GLK transcription factors accompany ELONGATED HYPOCOTYL5 to orchestrate light-induced seedling development in Arabidopsis.

Light-induced de-etiolation is an important aspect of seedling photomorphogenesis. GOLDEN2 LIKE (GLK) transcriptional regulators are involved in chloroplast development, but to what extent they participate in photomorphogenesis is not clear. Here, we show that ELONGATED HYPOCOTYL5 (HY5) binds to GLK promoters to activate their expression, and also interacts with GLK proteins in Arabidopsis (Arabidopsis thaliana). The chlorophyll content in the de-etiolating Arabidopsis seedlings of the hy5 glk2 double mutants was lower than that in the hy5 single mutant. GLKs inhibited hypocotyl elongation, and the phenotype could superimpose on the hy5 phenotype. Correspondingly, GLK2 regulated the expression of photosynthesis and cell elongation genes partially independent of HY5. Before exposure to light, DE-ETIOLATED 1 (DET1) affected accumulation of GLK proteins. The enhanced etioplast development and photosystem gene expression observed in the det1 mutant were attenuated in the det1 glk2 double mutant. Our study reveals that GLKs act downstream of HY5, or additive to HY5, and are likely quantitatively adjusted by DET1, to orchestrate multiple developmental traits during the light-induced skotomorphogenesis-to-photomorphogenesis transition in Arabidopsis.

Negative schizotypal traits predict the reduction of reward motivation in effort-reward imbalance.

The schizotypy construct is useful for studying the effects of environmental stress on development of subclinical negative symptoms. The relationship among self-report motivation, effort-reward imbalance (ERI), and schizotypal features has seldom been studied. We aimed to examine the possible moderation effect of schizotypal traits on ERI and reward motivation. Eight-hundred-and-forty-three college students were recruited online to complete a set of self-reported measures capturing schizotypal traits, effort-reward imbalance and reward motivation, namely the Schizotypal Personality Questionnaire (SPQ), the Effort-Reward Imbalance-School Version Questionnaire (C-ERI-S) and the Motivation and Pleasure Scale-Self Report (MAP-SR). We conducted multiple linear regression to construct models to investigate the moderating effects of schizotypal traits on the relationship between ERI and reward motivation. Stressful ERI situation predicted the reduction of reward motivation. Negative schizotypal traits showed a significant negative moderating effect on the relationship between ERI and reward motivation, while positive and disorganized schizotypal traits had significant positive moderating effects. Schizotypal traits subtypes differently moderate the relationship between ERI and reward motivation. Only negative schizotypal traits and stressful ERI situation together have negative impact on reward motivation.

Altered neural mechanism of social reward anticipation in individuals with schizophrenia and social anhedonia.

Altered social reward anticipation could be found in schizophrenia (SCZ) patients and individuals with high levels of social anhedonia (SA). However, few research investigated the putative neural processing for altered social reward anticipation in these populations on the SCZ spectrum. This study aimed to examine the underlying neural mechanisms of social reward anticipation in these populations. Twenty-three SCZ patients and 17 healthy controls (HC), 37 SA individuals and 50 respective HCs completed the Social Incentive Delay (SID) imaging task while they were undertaking MRI brain scans. We used the group contrast to examine the alterations of BOLD activation and functional connectivity (FC, psychophysiological interactions analysis). We then characterized the beta-series social brain network (SBN) based on the meta-analysis results from NeuroSynth and examined their prediction effects on real-life social network (SN) characteristics using the partial least squared regression analysis. The results showed that SCZ patients exhibited hypo-activation of the left medial frontal gyrus and the negative FCs with the left parietal regions, while individuals with SA showed the hyper-activation of the left middle frontal gyrus when anticipating social reward. For the beta-series SBNs, SCZ patients had strengthened cerebellum-temporal FCs, while SA individuals had strengthened left frontal regions FCs. However, such FCs of the SBN failed to predict the real-life SN characteristics. These preliminary findings suggested that SCZ patients and SA individuals appear to exhibit altered neural processing for social reward anticipation, and such neural activities showed a weakened association with real-life SN characteristics.

Reward motivation adaptation in people with negative schizotypal features: development of a novel behavioural paradigm and identifying its neural correlates using resting-state functional connectivity analysis.

