Phosphorylation of AQP4 by LRRK2 R1441G impairs glymphatic clearance of IFNγ and aggravates dopaminergic neurodegeneration.

Aquaporin-4 (AQP4) is essential for normal functioning of the brain's glymphatic system. Impaired glymphatic function is associated with neuroinflammation. Recent clinical evidence suggests the involvement of glymphatic dysfunction in LRRK2-associated Parkinson's disease (PD); however, the precise mechanism remains unclear. The pro-inflammatory cytokine interferon (IFN) γ interacts with LRRK2 to induce neuroinflammation. Therefore, we examined the AQP4-dependent glymphatic system's role in IFNγ-mediated neuroinflammation in LRRK2-associated PD. We found that LRRK2 interacts with and phosphorylates AQP4 in vitro and in vivo. AQP4 phosphorylation by LRRK2 R1441G induced AQP4 depolarization and disrupted glymphatic IFNγ clearance. Exogeneous IFNγ significantly increased astrocyte expression of IFNγ receptor, amplified AQP4 depolarization, and exacerbated neuroinflammation in R1441G transgenic mice. Conversely, inhibiting LRRK2 restored AQP4 polarity, improved glymphatic function, and reduced IFNγ-mediated neuroinflammation and dopaminergic neurodegeneration. Our findings establish a link between LRRK2-mediated AQP4 phosphorylation and IFNγ-mediated neuroinflammation in LRRK2-associated PD, guiding the development of LRRK2 targeting therapy.

Surgical treatment of preauricular fistulas: a 12-year single-center clinical observation.

OBJECTIVE: This study aimed to assess the effects of surgical timing and approach on operative duration, postoperative suture removal time, and postoperative recurrence rate in the management of preauricular fistula. A 12-year single-center clinical observation was conducted to analyze the potential effects of different surgical strategies on these critical outcomes. METHODS: The clinical data from 576 (782 ears) patients who underwent surgical resection for preauricular fistulas were examined in this retrospective study. The patients were classified into various groups based on differences in operative duration, surgical techniques and the use of intraoperative magnifying equipment. Furthermore, the specific data on operative duration, postoperative suture removal time, and postoperative recurrence rate were also recorded. RESULTS: The average operative duration for 782 ears and the average time required for postoperative suture removal were determined to be (34.57 ± 4.25) min and (3.62 ± 0.76) days, respectively. Among the cases examined, recurrence occurred in 13 ears, but all of them were cured after a second surgery, resulting in a recurrence rate of 1.67% (13/782). Interestingly, the operative and postoperative suture removal time was prolonged during the infection period (P < 0.05). The postoperative recurrence rate was significantly higher in the absence of magnifying equipment, as compared to those with the use of a microscope with 2.5× magnification (P < 0.05). No statistically significant differences were noted in the recurrence rate when comparing different anesthesia methods and types of surgical incisions, as well as the intraoperative use of methylene blue, and partial removal of cartilage of the pedicle (P > 0.05). CONCLUSION: The use of methylene blue, partial removal of the cartilage of the pedicle, and surgical incision during preauricular fistula resection did not affect the operative duration, postoperative suture removal time, and postoperative recurrence rate. Therefore, surgeons can select their preferred approaches based on their individual practices and patient-specific situations. However, the use of magnifying equipment during surgery is associated with a reduced risk of recurrence.

Mutant VPS35-D620N induces motor dysfunction and impairs DAT-mediated dopamine recycling pathway.

