TIAM-1 differentially regulates dendritic and axonal microtubule organization in patterning neuronal development through its multiple domains.

Axon and dendrite development require the cooperation of actin and microtubule cytoskeletons. Microtubules form a well-organized network to direct polarized trafficking and support neuronal processes formation with distinct actin structures. However, it is largely unknown how cytoskeleton regulators differentially regulate microtubule organization in axon and dendrite development. Here, we characterize the role of actin regulators in axon and dendrite development and show that the RacGEF TIAM-1 regulates dendritic patterns through its N-terminal domains and suppresses axon growth through its C-terminal domains. TIAM-1 maintains plus-end-out microtubule orientation in posterior dendrites and prevents the accumulation of microtubules in the axon. In somatodendritic regions, TIAM-1 interacts with UNC-119 and stabilizes the organization between actin filaments and microtubules. UNC-119 is required for TIAM-1 to control axon growth, and its expression levels determine axon length. Taken together, TIAM-1 regulates neuronal microtubule organization and patterns axon and dendrite development respectively through its different domains.

Palladium(0) π-Lewis Base Catalysis: Concept and Development.

The development of a new catalytic strategy plays a vital role in modern organic chemistry since it permits bond formation in an unprecedented and more efficient manner. Although the application of preformed metal complexes as π-base-activated reagents have enabled diverse transformations elegantly, the concept and strategy by directly utilizing transition metals as efficient π-Lewis base catalysts remain underdeveloped, especially in the field of asymmetric catalysis. Here, we outline our perspective on the discovery of palladium(0) as an efficient π-Lewis base catalyst, which is capable of increasing the highest occupied molecular orbital (HOMO) energy of both electron-neutral and electron-deficient 1,3-dienes and 1,3-enynes upon flexible η2-complexes formed in situ and resultant π-backdonation. Thus, fruitful carbon-carbon-forming reactions with diverse electrophiles can be achieved enantioselectively in a vinylogous addition pattern, which is conceptually different from the classical oxidative cyclization mechanism. Emphasis will be given to the concept and mechanism elucidation, catalytic features, and reaction design together with perspective on the further development of this emerging field.

Pd(0)-Catalyzed Asymmetric Cyclization/Coupling Cascade of Alkyne-Tethered Unsaturated Carbonyls: Development and Mechanism Elucidation.

While the Pd(0)-catalyzed cyclization of alkyne-tethered unsaturated carbonyl substrates has been reported, the mechanism has not been well elucidated, and the potential asymmetric version remains to be developed. Here, we disclose that a chiral Pd(0) complex can efficiently promote the desymmetrizative cyclization of alkyne-tethered cyclohexadienones in CH3OH, and the resultant Pd(II) intermediates further undergo an array of tandem coupling reactions, including Suzuki, Sonogashira, and even chemoselective reduction by CH3OH in the absence of additional coupling partners. As a result, a broad spectrum of hydrobenzofuran derivatives, having a tetra- or trisubstituted exo-alkene motif, is constructed with moderate to outstanding enantioselectivity in an exclusive cis-difunctionalization pattern. In addition, this enantioselective protocol can be well expanded to linear alkyne-tethered unsaturated carbonyls, and a new desymmetrizative and asymmetric cyclization/coupling cascade of bis-alkyne-tethered enones is further realized efficiently, furnishing diversely structured frameworks with high stereoselectivity. Moreover, kinetic transformation for various racemic alkyne-tethered enones can be accomplished under similar catalytic conditions, and unusual kinetic reactions by chemoselectively undertaking Suzuki or Sonogashira coupling, or reduction by CH3OH, occur sequentially, finally yielding two types of chiral products, both with high enantioselectivity via either ligand- or substrate-based control. The experimental results demonstrate that the current Pd(0)-based strategy is superior to the classical Pd(II)-catalyzed carbopalladation/cyclization process of the identical substrates with regard to enantioselectivity and synthetic versatility. Moreover, density functional theory calculations are conducted to rationalize the Pd(0)-catalyzed oxidative cyclometalation pathway in the key cyclization step, which leads to the observed cis-difunctionalized products exclusively.

