Generating detailed intercellular communication patterns in psoriasis at the single-cell level using social networking, pattern recognition, and manifold learning methods to optimize treatment strategies.

Psoriasis, a complex and recurrent chronic inflammatory skin disease involving various inflammatory cell types, requires effective cell communication to maintain the homeostatic balance of inflammation. However, patterns of communication at the single-cell level have not been systematically investigated. In this study, we employed social network analysis tools, pattern recognition, and manifold learning to compare molecular communication features between psoriasis cells and normal skin cells. Utilizing a process that facilitates the discovery of cell type-specific regulons, we analyzed internal regulatory networks among different cells in psoriasis. Advanced techniques for the quantitative detection of non-targeted proteins in pathological tissue sections were employed to demonstrate protein expression. Our findings revealed a synergistic interplay among the communication signals of immune cells in psoriasis. B-cells were activated, while Langerhans cells shifted into the primary signaling output mode to fulfill antigen presentation, mediating T-cell immunity. In contrast to normal skin cells, psoriasis cells shut down numerous signaling pathways, influencing the balance of skin cell renewal and differentiation. Additionally, we identified a significant number of active cell type-specific regulons of resident immune cells around the hair follicle. This study unveiled the molecular communication features of the hair follicle cell-psoriasis axis, showcasing its potential for therapeutic targeting at the single-cell level. By elucidating the pattern of immune cell communication in psoriasis and identifying new molecular features of the hair follicle cell-psoriasis axis, our findings present innovative strategies for drug targeting to enhance psoriasis treatment.

High modulation efficiency and large bandwidth thin-film lithium niobate modulator for visible light.

We experimentally demonstrate an integrated visible light modulator at 532 nm on the thin-film lithium niobate platform. The waveguides on such platform feature a propagation loss of 2.2 dB/mm while a grating for fiber interface has a coupling loss of 5 dB. Our fabricated modulator demonstrates a low voltage-length product of 1.1 V·cm and a large electro-optic bandwidth with a roll-off of -1.59 dB at 25 GHz for a length of 3.3 mm. This device offers a compact and large bandwidth solution to the challenge of integrated visible wavelength modulation in lithium niobate and paves the way for future small-form-factor integrated systems at visible wavelengths.

Folded thin-film lithium niobate modulator based on a poled Mach-Zehnder interferometer structure.

The thin-film lithium niobate structure has been used recently to construct compact and high-performance electro-optical modulators. Due to the moderate electro-optical coefficient of the lithium niobate material, the device length of such a modulator is still long, a few centimeters usually. Here, a folded Mach-Zehnder interferometer based modulator on x-cut thin-film lithium niobate is demonstrated. An effective poling procedure is developed to activate the device. The proposed modulator structure can shorten the device length without affecting its performance. The measured VπL product of a fabricated and completely poled folded modulator is about 2.74V⋅cm, and the 3 dB electro-optical bandwidth is about 55 GHz. They are close to those of a conventional Mach-Zehnder modulator with a straight modulation section.

Plant cell-surface GIPC sphingolipids sense salt to trigger Ca2+ influx.

Salinity is detrimental to plant growth, crop production and food security worldwide. Excess salt triggers increases in cytosolic Ca2+ concentration, which activate Ca2+-binding proteins and upregulate the Na+/H+ antiporter in order to remove Na+. Salt-induced increases in Ca2+ have long been thought to be involved in the detection of salt stress, but the molecular components of the sensing machinery remain unknown. Here, using Ca2+-imaging-based forward genetic screens, we isolated the Arabidopsis thaliana mutant monocation-induced [Ca2+]i increases 1 (moca1), and identified MOCA1 as a glucuronosyltransferase for glycosyl inositol phosphorylceramide (GIPC) sphingolipids in the plasma membrane. MOCA1 is required for salt-induced depolarization of the cell-surface potential, Ca2+ spikes and waves, Na+/H+ antiporter activation, and regulation of growth. Na+ binds to GIPCs to gate Ca2+ influx channels. This salt-sensing mechanism might imply that plasma-membrane lipids are involved in adaption to various environmental salt levels, and could be used to improve salt resistance in crops.

Identification of Mutation Regions on NF1 Responsible for High- and Low-Risk Development of Optic Pathway Glioma in Neurofibromatosis Type I.

