the farnesylation of PARIS and restoring PGC-1α activity.

GARP and GARP-Treated tDC Prevented the Formation of Atherosclerotic Plaques in ApoE-/- Mice

Purpose

This study aims to clarify the specific mechanism by which GARP affects the atherosclerotic plaques in ApoE^−/- mice and the effect of GARP-tDC on atherosclerosis.

Methods

The mice were randomly divided into three groups: the control group, the GARP-overexpressed group and the GARP-inhibited group. After 12 weeks, all the mice were euthanized, and the specimens were collected. In vitro, experiments were conducted to observe the effect of GARP on DC phenotype and the changes of the proportion of CD4⁺CD25⁺Foxp3⁺ Treg cells when GARP-tDCs were co-cultured with CD4⁺ T cells. Furthermore, adoptive transmission of GARP-tDCs was used to observe the effect on atherosclerotic plaque in mice.

Results

The GARP-overexpressed group enhanced the biological activity of Foxp3⁺ CD4⁺CD25⁺ Tregs and resulted in increased expression of LAP in T cells. In addition, the GARP-overexpressed group significantly suppressed the function of Th1 and Th17, and decreased the secretion of INF-γ and IL-17A. Thus, GARP had a protective effect on atherosclerosis. In vitro, we found that GARP-tDC had a tolerance-inducing phenotype, and GARP-tDC also had the ability to induce tolerance when co-cultured with CD4⁺ T cells. More importantly, adoptive transmission of GARP-tDCs reduced the size of atherosclerotic plaques.

Conclusion

GARP and the GARP-tDC play protective roles in atherosclerosis. The protective effect of GARP on atherosclerosis is achieved by increasing CD4⁺CD25⁺Foxp3⁺ Treg cells and inhibiting the production of IFN-γ and IL-17A.

Mechanistic basis for receptor-mediated pathological α-synuclein fibril cell-to-cell transmission in Parkinson's disease

The spread of pathological α-synuclein (α-syn) is a crucial event in the progression of Parkinson's disease (PD). Cell surface receptors such as lymphocyte activation gene 3 (LAG3) and amyloid precursor-like protein 1 (APLP1) can preferentially bind α-syn in the amyloid over monomeric state to initiate cell-to-cell transmission. However, the molecular mechanism underlying this selective binding is unknown. Here, we perform an array of biophysical experiments and reveal that LAG3 D1 and APLP1 E1 domains commonly use an alkaline surface to bind the acidic C terminus, especially residues 118 to 140, of α-syn. The formation of amyloid fibrils not only can disrupt the intramolecular interactions between the C terminus and the amyloid-forming core of α-syn but can also condense the C terminus on fibril surface, which remarkably increase the binding affinity of α-syn to the receptors. Based on this mechanism, we find that phosphorylation at serine 129 (pS129), a hallmark modification of pathological α-syn, can further enhance the interaction between α-syn fibrils and the receptors. This finding is further confirmed by the higher efficiency of pS129 fibrils in cellular internalization, seeding, and inducing PD-like α-syn pathology in transgenic mice. Our work illuminates the mechanistic understanding on the spread of pathological α-syn and provides structural information for therapeutic targeting on the interaction of α-syn fibrils and receptors as a potential treatment for PD.

Dupilumab reduces systemic corticosteroid use and sinonasal surgery rate in CRSwNP

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery.

METHODOLOGY

SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153).

RESULTS

Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test.

CONCLUSIONS

Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery.

Emerging Nanotechnology for Treatment of Alzheimer's and Parkinson's Disease

The prevalence of the two most common neurodegenerative diseases, Parkinson's disease (PD) and Alzheimer's Disease (AD), are expected to rise alongside the progressive aging of society. Both PD and AD are classified as proteinopathies with misfolded proteins α-synuclein, amyloid-β, and tau. Emerging evidence suggests that these misfolded aggregates are prion-like proteins that induce pathological cell-to-cell spreading, which is a major driver in pathogenesis. Additional factors that can further affect pathology spreading include oxidative stress, mitochondrial damage, inflammation, and cell death. Nanomaterials present advantages over traditional chemical or biological therapeutic approaches at targeting these specific mechanisms. They can have intrinsic properties that lead to a decrease in oxidative stress or an ability to bind and disaggregate fibrils. Additionally, nanomaterials enhance transportation across the blood-brain barrier, are easily functionalized, increase drug half-lives, protect cargo from immune detection, and provide a physical structure that can support cell growth. This review highlights emergent nanomaterials with these advantages that target oxidative stress, the fibrillization process, inflammation, and aid in regenerative medicine for both PD and AD.

