Noof Abdulrahman Alrabiah

Introduction: The role of natural dietary fibers in supporting immune function and systemic physiological responses is increasingly recognized. This study evaluated the effect of long-term oral administration of gum arabic (GA) on the immune function of rats. Method: Seventy-six adult male Wistar rats were assigned to five groups: controls, GA treated (5% or 10% in drinking water for 6 weeks), and GA combined with LPS or dexamethasone, alongside corresponding LPS and dexamethasone controls.Phagocytic, histological, and immune markers were estimated and evaluated statistically by using one-way ANOVA followed by Duncan’s multiple range test. Results: GA treatment significantly increased serum complement-3 levels, lysozyme activity, immunoglobulin M (IgM), and nitric oxide (p < 0.05). GA also increased phagocytic index, neopterin, and intestinal mucosal eosinophil count, while spleen weight and mucosal mast cell count remained unchanged. GA mitigated the inhibitory effects of intramuscular dexamethasone on immune parameters and improved intravascular carbon clearance, and effectively attenuated the LPS induced increase in the pro-inflammatory cytokines (IL-1α, IL-4, IL-6, and TNF-α). Conclusion: These findings suggest that GA modulates selected immune parameters, enhances innate immune responses, and maintains systemic immune responsiveness under both normal and challenged conditions in rats.

Recent developments in single-cell multi-omics technologies have provided the ability to identify diverse cell types and decipher key components of the tumor microenvironment (TME), leading to important advancements toward a much deeper understanding of how tumor microenvironment heterogeneity contributes to cancer progression and therapeutic resistance. These technologies are able to integrate data from molecular genomic, transcriptomic, proteomics, and metabolomics studies of cells at a single-cell resolution scale that give rise to the full cellular and molecular complexity in the TME. Understanding the complex and sometimes reciprocal relationships among cancer cells, CAFs, immune cells, and ECs has led to novel insights into their immense heterogeneity in functions, which can have important consequences on tumor behavior. In-depth studies have uncovered immune evasion mechanisms, including the exhaustion of T cells and metabolic reprogramming in response to hypoxia from cancer cells. Single-cell multi-omics also revealed resistance mechanisms, such as stromal cell-secreted factors and physical barriers in the extracellular matrix. Future studies examining specific metabolic pathways and targeting approaches to reduce the heterogeneity in the TME will likely lead to better outcomes with immunotherapies, drug delivery, etc., for cancer treatments. Future studies will incorporate multi-omics data, spatial relationships in tumor micro-environments, and their translation into personalized cancer therapies. This review emphasizes how single-cell multi-omics can provide insights into the cellular and molecular heterogeneity of the TME, revealing immune evasion mechanisms, metabolic reprogramming, and stromal cell influences. These insights aim to guide the development of personalized and targeted cancer therapies, highlighting the role of TME diversity in shaping tumor behavior and treatment outcomes.

The acquisition of oocyte competence in cattle, encompassing both cytoplasmic and nuclear maturation, is essential for successful fertilization and embryonic development. This competence is progressively achieved during the latter stages of the oocyte growth phase and completed within the dominant follicle (DF). The unique hormonal and immunological environment of the DF during oestrous supports oocyte “capacitation,” a process involving organelle reorganization, mRNA storage and meiosis resumption, which fully prepares the oocyte for fertilization. These changes differentiate oocytes from the DF from those of subordinate follicles, explaining why only oocytes from the DF mature and ovulate successfully. Despite advances in assisted reproductive technologies like in vitro maturation (IVM) and in vitro fertilization (IVF), developmental outcomes remain inferior compared to in vivo matured oocytes, largely due to incomplete or altered oocyte maturation in vitro. Blastocyst rates after IVM/IVF are substantially lower (~35%) than those from in vivo matured oocytes (58-78%). The heterogeneity of oocytes retrieved from antral follicles and the lack of exposure to the natural follicular environment during IVM are key factors limiting developmental competence. Here we describe the molecular changes in bovine oocytes from DFs, collected at 24 and 2 h before ovulation without ovarian stimulation, using single-cell RNA sequencing and bisulfite sequencing to assess gene expression and DNA methylation dynamics. Results revealed significant shifts in transcripts related to oxidative phosphorylation, highlighting the crucial role of energy metabolism during oocyte capacitation. DNA methylation changes were subtle but indicated a more dynamic and less stable epigenome in fully-grown oocytes than previously assumed. Overall, understanding the gene expression and epigenetic landscape during oocyte maturation in the DF offers valuable insights into improving oocyte quality and ART outcomes in cattle. Optimizing the maturation environment to better mimic natural follicular conditions could enhance reproductive efficiency in bovine production systems.

