Dynamics of carbon budget and meteorological factors of a typical maize ecosystem in Songnen Plain, China

Aim of study: Understanding the carbon budget and meteorological factor impacts of farmland ecosystems is helpful for scientific assessment of carbon budget and low-carbon agricultural production practices. Area of study: The Songnen Plain, NE China, in 2019. Material and methods: Based on eddy-related flux and soil heterotrophic respiration observations from a typical maize farmland ecosystem, using mathematical statistics and carbon balance equation methods, were analyzed. Main results: Soil respiration rate (Rs) and composition were influenced and controlled by the synergistic effect of surface soil temperature (Ts) and water content (Wcs). Ts played a leading role, while Wcs played an important role. Ts and Wcs had the greatest influence on the heterotrophic respiration rate (Rh), followed by Rs and autotrophic respiration rate (Ra). Daily variations of net ecosystem productivity were correlated with daily mean air temperature, latent heat flux, and sensible heat flux. Annual carbon revenue was 1139.67 g C m-2, annual carbon expenditure was 456.14 g C m-2, and annual carbon budget was -683.53 g C m-2 in 2019. While considering that maize grain yield (-353.44 g C m-2) was moved out of the field at harvest, the net ecosystem carbon balance was -330.09 g C m-2; then it was carbon sink in 2019. By fully utilizing climate resources and improving agricultural managements, carbon sink is increased in farmland ecosystems. Research highlights: Soil respiration rate and composition were influenced and controlled by the synergistic effect of soil temperature and water content; the maize farmland ecosystem is carbon sink

Relationship between individual differences in pain empathy and task- and resting-state EEG

Pain empathy is a complex form of psychological inference that enables us to understand how others feel in the context of pain. Since pain empathy may be grounded in our own pain experiences, it exhibits huge inter-individual variability. However, the neural mechanisms behind the individual differences in pain empathy and its association with pain perception are still poorly understood. In this study, we aimed to characterize brain mechanisms associated with individual differences in pain empathy in adult participants (n = 24). The 32-channel electroencephalography (EEG) was recorded at rest and during a pain empathy task, and participants viewed static visual stimuli of the limbs submitted to painful and nonpainful stimulation to solicit empathy. The pain sensitivity of each participant was measured using a series of direct current stimulations. In our results, the N2 of Fz and the LPP of P3 and P4 were affected by painful pictures. We found that both delta and alpha bands in the frontal and parietal cortex were involved in the regulation of pain empathy. For the delta band, a close relationship was found between average power, either in the resting or task state, and individual differences in pain empathy. It suggested that the spectral power in Fz's delta band may reflect subjective pain empathy across individuals. For the alpha band, the functional connectivity between Fz and P3 under painful picture stimulation was correlated to individuals' pain sensitivity. It indicated that the alpha band may reflect individual differences in pain sensitivity and be involved in pain empathy processing. Our results suggested the distinct role of the delta and alpha bands of EEG signals in pain empathy processing and may deepen our understanding of the neural mechanisms underpinning pain empathy

SRSF1 Facilitates Cytosolic DNA-Induced Production of Type I Interferons Recognized by RIG-I

<div><p>Background</p><p>Evidence has shown that psoriasis is closely associated with infection; however, the mechanism of this association remains unclear. In mammalian cells, viral or bacterial infection is accompanied by the release of cytosolic DNA, which in turn triggers the production of type-I interferons (IFNs). Type I IFNs and their associated genes are significantly upregulated in psoriatic lesions. RIG-I is also highly upregulated in psoriatic lesions and is responsible for IFN production. However, RIG-I mediated regulatory signaling in psoriasis is poorly understood.</p><p>Methods</p><p>We screened a cDNA library and identified potential RIG-I interacting partners that may play a role in psoriasis.</p><p>Results</p><p>We found that serine/arginine-rich splicing factor 1 (SRSF1) could specifically interact with RIG-I to facilitate RIG-I mediated production of type-I IFN that is triggered by cytosolic DNA. We found SRSF1 associates with RNA polymerase III and RIG-I in a DNA-dependent manner. In addition, treatment with a TNFα inhibitor downregulated SRSF1 expression in peripheral blood mononuclear cells (PBMCs) from psoriasis vulgaris patients.</p><p>Discussion</p><p>Based on the abundance of pathogenic cytosolic DNA that is detected in psoriatic lesions, our finding that RIG-I interacts with SRSF1 to regulate type-I IFN production reveals a critical link regarding how cytosolic DNA specifically activates aberrant IFN expression. These data may provide new therapeutic targets for the treatment of psoriasis.</p></div

