Integration of single-cell RNA sequencing and bulk RNA transcriptome sequencing reveals a heterogeneous immune landscape and pivotal cell subpopulations associated with colorectal cancer prognosis

IntroductionColorectal cancer (CRC) is a highly heterogeneous cancer. The molecular and cellular characteristics differ between the colon and rectal cancer type due to the differences in their anatomical location and pathological properties. With the advent of single-cell sequencing, it has become possible to analyze inter- and intra-tumoral tissue heterogeneities.MethodsA comprehensive CRC immune atlas, comprising 62,398 immune cells, was re-structured into 33 immune cell clusters at the single-cell level. Further, the immune cell lineage heterogeneity of colon, rectal, and paracancerous tissues was explored. Simultaneously, we characterized the TAM phenotypes and analyzed the transcriptomic factor regulatory network of each macrophage subset using SCENIC. In addition, monocle2 was used to elucidate the B cell developmental trajectory. The crosstalk between immune cells was explored using CellChat and the patterns of incoming and outgoing signals within the overall immune cell population were identified. Afterwards, the bulk RNA-sequencing data from The Cancer Genome Atlas (TCGA) were combined and the relative infiltration abundance of the identified subpopulations was analyzed using CIBERSORT. Moreover, cell composition patterns could be classified into five tumor microenvironment (TME) subtypes by employing a consistent non-negative matrix algorithm. Finally, the co-expression and interaction between SPP1+TAMs and Treg cells in the tumor microenvironment were analyzed by multiplex immunohistochemistry.ResultsIn the T cell lineage, we found that CXCL13+T cells were more widely distributed in colorectal cancer tissues, and the proportion of infiltration was increased. In addition, Th17 was found accounted for the highest proportion in CD39+CD101+PD1+T cells. Mover, Ma1-SPP1 showed the characteristics of M2 phenotypes and displayed an increased proportion in tumor tissues, which may promote angiogenesis. Plasma cells (PCs) displayed a significantly heterogeneous distribution in tumor as well as normal tissues. Specifically, the IgA+ PC population could be shown to be decreased in colorectal tumor tissues whereas the IgG+ PC one was enriched. In addition, information flow mediated by SPP1 and CD44, regulate signaling pathways of tumor progression. Among the five TME subtypes, the TME-1 subtype displayed a markedly reduced proportion of T-cell infiltration with the highest proportion of macrophages which was correlated to the worst prognosis. Finally, the co-expression and interaction between SPP1+TAMs and Treg cells were observed in the CD44 enriched region.DiscussionThe heterogeneity distribution and phenotype of immune cells were analyzed in colon cancer and rectal cancer at the single-cell level. Further, the prognostic role of major tumor-infiltrating lymphocytes and TME subtypes in CRC was evaluated by integrating bulk RNA. These findings provide novel insight into the immunotherapy of CRC

Contrast, Attend and Diffuse to Decode High-Resolution Images from Brain Activities

Decoding visual stimuli from neural responses recorded by functional Magnetic Resonance Imaging (fMRI) presents an intriguing intersection between cognitive neuroscience and machine learning, promising advancements in understanding human visual perception and building non-invasive brain-machine interfaces. However, the task is challenging due to the noisy nature of fMRI signals and the intricate pattern of brain visual representations. To mitigate these challenges, we introduce a two-phase fMRI representation learning framework. The first phase pre-trains an fMRI feature learner with a proposed Double-contrastive Mask Auto-encoder to learn denoised representations. The second phase tunes the feature learner to attend to neural activation patterns most informative for visual reconstruction with guidance from an image auto-encoder. The optimized fMRI feature learner then conditions a latent diffusion model to reconstruct image stimuli from brain activities. Experimental results demonstrate our model's superiority in generating high-resolution and semantically accurate images, substantially exceeding previous state-of-the-art methods by 39.34% in the 50-way-top-1 semantic classification accuracy. Our research invites further exploration of the decoding task's potential and contributes to the development of non-invasive brain-machine interfaces.Comment: 17 pages, 6 figures, conferenc

PO-181 The Comparative Study on the Maximum Oxygen Uptake Test of 10- Month Old Wistar Rats: There is no full text article associated with this abstract