The D620N mutation in vacuolar protein sorting protein 35 (VPS35) gene has been identified to be linked to late onset familial Parkinson disease (PD). However, the pathophysiological roles of VPS35-D620N in PD remain unclear. Here, we generated the transgenic Caenorhabditis elegans overexpressing either human wild type or PD-linked mutant VPS35-D620N in neurons. C. elegans expressing VPS35-D620N, compared with non-transgenic controls, showed movement disorders and dopaminergic neuron loss. VPS35-D620N worms displayed more swimming induced paralysis but showed no defects in BSR assays, thus indicating the disruption of dopamine (DA) recycling back inside neurons. Moreover, VPS35 formed a protein interaction complex with DA transporter (DAT), RAB5, RAB11 and FAM21. In contrast, the VPS35-D620N mutant destabilized these interactions, thus disrupting DAT transport from early endosomes to recycling endosomes, and decreasing DAT at the cell surface. These effects together increased DA in synaptic clefts, and led to dopaminergic neuron degeneration and motor dysfunction. Treatment with reserpine significantly decreased the swimming induced paralysis in VPS35-D620N worms, as compared with vehicle treated VPS35-D620N worms. Our studies not only provide novel insights into the mechanisms of VPS35-D620N-induced dopaminergic neuron degeneration and motor dysfunction via disruption of DAT function and the DA signaling pathway but also indicate a potential strategy to treat VPS35-D620N-related PD and other disorders.

Molecular Insight into Bubble Nucleation on the Surface with Wettability Transition at Controlled Temperatures.

A surface with a smart wettability transition has recently been proposed to enhance the boiling heat transfer in either macro- or microscale systems. This work explores the mechanisms of bubble nucleation on surfaces with wettability transitions at controlled temperatures by molecular simulations. The results of the interaction energy at the interface and potential energy distribution of water molecules show that the nanostructure promotes nucleation over the copper surface and causes lower absolute potential energy to provide fixed nucleation sites for the initial generation of the bubble nucleus and shortens the incipient nucleation time, as compared to the mixed-wettability or hydrophilic nanostructure surface. An investigation on more nanostructured surfaces shows that a surface (F) with a wettability transition temperature of 620.0 K has the shortest average incipient nucleation time at 1672 ps with a wall temperature of 634.3 K. The surface with tunable wettability has also a high interfacial thermal conductance at low superheats, but it may not promote the critical heat flux at high superheats. The heat-transfer performance of the smart surface is better than the plate, the hydrophobic nanostructure, and the mixed-wettability surfaces, while it is lower than the hydrophilic nanostructure surface. This proposes a new method and provides insight for promoting bubble nucleation on a surface with temperature-dependent wettability.

Simultaneous measurements of thin film thickness using total internal reflection fluorescence microscopy and disjoining pressure using Scheludko cell.

This work describes a method for measuring the thin film thickness using total internal reflection fluorescence microscopy, with the use of evanescent wave illumination. The thin liquid film was formed in a hole drilled at the center of a porous plate, which is used for measurement of the disjoining pressure by using the Scheludko cell method. The aim of simultaneous and in situ measurements of thin film thickness and disjoining pressure is to obtain the relationship between them, which is critical for explicitly depicting the thin film profile that determines the interfacial mass and heat fluxes in the thin film region near the triple line. This method can overcome the drawbacks of the optical methods that are insufficient for measuring the thickness of a thin film with curvature. The influence of structural forces formed by tracer nanoparticles seeded in the thin liquid film on the relationship was analyzed. The obtained expression for disjoining pressure vs thin film thickness provides a basis for analyzing the formation, evolution, and stability of the thin liquid film, which is the dominant mechanism of controlling the mesoscopic structure in many transport processes.

Fluid Flow and Thin-Film Evolution near the Triple Line during Droplet Evaporation of Self-Rewetting Fluids.

The microscopic region near the triple line plays an important role in the heat and mass transfer of droplets, although the mechanisms of evaporation and internal flow remain unclear. This paper describes an experimental study of fluid flow and thin-film evolution near the triple line in sessile droplets of self-rewetting fluids, aqueous solutions of alcohols with the number of carbon atoms varying from 1 to 7, to analyze the influence of various factors on the mesoscale flows. The mechanism of internal flow for self-rewetting fluid droplets was different from that of conventional fluids, and hence, a novel expression of the in-plane average velocity was fitted for them. The temporal and spatial evolution of the thin-film thickness near the triple line during droplet evaporation was obtained by using a proposed subregion method, which was developed from an evanescent-wave-based multilayer nanoparticle image velocimetry technique. The self-rewetting fluids are conducive to increase the microscopic critical contact angle and the energy barrier of the contact line, which reduces the rate of thin-film thickness variation. The inhibited impact of self-rewetting fluids on evaporation increases gradually with an increasing number of carbon atoms.