Neurofibromatosis type I is a rare neurocutaneous syndrome resulting from loss-of-function mutations of NF1. The present study sought to determine a correlation between mutation regions on NF1 and the risk of developing optic pathway glioma (OPG) in patients with neurofibromatosis type I. A total of 215 patients with neurofibromatosis type I, from our clinic or previously reported literature, were included in the study after applying strict inclusion and exclusion criteria. Of these, 100 patients with OPG were classified into the OPG group and 115 patients without OPG (aged ≥ 10 years) were assigned to the Non-OPG group. Correlation between different mutation regions and risk of OPG was analyzed. The mutation clustering in the 5' tertile of NF1 was not significantly different between OPG and Non-OPG groups (P = 0.131). Interestingly, patients with mutations in the cysteine/serine-rich domain of NF1 had a higher risk of developing OPG than patients with mutations in other regions [P = 0.019, adjusted odds ratio (OR) = 2.587, 95% confidence interval (CI) = 1.167-5.736], whereas those in the HEAT-like repeat region had a lower risk (P = 0.036, adjusted OR = 0.396, 95% CI = 0.166-0.942). This study confirms a new correlation between NF1 genotype and OPG phenotype in patients with neurofibromatosis type I, and provides novel insights into molecular functions of neurofibromin.

Increased serum IL-36α and IL-36γ levels in patients with systemic lupus erythematosus: Association with disease activity and arthritis.

IL-36 cytokines (IL-36Ra, IL-36α, IL-36ß and IL-36γ) belong to the IL-1 family and have been linked to several autoimmune diseases. However, little is known about the relationships between systemic lupus erythematosus (SLE) and IL-36 cytokines. In this study, serum IL-36 cytokine levels were determined by enzyme-linked immunosorbent assay (ELISA), and their associations with SLE-related parameters were analyzed in 72 SLE patients and 63 healthy controls. Additionally, IL-36 cytokine mRNA levels were assessed in 30 of 72 SLE patients and 20 of 63 healthy controls using real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). Compared to healthy controls, SLE patients had significantly decreased serum IL-36Ra levels (P = 0.001) and markedly increased serum IL-36α and IL-36γ levels (P = 0.004 and P = 0.001, respectively). Serum IL-36α and IL-36γ levels were significantly higher in active SLE patients [SLE Disease Activity Index (SLEDAI) score ≥ 5] than in inactive patients (SLEDAI score ≤ 4) (P = 0.020 and P = 0.017, respectively). Serum IL-36α and IL-36γ levels were strongly correlated with SLEDAI score (r = 0.308, P = 0.008 and r = 0.400, P = 0.001, respectively) and complement C3 levels (r = -0.276, P = 0.019 and r = -0.314, P = 0.007, respectively). Moreover, SLE patients with arthritis had significantly higher serum IL-36α and IL-36γ levels than those without arthritis (P = 0.001 and P < 0.001, respectively). Our study indicates that the imbalanced antagonist/agonist profile of IL-36 cytokines may be linked to SLE pathogenesis. Furthermore, IL-36α and IL-36γ may participate in arthritis and may be good biomarkers of SLE disease activity.

In Vivo and in Vitro Synthesis of Phosphatidylglycerol by an Escherichia coli Cardiolipin Synthase.

Phosphatidylglycerol (PG) makes up 5-20% of the phospholipids of Escherichia coli and is essential for growth in wild-type cells. PG is synthesized from the dephosphorylation of its immediate precursor, phosphatidylglycerol phosphate (PGP) whose synthase in E. coli is PgsA. Using genetic, biochemical, and highly sensitive mass spectrometric approaches, we identified an alternative mechanism for PG synthesis in E. coli that is PgsA independent. The reaction of synthesis involves the conversion of phosphatidylethanolamine and glycerol into PG and is catalyzed by ClsB, a phospholipase D-type cardiolipin synthase. This enzymatic reaction is demonstrated herein both in vivo and in vitro as well as by using the purified ClsB protein. When the growth medium was supplemented with glycerol, the expression of E. coli ClsB significantly increased PG and cardiolipin levels, with the growth deficiency of pgsA null strain also being complemented under such conditions. Identification of this alternative mechanism for PG synthesis not only expands our knowledge of bacterial anionic phospholipid biosynthesis, but also sheds light on the biochemical functions of the cls gene redundancy in E. coli and other bacteria. Finally, the PGP-independent PG synthesis in E. coli may also have important implications for the understanding of PG biosynthesis in eukaryotes that remains incomplete.

Structure of the polyisoprenyl-phosphate glycosyltransferase GtrB and insights into the mechanism of catalysis.