Quantum pBac: An effective, high-capacity piggyBac-based gene integration vector system for unlocking gene therapy potential.

Recent advances in gene therapy have brought novel treatment options for cancer. However, the full potential of this approach has yet to be unlocked due to the limited payload capacity of commonly utilized viral vectors. Virus-free DNA transposons, including piggyBac, have the potential to obviate these shortcomings. In this study, we improved a previously modified piggyBac system with superior transposition efficiency. We demonstrated that the internal domain sequences (IDS) within the 3' terminal repeat domain of hyperactive piggyBac (hyPB) donor vector contain dominant enhancer elements. Plasmid-free donor vector devoid of IDS was used in conjunction with a helper plasmid expressing Quantum PBase™ v2 to generate an optimal piggyBac system, Quantum pBac™ (qPB), for use in T cells. qPB outperformed hyPB in CD20/CD19 CAR-T production in terms of performance as well as yield of the CAR-T cells produced. Furthermore, qPB also produced CAR-T cells with lower donor-associated variabilities compared to lentiviral vector. Importantly, qPB yielded mainly CD8+ CAR-TSCM cells, and the qPB-produced CAR-T cells effectively eliminated CD20/CD19-expressing tumor cells both in vitro and in vivo. Our findings confirm qPB as a promising virus-free vector system with an enhanced payload capacity to incorporate multiple genes. This highly efficient and potentially safe system will be expected to further advance gene therapy applications.

CRMP/UNC-33 organizes microtubule bundles for KIF5-mediated mitochondrial distribution to axon.

Neurons are highly specialized cells with polarized cellular processes and subcellular domains. As vital organelles for neuronal functions, mitochondria are distributed by microtubule-based transport systems. Although the essential components of mitochondrial transport including motors and cargo adaptors are identified, it is less clear how mitochondrial distribution among somato-dendritic and axonal compartment is regulated. Here, we systematically study mitochondrial motors, including four kinesins, KIF5, KIF17, KIF1, KLP-6, and dynein, and transport regulators in C. elegans PVD neurons. Among all these motors, we found that mitochondrial export from soma to neurites is mainly mediated by KIF5/UNC-116. Interestingly, UNC-116 is especially important for axonal mitochondria, while dynein removes mitochondria from all plus-end dendrites and the axon. We surprisingly found one mitochondrial transport regulator for minus-end dendritic compartment, TRAK-1, and two mitochondrial transport regulators for axonal compartment, CRMP/UNC-33 and JIP3/UNC-16. While JIP3/UNC-16 suppresses axonal mitochondria, CRMP/UNC-33 is critical for axonal mitochondria; nearly no axonal mitochondria present in unc-33 mutants. We showed that UNC-33 is essential for organizing the population of UNC-116-associated microtubule bundles, which are tracks for mitochondrial trafficking. Disarrangement of these tracks impedes mitochondrial transport to the axon. In summary, we identified a compartment-specific transport regulation of mitochondria by UNC-33 through organizing microtubule tracks for different kinesin motors other than microtubule polarity.

Enantioselective Construction of Eight-Membered N-Heterocycles from Simple 1,3-Dienes via Pd(0) Lewis Base Catalysis.

We report herein an unprecedented enantioselective (4+4) cycloaddition of simple 1,3-dienes with azadienes for the construction of fused eight-membered N-heterocycles. In this transformation, the π-Lewis basic Pd(0) catalyst achieves activation of 1,3-dienes to induce nucleophilic addition to azadienes followed by ring cyclization via a selective terminal allylic substitution. Furthermore, highly efficient and diastereoselective derivatizations of the eight-membered rings provide a facile access to diverse enantiopure fused tetra- to hexacyclic compounds with potential application in medicinal chemistry.

