Activation and Signaling Mechanism Revealed by Cannabinoid Receptor-Gi Complex Structures.

Human endocannabinoid systems modulate multiple physiological processes mainly through the activation of cannabinoid receptors CB1 and CB2. Their high sequence similarity, low agonist selectivity, and lack of activation and G protein-coupling knowledge have hindered the development of therapeutic applications. Importantly, missing structural information has significantly held back the development of promising CB2-selective agonist drugs for treating inflammatory and neuropathic pain without the psychoactivity of CB1. Here, we report the cryoelectron microscopy structures of synthetic cannabinoid-bound CB2 and CB1 in complex with Gi, as well as agonist-bound CB2 crystal structure. Of important scientific and therapeutic benefit, our results reveal a diverse activation and signaling mechanism, the structural basis of CB2-selective agonists design, and the unexpected interaction of cholesterol with CB1, suggestive of its endogenous allosteric modulating role.

5-HT2C Receptor Structures Reveal the Structural Basis of GPCR Polypharmacology.

Drugs frequently require interactions with multiple targets-via a process known as polypharmacology-to achieve their therapeutic actions. Currently, drugs targeting several serotonin receptors, including the 5-HT2C receptor, are useful for treating obesity, drug abuse, and schizophrenia. The competing challenges of developing selective 5-HT2C receptor ligands or creating drugs with a defined polypharmacological profile, especially aimed at G protein-coupled receptors (GPCRs), remain extremely difficult. Here, we solved two structures of the 5-HT2C receptor in complex with the highly promiscuous agonist ergotamine and the 5-HT2A-C receptor-selective inverse agonist ritanserin at resolutions of 3.0 Å and 2.7 Å, respectively. We analyzed their respective binding poses to provide mechanistic insights into their receptor recognition and opposing pharmacological actions. This study investigates the structural basis of polypharmacology at canonical GPCRs and illustrates how understanding characteristic patterns of ligand-receptor interaction and activation may ultimately facilitate drug design at multiple GPCRs.

Chlorogenic acid ameliorates intestinal inflammation via miRNA-microbe axis in db/db mice.

Chlorogenic acid improves diabetic symptoms, including inflammation, via the modulation of the gut microbiota. However, the mechanism by which the microbiota is regulated by chlorogenic acid remains unknown. In this study, we firstly explored the effects of chlorogenic acid on diabetic symptoms, colonic inflammation, microbiota composition, and microRNA (miRNA) expression in db/db mice. The results showed that chlorogenic acid decreased body weight, improved glucose tolerance and intestinal inflammation, altered gut microbiota composition, and upregulated the expression level of five miRNAs, including miRNA-668-3p, miRNA-467d-5p, miRNA-129-1-3p, miRNA-770-3p, and miRNA-666-5p in the colonic content. Interestingly, the levels of these five miRNAs were positively correlated with the abundance of Lactobacillus johnsonii. We then found that miRNA-129-1-3p and miRNA-666-5p promoted the growth of L. johnsonii. Importantly, miRNA-129-1-3p mimicked the effects of chlorogenic acid on diabetic symptoms and colonic inflammation in db/db mice. Furthermore, L. johnsonii exerted beneficial effects on db/db mice similar to those of chlorogenic acid. In conclusion, chlorogenic acid regulated the gut microbiota composition via affecting miRNA expression and ameliorated intestinal inflammation via the miRNA-microbe axis in db/db mice.

Systematic pan-cancer analysis insights into ICAM1 as an immunological and prognostic biomarker.

