Autonomic ganglionic injection of α-synuclein fibrils as a model of pure autonomic failure α-synucleinopathy.

α-Synucleinopathies are characterized by autonomic dysfunction and motor impairments. In the pure autonomic failure (PAF), α-synuclein (α-Syn) pathology is confined within the autonomic nervous system with no motor features, but mouse models recapitulating PAF without motor dysfunction are lacking. Here, we show that in TgM83+/- mice, inoculation of α-Syn preformed fibrils (PFFs) into the stellate and celiac ganglia induces spreading of α-Syn pathology only through the autonomic pathway to both the central nervous system (CNS) and the autonomic innervation of peripheral organs bidirectionally. In parallel, the mice develop autonomic dysfunction, featured by orthostatic hypotension, constipation, hypohidrosis and hyposmia, without motor dysfunction. Thus, we have generated a mouse model of pure autonomic dysfunction caused by α-Syn pathology. This model may help define the mechanistic link between transmission of pathological α-Syn and the cardinal features of autonomic dysfunction in α-synucleinopathy.

Rational modulation of coumarin-hemicyanine platform based on OH substitution for higher selective detection of hypochlorite.

To monitor delicate changes of biological HOCl in vivo, a new probe (OH-substituted coumarin-hemicyanine, probe 2) was synthesized for NIR and ratiometric HOCl detection. Selectivity studies indicated that the electron-donating group (OH) substituted on the indolium moiety enhanced the selectivity to detect HOCl. With HOCl, the probe showed a ratiometric fluorescence (I500/I650) with a low detection limit (49.1 nM) and a rapid response (within 2 min). In addition, probe 2 was successfully applied to visualize exogenous and endogenous HOCl in living cells and animals and exhibited a perfect mitochondria target ability. This probe has been further studied as a potential and powerful tool to probe HOCl in arthritis models.

The Arabidopsis UDP-glycosyltransferase75B1, conjugates abscisic acid and affects plant response to abiotic stresses.

KEY MESSAGE: This study revealed that the Arabidopsis UGT75B1 plays an important role in modulating ABA activity by glycosylation when confronting stress environments. The cellular ABA content and activity can be tightly controlled in several ways, one of which is glycosylation by family 1 UDP-glycosyltransferases (UGTs). Previous analysis has shown UGT75B1 activity towards ABA in vitro. However, the biological role of UGT75B1 remains to be elucidated. Here, we characterized the function of UGT75B1 in abiotic stress responses via ABA glycosylation. GUS assay and qRT-PCR indicated that UGT75B1 is significantly upregulated by adverse conditions, such as osmotic stress, salinity and ABA. Overexpression of UGT75B1 in Arabidopsis leads to higher seed germination rates and seedling greening rates upon exposure to salt and osmotic stresses. In contrast, the big UGT75B1 overexpression plants are more sensitive under salt and osmotic stresses. Additionally, the UGT75B1 overexpression plants showed larger stomatal aperture and more water loss under drought condition, which can be explained by lower ABA levels examined in UGT75B1 OE plants in response to water deficit conditions. Consistently, UGT75B1 ectopic expression leads to downregulation of many ABA-responsive genes under stress conditions, including ABI3, ABI5 newly germinated seedlings and RD29A, KIN1, AIL1 in big plants. In summary, our results revealed that the Arabidopsis UGT75B1 plays an important role in coping with abiotic stresses via glycosylation of ABA.

Design, synthesis and evaluation of novel ferulic acid derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

A series of new ferulic acid derivatives were designed, synthesized and evaluated as multi-target inhibitors against Alzheimer's disease. In vitro studies indicated that most compounds showed significant potency to inhibit self-induced ß-amyloid (Aß) aggregation and acetylcholinesterase (AChE), and had good antioxidant activity. Specifically, compound 4g exhibited the potent ability to inhibit cholinesterase (ChE) (IC50, 19.7 nM for hAChE and 0.66 µM for hBuChE) and the good Aß aggregation inhibition (49.2% at 20 µM), and it was also a good antioxidant (1.26 trolox equivalents). Kinetic and molecular modeling studies showed that compound 4g was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, compound 4g could remarkably increase PC12 cells viability in hydrogen peroxide-induced oxidative cell damage and Aß-induced cell damage. Finally, compound 4g had good ability to cross the BBB using the PAMPA-BBB assay. These results suggested that compound 4g was a promising multifunctional ChE inhibitor for the further investigation.

