Striatal CDK5 Regulates Cholinergic Neuron Activation and Dyskinesia-like Behaviors through BK Channels.

Disturbance of the cholinergic system plays a crucial role in the pathological progression of neurological diseases that cause dyskinesia-like behaviors. However, the molecular mechanisms underlying this disturbance remain elusive. Here, we showed that cyclin-dependent kinase 5 (Cdk5) was reduced in cholinergic neurons of midbrain according to the single-nucleus RNA sequencing analysis. Serum levels of CDK5 also decreased in patients with Parkinson's disease accompanied by motor symptoms. Moreover, Cdk5 deficiency in cholinergic neurons triggered paw tremors, abnormal motor coordination, and motor balance deficits in mice. These symptoms occurred along with cholinergic neuron hyperexcitability and increases in the current density of large-conductance Ca2+-activated K+ channels (BK channels). Pharmacological inhibition of BK channels restrained the excessive intrinsic excitability of striatal cholinergic neurons in Cdk5-deficient mice. Furthermore, CDK5 interacted with BK channels and negatively regulated BK channel activity via phosphorylation of threonine-908. Restoration of CDK5 expression in striatal cholinergic neurons reduced dyskinesia-like behaviors in ChAT-Cre;Cdk5f/f mice. Together, these findings indicate that CDK5-induced phosphorylation of BK channels involves in cholinergic-neuron-mediated motor function, providing a potential new therapeutic target for treating dyskinesia-like behaviors arising from neurological diseases.

A hnRNPA2B1 agonist effectively inhibits HBV and SARS-CoV-2 omicron in vivo.

The twenty-first century has already recorded more than ten major epidemics or pandemics of viral disease, including the devastating COVID-19. Novel effective antivirals with broad-spectrum coverage are urgently needed. Herein, we reported a novel broad-spectrum antiviral compound PAC5. Oral administration of PAC5 eliminated HBV cccDNA and reduced the large antigen load in distinct mouse models of HBV infection. Strikingly, oral administration of PAC5 in a hamster model of SARS-CoV-2 omicron (BA.1) infection significantly decreases viral loads and attenuates lung inflammation. Mechanistically, PAC5 binds to a pocket near Asp49 in the RNA recognition motif of hnRNPA2B1. PAC5-bound hnRNPA2B1 is extensively activated and translocated to the cytoplasm where it initiates the TBK1-IRF3 pathway, leading to the production of type I IFNs with antiviral activity. Our results indicate that PAC5 is a novel small-molecule agonist of hnRNPA2B1, which may have a role in dealing with emerging infectious diseases now and in the future.

Divergent projections of the prelimbic cortex mediate autism- and anxiety-like behaviors.

The comorbidity of autism spectrum disorder and anxiety is common, but the underlying circuitry is poorly understood. Here, Tmem74-/- mice showed autism- and anxiety-like behaviors along with increased excitability of pyramidal neurons (PNs) in the prelimbic cortex (PL), which were reversed by Tmem74 re-expression and chemogenetic inhibition in PNs of the PL. To determine the underlying circuitry, we performed conditional deletion of Tmem74 in the PNs of PL of mice, and we found that alterations in the PL projections to fast-spiking interneurons (FSIs) in the dorsal striatum (dSTR) (PLPNs-dSTRFSIs) mediated the hyperexcitability of FSIs and autism-like behaviors and that alterations in the PL projections to the PNs of the basolateral amygdaloid nucleus (BLA) (PLPNs-BLAPNs) mediated the hyperexcitability of PNs and anxiety-like behaviors. However, the two populations of PNs in the PL had different spatial locations, optogenetic manipulations revealed that alterations in the activity in the PL-dSTR or PL-BLA circuits led to autism- or anxiety-like behaviors, respectively. Collectively, these findings highlight that the hyperactivity of the two populations of PNs in the PL mediates autism and anxiety comorbidity through the PL-dSTR and PL-BLA circuits, which may lead to the development of new therapeutics for the autism and anxiety comorbidity.

BOD1 regulates the cerebellar IV/V lobe-fastigial nucleus circuit associated with motor coordination.