Intercellular adhesion molecule 1 (ICAM1) is a cell surface adhesion glycoprotein in the immunoglobulin supergene family. It is associated with several epithelial tumorigenesis processes, as well as with inflammation. However, the function of ICAM1 in the prognosis of tumor immunity is still unclear. This study aimed to examine the immune function of ICAM1 in 33 tumor types and to investigate the prognostic value of tumors. Using datasets from the Cancer Genome Atlas (TCGA), Genotype Tissue Expression (GTEx), Cancer Cell Lines Encyclopedia (CCLE), Human Protein Atlas (HPA), and cBioPortal, we investigated the role of ICAM1 in tumors. We explored the potential correlation between ICAM1 expression and tumor prognosis, gene mutations, microsatellite instability, and tumor immune cell levels in various cancers. We observed that ICAM1 is highly expressed in multiple malignant tumors. Furthermore, ICAM1 is negatively or positively associated with different malignant tumor prognoses. The expression levels of ICAM1 were correlated with the tumor mutation burden (TMB) in 11 tumors and with MSI in eight tumors. ICAM1 is a gene associated with immune infiltrating cells, such as M1 macrophages and CD8+ T cells in gastric and colon cancer. Meanwhile, the expression of ICAM1 is associated with several immune-related functions and immune-regulation-related signaling pathways, such as the chemokine signaling pathway. Our study shows that ICAM1 can be used as a prognostic biomarker in many cancer types because of its function in tumorigenesis and malignant tumor immunity.

Inhibition of OGFOD1 by FG4592 confers neuroprotection by activating unfolded protein response and autophagy after ischemic stroke.

BACKGROUND: Acute ischemic stroke is a common neurological disease with a significant financial burden but lacks effective drugs. Hypoxia-inducible factor (HIF) and prolyl hydroxylases (PHDs) participate in the pathophysiological process of ischemia. However, whether FG4592, the first clinically approved PHDs inhibitor, can alleviate ischemic brain injury remains unclear. METHODS: The infarct volumes and behaviour tests were first analyzed in mice after ischemic stroke with systemic administration of FG4592. The knockdown of HIF-1α and pretreatments of HIF-1/2α inhibitors were then used to verify whether the neuroprotection of FG4592 is HIF-dependent. The targets predicting and molecular docking methods were applied to find other targets of FG4592. Molecular, cell biological and gene knockdown methods were finally conducted to explore the potential neuroprotective mechanisms of FG4592. RESULTS: We found that the systemic administration of FG4592 decreased infarct volume and improved neurological defects of mice after transient or permanent ischemia. Meanwhile, FG4592 also activated autophagy and inhibited apoptosis in peri-infarct tissue of mice brains. However, in vitro and in vivo results suggested that the neuroprotection of FG4592 was not classical HIF-dependent. 2-oxoglutarate and iron-dependent oxygenase domain-containing protein 1 (OGFOD1) was found to be a novel target of FG4592 and regulated the Pro-62 hydroxylation in the small ribosomal protein s23 (Rps23) with the help of target predicting and molecular docking methods. Subsequently, the knockdown of OGFOD1 protected the cell against ischemia/reperfusion injury and activated unfolded protein response (UPR) and autophagy. Moreover, FG4592 was also found to activate UPR and autophagic flux in HIF-1α independent manner. Blocking UPR attenuated the neuroprotection, pro-autophagy effect and anti-apoptosis ability of FG4592. CONCLUSION: This study demonstrated that FG4592 could be a candidate drug for treating ischemic stroke. The neuroprotection of FG4592 might be mediated by inhibiting alternative target OGFOD1, which activated the UPR and autophagy and inhibited apoptosis after ischemic injury. The inhibition of OGFOD1 is a novel therapy for ischemic stroke.

Genome-Driven Discovery of Antiviral Atralabdans A-C from the Soil-Dwelling Streptomyces atratus.