The attachment of a sugar to a hydrophobic polyisoprenyl carrier is the first step for all extracellular glycosylation processes. The enzymes that perform these reactions, polyisoprenyl-glycosyltransferases (PI-GTs) include dolichol phosphate mannose synthase (DPMS), which generates the mannose donor for glycosylation in the endoplasmic reticulum. Here we report the 3.0 Å resolution crystal structure of GtrB, a glucose-specific PI-GT from Synechocystis, showing a tetramer in which each protomer contributes two helices to a membrane-spanning bundle. The active site is 15 Å from the membrane, raising the question of how water-soluble and membrane-embedded substrates are brought into apposition for catalysis. A conserved juxtamembrane domain harbours disease mutations, which compromised activity in GtrB in vitro and in human DPM1 tested in zebrafish. We hypothesize a role of this domain in shielding the polyisoprenyl-phosphate for transport to the active site. Our results reveal the basis of PI-GT function, and provide a potential molecular explanation for DPM1-related disease.

Biomarkers of NAFLD progression: a lipidomics approach to an epidemic.

The spectrum of nonalcoholic fatty liver disease (NAFLD) includes steatosis, nonalcoholic steatohepatitis (NASH), and cirrhosis. Recognition and timely diagnosis of these different stages, particularly NASH, is important for both potential reversibility and limitation of complications. Liver biopsy remains the clinical standard for definitive diagnosis. Diagnostic tools minimizing the need for invasive procedures or that add information to histologic data are important in novel management strategies for the growing epidemic of NAFLD. We describe an "omics" approach to detecting a reproducible signature of lipid metabolites, aqueous intracellular metabolites, SNPs, and mRNA transcripts in a double-blinded study of patients with different stages of NAFLD that involves profiling liver biopsies, plasma, and urine samples. Using linear discriminant analysis, a panel of 20 plasma metabolites that includes glycerophospholipids, sphingolipids, sterols, and various aqueous small molecular weight components involved in cellular metabolic pathways, can be used to differentiate between NASH and steatosis. This identification of differential biomolecular signatures has the potential to improve clinical diagnosis and facilitate therapeutic intervention of NAFLD.

OSCA1 mediates osmotic-stress-evoked Ca2+ increases vital for osmosensing in Arabidopsis.

Water is crucial to plant growth and development. Environmental water deficiency triggers an osmotic stress signalling cascade, which induces short-term cellular responses to reduce water loss and long-term responses to remodel the transcriptional network and physiological and developmental processes. Several signalling components that have been identified by extensive genetic screens for altered sensitivities to osmotic stress seem to function downstream of the perception of osmotic stress. It is known that hyperosmolality and various other stimuli trigger increases in cytosolic free calcium concentration ([Ca(2+)]i). Considering that in bacteria and animals osmosensing Ca(2+) channels serve as osmosensors, hyperosmolality-induced [Ca(2+)]i increases have been widely speculated to be involved in osmosensing in plants. However, the molecular nature of corresponding Ca(2+) channels remain unclear. Here we describe a hyperosmolality-gated calcium-permeable channel and its function in osmosensing in plants. Using calcium-imaging-based unbiased forward genetic screens we isolated Arabidopsis mutants that exhibit low hyperosmolality-induced [Ca(2+)]i increases. These mutants were rescreened for their cellular, physiological and developmental responses to osmotic stress, and those with clear combined phenotypes were selected for further physical mapping. One of the mutants, reduced hyperosmolality-induced [Ca(2+)]i increase 1 (osca1), displays impaired osmotic Ca(2+) signalling in guard cells and root cells, and attenuated water transpiration regulation and root growth in response to osmotic stress. OSCA1 is identified as a previously unknown plasma membrane protein and forms hyperosmolality-gated calcium-permeable channels, revealing that OSCA1 may be an osmosensor. OSCA1 represents a channel responsible for [Ca(2+)]i increases induced by a stimulus in plants, opening up new avenues for studying Ca(2+) machineries for other stimuli and providing potential molecular genetic targets for engineering drought-resistant crops.

SKP1 is involved in abscisic acid signalling to regulate seed germination, stomatal opening and root growth in Arabidopsis thaliana.

