Publications by authors named "Shiyun Jin"

10 Publications

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Spinal astrocyte aldehyde dehydrogenase-2 mediates ethanol metabolism and analgesia in mice.

Br J Anaesth 2021 08 29;127(2):296-309. Epub 2021 Apr 29.

Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA. Electronic address:

Background: Little is known about the targets in the CNS that mediate ethanol analgesia. This study explores the role of spinal astrocyte aldehyde dehydrogenase-2 (ALDH2), a key ethanol-metabolising enzyme, in the analgesic effects of ethanol in mice.

Methods: Astrocyte and hepatocyte ALHD2-deficient mice were generated and tested in acute and chronic pain models. Cell-type-specific distribution of ALDH2 was analysed by RNA in situ hybridisation in spinal slices from astrocytic ALDH2-deficient mice and their wild-type littermates. Spinal ethanol metabolites and γ-aminobutyric acid (GABA) content were measured using gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry.

Results: ALDH2 mRNA was expressed in both astrocytes and neurones in spinal cord slices. Astrocyte ALDH2-deficient mice had decreased expression of ALDH2 mRNA in astrocytes, but not in neurones. Astrocyte ALDH2 deficiency inhibited ethanol-derived acetate, but not acetaldehyde content in spinal cord tissues. Depletion of spinal astrocyte ALDH2 selectively inhibited ethanol-induced anti-nociceptive effect, but not the effect of ethanol, on motor function. Astrocyte ALDH2 deficiency abolished ethanol-induced GABA elevation. The ethanol metabolite acetate produced anti-nociception and increased GABA synthesis in a manner similar to ethanol. I.T. delivery of either GABA or GABA receptor antagonists prevented ethanol and acetate-induced analgesia.

Conclusions: These findings provide evidence that ALDH2 in spinal astrocytes mediates spinal ethanol metabolism and ethanol-induced analgesic effects by promoting GABA synthesis and GABAergic transmission in spinal cord.
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http://dx.doi.org/10.1016/j.bja.2021.02.035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8362281PMC
August 2021

Brain ethanol metabolism by astrocytic ALDH2 drives the behavioural effects of ethanol intoxication.

Nat Metab 2021 03 22;3(3):337-351. Epub 2021 Mar 22.

Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.

Alcohol is among the most widely used psychoactive substances worldwide. Ethanol metabolites such as acetate, thought to be primarily the result of ethanol breakdown by hepatic aldehyde dehydrogenase 2 (ALDH2), contribute to alcohol's behavioural effects and alcoholism. Here, we show that ALDH2 is expressed in astrocytes in the mouse cerebellum and that ethanol metabolism by astrocytic ALDH2 mediates behavioural effects associated with ethanol intoxication. We show that ALDH2 is expressed in astrocytes in specific brain regions and that astrocytic, but not hepatocytic, ALDH2 is required to produce ethanol-derived acetate in the mouse cerebellum. Cerebellar astrocytic ALDH2 mediates low-dose ethanol-induced elevation of GABA levels, enhancement of tonic inhibition and impairment of balance and coordination skills. Thus, astrocytic ALDH2 controls the production, cellular and behavioural effects of alcohol metabolites in a brain-region-specific manner. Our data indicate that astrocytic ALDH2 is an important, but previously under-recognized, target in the brain to alter alcohol pharmacokinetics and potentially treat alcohol use disorder.
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http://dx.doi.org/10.1038/s42255-021-00357-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8294184PMC
March 2021

The incommensurately modulated structures of low-temperature labradorite feldspars: a single-crystal X-ray and neutron diffraction study.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2020 Feb 28;76(Pt 1):93-107. Epub 2020 Jan 28.

Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA.

Labradorite feldspars of the plagioclase solid solution series have been known for their complicated subsolidus phase relations and enigmatic incommensurately modulated structures. Characterized by the irrationally indexed e-reflections in the diffraction pattern, e-labradorite shows the largest variation in the incommensurate ordering states among the e-plagioclase structures. The strongly ordered low-temperature e-labradorite is one of the last missing pieces of the e-plagioclase puzzle. Nine plutonic and metamorphic labradorite feldspar samples from Canada, Ukraine, Minnesota (USA), Tanzania and Greenland with compositions ranging from An to An were studied with single-crystal X-ray diffraction. Two crystals from Labrador, Canada, and Duluth, MN, USA, with wide enough twin lamellae were analyzed with single-crystal neutron diffraction. The incommensurately modulated structures of e-plagioclase are refined for the first time with neutron diffraction data, which confirmed that the T-O distance modulation in the low-temperature e-plagioclase results from the Al-Si ordering in the framework. Detailed configurations of the M site are also observed in the structures refined from neutron diffraction data, which were not possible to see with X-ray diffraction data. The relation between the q-vectors and the mole% An composition is revealed for the entire compositional range of e-plagioclase, from An to An. The previously proposed two-trend relation depending on the cooling rate and phase transition path is confirmed. A new classification of e-plagioclase (e, e and e) is proposed based on the q-vector of the structure, which makes it an independent character from the presence/absence of density modulation. New parameters are proposed to quantify the ordering states of these complicated aperiodic structures of e-plagioclases, such as the difference between 〈To-O〉 and 〈Tm-O〉 at phase t = 0.2 or the normalized intensity of the (071\bar 1) reflection.
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http://dx.doi.org/10.1107/S2052520619017128DOI Listing
February 2020