Reward motivation in individuals with high levels of negative schizotypal traits (NS) has been found to be lower than that in their counterparts. But it is unclear that whether their reward motivation adaptively changes with external effort-reward ratio, and what resting-state functional connectivity (rsFC) is associated with this change. Thirty-five individuals with high levels of NS and 44 individuals with low levels of NS were recruited. A 3T resting-state functional brain scan and a novel reward motivation adaptation behavioural task were administrated in all participants. The behavioural task was manipulated with three conditions (effort > reward condition vs. effort < reward condition vs. effort = reward condition). Under each condition were rated 'wanting' and 'liking' for rewards. The seed-based voxel-wise rsFC analysis was conducted to explore the rsFCs associated with the 'wanting' and 'liking' ratings in individuals with high levels of NS. 'Wanting' and 'liking' ratings of individuals with high levels of NS significantly declined in the effort > reward condition but did not rebound as high as their counterparts in the effort < reward condition. The rsFCs in NS group associated with these ratings were altered. The altered rsFCs in NS group involved regions in the prefrontal lobe, dopaminergic brain regions (ventral tegmental area, substantia nigra), hippocampus, thalamus and cerebellum. Individuals with high levels of NS manifested their reward motivation adaptation impairment as a failure of adjustment adaptively during effort-reward imbalance condition and altered rsFCs in prefrontal, dopaminergic and other brain regions.

Altered brain structural and functional connectivity in schizotypy.

BACKGROUND: Schizotypy refers to schizophrenia-like traits below the clinical threshold in the general population. The pathological development of schizophrenia has been postulated to evolve from the initial coexistence of 'brain disconnection' and 'brain connectivity compensation' to 'brain connectivity decompensation'. METHODS: In this study, we examined the brain connectivity changes associated with schizotypy by combining brain white matter structural connectivity, static and dynamic functional connectivity analysis of diffusion tensor imaging data and resting-state functional magnetic resonance imaging data. A total of 87 participants with a high level of schizotypal traits and 122 control participants completed the experiment. Group differences in whole-brain white matter structural connectivity probability, static mean functional connectivity strength, dynamic functional connectivity variability and stability among 264 brain sub-regions of interests were investigated. RESULTS: We found that individuals with high schizotypy exhibited increased structural connectivity probability within the task control network and within the default mode network; increased variability and decreased stability of functional connectivity within the default mode network and between the auditory network and the subcortical network; and decreased static mean functional connectivity strength mainly associated with the sensorimotor network, the default mode network and the task control network. CONCLUSIONS: These findings highlight the specific changes in brain connectivity associated with schizotypy and indicate that both decompensatory and compensatory changes in structural connectivity within the default mode network and the task control network in the context of whole-brain functional disconnection may be an important neurobiological correlate in individuals with high schizotypy.

A network analysis of interoception, self-awareness, empathy, alexithymia, and autistic traits.

Altered interoception has been consistently found in people with autism spectrum disorder (ASD), and this impairment may contribute to social cognitive dysfunctions. However, little is known regarding the intercorrelations between interoceptive sensibility, autistic, alexithymic, empathic, and self-related traits. We recruited 1360 non-clinical college students and adults to investigate the complex inter-relationship between these variables using network analysis. The resultant network revealed patterns connecting autistic traits to interoceptive sensibility, empathy, alexithymia, and self-awareness, with reasonable stability and test-retest consistency. The node of alexithymia exhibited the highest centrality and expected influence. As revealed by the network comparison test, networks constructed in high- and low-autistic subgroups were comparable in global strength and structure. Our findings suggested that alexithymia serves as an important node, bridging interoceptive deficits, self-awareness, and empathic impairments of autism spectrum disorder. The co-morbidity of alexithymia should be considered carefully in future studies of interoceptive impairments and social deficits in ASD.

Hub-connected functional connectivity within social brain network weakens the association with real-life social network in schizophrenia patients.

Hubs in the brain network are the regions with high centrality and are crucial in the network communication and information integration. Patients with schizophrenia (SCZ) exhibit wide range of abnormality in the hub regions and their connected functional connectivity (FC) at the whole-brain network level. Study of the hubs in the brain networks supporting complex social behavior (social brain network, SBN) would contribute to understand the social dysfunction in patients with SCZ. Forty-nine patients with SCZ and 27 healthy controls (HC) were recruited to undertake the resting-state magnetic resonance imaging scanning and completed a social network (SN) questionnaire. The resting-state SBN was constructed based on the automatic analysis results from the NeuroSynth. Our results showed that the left temporal lobe was the only hub of SBN, and its connected FCs strength was higher than the remaining FCs in both two groups. SCZ patients showed the lower association between the hub-connected FCs (compared to the FCs not connected to the hub regions) with the real-life SN characteristics. These results were replicated in another independent sample (30 SCZ and 28 HC). These preliminary findings suggested that the hub-connected FCs of SBN in SCZ patients exhibit the abnormality in predicting real-life SN characteristics.