An experimental rabbit model of symptomatic cerebral vasospasm with in vivo neuroimaging assessment and ex vivo histological validation.

Cerebral vasospasm (CVS) is a severe complication that occurs following aneurysmal subarachnoid hemorrhage (SAH). Magnetic resonance angiography (MRA) has been used to evaluate brain injury following SAH in humans. The present study was designed to assess a rabbit model of symptomatic CVS (SCVS) and the utility of MRA in evaluating SCVS in rabbits. Japanese white rabbits (n=24) were randomly divided into 2 equal groups: A sham group and a SAH group. Neurological scores were evaluated for 7 days following SAH. Basilar artery (BA) diameters were measured using MRA preoperatively and 7 days postoperatively. Rabbits were sacrificed 7 days following SAH and the BA diameter of each rabbit was determined using histological evaluation. Compared with the Sham group, neurological function was significantly reduced in the SAH group at all time points (P<0.05). Furthermore, the BA diameter was significantly smaller in the SAH group on day 7 compared with the baseline measurement (P<0.05). No significant difference was observed between histological and MRA findings in either group at day 7. Histological changes in the hippocampus consistent with ischemia were observed in the SAH group. Hippocampal ischemia was also identified in the SAH group via MRA and there was no difference in detection rates following the use of MRA and histochemistry. MRA appears to be an effective method for assessing vasospasms of the BA and ischemic changes to the hippocampus in a rabbit model of SCVS. Furthermore, the animal model used in the present study may be beneficial for the future study of SCVS.

Parkinson's disease-associated pathogenic VPS35 mutation causes complex I deficits.

Defect in the complex I of the mitochondrial electron-transport chain is a characteristic of Parkinson's disease (PD) which is thought to play a critical role in the disease pathogenesis. Mutations in vacuolar protein sorting 35 (VPS35) cause autosomal dominant PD and we recently demonstrated that pathogenic VPS35 mutations cause mitochondrial damage through enhanced mitochondrial fragmentation. In this study, we aimed to determine whether pathogenic VPS35 mutation impacts the activity of complex I and its underlying mechanism. Indeed, VPS35 D620N mutation led to decreased enzymatic activity and respiratory defects in complex I and II in patient fibroblasts. While no changes in the expression of the complex I and II subunits were noted, the level of assembled complex I and II as well as the supercomplex was significantly reduced in D620N fibroblasts. Importantly, inhibition of mitochondrial fission rescued the contents of assembled complexes as well as the functional defects in complex I and II. Overall, these results suggest that VPS35 D620N mutation-induced excessive mitochondrial fission leads to the defects in the assembled complex I and supercomplex and causes bioenergetics deficits.

Deposition pattern and tracer particle motion of evaporating multi-component sessile droplets.

The understanding of near-wall motion, evaporation behavior and dry pattern of sessile nanofluid droplets is fundamental to a wide range of applications such as painting, spray drying, thin film coating, fuel injection and inkjet printing. However, a deep insight into the heat transfer, fluid flow, near-wall particle velocity and their effects on the resulting dry patterns is still much needed to take the full advantage of these nano-sized particles in the droplet. This work investigates the effect of direct absorptive silicon/silver (Si/Ag) hybrid nanofluids via two experiments. The first experiment identifies the motion of tracer particles near the triple line of a sessile nanofluid droplet on a super-hydrophilic substrate under ambient conditions by the multilayer nanoparticle image velocimetry (MnPIV) technique. The second experiment reveals the effect of light-sensitive Si/Ag composite nanoparticles on the droplet evaporation rate and subsequent drying patterns under different radiation intensities. The results show that the presence of nanoparticle in a very small proportion significantly affects the motion of tracer particles, leading to different drying patterns and evaporation rates, which can be very important for the applications such as spray coating and inkjet printing.