Asymmetric Inverse-Electron-Demand Oxa-Diels-Alder Reaction with Morita-Baylis-Hillman Carbonates of 2-Cyclopentenone via a Palladium-Catalyzed Umpolung Strategy.

Here we uncovered that the dienones generated from the Morita-Baylis-Hillman carbonates of 2-cyclopentenone under Pd(0) catalysis could be umpolunged by regioselectively forming η2-Pd(0) complexes via π-Lewis base activation, and underwent asymmetric inverse-electron-demand oxa-Diels-Alder reaction with α-cyano chalcones. An array of fused pyran frameworks with dense substitutions was constructed with excellent stereoselectivity (up to 99% ee, >19:1 dr), which could be elaborated to access enantioenriched architectures with higher molecular complexity.

Palladium-Catalyzed Inverse and Normal Dehydrogenative Aza-Morita-Baylis-Hillman Reactions with γ,δ-Unsaturated Compounds.

σ-Lewis base-catalyzed regio- and enantioselective aza-Morita-Baylis-Hillman (MBH) reaction of α,ß,γ,δ-unsaturated systems remains a challenge due to the intrinsic covalent activation mode. Here we demonstrate that a Pd0 complex can mediate the dehydrogenative reaction of γ,δ-unsaturated compounds to give corresponding electron-poor dienes, which further undergo δ-regioselective umpolung Friedel-Crafts-type addition to imines via auto-tandem Pd0 -π-Lewis base catalysis. After ß-H elimination of in situ formed PdII -complexes, unprecedented and chemically inverse aza-MBH-type adducts are finally furnished with fair to outstanding enantioselectivity, and a diversity of functional groups and both ketimine and aldimine acceptors can be well tolerated. Moreover, switchable α-regioselective normal aza-MBH-type reaction also can be realized by tuning catalytic conditions, whereas moderate to good enantioselectivity with low to excellent Z/E-selectivity is attained.

Asymmetric Formal Nucleophilic o-Cresolylation with Morita-Baylis-Hillman Carbonates of 2-Cyclohexenones via Palladium Catalysis.

Here we report an asymmetric formal nucleophilic o-cresolylation reaction with the Morita-Baylis-Hillman (MBH) carbonates from 2-cyclohexanones and diverse aldehydes under palladium catalysis, by in situ generation of electron-neutral and HOMO-raised η2-Pd(0)-dienone complexes via an oxidative insertion/π-σ-isomerization/ß-H elimination activation sequence. The subsequent umpolung vinylogous addition to a variety of imines is realized upon Pd(0)-mediated π-Lewis base catalysis, finally furnishing o-cresolylated products followed by another cascade of a π-σ-isomerization/ß-H elimination/aromatization process. Moderate to excellent diastereo- and enantioselectivity are achieved for substantial substrate assemblies by employing a newly designed bulky chiral phosphonamidite ligand, and the resultant multifunctional products can be facilely elaborated to access diverse enantioenriched architectures. In addition, the catalytic reaction pathway is finely illuminated by control experiments.

Use of (E,E)-Dienoic Acids as Switchable (E,E)- and (Z,E)-Dienyl Anion Surrogates via Ligand-Controlled Palladium Catalysis.

Carboxylic acids are not readily applied as carbon-based nucleophiles due to their intrinsic acidic group. Here, we demonstrate that free (E,E)-2,4-dienoic acids form electron-neutral and highest occupied molecular orbital-raised η2-complexes with Pd(0) and undergo Friedel-Crafts-type additions to imines with exclusive α-regioselectivity, giving formal dienylated products after decarboxylation. Unusual and switchable (E,E)- and (Z,E)-selectivity, along with excellent enantioselectivity, is achieved via ligand-controlled outer-sphere or inner-sphere reaction modes, respectively, which are well supported by comprehensive density functional theory calculation studies. An unprecedented formal reductive Mannich reaction between (E,E)-dienoic acids and imines is also developed to furnish enantioenriched ß-amino acid derivatives.