The incommensurately modulated structures of volcanic plagioclase: displacement, ordering and phase transition.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2019 Aug 13;75(Pt 4):643-656. Epub 2019 Jul 13.

Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA.

Four basaltic phenocryst samples of plagioclase, with compositions ranging from An (andesine) to An (labradorite), have been studied with single-crystal X-ray and neutron diffraction techniques. The samples were also subjected to a heating experiment at 1100°C for two weeks in an effort to minimize the Al-Si ordering in their structures. The average and the modulated structures of the samples (before and after the heating experiment) were compared, in order to understand the mechanism of the phase transition from the disordered C\bar 1 structure to the e-plagioclase structure. A comparison between the structures from neutron and X-ray diffraction data shows that the 〈T-O〉 distance does not solely depend on the Al occupancy as previously thought. A dramatic decrease of the Al-Si ordering is observed after heating at 1100°C for two weeks for all four samples, with an obvious change in the intensities of the satellite reflections (e-reflections) in the diffraction pattern. Evident changes in the modulation period were also observed for the more calcic samples. No obvious change in the Ca-Na ordering was observed after the heating experiment. An in situ heating X-ray diffraction experiment was carried out on the andesine sample (An) to study the change in the satellite intensity at high temperature. A dramatic weakening of the satellite peaks was observed between 477°C and 537°C, which strongly supports the displacive nature of the initiation of e2 ordering. Rigid-Unit Mode (RUM) analysis of the plagioclase structure suggests the initial position of the e-reflections is determined by the anti-RUMs in the framework.
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http://dx.doi.org/10.1107/S2052520619006243DOI Listing
August 2019

Inhibition of DRG-TRPV1 upregulation in myocardial ischemia contributes to exogenous cardioprotection.

J Mol Cell Cardiol 2020 01 10;138:175-184. Epub 2019 Dec 10.

Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601, China; Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China. Electronic address:

Myocardium ischemia-reperfusion injury (IRI) is the major cause of postoperative cardiac dysfunction. While intrathecal morphine preconditioning (ITMP) can reduce IRI in animals, the molecular processes underlying IRI and ITMP remain elusive. Transient receptor potential vanilloid type 1 (TRPV1) is highly expressed in cardiac sensory neurons and has a crucial role in detecting myocardial ischemia. This study aimed to determine the role of up-regulated dorsal root ganglion (DRG)-TRPV1 in IRI and whether its inhibition contributes to ITMP-induced cardioprotection. Animal model of IRI was established by left coronary artery occlusion (30 min) and reperfusion (2 h) in rats. Intrathecal intubation was prepared for morphine preconditioning, TRPV1-shRNA or selective TRPV1 antagonist administration. After IRI, both protein and phosphorylation levels of TRPV1 were significantly increased, and the immunofluorescence intensity of TRPV1 was increased and colocalized with μ-opioid receptors in DRG. Intrathecal pre-administration of either TRPV1-shRNA or TRPV1 antagonist significantly reduced myocardial injury and the upregulation of TRPV1 in DRG induced by IRI. Simultaneously, ITMP significantly suppressed TRPV1 protein expression and phosphorylation in DRG, as well as the heart infarct size and arrhythmia score caused by IRI. The suppression of TRPV1 elevation and activation by ITMP were reversed by intrathecal injection of the selective μ receptor antagonist. Furthermore, IRI elevated DRG cAMP, while intrathecal administration of the selective cAMP-PKA inhibitor reduced myocardial injury. Finally, we showed that activation of opioid receptor by morphine inhibited PKA activator-induced TRPV1 channel activity at the cellular level. These findings suggest that the elevation and activation of TRPV1 in DRG during myocardial ischemia-reperfusion might be responsible for cardiac injury. ITMP exerts cardioprotection by inhibiting DRG-TRPV1 activity via modulation cAMP. Therefore, inhibition of TRPV1 upregulation in DRG might be used as a novel therapeutic mechanism for myocardium ischemia-reperfusion injury.
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http://dx.doi.org/10.1016/j.yjmcc.2019.12.003DOI Listing
January 2020

Jinshajiangite: structure, twinning and pseudosymmetry.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2018 Aug 5;74(Pt 4):325-336. Epub 2018 Jun 5.