A conserved retromer sorting motif is essential for mitochondrial DLP1 recycling by VPS35 in Parkinson's disease model.

Impaired mitochondria dynamics and quality control are involved in mitochondrial dysfunction and pathogenesis of Parkinson's disease (PD). VPS35 mutations cause autosomal dominant PD and we recently demonstrated that fPD-associated VPS35 mutants can cause mitochondrial fragmentation through enhanced VPS35-DLP1 interaction. In this study, we focused on the specific sites on DLP1 responsible for the VPS35-DLP1 interaction. A highly conserved FLV motif was identified in the C-terminus of DLP1, mutation of which significantly reduced VPS35-DLP1 interaction. A decoy peptide design based on this FLV motif could block the VPS35-DLP1 interaction and inhibit the recycling of mitochondrial DLP1 complexes. Importantly, VPS35 D620N mutant-induced mitochondrial fragmentation and respiratory deficits could be rescued by the treatment of this decoy peptide in both M17 cells overexpressing D620N or PD fibroblasts bearing this mutation. Overall, our results lend further support to the notion that VPS35-DLP1 interaction is key to the retromer-dependent recycling of mitochondrial DLP1 complex during mitochondrial fission and provide a novel therapeutic target to control excessive fission and associated mitochondrial deficits.

Near-Field Radiative Heat Transfer Between Two SiC Plates With/Without Coated Metal Films.

Near-field radiation is important in many nanotechnological applications, such as thermophotovoltaic system. In this paper, we employ the Rytov theory to calculate the near-field heat transfer between two silicon carbide (SiC) plates at finite vacuum gaps. The result shows that the total energy transfer rate increases with decreasing distance, and a maximum energy transfer rate can be found with respect to frequency. We then analyze the near-field thermal radiation of an aluminum-coated SiC plane in vacuum. The relation among film thickness, gap distance and energy density is given. It shows that the contribution of transverse electric (TE) mode to the energy density vanishes when the film thickness is nearly zero; and the contribution of transverse magnetic (TM) mode increases, but remains finite that can be illustrated by simple Drude model. The spectral density of p state of the thermally stimulated field in the vacuum-Al-SiC structure with fixed film thickness would have more resonance and large value can be obtained when increasing the distance; while the spectral density of p state in the thermally stimulated field in the structure with fixed distance has no apparent difference when varying the film thicknesses. This investigation can be extended for many other basic researches in near-field radiation.

Near-Wall Velocity and Temperature Measurements in the Meniscus Region for Staggered Glass Beads.

Velocity and temperature fields in the meniscus are crucial for the heat transfer mechanism in porous medium. The meniscus zone, however, is narrow so that it is difficult for observation. The velocimetry and thermometry in the near-wall region of the surface provide possible measurement methods with the development of micro/nanotechnology. Being exponentially decay in the intensity, the evanescent-wave illumination has the advantage of high spatial resolution and non-intrusion for these measurement methods. The multilayer nano-particle image velocimetry (MnPIV) uses the evanescent-wave illumination, decayed exponentially with the wall-normal distance, to obtain near-wall velocity data at different distances from the wall. The thermometry in the meniscus region could also use the evanescent-wave to illuminate the fluorescence dye, the emitted intensity of which changes with temperature. In this paper, these techniques are employed to measure the near-wall velocity and temperature between the porous media and the ITO heater, in order to explore the role of meniscus during convection of water. Near-wall velocity and temperature of the deionized water, seeded with 100 nm fluorescent colloidal tracers and flow in the staggered glass beads with diameters ranging from 2 mm to 6 mm, are obtained and discussed.

Levobupivacaine inhibits lipopolysaccharide-induced high mobility group box 1 release in vitro and in vivo.