Role of anterior midcingulate cortex in self-reward representation and reward allocation judgments within social context.

Evaluating rewards for the self and others is essential for social interactions. Previous research has probed the neural substrates signaling rewards in social decision-making tasks as well as the differentiation between self- and other-reward representations. However, studies with different designs have yielded mixed results. After analyzing and comparing previous designs, we differentiated three components in this study: task (reward representation vs. social judgment of reward allocation), agency (self vs. other), and social context (without vs. within). Participants were asked to imagine various share sizes as a proposer in a dictator game during fMRI, and then rated their willingness and preference for these offers in a post-scan behavioral task. To differentiate the regions involved in processing rewards without and within context, we presented the reward to each agent in two sequential frames. Parametric analyses showed that, in the second frame (i.e., within social context), the anterior midcingulate cortex (aMCC) signaled self-reward and preferences for the offer, whereas the right insula tracked the likelihood of proposing the offer. Belief in a just world is positively associated with aMCC responses to self-reward. These results shed light on the role of the aMCC in coding self-reward within the social context to guide social behaviors.

Genetic insight into primary glomerulonephritis.

Primary glomerulonephritis is a major global health concern and a disorder with significant heritable components. Rapid advances in sequencing technologies have led to genome-wide, high-throughput investigations of the genetic basis of complex human traits. Genetic studies have successfully mapped several susceptibility loci and disease-causing genes for different subtypes of primary glomerulonephritis. These studies have revealed that IgA nephropathy-associated genes have a highly complex, polygenic and pleiotropic genetic architecture and that genetic susceptibility to membranous nephropathy may be driven by a few large-effect loci. Furthermore, both susceptibility genes and high-penetrant gene mutations reportedly contribute to the development of the most heterogeneous phenotype of focal segmental glomerulosclerosis. The genetic heterogeneity between each glomerular disease type and within different populations has indicated disease-specific and ethnicity-specific underlying molecular mechanisms for the disorders. The findings from genome-wide association studies (GWAS) have mainly included variants on or near the major histocompatibility (MHC) loci, highlighting the molecular basis for the shared pathogenesis of the immune-mediated disease. Recent studies with increased sample sizes and higher resolutions of genome-wide imputation have provided novel insights into the pathogenesis of glomerular disorders. Further integration of results from genomic studies with functional genomics datasets can indicate novel targets for drug discovery as well as potential tools for patient diagnosis and stratification. However, larger GWASs and sequencing studies in independent cohorts and more standardized inclusion of phenotypes across studies are required for each subtype of glomerular disease.

Application of a virtual reality tracker-based system to measure seated postural stability in stroke patients.

BACKGROUND: Postural stability while sitting is an important indicator of balance and an early predictor for future functional improvement in neurorehabilitation, but the evaluation is usually dependent on clinical balance function measures. Meanwhile, instrumental posturography has been used widely to obtain quantitative data and characterize balance abilities and underlying control mechanisms, but not as often for sitting balance. Moreover, traditional kinetic methods using a force platform to test sitting stability often require modification and are costly. We proposed a tracker-based posturography with a commercial virtual reality system, the VIVE Pro system (HTC, Inc. Taiwan), to record the trunk displacement (TD) path with a lumbar tracker for evaluation of sitting stability. The goals were to test the reliability and validity of the TD parameters among stroke patients. METHODS: Twenty-one stroke individuals and 21 healthy adults had their postural sway measured with this system under four sitting conditions, i.e., sitting on a solid surface or a soft surface, with eyes open or closed. The test-retest reliability of the TD parameters was evaluated with intraclass correlation coefficients in 22 participants. We also tested the discriminative validity of these parameters to discriminate between stroke and healthy controls, and among four sitting conditions. Furthermore, the TD parameters were correlated with the three balance function tests: the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke Patients (PASS) and the Function in Sitting Test (FIST). RESULTS: The results indicated that the TD parameters obtained by tracker-based posturography had mostly moderate to good reliability across the four conditions, with a few exceptions in the solid surface and eyes open tasks. The TD parameters could discriminate the postural stability between sitting on solid and soft surfaces. The stroke group had more seated postural sway than the control group, especially while sitting on a soft surface. In addition, velocity measures in the sagittal and frontal planes had moderate to high correlations with the PASS and BBS scores. CONCLUSIONS: This tracker-based system is a cost-effective option for the clinical assessment of body stability for stroke patients in a seated position and shows acceptable reliability and validity.