Altered empathy-related resting-state functional connectivity in patients with bipolar disorder.

Empathy is the ability to generate emotional responses (i.e., cognitive empathy) and to make cognitive inferences (i.e., affective empathy) to other people's emotions. Empirical evidence suggests that patients with bipolar disorder (BD) exhibit impairment in cognitive empathy, but findings on affective empathy are inconsistent. Few studies have examined the neural mechanisms of cognitive and affective empathy in patients with BD. In this study, we examined the empathy-related resting-state functional connectivity (rsFC) in BD patients. Thirty-seven patients with BD and 42 healthy controls completed the self-report Questionnaires of Cognitive and Affective Empathy (QCAE), the Yoni behavioural task, and resting-sate fMRI brain scans. Group comparison of empathic ability was conducted. The interactions between group and empathic ability on seed-based whole brain rsFC were examined. BD patients scored lower on the Online Simulation subscale of the QCAE and showed positive correlations between cognitive empathy and the rsFC of the dorsal Medial Prefrontal Cortex (dmPFC) with the lingual gyrus. The correlations between cognitive empathy and the rsFC of the temporal-parietal junction (TPJ) with the fusiform gyrus, the cerebellum and the parahippocampus were weaker in BD patients than that in healthy controls. These findings highlight the underlying neural mechanisms of empathy impairments in BD patients.

Expression of caveolin family proteins in serum of patients with systemic lupus erythematosus.

OBJECTIVES: Caveolin family proteins, including caveolin-1 (Cav-1), caveolin-2 (Cav-2), and caveolin-3 (Cav-3), are identified as the principal protein components of caveolae in mammalian cells. Circulating form of caveolin family proteins can be used as a good potential biomarker for predicting disease. METHODS: To investigate the clinical significance of the serological levels of caveolin family proteins in patients with systemic lupus erythematosus (SLE), we evaluated the soluble serum levels of caveolin family proteins in patients with SLE by enzyme-linked immunosorbent assay (ELISA) and assessed their associations with various known clinical variables. RESULTS: The major findings of our study are as follows: Cav-2 was not detected in serum of SLE patients and normal controls (NCs). Serum Cav-1 and Cav-3 levels were higher in SLE patients compared with NCs. There were no significant correlations between serum Cav-1 and Cav-3 levels and SLE disease activity. Further analysis showed that serum Cav-3 may be more valuable as a marker than serum Cav-1 in SLE patients. CONCLUSION: Serum levels of Cav-1 and Cav-3 might have a diagnostic role in patients with SLE. However, their predictive and prognostic value was not determined. Further studies are necessary to determine the potential clinical significance of these assays in SLE.

Validation of the Questionnaire of Cognitive and Affective Empathy in patients with schizophrenia, major depressive disorder and bipolar disorder.

INTRODUCTION: Alteration of empathy is common in patients with psychiatric disorders. Reliable and valid assessment tools for measuring empathy of clinical samples is needed. The Questionnaire of Cognitive and Affective Empathy (QCAE) is a newly-developed instrument to capture cognitive and affective components of empathy. This study aimed to validate the QCAE and compared self-reported empathy between clinical groups with varied psychiatric diagnoses and healthy sample. METHODS: The present study performed factor analysis for the QCAE on clinical samples in the Chinese setting (n = 534), including patients with schizophrenia (n = 158), bipolar disorder (n = 213) and major depressive disorder (n = 163). Internal consistency, internal correlation and convergent validity was examined in the subsample (n = 361). Group comparison among patients with schizophrenia, bipolar disorder, major depressive disorder and healthy controls (n = 107) was conducted to assess the discriminant validity. RESULTS: Our results indicated acceptable factor model, good reliability and validity of the QCAE. Impaired cognitive empathy was found in clinical samples, especially in patients with schizophrenia, while higher affective empathy was found in patients with bipolar disorder and major depressive disorder. CONCLUSION: The QCAE is a useful tool in assessing empathy in patients with varied psychiatric diagnoses.

Screening of miRNAs in human follicular fluid reveals an inverse relationship between microRNA-663b expression and blastocyst formation.