The association of SRSF1 with RNA polymerase III is dependent on the DNA template.

<p>(A) HEK293T cells were transfected with salmon sperm DNA and lysed using RIPA buffer. Cell lysates were immunoprecipitated with the RNA polymerase III subunit C7 antibody and immunoblotted using the SRSF1 antibody. Lysates were left untreated or were treated for 1 h with RNase A or DNase I before immunoprecipitation. (B) HEK293T cells were stimulated with 500 ng Poly(dA:dT)/LyoVec. After 24 h, cell lysates were immunoprecipitated with the anti-RIG-I antibody or anti-Pol-III RPC32 antibody and incubated overnight with protein(A+G). Immunoprecipitated products, as well as 1% input from whole cell lysates, were immunoblotted with anti-SRSF1, anti-RIG-I, and anti-Pol III antibodies.</p

Downregulated SRSF1 in psoriasis patients after treatment and <i>SRSF1</i> knockdown decreases type I IFN production.

<p>A. <i>SRSF1</i> mRNA levels in PBMCs from patients with psoriasis at week 0 or after 12 weeks of treatment with adalimumab. B. Specific <i>SRSF1</i> knockdown was evaluated in PBMCs transfected with <i>SRSF1</i> siRNA or scrambled siRNA. PBMC samples are from two psoriasis patients before drug treatment. Cells were combined and electroporated with scrambled siRNA or <i>SRSF1</i> siRNA. C. IFN-β concentration in the supernatant of samples stimulated for 24 h with 1 μg/mL poly(dA:dT)/LyoVec for 24hrs. D. IL-6, TNFα, and IL-1β concentration in the supernatant of samples stimulated for 24 h with 1 μg/mL poly(dA:dT)/LyoVec.</p

SRSF1 facilitates cytosolic DNA-mediated activation of RIG-I.

<p>(A, B) HEK293T cells were transfected with the indicated plasmids, along with ISRE-luc. Twenty-four hours after transfection, cells were stimulated for 12 h with poly(I:C)/LyoVec or poly(dA:dT)/LyoVec (A) or total 293T RNA/salmon sperm DNA (B). (C) <i>SRSF1</i> was knocked down and RIG-I was overexpressed in 293T cells. ISRE-luciferase activity was determined after poly(I:C)/LyoVec or poly(dA:dT)/LyoVec treatment. (D) <i>SRSF1</i> was knocked down in 293T cells. ISRE-luciferase activity was determined after poly(I:C)/LyoVec or poly(dA:dT)/LyoVec treatment.</p

SRSF1 interacts with RIG-I <i>in vitro</i> and <i>in vivo</i>.

<p>A. HEK293T cells were transfected with Flag-RIG-I, Flag-MDA5, Flag-MAVS, FLAG-TBK1, Flag-IKKi, Flag-IRF3, and HA-SRSF1. Flag-tagged proteins were immunoprecipitated using anti-Flag beads and immunoblotted with the HA antibody. B. HEK293T cells were transfected with Flag-tagged cGAS, STING, or RIG-I and HA-tagged SRSF1. Flag-tagged proteins were immunoprecipitated using anti-Flag beads and immunoblotted with the anti-HA antibody. C. THP-1 cells were lysed in low-salt lysis buffer. Cell lysates were immunoprecipitated with the control antibody or the anti-RIG-I antibody, and incubated overnight with protein (A+G). Immunoprecipitated products were immunoblotted with the anti-SRSF1 antibody. WCL, whole cell lysate.</p