Objective The maximum oxygen uptake (VO2max) is an ideal index to objectively evaluate the cardiopulmonary function, as well as the basic to define exercise intensity. In the field of sports science, laboratory animals are often used to explore the effect and mechanism of exercise intervention. Therefore, it is very important to design optimal VO2max test protocol and to ensure the accuracy of VO2max according to the characteristics of the experimental animal itself. In this study, Wistar rats were selected, and various VO2max test protocols were designed and analyzed to screen out the optimal VO2max test protocol for the 10-month old wistar rats. Methods  20 SPF Wistar rats (male, 10 month old) were tested for maximal oxygen uptake by a four channel metabolic monitoring system and running treadmill. Five different test protocols were executed. Each rat completed five test protocols in random order with 3 days’ interval. The exercise performance (coordination degree, exhaustion state), oxygen uptake platform, finish time, VO2max and RER value were recorded during the test of each program, and the performance and test data were compared. Results  1) 12 rats completed all 5 test protocols of VO2max. The induction ratio of VO2max of P1 was only 58%, and P2 and P4 were 75%. While, the induction rate of P3 and P5 were both 83%. 2) For the Bedford improvement protocol (P1), due to the intense increased exercise load, the rats showed more intense stress, the less coordination degree, injured even death, and lower induction rate of VO2max. 3) The VO2max and RER values induced by the P5 are significantly higher than that of P1 (p<0.05). The finish time of P3 is significantly higher than that of P1 (p<0.01) and P5 (p<0.05). Conclusions For the VO2max test for middle aged rats, with the suitable speed of the running treadmill, the change of gradient should be as the main way of increasing load, or increasing the gradient of the slope firstly, which can obtained optimal VO2max, meanwhile reduce the stress response and the risk of injury and serious damage

PL - 034 Impact of PM2.5 Exposures and Pre-exercise on Pulmonary Function and Leukocyte Count in Aged Rats

Objective Exposure of PM2.5 has been associated with adverse respiratory and the risk of inflammation. While regular physical activity (PA) reduces the risk of many adverse health effects. This study aimed to examine the protection of pre-exercise on adverse health effects of Pulmonary Function and inflammatory induced by PM2.5 exposures in aged rats. Methods 24 male wistar rats, aged 16 months, were randomly divided into 4 groups: Sedentary (S), Exercise (E), Sedentary+ PM2.5 exposures (S+PM), and Exercise+ PM2.5 exposures (E+PM). The rats in all E-related groups went through an aerobic treadmill exercise protocol (15m/min, 30 min) at every other day. The PM-related groups of aged rats were exposed to concentrated ambient particles of less than 2.5 μm (PM2.5) or filtered air (FA) in Beijing, for 4 hours per day, 7 days per week for a total of 2 weeks. After 2-week PM Exposure, blood was taken to measure the count of white blood cell (WC), neutrophil (NE), lymphocytes (LY), monocyte (MO), eosinophils (EO) and basophil (BA), and pulmonary function examined by whole body plethysmography. Results After 2-week PM exposure, compared with E group, S+PM group’ s percentage of NE decreased significantly (p＜0.05), while the decline of NE% in E+PM group was small. Meanwhile, the obviously rise of BA% occurred in S+PM and E+PM group compared with sedentary group (p＜0.05). 2) Compared with E group, the Index of constriction (Penh and PAU) were increased evidently in S+PM group after PM exposure (p＜0.05), while the value of Penh were significantly improved in E+PM group (p＜0.05). 3) Compared with E group, the rejection index (RinX) (p＜0.01) and duration of pause before inspiration (TP) (p＜0.05) were appeared a clearly inclined in S+PM group, as well as several up-regulated of RinX and TP showed in E+PM group. Conclusions 2-week PM2.5 exposures led to an increased susceptibility of infections, index of constriction and susceptibility of pulmonary function in aged rats. Moderate pre-exercise has beneficial effects on pulmonary function and immune function

CYP-omega-hydroxylation-dependent metabolites of arachidonic acid inhibit the basolateral 10pS chloride channel in the rat thick ascending limb