RESEARCH QUESTION: Are miRNAs found in follicular fluid related to blastocyst formation from the corresponding oocytes? DESIGN: In this study, 91 individual follicular fluid samples from single follicles containing mature oocytes from 91 women were collected and classified into group 1 (n = 38) with viable blastocysts, and group 2 (n = 53) with no blastocyst. TaqMan human miRNA cards and quantitative reverse transcription polymerase chain reaction were used to identify differently expressed follicular fluid miRNAs between the two groups. RESULTS: We found MIR-663B to be significantly differentially expressed in follicular fluid of oocytes that yielded viable blastocysts versus those that did not develop into blastocysts (14.16 ± 7.00 versus 23.68 ± 17.02; P = 0.019), as well as for those which develop into blastocysts with good morphology versus those with poor morphology (11.69 ± 3.49 versus 20.16 ± 9.33; P = 0.003). CONCLUSIONS: MIR-663B expression levels in human follicular fluid samples were significantly negatively related to viable blastocyst formation and may become an objective evaluation criterion for embryo development potential after IVF.

Global Analysis Reveals the Crucial Roles of DNA Methylation during Rice Seed Development.

Seed development is an important process of reproductive development and consists of embryo and endosperm development; both comprise several key processes. To determine and investigate the functions of the dynamic DNA methylome during seed development, we profiled the DNA methylation genome wide in a series of developmental stages of rice (Oryza sativa) embryo and endosperm by methylcytosine immunoprecipitation followed by Illumina sequencing. The results showed that embryo is hypermethylated predominantly around non-transposable element (TE) genes, short DNA-TEs, and short interspersed TEs compared with endosperm, and non-TE genes have the most diverse methylation status across seed development. In addition, lowly expressed genes are significantly enriched in hypermethylated genes, but not vice versa, confirming the crucial role of DNA methylation in suppressing gene transcription. Further analysis revealed the significantly decreased methylation at early developing stages (from 2 to 3 d after pollination), indicating a predominant role of demethylation during early endosperm development and that genes with a consistent negative correlation between DNA methylation change and expression change may be potentially directly regulated by DNA methylation. Interestingly, comparative analysis of the DNA methylation profiles revealed that both rice indica and japonica subspecies showed robust fluctuant profiles of DNA methylation levels in embryo and endosperm across seed development, with the highest methylation level at 6 d after pollination (2 d after pollination of endosperm in japonica as well), indicating that a complex and finely controlled methylation pattern is closely associated with seed development regulation. The systemic characterization of the dynamic DNA methylome in developing rice seeds will help us understand the effects and mechanism of epigenetic regulation in seed development.

Relationship Between Hematocrit Level and Cardiovascular Risk Factors in a Community-Based Population.

BACKGROUND: This study aimed to determine the relationship between hematocrit (HCT) levels and cardiovascular risk factors in a community-based population of middle-aged adults. METHODS: From April 2011 to February 2012, a total of 1,884 middle-aged adults were selected from a community-based population in China. Blood and urine samples were collected for routine blood and urine tests, and measurement of plasma glucose and lipid levels. Baseline information including traditional cardiovascular risk factors was obtained by standard questionnaire to analyze. We evaluated the distribution of the HCT values for middle-aged adults with or without cardiovascular risk factors. There were 548 males and 1,336 females in this study. The mean age of all subjects was 54.7 ± 6.7 years. There were 1,209 subjects with risk factors and 675 without risk factors. RESULTS: The HCT levels in subjects with risk factors were higher than those without risk factors (P = 0.005). According to a simplified tool for evaluation of the 10-year risk of ischemic cardiovascular diseases (CVDs) in Chinese populations, all subjects were divided into four groups: the ultralow-risk group (1,367, 72.6%), low-risk group (232, 12.3%), intermediate-risk group (201, 10.7%), and high-risk/ultrahigh-risk group (84, 4.4%). Compared with HCT levels in the ultralow-risk group, significant differences were found in the low-risk, intermediate-risk, and high-risk/ultrahigh-risk groups (all P < 0.05). CONCLUSION: Our results indicate that elevated HCT levels may be positively associated with cardiovascular risk factors. Thus, the combination of HCT values and cardiovascular risk factors may enable early diagnosis of CVDs.

Exploring the association of physical activity on cognitive function in older adults from observational and genetic insights: a combined NHANES and Mendelian randomization study.