Heterologous expression of an atr terpenoid gene cluster derived from Streptomyces atratus Gö66 in S. albus J1074 led to the discovery of three novel labdane diterpenoids featuring an unprecedented 6/6/5-fused tricyclic skeleton, designated as atralabdans A-C (1-3), along with a known compound, labdanmycin A. Compounds 1-3 were identified through extensive spectroscopic analysis, including NMR calculations with DP4+ probability analysis, and a comparative assessment of experimental and theoretical electronic circular dichroism (ECD) spectra. A plausible biosynthetic pathway for these compounds was proposed. Compounds 1-3 exhibited inhibitory activity against the human neurotropic coxsackievirus B3 (CVB3); 1 was the most potent, surpassing the positive control ribavirin with a higher therapeutic index.

Functional studies of McSTE24, McCYP305a1, and McJHEH, three essential genes act in cantharidin biosynthesis in the blister beetle (Coleoptera: Meloidae).

Cantharidin is a toxic defensive substance secreted by most blister beetles when attacked. It has been used to treat many complex diseases since ancient times and has recently regained popularity as an anticancer agent. However, the detailed mechanism of the cantharidin biosynthesis has not been completely addressed. In this study, we cloned McSTE24 (encoding STE24 endopeptidase) from terpenoid backbone pathway, McCYP305a1 (encoding cytochrome P450, family 305) and McJHEH [encoding subfamily A, polypeptide 1 and juvenile hormone (JH) epoxide hydrolase] associated to JH synthesis/degradation in the blister beetle Mylabris cichorii (Linnaeus, 1758, Coleoptera: Meloidae). Expression pattern analyses across developmental stages in adult males revealed that the expressions of 3 transcripts were closely linked to cantharidin titer exclusively during the peak period of cantharidin synthesis (20-25 days old). In contrast, at other stages, these genes may primarily regulate different biological processes. When RNA interference with double-stranded RNA suppressed the expressions of the 3 genes individually, significant reductions in cantharidin production were observed in males and also in females following McJHEH knockdown, indicating that these 3 genes might primarily contribute to cantharidin biosynthesis in males, but not in females, while females could self-synthesis a small amount of cantharidin. These findings support the previously hypothesized sexual dimorphism in cantharidin biosynthesis during the adult phase. McCYP305a1 collaborates with its upstream gene McSTE24 in cantharidin biosynthesis, while McJHEH independently regulates cantharidin biosynthesis in males.

Fast-acting γδ T-cell subpopulation and protective immunity against infections.

Unique Vγ2Vδ2 (Vγ9Vδ2) T cells existing only in human and non-human primates, account for the majority of circulating γδ T cells in human adults. Vγ2Vδ2 T cells are the sole γδ T-cell subpopulation capable of recognizing the microbial (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) produced by selected pathogens during infections. Recent seminal studies in non-human primate models have demonstrated that the unique HMBPP-specific Vγ2Vδ2 T cells are fast-acting, multi-functional, and protective during infections. This article reviews the recent seminal observations of Vγ2Vδ2 T cells in protective mechanisms against tuberculosis and other infections.

Evaluation of RNAi therapeutics VIR-2218 and ALN-HBV for chronic hepatitis B: Results from randomized clinical trials.