Early wound repair versus later scar repair in children with treadmill hand friction burns

The incidence of pediatric treadmill hand friction burns has been increasing every year. The injuries are deeper than thermal hand burns, the optimal treatment remains unclear. This was a retrospective study of children who received surgery for treadmill hand friction burns from January 1, 2015, to December 31, 2019, in a single burn center. A total of 22 children were surveyed. The patients were naturally divided into two groups: the wound repair group (13 patients), which was admitted early to the hospital after injury and received debridement and vacuum sealing drainage initially, and a full-thickness skin graft later; and the scar repair group (9 patients), in which a scar contracture developed as a result of wound healing and received scar release and skin grafting later. The Modified Michigan Hand Questionnaire score in the wound repair group was 116.31 ± 10.55, and the corresponding score in the scar repair group was 117.56 ± 8.85 (P>0.05), no statistically significant difference. The Vancouver Scar Scale score in the wound repair group was 4.15 ± 1.21, and the corresponding score in the scar repair group was 7.22 ± 1.09 (P<0.05). Parents were satisfied with the postoperative appearance and function of the hand. None in the two groups required secondary surgery. If the burns are deep second degree, third degree, or infected, early debridement, vacuum sealing drainage initially, and a full-thickness skin graft can obviously relieve pediatric pain, shorten the course of the disease, and restore the function of the hand as soon as possible.

Network Pharmacology for Analyzing the Key Targets and Potential Mechanism of Wogonin in Gliomas

Objective: To analyze the key targets and potential mechanisms underlying the volatile components of Scutellaria baicalensis Georgi acting on gliomas through network pharmacology combined with biological experiments.

Methods: We have extracted the volatile components of Scutellaria baicalensis by gas chromatography-mass spectrometry (GC-MS) and determined the active components related to the onset and development of gliomas by combining the results with the data from the Traditional Chinese Medicine Systems Pharmacology database. We screened the same targets for the extracted active components and gliomas through network pharmacology and then constructed a protein-protein interaction network. Using a Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, we analyzed the protein effects and regulatory pathways of the common targets. Lastly, we employed ELISA and Western blot in verifying the key targets in the regulatory pathway.

Results: We ultimately determined that the active component in S. baicalensis Georgi related to the onset and development of gliomas was Wogonin. The results of the network pharmacology revealed 85 targets for glioma and Wogonin. We used gene ontology to analyze these target genes and found that they involved 30 functions, such as phosphatidylinositol phosphokinase activation, while the KEGG analysis showed that there were 10 regulatory pathways involved. Through the following analysis, we found that most of the key target genes are distributed in the PI3K-Akt and interleukin 17 signaling pathways. We then cultured U251 glioma cells for the experiments. Compared with the control group, no significant change was noted in the caspase-3 expression; however, cleaved caspase-3 expression increased significantly and was dose-dependent on Wogonin. The expression of Bad and Bcl-2 with 25 μM of Wogonin has remained unchanged, but when the Wogonin dose was increased to 100 μM, the expression of Bad and Bcl-2 was noted to change significantly (Bad was significantly upregulated, while Bcl-2 was significantly downregulated) and was dose-dependent on Wogonin. The ELISA results showed that, compared with the control group, the secretion of tumor necrosis factor alpha, IL-1β, and IL-6 decreased as the Wogonin concentration increased. Tumor necrosis factor alpha downregulation had no significant dose-dependent effect on Wogonin, the inhibitory effect of 25 μM of Wogonin on IL-6 was not significant, and IL-1β downregulation had a significant dose-dependent effect on Wogonin.

Conclusion: Wogonin might promote the apoptosis of glioma cells by upregulating proapoptotic factors, downregulating antiapoptotic factors, and inhibiting the inflammatory response, thereby inhibiting glioma progression.