Metabolites of arachidonic acid influence sodium chloride (NaCl) transport in the thick ascending limb. Because a 10pS Cl channel is the major type of chloride channel in the basolateral membrane of this nephron segment, we explored the effect of arachidonic acid on this channel in cell-attached patches. Addition of 5μmol arachidonic acid significantly decreased channel activity (a product of channel number and open probability) while linoleic acid had no effect. To determine if this was mediated by acachidonic acid per se or by its metabolites, we measured channel activity in the presence of the cyclooxygenase inhibitor indomethacin, the selective lipoxygenase inhibitor nordihydroguaiaretic acid, and the cytochrome P-450 (CYP)-ω-hydroxylation inhibitor 17-octadecynoic acid. Neither cyclooxygenase nor lipoxygenase inhibition had an effect on basal chloride channel activity; further they failed to abolish the inhibitory effect of arachidonate on the 10pS channel. However, inhibition of CYP-ω-hydroxylation completely abolished the effect of arachidonic acid. The similarity of the effects of 20-hydroxyeicosatetraenoic acid (20-HETE) and arachidonic acid suggests that the effect of arachidonic acid was mediated by CYP-ω-hydroxylation-dependent metabolites. We conclude that arachidonic acid inhibits the 10pS chloride channel in the basolateral membrane of the medullary thick ascending limb, an effect mediated by the CYP-ω-hydroxylation-dependent metabolite 20-HETE

A self-starting bi-chromatic LiNbO_3 soliton microcomb

The wide range of functions that are possible with lithium niobate (LN) waveguide devices, including phase and intensity modulation, second-harmonic generation, and difference-frequency generation, makes it attractive as a potential microcomb material. LN microcombs would combine essential comb self-referencing and control functions with the pulse generation process in a single microresonator device. Here, we demonstrate a soliton microcomb in a monolithic high-Q LN resonator. Direct frequency doubling of the soliton spectrum is observed inside the same cavity. The LN soliton mode-locking process also self-starts and allows bi-directional switching of soliton states, effects that are shown to result from the LN photorefractive effect. The Kerr solitons exhibit a self-frequency shift resulting from the Raman effect of LN. This microcomb platform can dramatically simplify miniature time keeping, frequency synthesis/division, and spectroscopy systems. Moreover, direct generation of femtosecond timescale pulses within LN microresonators can benefit quantum photonics and signal processing systems

Acupuncture for chronic, stable angina pectoris and an investigation of the characteristics of acupoint specificity: study protocol for a multicenter randomized controlled trial

BACKGROUND: Chronic stable angina pectoris (CSAP) is a common cardiovascular condition that endangers a patient’s life quality and longevity. As demonstrated in several clinical trials, acupuncture is attested to be effective for CSAP. Current trials are not adequate enough to provide high-quality evidence for clinical decision making, as a result of inadequate methodology design and small sample size. Notably, stark controversy toward acupoint specificity also exists in the clinical acupuncture trials for CSAP. Therefore, we designed the present study as a randomized controlled trial primarily to investigate the effectiveness of acupuncture in addition to routine care among patients with CSAP. Meanwhile, we examined whether acupoint on the disease-affected meridian (DAM) is superior to either acupoint on the non-affected meridian (NAM) or non-acupoint (NA), to further investigate the meridian-based characteristics of acupoint specificity. METHODS/DESIGN: This study was a multicenter, assessor and statistician blinded, randomized controlled trial in China. In this study, 404 participants in sum will be randomly assigned to four groups through central randomization in a 1:1:1:1 ratio. The whole study period is 20 weeks including a 4-week baseline period, a 4-week treatment period and a 12-week follow-up. Participants in the DAM group receive acupuncture stimulation at acupoints on the disease-affected meridian, and three different control groups will undergo acupuncture stimulation at the NAM, the non-acupoint and no intervention respectively, in addition to basic treatment. Participants in the acupuncture groups will receive 12 sessions of acupuncture treatment over 4 weeks, while the wait-listed (WL) group would receive free acupuncture treatment after the completion of the study. The outcome measures in this trial include the frequency of angina attack during 4 weeks as the primary outcome and eight other secondary outcomes. DISCUSSION: This trial will provide new and relatively high-quality evidence in acupuncture treatment for CSAP. Moreover, this trial may further validate the meridian-based characteristics of acupoint specificity by comparing the strength of acupoints on the disease-affected meridian versus that of the non-affected meridian, to further inspire optimization of acupuncture therapy for CSAP. TRIAL REGISTRATION: Clinical Trials.gov NCT0168623