BACKGROUND & AIMS: Current therapy for chronic hepatitis B virus (cHBV) infection involves lifelong treatment. New treatments that enable HBV functional cure would represent a clinically meaningful advance. ALN-HBV and VIR-2218 are investigational RNA interference therapeutics that target all major HBV transcripts. METHODS: We report on: i) the safety of single doses of VIR-2218 (modified from ALN-HBV by enhanced stabilization chemistry plus technology to reduce off-target, seed-mediated binding while maintaining on-target antiviral activity) and ALN-HBV in humanized mice; ii) a cross-study comparison of the safety of single doses of VIR-2218 and ALN-HBV in healthy human volunteers (n = 24 and n = 49, respectively); and iii) the antiviral activity of two doses of 20, 50, 100, 200 mg of VIR-2218 (total n = 24) vs. placebo (n = 8), given 4 weeks apart, in participants with cHBV infection. RESULTS: In humanized mice, alanine aminotransferase (ALT) levels were markedly lower following administration of VIR-2218 compared with ALN-HBV. In healthy volunteers, post-treatment ALT elevations occurred in 28% of participants receiving ALN-HBV compared with none in those receiving VIR-2218. In participants with cHBV infection, VIR-2218 was associated with dose-dependent reductions in hepatitis B surface antigen (HBsAg). The greatest mean reduction of HBsAg at Week 20 in participants receiving 200 mg was 1.65 log IU/ml. The HBsAg reduction was maintained at 0.87 log IU/ml at Week 48. No participants had serum HBsAg loss or hepatitis B surface antibody seroconversion. CONCLUSIONS: VIR-2218 demonstrated an encouraging hepatic safety profile in preclinical and clinical studies as well as dose-dependent HBsAg reductions in patients with cHBV infection. These data support future studies with VIR-2218 as part of combination regimens with a goal of HBV functional cure. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT02826018 and NCT03672188. IMPACT AND IMPLICATIONS: A significant unmet need exists for therapies for chronic HBV (cHBV) infection that achieve functional cure. We report clinical and non-clinical data on two investigational small-interfering RNAs that target HBx, ALN-HBV and VIR-2218, demonstrating that incorporation of enhanced stabilization chemistry plus technology in VIR-2218 reduces its propensity to cause ALT elevations relative to its parent compound, ALN-HBV. We also show that VIR-2218 reduces hepatitis B surface antigen levels in a dose-dependent manner in participants with cHBV infection. These studies support the continued development of VIR-2218 as part of therapeutic regimens for cHBV infection, with the goal of a functional cure, and are important for HBV researchers and physicians.

Astragaloside IV suppresses the migration and EMT progression of cervical cancer cells by inhibiting macrophage M2 polarization through TGFß/Smad2/3 signaling.

Cervical cancer (CC) is a gynecological malignant tumor worldwide. Astragaloside IV (AS-IV) has been found to exert antitumor effects on CC. In addition, M2-polarized macrophages, known as tumor-associated macrophages (TAMs), play an important role in promoting cancer cell growth and angiogenesis. Thus, we explored the association between the antitumor effect of AS-IV and macrophage polarization in CC. Flow cytometry, ELISA, and RT‒qPCR assays were applied to detect the levels of CD163, IL-10, TGFß, and CD206 in M2 macrophages with or without AS-IV treatment. In addition, conditioned medium (CM) was collected from these M2 macrophages, and CC cells were then cultured in various CMs. Wound healing and transwell assays were used to assess the migratory ability of CC cells. In this study, we found that AS-IV significantly inhibited M2 polarization of macrophages, as shown by decreased CD163, IL-10, TGFß, and CD206 expression. In addition, compared with CM from M2 macrophages, CM from AS-IV-treated M2 macrophages notably inhibited angiogenesis, migration, and epithelial-mesenchymal transition (EMT) in CC cells. Furthermore, compared with CM from M2 macrophages, CM from AS-IV-treated M2 macrophages markedly reduced p-Smad2 and p-Smad3 protein expression in CC cells, and these changes were reversed by TGF-ß treatment. Collectively, suppression of M2-like polarization of macrophages by AS-IV could prevent the migration and EMT of CC cells by inactivating TGF-ß/Smad2/3 signaling. These findings might provide some theoretical support for exploring novel treatments for CC.

Lung function and risk of incident dementia: A prospective cohort study of 431,834 individuals.