Background: Cognitive function (CF) deterioration is a pressing concern in geriatric research. This study aimed to explore the relationship between physical activity (PA) and CF in older adults. Methods: This study adopted a dual approach, employing both observational and genetic approaches through data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 and Mendelian Randomization (MR) analysis. For the NHANES component, PA levels were evaluated using the Global Physical Activity Questionnaire, and CF was assessed via standardized tests. Multivariate regression, threshold effect analysis, smoothing curve fitting, and subgroup analyses were conducted to examine the association between PA and CF. In parallel, MR methods, using genetic variants as instrumental variables, assessed the causal impact of PA on CF and related conditions such as Alzheimer's disease and dementia. Results: Observational findings from NHANES demonstrated a positive correlation between PA and CF, notably among female participants. The detailed analysis identified specific thresholds of PA that correlate with cognitive enhancements. However, MR results did not support a significant causal relationship between PA and CF or dementia-related outcomes, indicating an absence of a direct genetic basis for the observational associations. Conclusion: Although observational data from NHANES suggest that PA is positively associated with CF in older adults, particularly among women, MR analysis did not confirm these findings as causally related. The discrepancy highlights the complexity of the PA-CF relationship and underscores the need for further research. These results emphasize the potential of PA as a modifiable risk factor for CF, though causal effects remain to be definitively established.

Neural correlates of audiovisual speech synchrony perception and its relationship with autistic traits.

The anterior insula (AI) has the central role in coordinating attention and integrating information from multiple sensory modalities. AI dysfunction may contribute to both sensory and social impairments in autism spectrum disorder (ASD). Little is known regarding the brain mechanisms that guide multisensory integration, and how such neural activity might be affected by autistic-like symptoms in the general population. In this study, 72 healthy young adults performed an audiovisual speech synchrony judgment (SJ) task during fMRI scanning. We aimed to investigate the SJ-related brain activations and connectivity, with a focus on the AI. Compared with synchronous speech, asynchrony perception triggered stronger activations in the bilateral AI, and other frontal-cingulate-parietal regions. In contrast, synchronous perception resulted in greater involvement of the primary auditory and visual areas, indicating multisensory validation and fusion. Moreover, the AI demonstrated a stronger connection with the anterior cingulate gyrus (ACC) in the audiovisual asynchronous (vs. synchronous) condition. To facilitate asynchrony detection, the AI may integrate auditory and visual speech stimuli, and generate a control signal to the ACC that further supports conflict-resolving and response selection. Correlation analysis, however, suggested that audiovisual synchrony perception and its related AI activation and connectivity did not significantly vary with different levels of autistic traits. These findings provide novel evidence for the neural mechanisms underlying multisensory temporal processing in healthy people. Future research should examine whether such findings would be extended to ASD patients.

Characterizing emotion profiles in non-clinical population: A cluster analytical study.

Emotion processing and beliefs about pleasure can influence the development and severity of depressive symptoms. This cluster analysis study aimed to profile a large sample of college students using pleasure experience, emotion expression and regulation as well as beliefs about pleasure. We also aimed to validate the resultant clusters in terms of depressive symptoms. A set of checklists capturing beliefs about pleasure and the three facets of emotion processing was administered to 1028 college students. A two-stage cluster analysis was used to analyze the profile of these emotional aspects in these college students. Our results showed that a three-cluster solution best fit the data. Cluster 1 (n = 536) was characterized by moderate levels of beliefs about pleasure, pleasure experience, emotion expression, and regulation; Cluster 2 (n = 402) was characterized by generally high levels of beliefs about pleasure, pleasure experience, emotion expression, and regulation; Cluster 3 (n = 90) was characterized by relatively low levels of beliefs about pleasure, pleasure experience, emotion expression, and regulation. The three clusters differed significantly in the severity of depressive symptoms. Our findings suggest the existence of three emotional subtypes, which may be useful in early detection of youth at risk of developing depression.

Relationships between childhood trauma and dimensional schizotypy: A network analysis and replication.

OBJECTIVES: Childhood trauma (CT) has been found to increase the risk of developing schizophrenia and other psychiatric disorders. Little is known regarding the complex interplay between CT, subclinical psychotic, and affective symptoms in the general population. This cross-sectional study adopted network analysis to examine such a complex relationship. We hypothesized that CT would show strong connections with schizotypy dimensions, and the high schizotypy subgroup would show a network with higher global strength compared with the low schizotypy subgroup. METHODS: A total of 1813 college students completed a set of self-report questionnaires measuring CT, schizotypal features, bipolar traits, and depressive symptoms. The subscales of these questionnaires were used as nodes, and the partial correlations between nodes were used as edges to construct a network. Network Comparison Tests were used to investigate the differences between participants with high schizotypy and low schizotypy. An independent sample (n = 427) was used to examine the replicability of the results. RESULTS: Findings from the main dataset showed that CT was closely connected with schizotypy and motivation, after controlling for the inter-relationships between all nodes in the network. Relative to the low schizotypy subgroup, the network of the high schizotypy subgroup showed higher global strength. The two subgroups did not differ in network structure. Network analysis using the replication dataset showed comparable global strength and network structure. CONCLUSIONS: Our findings support specific links between CT and schizotypy dimensions in healthy youth populations, and such links appear to become stronger in those with high schizotypy.