A Ratiometric and Colorimetric Hemicyanine Fluorescent Probe for Detection of SO2 Derivatives and Its Applications in Bioimaging.

Based upon the intramolecular charge transfer (ICT) mechanism, a novel ratiometric fluorescent probe EB was developed to detect SO32-/HSO3-. The probe displayed both colorimetric and ratiometric responses toward SO32-/HSO3-. It displayed a quick response (within 60 s), good selectivity and high sensitivity (a detection limit of 28 nM) towards SO32-/HSO3-. The SO32-/HSO3- sensing mechanism was confirmed as the Michael addition reaction by ESI-MS. Moreover, the probe could be applied to measure the level of sulfite in real samples, like sugar and chrysanthemum, and it could also be used to detect SO32-/HSO3- in HepG2 cells through confocal fluorescence microscopy, which proved its practical application in clinical diagnosis.

A near-infrared Nile red fluorescent probe for the discrimination of biothiols by dual-channel response and its bioimaging applications in living cells and animals.

Biothiols, including cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and H2S, play important roles in human physiological processes. However, it is a great difficulty to distinguish biothiols from each other because of their similar chemical properties. Based on Nile red, we have designed and synthesized a near-infrared fluorescent probe for discriminating Cys/Hcy from GSH/H2S by a dual-channel detection method. Using an ether bond, near-infrared Nile red was attached to 7-nitrobenzofurazan to construct the probe. Due to the photo-induced electron transfer, the probe showed almost no fluorescence from the green to red emission band. But upon the addition of Cys (0-150 µM) or Hcy (0-200 µM), the probe exhibited a noteworthy fluorescence "turn-on" signal in two unique emission bands (Green and Red) with a fast response (within 30 min). In contrast, the probe displayed an increase in fluorescence only in the red channel when encountering GSH (0-70 µM) or H2S (0-50 µM), and GSH/H2S could be tested respectively by different response time. The limit of detection was calculated to be 0.09 µM (Cys), 0.30 µM (Hcy), 0.24 µM (GSH), and 0.04 µM (H2S), respectively (based on S/N = 3). The desirable dual-channel detection could be achieved in serum samples and living cells. Moreover, the probe could be applied for bioimaging in mice, which indicated its potential application in the clinic.

Ectopic expression of UGT84A2 delayed flowering by indole-3-butyric acid-mediated transcriptional repression of ARF6 and ARF8 genes in Arabidopsis.

KEY MESSAGE: Ectopic expression of auxin glycosyltransferase UGT84A2 in Arabidopsis can delay flowering through increased indole-3-butyric acid and suppressed transcription of ARF6, ARF8 and flowering-related genes FT, SOC1, AP1 and LFY. Auxins are critical regulators for plant growth and developmental processes. Auxin homeostasis is thus an important issue for plant biology. Here, we identified an indole-3-butyric acid (IBA)-specific glycosyltransferase, UGT84A2, and characterized its role in Arabidopsis flowering development. UGT84A2 could catalyze the glycosylation of IBA, but not indole-3-acetic acid (IAA). UGT84A2 transcription expression was clearly induced by IBA. When ectopically expressing in Arabidopsis, UGT84A2 caused obvious delay in flowering. Correspondingly, the increase of IBA level, the down-regulation of AUXIN RESPONSE FACTOR 6 (ARF6) and ARF8, and the down-regulation of flowering-related genes such as FLOWERING LOCUS T (FT), SUPPRESSOR OF OVEREXPRESSION OF CO1(SOC1), APETALA1 (AP1), and LEAFY(LFY) were observed in transgenic plants. When exogenously applying IBA to wild-type plants, the late flowering phenotype, the down-regulation of ARF6, ARF8 and flowering-related genes recurred. We examined the arf6arf8 double mutants and found that the expression of flowering-related genes was also substantially decreased in these mutants. Together, our results suggest that glycosyltransferase UGT84A2 may be involved in flowering regulation through indole-3-butyric acid-mediated transcriptional repression of ARF6, ARF8 and downstream flowering pathway genes.

The Arabidopsis UDP-glycosyltransferases UGT79B2 and UGT79B3, contribute to cold, salt and drought stress tolerance via modulating anthocyanin accumulation.