BACKGROUND: The aim of the study was to investigate whether levobupivacaine (LB) suppressed lipopolysaccharide (LPS)-induced high mobility group box 1 (HMGB1) release in vitro and in vivo, and to determin its molecular mechanisms of action. MATERIALS AND METHODS: RAW264.7 cells were treated with LPS and LB for 24 h. Levels of HMGB1, nuclear factor-kappa B (NF-κB) and phosphorylated p38 mitogen-activated protein kinase (MAPK) were measured by Enzyme-linked immunosorbent assay and Western blotting; the levels of HMGB1 messenger RNA were measured by real-time polymerase chain reaction. In addition, cecal ligation and puncture-induced septic C57BL/6 received LB infusion, and the levels of HMGB1 and functional parameters of multiple organs determined using several detection kits. RESULTS: LB inhibited HMGB1 release in vitro and in vivo. Furthermore, LB inhibited the translocation of NF-κB and phosphorylation of p38 MAPK in vitro. Mice treated with LB infusion improved survival in mice and significantly reduced cecal ligation and puncture-induced dysfunction of organs. CONCLUSIONS: LB suppresses LPS-induced HMGB1 release in vitro and in vivo by partially inhibiting NF-κB/p38 MAPK pathways. LB can rescue mice from sepsis and protect against organ dysfunction in septic mice.

[Effects of human urinary tissue kallikreins on vasodilation of basilar artery in rabbits with symptomatic cerebral vasospasm].

OBJECTIVE: To evaluate the effects of urinary kallidinogenase on subarachnoid hemorrhage (SAH) in rabbits. METHODS: Rabbits symptomatic cerebral vasospasm model was built though Endo method, among the 40 rabbits, 8 died or had severe nervous system syndrome, the other 32 were randomly divided into 4 groups:group A, control group, injection of normal saline to the cisterna magna;group B, subarachnoid hemorrhage;group C, injection of human urinary tissue kallikreins;group D, treated with Nimodipine. The behavior scores, neurological scores and cerebral angiography changes were observed. RESULTS: Food intake obviously decreased and neurological deficit were seen in group B, while which were attenuated in group C and group D, and group A was normal. Comparing the diameter of basilar artery was (1.9 +/- 0.3) mm before SAH, the diameter of group B 4 d later was (1.5 +/- 0.3) mm, 7 d later (1.4 +/- 0.3) mm, the difference was significant (P < 0.05). Comparing with group C on the day 4th and 7th, the diameters of basilar artery were significantly different (P < 0.001). Comparing with group D on the day 4th, 7th and 14th, there was no obvious improvement. CONCLUSION: Urinary kallidinogenase and Nimodipine can obviously alleviate symptomatic cerebral vasospasm in rabbits remarkably, but the former's effect of attenuating vasospasm is better than that of Nimodipine.

[Effects of human tissue kallikrein on cerebral vasospasm: experiment with rabbits].

OBJECTIVE: To study the effects of human tissue kallikrein (HTK) on symptomatic cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH). METHODS: Forty rabbits underwent occlusion of bilateral carotid. Two weeks later the 28 surviving rabbits were randomly divided into to 4 groups: shamed-operation group (n = 8) undergoing injection of normal saline into the cisterna magna on day 1 and day 3, SAH group (n = 6) undergoing injection of nonheparinized autologous arterial blood into the cisterna magna, HTK therapy group (n = 6) undergoing blood injection into the cisterna magna and then injection of HTK via ear marginal vein daily for 3 days, and nimodipine (ND) therapy group (n = 6) undergoing blood injection into the cisterna magna and then injection of ND via ear marginal vein. 3-dimension-CT angiography (3-D CTA) was used to measure the basilar artery diameter on D(0) and D(5). On D(6) the rabbits were killed with their basilar arteries taken out to undergo light microscopic examination. RESULTS: Blood could be seen in the basis cephalic of the 3 groups undergoing blood injection. 3-D CTA showed that arteriospasm was seen in the SAH and ND groups but not in the HTK group. Microscopy showed obvious pathological changes in basilar artery in the SAH and ND groups but not in the HTK group. CONCLUSION: HTK given early after SAH effectively alleviates the symptomatic cerebral vasospasm.