Surra, a wasting disease caused by Trypanosoma evansi, is one of the major animal health burdens in camel-rearing countries, imposing significant economic losses due to reduced fertility and high mortality rates. The present study used inactivated T. evansi (from the Card Agglutination Test for Trypanosomes/Trypanosoma evansi; CATT/T. evansi) and flow cytometry to investigate their binding and activation potential toward camel leukocyte subsets. Labeling T. evansi with propidium iodide (PI) enabled their flow cytometric enumeration and identification with forward scatter (FSC; indicative for cell size) and side scatter (SSC; indicative for cell internal complexity) characteristics that are comparable with values reported for Trypanosoma cruzi. The incubation of PI-labeled non-opsonized T. evansi with camel leukocyte populations revealed that camel monocytes have the highest potential to bind T. evansi, followed by granulocytes and lymphocytes. The identification of pattern recognition receptors (PRRs) on camel immune cells and the pathogen-associated molecular patterns (PAMPs) in T. evansi that are responsible for this different binding capacity requires further studies. Stimulation of camel neutrophils with Trypanosoma evansi induced shape change, reactive oxygen species (ROS) production, and neutrophil extracellular traps (NET)-formation. To ensure that T. evansi, in the parasite concentration used in this study, is not apoptotic or necrotic to camel leukocytes, we evaluated cell apoptosis and necrosis after stimulation with T. evansi. The results revealed no impact of T. evansi stimulation for 2 h on the cell viability of camel leukocytes. Subsequent work may focus on the diagnostic employment of labeled T. evansi and flow cytometry for the detection of anti-Trypanosoma antibodies in camel serum. In addition, more efforts should be deployed to investigate the host–pathogen interaction mechanisms and the escape mechanisms of T. evansi in camels. To complete these data, further studies using the living or freshly killed parasites could also be implemented in camels and/or horses.

Follicular fluid (FF), a product of vascular transudate and granulosa and thecal cell secretions, is the milieu that has evolved to support oocyte growth and maturation which plays a central role in oocyte quality determination. Therefore, a suboptimal FF composition may be reflected in compromised oocyte progression through maturation, fertilization, or embryo development. To date, the composition of bovine FF remains understudied. To address this, we comprehensively characterized the metabolomic constituency of bovine FF in the period during which the oocyte undergoes meiotic maturation. More specifically, FF from pre (−24 h) and peri (−2 h)-ovulatory follicles was profiled by high-throughput untargeted ultra-HPLC tandem mass spectroscopy. A total of 634 metabolites were identified, comprising lipids (37.1%), amino acids (30.0%), xenobiotics (11.5%), nucleotides (6.8%), carbohydrates (4.4%), cofactors and vitamins (4.4%), peptides (3.6%), and energy substrates (2.1%). The concentrations of 67 metabolites were significantly affected by the stage of follicle development, 33.3% (n = 21) were reduced (P ≤ 0.05) by a mean of 9.0-fold, whereas 46 were elevated (P ≤ 0.05) by a mean of 1.7-fold in peri- vs pre-ovulatory FF. The most pronounced individual metabolite concentration decreases were observed in hypoxanthine (98.9-fold), xanthine (65.7-fold), 17β-oestradiol (12.4-fold), and inosine (4.6-fold). In contrast, the greatest increases were in retinal (4.9-fold), 1-methyl-5-imidazoleacetate (2.7-fold), and isovalerylcarnitine (2.7-fold). This global metabolomic analysis of bovine FF temporal dynamics provides new information for understanding the environment supporting oocyte maturation and facilitating ovulation that has the potential for improving oocyte quality both invivo and in vitro. Lay Summary: The ovaries are part of the female reproductive system, and they produce and store eggs in structures known as ‘follicles’. Depending on the species, one or more follicles release an egg from the ovary during ovulation. FF, which is formed from the secretions of follicle cells and substances delivered from the bloodstream, bathes the eggs as they develop within their follicles. For pregnancy to happen, the egg must be capable of being fertilised by a sperm cell, developing into an embryo and implanting it in the womb. FF has evolved to support the egg to achieve this. Using the cow as a model, this study looks at the composition of FF during the final hours before ovulation, when the egg becomes mature and ready for fertilisation. More than 600 different substances were identified, providing new information, that has the potential to improve egg quality.