Abscisic acid (ABA) regulates many aspects of plant development, including seed dormancy and germination, root growth and stomatal closure. Plant SKP1 proteins are subunits of the SCF complex E3 ligases, which regulate several phytohormone signalling pathways through protein degradation. However, little is known about SKP1 proteins participating in ABA signalling. Here, we report that the overexpression of Triticum aestivum SKP1-like 1 (TSK1) in Arabidopsis thaliana (Arabidopsis) resulted in delayed seed germination and hypersensitivity to ABA. The opening of stomatal guard cells and the transcription of several ABA-responsive genes were affected in transgenic plants. In contrast, Arabidopsis skp1-like 1 (ask1)/ask1 ASK2/ask2 seedlings exhibited reduced ABA sensitivity. Furthermore, the transcription of ASK1 and ASK2 was down-regulated in abi1-1 and abi5-1 mutants compared with that in wild type. ASK1 or ASK2 overexpression could rescue or partially rescue the ABA insensitivity of abi5-1 mutants, respectively. Our work demonstrates that SKP1 is involved in ABA signalling and that SKP1-like genes may positively regulate ABA signalling by SCF-mediated protein degradation.

Pathway for lipid A biosynthesis in Arabidopsis thaliana resembling that of Escherichia coli.

The lipid A moiety of Escherichia coli lipopolysaccharide is a hexa-acylated disaccharide of glucosamine that makes up the outer monolayer of the outer membrane. Arabidopsis thaliana contains nuclear genes encoding orthologs of key enzymes of bacterial lipid A biosynthesis, including LpxA, LpxC, LpxD, LpxB, LpxK and KdtA. Although structurally related lipid A molecules are found in most other gram-negative bacteria, lipid A and its precursors have not been directly detected in plants previously. However, homozygous insertional knockout mutations or RNAi knock-down constructs of Arabidopsis lpx and kdtA mutants revealed accumulation (or disappearance) of the expected monosaccharide or disaccharide lipid A precursors by mass spectrometry of total lipids extracted from 10-day old seedlings of these mutants. In addition, fluorescence microscopy of lpx-gfp fusions in transgenic Arabidopsis plants suggests that the Lpx and KdtA proteins are expressed and targeted to mitochondria. Although the structure of the lipid A end product generated by plants is still unknown, our work demonstrates that plants synthesize lipid A precursors using the same enzymatic pathway present in E. coli.

Cloning and expression analysis of TSK1, a wheat SKP1 homologue, and functional comparison with Arabidopsis ASK1 in male meiosis and auxin signalling.

Plants possess multiple homologues of the SKP1 gene encoding an essential subunit of the SCF ubiquitin ligases, but only ASK1 (Arabidopsis SKP1-like 1) and ASK2 have been characterised genetically. In addition, little is known about the function of SKP1 homologues in monocots. Here we report on a winter wheat homologue of SKP1 named TSK1 (Triticum aestivum SKP1-like 1). Expression analyses revealed that it was expressed predominantly in young roots and floral buds. RNA in situ hybridisation showed that it was expressed in the shoot apical meristem (SAM) and anthers, especially the tapetum and microsporocytes at the time of meiosis. It was also expressed in almost the entire meristematic and elongation zones of the root. These observations indicated that TSK1 might function in dividing cells. The Arabidopsis ask1-1 mutant with overexpressed TSK1 driven by the CaMV 35S promoter exhibited partial fertility, suggesting that TSK1 could partially restore function in meiosis to the ask1-1 mutant. In addition, overexpression of TSK1 in wild type Arabidopsis resulted in changes in auxin responses and auxin-related phenotypes, consistent with a role of ASK1 in Arabidopsis auxin response. These results suggest possible functional conservation between TSK1 and ASK1.

Microarray analysis of gene expression involved in anther development in rice (Oryza sativa L.).

In flowering plants, anthers bear male gametophytes whose development is regulated by the elaborate coordination of many genes. In addition, both gibberellic acid (GA3) and jasmonic acid (JA) play important roles in anther development and pollen fertility. To facilitate the analysis of anther development genes and how GA3 and JA regulate anther development, we performed microarray experiments using a 10-K cDNA microarray with probes derived from seedlings, meiotic anthers, mature anthers and GA3- or JA-treated suspension cells of rice. The expression level change of 2155 genes was significantly (by 2-fold or greater) detected in anthers compared with seedlings. Forty-seven genes, representing genes with potential function in cell cycle and cell structure regulation, hormone response, photosynthesis, stress resistance and metabolism, were differentially expressed in meiotic and mature anthers. Moreover, 314 genes responded to either GA3 or JA treatment, and 24 GA3- and 82 JA-responsive genes showed significant changes in expression between meiosis and the mature anther stages. RT-PCR demonstrated that gene y656d05 was not only highly expressed in meiotic anthers but also induced by GA3. Strong RNA signals of y656d05 were detected in pollen mother cells and tapetum in in situ hybridization. Further characterization of these candidate genes can contribute to the understanding of the molecular mechanism of anther development and the involvement of JA and GA3 signals in the control of anther development in rice.