[Effects of vestibular spontaneous nystagmus on visual smooth pursuit function]

Objective: The aim of the study is to analyze the effects of vestibular spontaneous nystagmus(SN) on the smooth pursuit function of visual ocularmotor system. Methods: A total of 46 patients with acute unilateral peripheral vestibular syndrome with SN (26 cases of vestibular neuritis, 6 cases of Ramsay Hunt Syndrome (RHS) with vertigo, 14 cases of sudden deafness with vertigo) were included in this work. In the study group, the results of SPT and SN test with videonystagmography(VNG) were also reviewed. Taking SPT parameters, the influence of SN intensity on SPT gain, asymmetry and waveform and their correlation were analyzed.SPSS19.0 software was used for statistical analysis. Results: Among the 46 patients, there were 36 cases of SN pointing to the healthy side(SN intensity range of 2.68°/s-32.53°/s), and 10 cases of SN pointing to the affected side (SN intensity range of 2.66°/s-16.54°/s). SN intensity was divided into 3 groups, including light(0.50°/s-5.00°/s), medium(5.01°/s-10.00°/s) and strong(>10.01°/s), accounting for 14 cases(30.4%), 18 cases(39.1%) and 14 cases(30.4%), respectively. The differences of the gain of SPT to the fast phase and slow phase direction in the overall groups and light, medium and strong groups of SN intensity respectively were statistically significant(t_total=13.338, t_light=6.184, t_medium=8.436, t_strong=8.477, all of P<0.001). The difference of SPT gain in SN fast phase direction between groups with different SN intensity was statistically significant(F=9.639, P<0.001),there was no statistically significant difference in SPT gain between the groups on the SN slow phase direction(F=1.137, P=0.330).The SN intensity significantly negatively correlated with the SPT gain of the fast phase direction of SN (r=-0.433, P=0.003), that was, the SPT gain on the fast phase direction of SN decreased with the increase of SN intensity. There was no significant correlation between SN intensity and the gain of SPT on the slow phase direction of SN (r=-0.061, P=0.687). SPT waveform analysis showed that type I, type II and type III accounted for 8 cases(17.4%), 21 cases(45.6%) and 17 cases(37.0%), respectively. The corresponding mean values of SN intensity were (3.71±0.69)°/s, (7.44±1.88)°/s, (20.04±5.53)°/s, respectively, without type IV wave. The intensity of SN was positively correlated with the asymmetric value of the gain of SPT left and right(r=0.450,P=0.002). That was, with the increase of SN strength, the asymmetric value also increased, and the worse the asymmetry of the gain of SPT left and right pursuit was, the worse the SPT waveform was. Conclusion: SPT gain, asymmetry and SPT waveforms are all affected by SN, and the greater the intensity of SN, the greater the influence on the three. When SN is strong, type III waves may occur, suggesting that acute peripheral vestibular syndrome can also affect the visual ocularmotor systems.

Lymphocyte Activation Gene 3 (Lag3) Contributes to α-Synucleinopathy in α-Synuclein Transgenic Mice

Aggregation of misfolded α-synuclein (α-syn) is the major component of Lewy bodies and neurites in Parkinson's disease (PD) and related α-synucleinopathies. Some α-syn mutations (e.g., A53T) in familial PD recapitulate the α-syn pathology in transgenic mice, which supports the importance of pathologic α-syn in driving the pathogenesis of α-synucleinopathies. Lymphocyte activation gene 3 (Lag3) is a receptor of α-syn fibrils facilitating pathologic α-syn spread; however, the role of Lag3 in mediating the pathogenesis in α-syn transgenic mice is not clear. Here, we report that depletion of Lag3 in human α-syn A53T transgenic (hA53T) mice significantly reduces the level of detergent-insoluble α-syn aggregates and phosphorylated ser129 α-syn, and inhibits activation of microglia and astrocytes. The absence of Lag3 significantly delays disease progression and reduces the behavioral deficits in hA53T transgenic mice leading to prolonged survival. Taken together, these results show that Lag3 contributes to the pathogenesis in the α-syn A53T transgenic mouse model.