Cerebellar ataxias are characterized by a progressive decline in motor coordination, but the specific output circuits and underlying pathological mechanism remain poorly understood. Through cell-type-specific manipulations, we discovered a novel GABAergic Purkinje cell (PC) circuit in the cerebellar IV/V lobe that projected to CaMKIIα+ neurons in the fastigial nucleus (FN), which regulated sensorimotor coordination. Furthermore, transcriptomics profiling analysis revealed various cerebellar neuronal identities, and we validated that biorientation defective 1 (BOD1) played an important role in the circuit of IV/V lobe to FN. BOD1 deficit in PCs of IV/V lobe attenuated the excitability and spine density of PCs, accompany with ataxia behaviors. Instead, BOD1 enrichment in PCs of IV/V lobe reversed the hyperexcitability of CaMKIIα+ neurons in the FN and ameliorated ataxia behaviors in L7-Cre; BOD1f/f mice. Together, these findings further suggest that specific regulation of the cerebellar IV/V lobePCs → FNCaMKIIα+ circuit might provide neuromodulatory targets for the treatment of ataxia behaviors.

Tauroursodeoxycholic acid (TUDCA) disparate pharmacological effects to lung tissue-resident memory T cells contribute to alleviated silicosis.

Exposure to crystalline silica (CS) results in a persistent pulmonary inflammatory response, which results in abnormal tissue repair and excessive matrix deposition. Due to vague pathogenesis, there is virtually no practical therapeutic approach. Here we showed the pharmacological effects of TUDCA on CS-induced pulmonary inflammation and fibrosis. It also helped a faster recovery of CS-impaired pulmonary function. Mechanistically, TUDCA suppressed interferon (IFN)-γ and interleukin (IL)-17A productions by pulmonary helper T (Th) cells. We demonstrated that CS-boosted cytokine-producing Th cells were effector memory (TEM) phenotype. TUDCA decreased the pathogenic TEM cells expansion in the lung. Using in vivo labeling method, we discovered the TEM cells were lung tissue residency with CD103 expression. TUDCA's anti-fibrotic effects were linked to decreasing IFN-γ producing CD103- TEM-like and IL-17A producing CD103+ TRM-like T cells as well as restricting TRM-like Treg cells in the lung. Specifically, TUDCA could restrain CD103+ TRM-like Treg cell proliferation but not limit the CD103- ones. Further characterization study proved that though the Tregs originally came from the thymus, the expressing levels of ST-2 were different, which provides insights into TUDCA's various effects on cell proliferation. Collectively, our data paved the way to understanding the pathogenesis of silicosis and may provide new treatments for this pulmonary fibrotic disease.

Isolation, synthesis and absolute configuration of 4,5-dihydroxypiperines improving behavioral disorder in AlCl3-induced dementia.

A pair of stereoisomers of new 4,5-dihydroxypiperine was isolated from P. retrofractum and showed profound activity on AlCl3-induced dementia. In order to determine their absolute configurations and biological activities, all four possible stereoisomers of 4,5-dihydroxypiperine were synthesized from piperidine by Sharpless asymmetric dihydroxylation and Mitsunobu reaction. Their absolute configurations were established as (4R,5R) (1), (4S,5S) (2), (4S,5R) (3) and (4R,5S) (4) by NMR, optical rotation and CD spectra. It is note that only compound 4 improved behavioral disorder in AlCl3-induced dementia. Accordingly, the pair of stereoisomers isolated from P. retrofractum was determined to be (4S,5S) and (4R,5S)-isomers (2 and 4). The ratio of the epimers was present as 1:0.7 (4:2).

New anti-HBV norbisabolane sesquiterpenes from Phyllantus acidus.

The norbisabolane-type sesquiterpenoids bearing a spiroketal functionality have been found in Phyllanthus spp. and showed anti-HBV activities. As part of an ongoing effort to search for promising anti-HBV sesquiterpenes from Phyllanthus plants, we report four new norbisabolane-type sesquiterpenoids, phyacidusin A (1), phyacidusin B (2), phllanthacidoid A1 (3) and phllanthacidoid N1 (4), from stem of P. acidus collected in Xishuangbanna, Yunnan province, China. The absolute configuration of new compounds was established by coupling constants and ROESY correlations, as well as comparation of NMR data with those of known compounds. The absolute configuration of new compounds 1 and 2 was further confirmed by X-ray diffraction. Compound 2 showed effect to HBsAg with an IC50 value of 11.2 ±â€¯0.01 µM, while compound 3 inhibited HBeAg secretion with an IC50 value of 57.1 ±â€¯0.02 µM. The results enriched the diversity of anti-HBV norbisabolane sesquiterpenes.