BACKGROUND: Whether lung function prospectively affects cognitive brain health independent of their overlapping factors remains largely unknown. This study aimed to investigate the longitudinal association between decreased lung function and cognitive brain health and to explore underlying biological and brain structural mechanisms. METHODS: This population-based cohort included 43,1834 non-demented participants with spirometry from the UK Biobank. Cox proportional hazard models were fitted to estimate the risk of incident dementia for individuals with low lung function. Mediation models were regressed to explore the underlying mechanisms driven by inflammatory markers, oxygen-carrying indices, metabolites, and brain structures. FINDINGS: During a follow-up of 3,736,181 person-years (mean follow-up 8.65 years), 5,622 participants (1.30 %) developed all-cause dementia, which consisted of 2,511 Alzheimer's dementia (AD) and 1,308 Vascular Dementia (VD) cases. Per unit decrease in lung function measure was each associated with increased risk for all-cause dementia (forced expiratory volume in 1 s [liter]: hazard ratio [HR, 95 %CI], 1.24 [1.14-1.34], P = 1.10 × 10-07; forced vital capacity [liter]: 1.16 [1.08-1.24], P = 2.04 × 10-05; peak expiratory flow [liter/min]: 1.0013 [1.0010-1.0017], P = 2.73 × 10-13). Low lung function generated similar hazard estimates for AD and VD risks. As underlying biological mechanisms, systematic inflammatory markers, oxygen-carrying indices, and specific metabolites mediated the effects of lung function on dementia risks. Besides, brain grey and white matter patterns mostly affected in dementia were substantially changed with lung function. INTERPRETATION: Life-course risk for incident dementia was modulated by individual lung function. Maintaining optimal lung function is useful for healthy aging and dementia prevention.

Genome-driven discovery of new serrawettin W2 analogues from Serratia fonticola DSM 4576.

By expressing a multimodular NRPS gene sefA from Serratia fonticola DSM 4576 in E. coli, four new serrawettin W2 analogues, namely sefopeptides A-D (1-4), were isolated and structurally characterized and their biosynthesis was proposed. A bioactivity assay showed that sefopeptide C (3) exhibits moderate cytotoxic activity against acute promyelocytic leukemia NB4 cells.

Macrophage targeted iron oxide nanodecoys augment innate immunological and drug killings for more effective Mycobacterium Tuberculosis clearance.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) infection, is still one of the top killers worldwide among infectious diseases. The escape of Mtb from immunological clearance and the low targeting effects of anti-TB drugs remain the substantial challenges for TB control. Iron is particularly required for Mtb growth but also toxic for Mtb in high dosages, which makes iron an ideal toxic decoy for the 'iron-tropic' Mtb. Here, a macrophage-targeted iron oxide nanoparticles (IONPs)-derived IONPs-PAA-PEG-MAN nanodecoy is designed to augment innate immunological and drug killings against intracellular Mtb. IONPs-PAA-PEG-MAN nanodecoy exhibits preferential uptake in macrophages to significantly increase drug uptake with sustained high drug contents in host cells. Moreover, it can serve as a specific nanodecoy for the 'iron-tropic' Mtb to realize the localization of Mtb contained phagosomes surrounding the drug encapsulated nanodecoys and co-localization of Mtb with the drug encapsulated nanodecoys in lysosomes, where the incorporated rifampicin (Rif) can be readily released under acidic lysosomal condition for enhanced Mtb killing. This drug encapsulated nanodecoy can also polarize Mtb infected macrophages into anti-mycobacterial M1 phenotype and enhance M1 macrophage associated pro-inflammatory cytokine (TNF-α) production to trigger innate immunological responses against Mtb. Collectively, Rif@IONPs-PAA-PEG-MAN nanodecoy can synergistically enhance the killing efficiency of intracellular Mtb in in vitro macrophages and ex vivo monocyte-derived macrophages, and also significantly reduce the mycobacterial burdens in the lung of infected mice with alleviated pathology. These results indicate that Rif@IONPs-PAA-PEG-MAN nanodecoy may have a potential for the development of more effective therapeutic strategy against TB by manipulating augmented innate immunity and drug killings.

Atractylodes Processing Products Protect against Gastric Ulcers in Rats by Influencing the NF-κB-MMP-9/TIMP-1 Regulatory Mechanism and Intestinal Flora.

