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Cyclic AMP (cAMP) is involved in many biological processes but little is known regarding its role in shaping immunity. Here we show that cAMP-PKA-CREB signaling (a pattern recognition receptor [PRR]-independent mechanism) regulates conventional type-2 Dendritic Cells (cDC2s) in mice and reprograms their Th17-inducing properties via repression of IRF4 and KLF4, transcription factors essential for cDC2-mediated Th2 induction. In mice, genetic loss of IRF4 phenocopies the effects of cAMP on Th17 induction and restoration of IRF4 prevents the cAMP effect. Moreover, curdlan, a PRR-dependent microbial product, activates CREB and represses IRF4 and KLF4, resulting in a pro-Th17 phenotype of cDC2s. These in vitro and in vivo results define a novel signaling pathway by which cDC2s display plasticity and provide a new molecular basis for the classification of novel cDC2 and cDC17 subsets. The findings also reveal that repressing IRF4 and KLF4 pathway can be harnessed for immuno-regulation.

Cadmium (Cd) is a non-essential trace element that poses significant toxic effects on fish. This review focuses on hematological and plasma biochemical parameters as key indicators of fish health under Cd exposure. Hematological parameters, such as red blood cell (RBC) count, hemoglobin (Hb) concentration, and hematocrit (Ht), were selected for their critical role in oxygen transport and their sensitivity to Cd-induced disruptions, which often result in anemia and impaired oxygen delivery to tissues. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) provide further insights into erythropoiesis and hemoglobin synthesis, both of which are essential for assessing Cd toxicity. Plasma biochemical parameters, including calcium, magnesium, glucose, cholesterol, total protein, and liver enzymes such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP), are crucial for understanding ionic balance, metabolic regulation, and organ function, especially in fish exposed to Cd. These biomarkers offer a comprehensive view of the physiological stress and organ damage caused by Cd toxicity. This review synthesizes literature findings on the toxic effects of Cd on these parameters. It also discusses potential mitigation strategies, including dietary supplementation with antioxidants and trace elements, to counteract the harmful effects of Cd exposure. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic has exacerbated existing healthcare disparities among American Indian/Alaska Native (AI/AN) populations rooted in historical traumas and systemic marginalization. Methods: This study conducted at a single Indian Health Service (IHS) clinic in central Michigan evaluates two educational interventions for enhancing COVID-19 knowledge and attitudes in a sample AI/AN population. Utilizing a pre/post-intervention prospective study design, participants received either a video or infographic educational intervention, followed by a survey assessing their COVID-19 knowledge and attitudes. Results: The results indicate significant improvements in knowledge and attitudes post-intervention, with both modalities proving effective. However, specific factors such as gender, political affiliation, and place of residence influenced COVID-19 attitudes and knowledge, emphasizing the importance of tailored interventions. Conclusions: Despite limitations, this study highlights the critical role of educational interventions in addressing vaccine hesitancy and promoting health equity within AI/AN communities. Moving forward, comprehensive strategies involving increased Indian Health Service funding, culturally relevant interventions, and policy advocacy are crucial in mitigating healthcare disparities and promoting health equity within AI/AN communities. [ABSTRACT FROM AUTHOR]

The effects of red light‐emitting diode (LED) light irradiation (630 nm, 0.5 W/m2) and melatonin (10−8 and 10−7 M) on oxidative stress and physiological responses in abalones exposed to high temperatures (28°C) were investigated. Changes in messenger RNA (mRNA) expressions of melatonin receptor (MT‐R), heat shock protein 70 (HSP70), and antioxidant enzymes, as well as alterations in H2O2 levels in the hemolymph, were examined. The results revealed that high‐temperature‐stressed abalones treated with melatonin injections or exposed to red LED light showed a significant increase in MT‐R mRNA expression, while HSP70 mRNA expression decreased. Notably, HSP70 mRNA expression levels in the red LED light‐irradiated group were similar to those in the group injected with 10−8 M melatonin after 24 h exposure. Abalones treated with melatonin at 20°C or irradiated with red LED light exhibited decreased H2O2 levels and reduced antioxidant enzyme mRNA expression compared with those of the control group. However, the high‐temperature environment induced oxidative stress in abalones, leading to increased antioxidant enzyme mRNA expression compared with that under 20°C conditions. Moreover, abalones exposed to high‐temperature stress exhibited hepatopancreatic DNA damage, which was attenuated by melatonin treatment or red LED light irradiation. Hence, red LED light reduces oxidative stress, boosts antioxidant enzymes, and alleviates DNA damage in high‐temperature‐stressed abalones, akin to 10−8 M melatonin treatment. Therefore, considering the practical challenges of continuous melatonin administration to abalones, utilizing red LED light emerges as a practical, effective alternative to protect abalones from oxidative stress compared to 10−8 M melatonin treatment. Research Highlights: High‐temperature stressed abalone responses to melatonin and red light were assessed.Red LED light irradiation increased abalone antioxidant enzyme expression levels.Melatonin or red LED light treatment attenuated hepatopancreatic DNA damage. [ABSTRACT FROM AUTHOR]

The South Korean aquaculture industry has incurred considerable production losses due to various infectious diseases. Artificially synthesized polyinosinic–polycytidylic acid (poly I:C), structurally similar to double-stranded RNA (dsRNA) and cytidine–phosphate–guanosine oligodeoxynucleotides, can enhance immune responses and protect against diseases. Here, we investigated dsRNA molecules with different cytidine–phosphate–guanosine (CpG) motifs (dsRNA-CpGMix) as fused agents to treat Miamiensis avidus and viral hemorrhagic septicemia virus (VHSV) infection in olive flounders. We further investigated the efficacy of specific sequence motifs in dsRNA in modulating immunostimulatory effects. Fish treated with poly I:C or dsRNA-CpGMix exhibited higher survival rates than the control group. Olive flounder leukocytes stimulated with poly I:C or dsRNA-CpGMix showed increased scuticocidal activity in the presence of inactivated immune sera. dsRNA with CpG motif sequences induced higher resistance against M. avidus and VHSV infections than dsRNA without CpG motif sequences, and the dsRNA-CpGMix group showed upregulated ISG15 or Mx compared to the dsRNA-GFP group. Thus, dsRNA containing CpG motifs can be used as effective immunostimulants to enhance resistance against viral and parasitic diseases in olive flounder. The specific sequences of the CpG motifs in dsRNA may be important for enhancing immune responses and resistance against M. avidus and VHSV infections in olive flounders. [ABSTRACT FROM AUTHOR]

This article provides information on Acute Hepatopancreatic Necrosis Disease (AHPND), a bacterial disease that has had a significant impact on the shrimp farming industry. The main causative agent of AHPND is Vibrio parahaemolyticus, but other Vibrio strains with similar toxin genes have also been reported. The article focuses on the identification and evaluation of a novel Vibrio strain isolated from a shrimp farm in South Korea. The strain, known as HJ-2023, was found to be highly virulent and resistant to certain antibiotics. The research emphasizes the importance of biosecurity measures to prevent the spread of AHPND in aquaculture. [Extracted from the article]