Relationship Between Interoception and Autistic Traits: A Resting-State Functional Connectivity Study.

Interoception, the sense of the physiological condition of our body, is impaired in individuals with autism spectrum disorders. Evidence suggests that subclinical autistic traits are mild manifestations of autistic symptoms, present in the general population. We examined the resting-state functional connectivity (rsFC) associating with interoception and autistic traits in 62 healthy young adults. Autistic traits correlated negatively with the rsFC between the lateral ventral anterior insula and anterior cingulate cortex. Interoceptive accuracy and sensibility correlated positively with the rsFC between interoceptive brain networks and the cerebellum, supplementary motor area, and visual regions. The results suggest that a negative relationship between interoception and autistic traits is largely accounted for by both self-report measures and decreased rsFC amongst the interoceptive brain network.

Protective effect of recombinant human brain natriuretic peptide against contrast-induced nephropathy in elderly acute myocardial infarction patients: A randomized controlled trial.

BACKGROUND: Increasing reports have demonstrated that recombinant human brain natriuretic peptide (rhBNP) can improve acute myocardial infarction (AMI) and heart failure. However, whether it can improve renal function and decrease the risk of contrast-induced nephropathy (CIN) in elderly AMI patients is still unclear. AIM: To explore the effect of rhBNP on CIN in elderly AMI patients after percutaneous coronary intervention (PCI). METHODS: One hundred and thirty-one elderly AMI patients underwent PCI from January 2017 to July 2021. Patients were either given 1 mL of 0.9% normal saline/(kg/h) for 72 h after PCI (control group, n = 66) and or intravenous rhBNP [1.5 mg/kg followed by 0.0075 mg/(kg/min)] for 72 h (rhBNP treatment group, n = 65). Serum creatinine and cystatin C levels, creatinine clearance rate, and eGFR were measured at 24 h, 48 h, and 72 h after PCI. Research nurses collected data on handwritten forms, and then stored them in password-protected electronic databases. RESULTS: The creatinine clearance rate and eGFR were increased, while the creatinine and cystatin C levels were decreased significantly in the rhBNP treatment group compared to the control group at 48 h and 72 h. The incidence of CIN (P = 0.028) and acute heart failure (P = 0.017) also significantly decreased in the rhBNP group. No significant difference was noted between the two groups in cardiac death and recurrent AMI. CONCLUSION: Early application of rhBNP could protect renal function and decrease the incidence of CIN after primary PCI and acute heart failure.

Air exchange rate and pollutant dispersion inside compact urban street canyons with combined wind and thermal driven natural ventilations: Effects of non-uniform building heights and unstable thermal stratifications.

In the present work, a delicate CFD research of a multi-street canyon model with varying thermal stratifications and non-uniformities of buildings was conducted to investigate the street ventilation and pollutant dispersion between the compact urban blocks. Non-isothermal turbulent wind flow, temperature field and pollutant dispersion in a two-dimensional computational domain were solved by the Renormalization Group (RNG) k-ε turbulence model along with the enhanced wall treatment. Present numerical results indicated that the variation of ground heating intensity has a significant influence on the airflow pattern in the step-down case, and the distribution of pollutants in the street canyons mainly depends on the variation of the upper clockwise vortex. The canyon ventilation performance became better as the unstable thermal stratification strengthened. Similarly, the increase of ground heating intensity could reduce ADF (atmospheric dispersion factor) in the step-down case and ADF became the lowest when Ri = -3.92 was maintained. Additionally, the increase of building unevenness further complicated the canyon airflow structure, which aggravated the pollution of the canyon. In the step-down configuration, as the standard deviation of adjacent building height gradually increases, canyon ventilation could be further enhanced. For the step-up configuration, the best ventilation performance was found at σH = 16.7 %. ADF of adjacent canyons also varied greatly. When σH = 33.3 % was maintained, the peak and bottom values of ADF were discovered in the step-up and step-down cases, respectively. Present research has provided a theoretical reference for guiding urban design and improve living environment in modern compact cities.