Atractylodes macrocephala Koidz. (AM) is a Chinese herbal medicine that is widely used for treating gastrointestinal diseases. However, little research has focused on it as a single medicine for treating gastric ulcers. Honey-bran stir-frying is a characteristic method of concocting AM, so we speculated that AM is more effective after this preparation process. Analysis by ultra-high-performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry revealed changes in the chemical composition of raw Atractylodes (SG), bran-fried Atractylodes (FG), and honey-bran-fried Atractylodes (MFG). MFG was superior to SG and FG in improving the pathological structure of gastric tissue in rats with acute gastric ulcers, reducing inflammatory cell infiltration in gastric tissue, and significantly reducing malondialdehyde while increasing superoxide dismutase and glutathione peroxidase, and reducing the damage caused by free radical accumulation in the gastric mucosa. In addition, MFG reduced the expression of matrix metalloproteinase-9 (MMP-9), an inhibitor of metalloproteinase-1 (TIMP-1) and nuclear factor kappa-B (NF-κB)proteins, inhibited inflammatory response, and regulated the degradation and rebalancing of the extracellular matrix. Fecal microbiota analysis also revealed that MFG normalized the intestinal flora to some extent. Our study shows that AM had a protective effect on rats with alcohol-induced acute gastric ulcers before and after processing, and AM-processed products were more effective than raw ones. Compared with MF, MFG had a higher rate of ulcer inhibition and a stronger anti-inflammatory effect, and its mechanism of action was related to the NF-κB-MMP-9/TIMP-1 signaling pathway.

Soft Sensor Modeling for 3D Transient Temperature Field of Large-Scale Aluminum Alloy Workpieces Based on Multi-Loss Consistency Optimization PINN.

Uniform temperature distribution during quenching thermal treatment is crucial for achieving exceptional mechanical and physical properties of alloy materials. Accurate and rapid prediction of the 3D transient temperature field model of large-scale aluminum alloy workpieces is key to realizing effective thermal treatment. This paper establishes a 3D transient temperature field model of large aluminum alloy workpieces and proposes a multi-loss consistency optimization-based physics-informed neural network (MCO-PINN) to realize soft sensing of the 3D temperature field model. The method is based on a MLP structure and adopts Gaussian activation functions. A surrogate model of the partial differential equation (PDE) is first constructed, and the residuals of the PDE, initial and boundary conditions, and observed data are encoded into the loss functions of the network. By establishing a Gaussian probability distribution model of each loss function and combining it with maximum likelihood estimation, the weight consistency optimization method of each loss function is then proposed to further improve the approximation ability of the model. To optimize the training speed of the network, an adaptive initial-value-eigenvector coding clustering (AIV-ECC) algorithm is finally proposed, which quickly determines the parameters of the Gaussian activation function, reduces the dependence on the initial value and improves the generalization performance of the network. Simulation and industrial experiments demonstrate that the proposed MCO-PINN can solve the 3D transient temperature field model with high precision and high time efficiency based on sparse measurements.

Baicalin suppress the development of polycystic ovary syndrome via regulating the miR-874-3p/FOXO3 and miR-144/FOXO1 axis.