Role of Retinal Amyloid-β in Neurodegenerative Diseases: Overlapping Mechanisms and Emerging Clinical Applications

Amyloid-β (Aβ) accumulations have been identified in the retina for neurodegeneration-associated disorders like Alzheimer's disease (AD), glaucoma, and age-related macular degeneration (AMD). Elevated retinal Aβ levels were associated with progressive retinal neurodegeneration, elevated cerebral Aβ accumulation, and increased disease severity with a decline in cognition and vision. Retinal Aβ accumulation and its pathological effects were demonstrated to occur prior to irreversible neurodegeneration, which highlights its potential in early disease detection and intervention. Using the retina as a model of the brain, recent studies have focused on characterizing retinal Aβ to determine its applicability for population-based screening of AD, which warrants a further understanding of how Aβ manifests between these disorders. While current treatments directly targeting Aβ accumulations have had limited results, continued exploration of Aβ-associated pathological pathways may yield new therapeutic targets for preserving cognition and vision. Here, we provide a review on the role of retinal Aβ manifestations in these distinct neurodegeneration-associated disorders. We also discuss the recent applications of retinal Aβ for AD screening and current clinical trial outcomes for Aβ-associated treatment approaches. Lastly, we explore potential future therapeutic targets based on overlapping mechanisms of pathophysiology in AD, glaucoma, and AMD.

RIP3-mediated necroptosis was essential for spiral ganglion neuron damage

To identify the role of RIP3 in ouabain-induced necroptosis and offer clinical implications to prevent spiral ganglion neurons (SGNs) from death, ouabain was applied in SGNs derived from fetal rats and injected into Sprague-Dawley rats to construct injury model in vitro and in vivo, respectively. The necroptosis rate of SGNs was determined by flow cytometry and MTT assays. The protein levels and phosphorylation of RIP3 were evaluated using western blotting and immunofluorescence. SGNs injury was observed using H&E staining and immunofluorescence. The hearing function of rats was evaluated by the auditory brainstem response (ABR) and Distortion Product Otoacoustic Emissions (DPOAE) methods. Ouabain caused dose-dependent necroptosis in SGNs and significant loss of SGNs of the cochlear axis in vivo. RIP3 and pRIP3 were upregulated with SGNs injury promoted, and RIP3 overexpression promoted ouabain-induced necroptosis in SGNs in vitro, which could be suppressed by necrostatin-1. RIP3 knockdown inhibited ouabain-induced necroptosis and reduced the phosphorylation of MLKL but no RIP3-dependent effect on the level of MLKL. RIP3 inhibition in vivo protected rats from ouabain-induced hearing damage with reducing ABR threshold shifts and promoting DPOAE amplitudes, while overexpression of RIP3 enhanced ouabain-induced injury that could be partially reversed by necrostatin-1. A decrease of SGNs density and an upregulation of pRIP3 were observed with RIP3 overexpression, which was in contrast when RIP3 was silenced. Therefore, RIP3 was essential for mediating necroptosis in ouabain-induced SGNs damage. Targeting RIP3 may prevent SGNs from death in clinical practice, and finally help the treatment of sensorineural hearing loss.

Determinants of seeding and spreading of α-synuclein pathology in the brain

In Parkinson's disease (PD), fibrillar forms of α-synuclein are hypothesized to propagate through synaptically coupled networks, causing Lewy pathology (LP) and neurodegeneration. To more rigorously characterize the determinants of spreading, preformed α-synuclein fibrils were injected into the mouse pedunculopontine nucleus (PPN), a brain region that manifests LP in PD patients and the distribution of developing α-synuclein pathology compared to that ascertained by anterograde and retrograde connectomic mapping. Within the PPN, α-synuclein pathology was cell-specific, being robust in PD-vulnerable cholinergic neurons but not in neighboring noncholinergic neurons. While nearly all neurons projecting to PPN cholinergics manifested α-synuclein pathology, the kinetics, magnitude, and persistence of the propagated pathology were unrelated to the strength of those connections. Thus, neuronal phenotype governs the somatodendritic uptake of pathological α-synuclein, and while the afferent connectome restricts the subsequent spreading of pathology, its magnitude and persistence is not a strict function of the strength of coupling.