Institute of Geochemistry at Guiyang, Chinese Academy of Science, Guiyang, Guizhou, People's Republic of China.

The crystal structure of jinshajiangite based on a sample from its original discovery location is studied using single-crystal X-ray diffraction and transmission electron microscopy methods. Jinshajiangite is a titanium silicate mineral with an ideal chemical formula of BaNaFeTi(SiO)O(OH)F. The structure of jinshajiangite is of P\bar 1 symmetry (triclinic system), with a = 8.7331 (2) Å, b = 8.7366 (2) Å, c = 11.0404 (3) Å, α = 81.477 (1)°, β = 110.184 (1)°, γ = 104.384 (1)° and V = 764.03 (3) Å, instead of the previously proposed C\bar 1 cell [a = 10.7059 (5) Å, b = 13.7992 (7) Å, c = 20.760 (1) Å, α = 90.008 (1)°, β = 94.972 (1)°, γ = 89.984 (1)°, V = 3055.4 (4) Å]. The basic topology of the new structure is similar to the previously proposed C\bar 1 structure, except there is only one type of titanium silicate and intermediate cation layer in the structure (instead of two types), which are all related by the translation along the c-axis. Even though there is a significant amount of Mn in the chemical composition, no obvious ordering between Fe and Mn is observed in the structure. All the mineral species of the perraultite-type structure (jinshajiangite, perraultite, surkhobite and bobshannonite) should have the same P\bar 1 structure as jinshajiangite with ∼10 Å d spacing, and all the previously proposed monoclinic space groups were pseudosymmetry generated by nanoscale polysynthetic twinning on the (001) composition plane. The similar phenomenon observed in bafertisite is also discussed in the paper with an alternative polytype structure model proposed.
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http://dx.doi.org/10.1107/S2052520618006753DOI Listing
August 2018

Minimum Alveolar Concentration-Awake of Sevoflurane Is Decreased in Patients With End-Stage Renal Disease.

Anesth Analg 2019 01;128(1):77-82

From the Department of Anesthesiology, Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.

Background: End-stage renal disease (ESRD) has been shown to be associated with abnormal neural function. Clinically used inhaled anesthetic agents typically exert their effect through multiple target receptors in the central nervous system. Pathological changes in the brain may alter sensitivity to inhaled anesthetic agents. This study aimed to determine the minimum alveolar concentration-awake (MACawake) of sevoflurane in patients with ESRD compared to patients with normal renal function.

Methods: Patients underwent inhalational induction of anesthesia and received sevoflurane at a preselected concentration according to a modified Dixon "up-and-down" method starting at 1.0% with a step size of 0.2%. The concentration of sevoflurane used for each consecutive patient was increased or decreased based on a positive or negative response to verbal command in the previous patient. Serum neuron-specific enolase, a biomarker of impaired neurons, was also measured.

Results: Forty-one patients were enrolled: 20 with ESRD and 21 as controls. The MACawake of sevoflurane in patients with ESRD was significantly lower than that observed in the control group (0.56% [standard deviation {SD} = 0.10%] vs 0.67% [SD = 0.08%]; P = .031). Patients with ESRD exhibited higher serum neuron-specific enolase levels compared to the control group (16.4 ng/mL [SD = 5.0] vs 8.7 ng/mL [SD = 2.9]; P < .001).

Conclusions: MACawake of sevoflurane is somewhat lower in patients with ESRD compared to those with normal renal function. Impaired cerebral function may partly contribute to the reduction in anesthetic requirement.
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http://dx.doi.org/10.1213/ANE.0000000000003676DOI Listing
January 2019

Revisiting the I{\overline {\bf 1}} structures of high-temperature Ca-rich plagioclase feldspar - a single-crystal neutron and X-ray diffraction study.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2018 Apr 17;74(Pt 2):152-164. Epub 2018 Mar 17.

Department of Geoscience, University of Wisconsin-Madison, 1215 West Dayton Street, Madison, WI 53706, USA.