CONTEXT: Polycystic ovary syndrome (PCOS) is a common and complex disease caused by endocrine and metabolic dysfunction in women of reproductive age. Baicalin is reported to ameliorate PCOS. OBJECTIVE: This study determines whether baicalin could affect the progression of PCOS. MATERIALS AND METHODS: To establish an animal model of PCOS, female Sprague-Dawley (SD) rats were subcutaneously injected with dehydroepiandrosterone (DHEA, 60 mg/kg) for 20 days. Next, normal and PCOS mice were divided into 3 groups: control, PCOS, PCOS + Baicalin (20 mg/kg) groups. In addition, the levels of microRNA-874-3p (miR-874-3p) and microRNA-144 (miR-144) in ovarian tissues were assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RESULTS: Compared to the PCOS group, baicalin treatment significantly declined free testosterone (33.71 pg/mL vs. 56.05 pg/mL) and luteinizing hormone (LH; 3971.73 pg/mL vs. 5201.50 pg/mL) levels in rats with PCOS. Additionally, compared to the control group, 100 µM baicalin lessened miR-874-3p and miR-144 levels in human ovarian granulosa cells (KGN cells) by 36.87% and 32.57%, respectively. Furthermore, forkhead box O (FOXO) proteins FOXO1 and FOXO3 are the direct targets of miR-144 and miR-874-3p, respectively. Meanwhile, baicalin induced G0-G1 phase arrest (69.56 ± 3.7% at baicalin with 100 µM vs. 51.24 ± 3.2%, control) in KGN cells correlating with decreased p27 Kip1 (FOXO proteins downstream effector gene) expression by 55.5%; however, miR-874-3p or miR-144 overexpression could abolish this effect. CONCLUSIONS: Baicalin could alleviate the symptoms of PCOS via regulating miR-874-3p/FOXO3 and miR-144/FOXO1 axis, demonstrating its potential utility in PCOS treatment.

Involvement of VIVID in white light-responsive pigmentation, sexual development and sterigmatocystin biosynthesis in the filamentous fungus Podospora anserina.

Light serves as a source of information and regulates diverse physiological processes in living organisms. Fungi perceive and respond to light through a complex photosensory system. Fungi have evolved the desensitization mechanism to adapt to the changing light signal in a natural environment. White light exerts multiple essential impacts on the model filamentous fungus Podospora anserina. However, the light sensing and response in this species has not been investigated. In this study, we demonstrated that the loss of function of the light desensitization protein VIVID (VVD) in P. anserina triggered exacerbated light responses and therefore led to drastic morphological and physiological changes. The white light-sensitive mutant Δvvd showed growth reduction, spermatia overproduction, enhanced hyphae pigmentation and reduced oxidative stress tolerance. We observed the decreased expression level of sterigmatocystin gene cluster by transcriptome analysis and finally detected the reduced production of sterigmatocystin in Δvvd in response to white light. Our data indicate that VVD acts as a repressor of white collar complex. This study exhibits a vital role of VVD in governing white light-responsive gene expression and secondary metabolite production and contributes to a better understanding of the photoreceptor VVD in P. anserina.

The Stem Cell Potential of O-2A Lineage Astroglia.

Astrocytes are the most common glial type in the central nervous system. They play pivotal roles in neurophysiological and neuropathological processes. Mounting evidence indicates that astrocytes may act as neural stem cells and contribute to adult neurogenesis. In previous reports, freshly isolated O-2A progenitors were shown to revert to neural stem-like cells (NSLCs) when cultured with a serum-containing glial medium or bone morphogenic proteins for 3 days and with basic fibroblast growth factor consecutively. NSLCs possess self-renewal and multipotential capacities that can give rise to neurons and glial cells, which suggests that they have stem cell-like properties. However, the underlying molecular mechanisms and cell fate commitment when exposed to a neural conditioned medium remain obscure. In this study, we demonstrated that NSLCs grown in the serum-containing neurobasal medium can differentiate into induced neural-like cells (iNLCs). It was noteworthy that astroglia mixed in these cells, particularly in iNLCs, were gradually replaced by neural phenotypes during this glia-neuron conversion. Remarkably, these glial cells can maintain high levels of proliferation and self-renewal ability by activating the NF-κB and MAPK signals. Finally, we found that Notch, STAT3, autophagy, bHLH, and Wnt signals appear to be critical modulators of these intricate events. Altogether, these data demonstrate that O-2A lineage astroglia can function as neural stem cells and display neurogenic plasticity. Dissecting the regulatory pathways involved in these processes is essential to the understanding of glial cell fate and its precise functions. This finding may foster a better understanding of astrocytic heterogeneity and lead to innovative ways to readily apply stem-like astroglia cells as candidate cell sources for neural repair.