Asymmetric Auto-Tandem Palladium Catalysis for 2,4-Dienyl Carbonates: Ligand-Controlled Divergent Synthesis.

Developing new asymmetric auto-tandem catalysis processes, especially in a divergent manner, is highly attractive but extremely challenging. Presented herein is a palladium-catalyzed auto-tandem reaction between 2,4-dienyl carbonates and o-TsNH arylimines or trifluoroacetophenones that proceeds through a consecutive N-allylation, vinylogous addition, π-σ-π isomerization, and another N-allylation sequence. Importantly, switchable diastereodivergent synthesis could be achieved by tuning the chiral bisphosphine ligands, which led to the construction of a broad spectrum of fused tetrahydroquinoline architectures with moderate to excellent enantioselectivity. Ligand control even enabled effective access to regiodivergent azetidine or chemodivergent ß-H elimination with fair enantioselectivity, further showing the versatility of the current auto-tandem catalysis.

Palladium-Catalyzed Modular and Enantioselective cis-Difunctionalization of 1,3-Enynes with Imines and Boronic Reagents.

Here we report that a palladium(0) complex can mediate the unprecedented intermolecular coupling reaction of 1,3-enynes and N-sulfonylimines regio- and stereoselectively, and the resultant palladium(II) species undergo a cascade Suzuki reaction with organoboronic reagents. The substrate scope is substantial for the asymmetric three-component process, and the enantioenriched all-carbon tetra-substituted alkene derivatives are efficiently constructed in a modular and cis-difunctionalized manner. Control experiments and density functional theory (DFT) calculations support the idea that the palladium(0) acts as a π-Lewis base catalyst by chemoselectively forming η2-complexes with the alkene moiety of 1,3-enynes, thus increasing the nucleophilicity of the alkyne group based on the principle of vinylogy, to attack imines enantioselectively. The preferable formation of aza-palladacyclopentene intermediates, via a 90° single bond rotation from the resultant π-allyl complex, guarantees the formal cis-carbopalladation of alkyne group. In addition, a palladium(0)-catalyzed enantioselective reductive coupling of 1,3-enyne and imine is realized by using formic acid as hydrogen transfer reagent.

A Palladium Complex as an Asymmetric π-Lewis Base Catalyst for Activating 1,3-Dienes.

Here we report that palladium(0) complexes can coordinate in a η2 fashion to 1,3-dienes and significantly raise the energy of their highest occupied molecular orbital (HOMO) by donating the electrons from the d-orbitals to the empty antibonding molecular orbitals of double bonds (π*) via back-bonding. Thus, the uncoordinated double bond, as a more reactive partner on the basis of the principle of vinylogy, can directly attack imines, furnishing a formal hydrodienylation reaction enantioselectively. A chemoselective cascade vinylogous addition/allylic alkylation difunctionalization process between 1,3-dienes and imines with a nucleophilic group is also compatible, by trapping in situ formed π-allylpalladium species after initial ene addition. This π-Lewis base catalytic mode, featuring simple η2coordination, vinylogous activation, and compatibility with both conjugated neutral polyenes and electron-deficient polyenes, is elucidated by control experiments and density functional theory (DFT) calculations.