The plant family 1 UDP-glycosyltransferases (UGTs) are the biggest GT family in plants, which are responsible for transferring sugar moieties onto a variety of small molecules, and control many metabolic processes; however, their physiological significance in planta is largely unknown. Here, we revealed that two Arabidopsis glycosyltransferase genes, UGT79B2 and UGT79B3, could be strongly induced by various abiotic stresses, including cold, salt and drought stresses. Overexpression of UGT79B2/B3 significantly enhanced plant tolerance to low temperatures as well as drought and salt stresses, whereas the ugt79b2/b3 double mutants generated by RNAi (RNA interference) and CRISPR-Cas9 strategies were more susceptible to adverse conditions. Interestingly, the expression of UGT79B2 and UGT79B3 is directly controlled by CBF1 (CRT/DRE-binding factor 1, also named DREB1B) in response to low temperatures. Furthermore, we identified the enzyme activities of UGT79B2/B3 in adding UDP-rhamnose to cyanidin and cyanidin 3-O-glucoside. Ectopic expression of UGT79B2/B3 significantly increased the anthocyanin accumulation, and enhanced the antioxidant activity in coping with abiotic stresses, whereas the ugt79b2/b3 double mutants showed reduced anthocyanin levels. When overexpressing UGT79B2/B3 in tt18 (transparent testa 18), a mutant that cannot synthesize anthocyanins, both genes fail to improve plant adaptation to stress. Taken together, we demonstrate that UGT79B2 and UGT79B3, identified as anthocyanin rhamnosyltransferases, are regulated by CBF1 and confer abiotic stress tolerance via modulating anthocyanin accumulation.

Ectopic expression of UGT75D1, a glycosyltransferase preferring indole-3-butyric acid, modulates cotyledon development and stress tolerance in seed germination of Arabidopsis thaliana.

The formation of auxin glucose conjugate is proposed to be one of the molecular modifications controlling auxin homeostasis. However, the involved mechanisms and relevant physiological significances are largely unknown or poorly understood. In this study, Arabidopsis UGT75D1 was at the first time identified to be an indole-3-butyric acid (IBA) preferring glycosyltransferase. Assessment of enzyme activity and IBA conjugates in transgenic plants ectopically expressing UGT75D1 indicated that the UGT75D1 catalytic specificity was maintained in planta. It was found that the expression pattern of UGT75D1 was specific in germinating seeds. Consistently, we found that transgenic seedlings with over-produced UGT75D1 exhibited smaller cotyledons and cotyledon epidermal cells than the wild type. In addition, UGT75D1 was found to be up-regulated under mannitol, salt and ABA treatments and the over-expression lines were tolerant to osmotic and salt stresses during germination, resulting in an increased germination rate. Quantitative RT-PCR analysis revealed that the mRNA levels of ABA INSENSITIVE 3 (ABI3) and ABI5 gene in ABA signaling were substantially down-regulated in the transgenic lines under stress treatments. Interestingly, AUXIN RESPONSE FACTOR 16 (ARF16) gene of transgenic lines was also dramatically down-regulated under the same stress conditions. Since ARF16 functions as an activator of ABI3 transcription, we supposed that UGT75D1 might play a role in stress tolerance during germination through modulating ARF16-ABI3 signaling. Taken together, our work indicated that, serving as the IBA preferring glycosyltransferase but distinct from other auxin glycosyltransferases identified so far, UGT75D1 might be a very important player mediating a crosstalk between cotyledon development and stress tolerance of germination at the early stage of plant growth.

[Peri-operative management of fracture in patients with diabetes mellitus].

OBJECTIVE: To study the characters of the treatment of perioperative period in fractures with diabetes mellitus (DM) and the effect of diabetes on the treatment of them. METHODS: To retrospectively analyze the clinical data of 97 fracture patients with DM (DM group) who accepted operation. Compare the difference of the average hospitalized length, medical cost and the incidence of postoperative complications with the controls. RESULTS: (1) Insulin dosage was less in postoperative period (0.5 +/- 0.2) U.d(-1).kg(-1) than steady period (0.7 +/- 0.2) U.d(-1).kg(-1) and operative period (0.7 +/- 0.3) U.d(-1).kg(-1), the difference is significant (P < 0.05); (2) There were more complications in DM group than that in the control group before operation. The fractured patients with DM could receive operation after preoperative treatment and improving micro-circulation; (3) Compared with control group, DM group had longer preoperative preparation period of in-hospital duration, and higher in-hospital medical costs; (4) There were no significant difference between DM group and control group (P > 0.05) in postoperative complications and wound healing. CONCLUSIONS: Fractured patients with DM should take effective methods to treat complications of DM and do adequate preparation for the operation. Rational treatment of preoperative complications is very important for preventing postoperative one and guarantee operation successful. But the longer of hospitalized length is, the higher of in-hospital medical costs are.