The I{\overline 1} structures of four natural Ca-rich plagioclase feldspars formed at high temperature were analysed using single-crystal neutron and X-ray diffraction. The neutron time-of-flight Laue diffractometer at the ORNL Spallation Neutron Source (Tennessee, USA) combined with a single-crystal X-ray diffraction instrument were able to reveal some new details about these already intensively studied structures. The split oxygen atoms refined from the neutron diffraction data show the underlying mechanism of Ca-Na ordering and the anisotropic P{\overline 1} ordering along the c-axis. The compositional ranges covered by the samples studied are quite rare for I{\overline 1} structures. The incommensurately modulated e2 structure of some plagioclase samples can easily be confused with an I{\overline 1} structure from the diffraction pattern, which puts some previously published I{\overline 1} structures into question. An incomplete phase diagram for Ca-rich plagioclase feldspar is proposed to explain the rarity of the I{\overline 1} structure in this compositional range, and a time-temperature-transformation diagram for the composition ∼An is provided accordingly.
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http://dx.doi.org/10.1107/S2052520618003219DOI Listing
April 2018

Investigations of the phase relations among e1, e2 and C{\bar {\bf 1}} structures of Na-rich plagioclase feldspars: a single-crystal X-ray diffraction study.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2017 Oct 29;73(Pt 5):992-1006. Epub 2017 Sep 29.

Department of Geoscience, University of Wisconsin-Madison, 1215 W. Dayton St., Madison, WI 53706, USA.

The subsolidus phase relations of plagioclase feldspar solid solution have been puzzling mineralogists and petrologists for decades, mainly due to the complicated structures of intermediate plagioclase at low temperature. The crystal structures of 12 Na-rich plagioclase samples are investigated by single-crystal X-ray diffraction analyses. The samples studied cover a compositional range from An to An (An is anorthite, CaAlSiO), as well as a wide variety of origins, from extremely slow-cooled gabbroic rocks to pegmatite and metamorphic rocks. The structures fall into three different types: C{\bar 1}, e2 and e1, with an obviously increasing trend in the ordering states of the structures. The phase transitions from C{\bar 1} to e2 and e2 to e1 are both continuous in nature, as no abrupt structure change is required for the transformation. However, the structural difference between C\bar 1 and e1 is large enough to create a miscibility gap causing the Bøggild intergrowth. As the plagioclase structure becomes more and more ordered, Al-Si reorganization in the framework would occur before the ordering of Ca and Na in M sites. Dramatic variations of Na occupancy would only appear in e1 structure with density modulation. This result confirms that Al-Si ordering is the major driving force of the formation of e-plagioclase structure. The composition of the lower end of the Bøggild intergrowth is precisely constrained to An-An, based on the structural differences between two samples from the same pegmatite crystal. The modulation periods and directions of e-plagioclase are dependent on the conditions at which e-ordering starts to happen, other than the composition of the plagioclase. However, the three components (δh, δk and δl) of the q vector show strong linear correlations among one another, indicating some crystallographic constraint on the modulation direction which might be independent from the composition. The detailed subsolidus phase relations among e1, e2 and C{\bar 1} are illustrated with a local phase diagram, and schematic free energy curves at different temperatures are provided.
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http://dx.doi.org/10.1107/S2052520617010976DOI Listing
October 2017

Incommensurate density modulation in a Na-rich plagioclase feldspar: Z-contrast imaging and single-crystal X-ray diffraction study.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2016 Dec 1;72(Pt 6):904-915. Epub 2016 Dec 1.

Bruker AXS Inc., 5465 E. Cheryl Parkway, Madison, WI 53711, USA.

Plagioclase feldspars are the most abundant mineral in the Earth's crust. Intermediate plagioclase feldspars commonly display incommensurately modulated or aperiodic structures. Z-contrast images show both Ca-Na ordering and density modulation. The local structure of lamellae domains has I1-like symmetry. The neighboring lamellae domains are in an inversion twinning relationship. With a state-of-the-art X-ray diffraction unit, second-order satellite reflections (f-reflections) are observed for the first time in andesine (An), a Na-rich e-plagioclase. The f-reflections indicate a structure with a density modulation which is close to a Ca-rich e-plagioclase. The similarity between this e-andesine structure and previously solved e-labradorite structure is confirmed. Refinement of the structure shows density modulation of ∼ 7 mol % in compositional variation of the anorthite (An) component. The results from Z-contrast imaging and low-temperature single X-ray diffraction (XRD) provide a structure consistent with density modulation. The discovery of f-reflections in Na-rich e-plagioclase extends the composition range of e1 structure with density modulation to as low as at least An, which is the lower end of the composition range of Bøggild intergrowth. The new result supports the loop-shaped solvus for Bøggild intergrowth, below which is a homogenous stable area for e1 structure in the phase diagram. The phase transition between e2 structure without density modulation and e1 structure with density modulation should happen at low temperature. There is a change in modulation period accompanying the phase transition, as well as higher occupancy of Al in the To site. The andesine with density modulation also indicates extremely slow cooling of its host rock.
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http://dx.doi.org/10.1107/S205252061601578XDOI Listing
December 2016
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