Functional Characterization of the GATA-Type Transcription Factor PaNsdD in the Filamentous Fungus Podospora anserina and Its Interplay with the Sterigmatocystin Pathway.

The model ascomycete Podospora anserina, distinguished by its strict sexual development, is a prolific but yet unexploited reservoir of natural products. The GATA-type transcription factor NsdD has been characterized by the role in balancing asexual and sexual reproduction and governing secondary metabolism in filamentous fungi. In the present study, we functionally investigated the NsdD ortholog PaNsdD in P. anserina. Compared to the wild-type strain, vegetative growth, ageing processes, sexual reproduction, stress tolerance, and interspecific confrontations in the mutant were drastically impaired, owing to the loss of function of PaNsdD. In addition, the production of 3-acetyl-4-methylpyrrole, a new metabolite identified in P. anserina in this study, was significantly inhibited in the ΔPaNsdD mutant. We also demonstrated the interplay of PaNsdD with the sterigmatocystin biosynthetic gene pathway, especially as the deletion of PaNsdD triggered the enhanced red-pink pigment biosynthesis that occurs only in the presence of the core polyketide synthase-encoding gene PaStcA of the sterigmatocystin pathway. Taken together, these results contribute to a better understanding of the global regulation mediated by PaNsdD in P. anserina, especially with regard to its unexpected involvement in the fungal ageing process and its interplay with the sterigmatocystin pathway. IMPORTANCE Fungal transcription factors play an essential role in coordinating multiple physiological processes. However, little is known about the functional characterization of transcription factors in the filamentous fungus Podospora anserina. In this study, a GATA-type regulator PaNsdD was investigated in P. anserina. The results showed that PaNsdD was a key factor that can control the fungal ageing process, vegetative growth, pigmentation, stress response, and interspecific confrontations and positively regulate the production of 3-acetyl-4-methylpyrrole. Meanwhile, a molecular interaction was implied between PaNsdD and the sterigmatocystin pathway. Overall, loss of function of PaNsdD seems to be highly disadvantageous for P. anserina, which relies on pure sexual reproduction in a limited life span. Therefore, PaNsdD is clearly indispensable for the survival and propagation of P. anserina in its complex ecological niches.

Investigating rare pathogenic/likely pathogenic exonic variation in bipolar disorder.

Bipolar disorder (BD) is a serious mental illness with substantial common variant heritability. However, the role of rare coding variation in BD is not well established. We examined the protein-coding (exonic) sequences of 3,987 unrelated individuals with BD and 5,322 controls of predominantly European ancestry across four cohorts from the Bipolar Sequencing Consortium (BSC). We assessed the burden of rare, protein-altering, single nucleotide variants classified as pathogenic or likely pathogenic (P-LP) both exome-wide and within several groups of genes with phenotypic or biologic plausibility in BD. While we observed an increased burden of rare coding P-LP variants within 165 genes identified as BD GWAS regions in 3,987 BD cases (meta-analysis OR = 1.9, 95% CI = 1.3-2.8, one-sided p = 6.0 × 10-4), this enrichment did not replicate in an additional 9,929 BD cases and 14,018 controls (OR = 0.9, one-side p = 0.70). Although BD shares common variant heritability with schizophrenia, in the BSC sample we did not observe a significant enrichment of P-LP variants in SCZ GWAS genes, in two classes of neuronal synaptic genes (RBFOX2 and FMRP) associated with SCZ or in loss-of-function intolerant genes. In this study, the largest analysis of exonic variation in BD, individuals with BD do not carry a replicable enrichment of rare P-LP variants across the exome or in any of several groups of genes with biologic plausibility. Moreover, despite a strong shared susceptibility between BD and SCZ through common genetic variation, we do not observe an association between BD risk and rare P-LP coding variants in genes known to modulate risk for SCZ.