Asymmetric ß,γ'-regioselective [4 + 3] and [4 + 2] annulations of α-vinylenals via cascade iminium ion-dienamine catalysis.

Introduction of an α-vinyl group into enal substrates can prohibit the traditional [3 + 2] cycloaddition with N-2,2,2-trifluoroethyl isatin imines catalysed by a chiral secondary amine, but give ß,γ'-regioselective [4 + 3] annulation products via cascade iminium ion-dienamine catalysis. A spectrum of CF3-containing spirooxindoles incorporating an azepane motif were constructed with good to excellent enantioselectivities. In addition, asymmetric [4 + 2] annulations between α-vinylenals and α,α-dicyanoalkenes were disclosed through a similar catalytic strategy, generally affording complex tricyclic frameworks with outstanding enantioselectivities.

A Double Deprotonation Strategy for Cascade Annulations of Palladium-Trimethylenemethanes and Morita-Baylis-Hillman Carbonates to Construct Bicyclo[3.1.0]hexane Frameworks.

Here we report that the chemoselective activation of Tsuji's 2-(cyanomethyl)allyl carbonates to generate the palladium-trimethylenemethane 1,3-dipoles via a deprotonation strategy can be realized in the presence of Morita-Baylis-Hillman carbonates from substantial activated ketones. The following SN 2'-addition enables the formation of new 1,3-dipole species having an activated alkene moiety through a second deprotonation process, which then undergo cascade [1+2]/[3+2] annulations to furnish complex bicyclic [3.1.0]hexane frameworks having three contiguous quaternary stereogenic centers with good to excellent enantioselectivity. Moreover, by using benzoyl aldehyde-derived substrates, a [1+4]/[3+2] annulation sequence is similarly developed to produce fused cyclopenta[b]furan architectures.

Selective Alkynylallylation of the C-C σ Bond of Cyclopropenes.

A Pd-catalyzed regio- and stereoselective alkynylallylation of a specific C-C σ bond in cyclopropenes, using allyl propiolates as both allylation and alkynylation reagents, has been achieved for the first time. By merging selective C(sp2 )-C(sp3 ) bond scission with conjunctive cross-couplings, this decarboxylative reorganization reaction features fascinating atom and step economy and provides an efficient approach to highly functionalized dienynes from readily available substrates. Without further optimization, gram-scale products can be easily obtained by such a simple, neutral, and low-cost catalytic system with high TONs. DFT calculations afford a rationale toward the formation of the products and indicate that the selective insertion of the double bond of cyclopropenes into the C-Pd bond of ambidentate Pd complex and the subsequent nonclassical ß-C elimination promoted by 1,4-palladium migration are critical for the success of the reaction.

π-Lewis-Base-Catalyzed Asymmetric Vinylogous Umpolung Reactions of Cyclopentadienones and Tropone.

We disclose that the carbonates of 4-hydroxy-2-cyclopentenones can form π-allylpalladium-based 1,2-carbodipoles, which isomerize to interesting η2 -Pd0 -cyclopentadienone complexes. Compared with the labile parent cyclopentadienone, the HOMO energy of the related η2 -complex was significantly raised via the back-bonding of Pd0 as a π-Lewis base, rendering the uncoordinated C=C bond an electron-richer dienophile in inverse-electron-demand aza-Diels-Alder-type reactions with diverse 1-azadienes. The vinylogous (aza)Morita-Baylis-Hillman or cross Rauhut-Currier addition to (imine)carbonyls or activated alkenes, respectively, was also realized to afford chiral [4+2] or [2+2] cycloadducts, respectively, after trapping the re-generated π-allylpalladium species. New C1 -symmetric ligands from simple chiral sources were developed, exhibiting high stereoselectivity even with racemic substrates via an unusual dynamic kinetic resolution process. Besides, tropone could be similarly activated by a Pd0 complex.