Biology subjects

Islam, M. Z.

Publications and source records attributed to Islam, M. Z..

4 recordsLinked to original sources

bioRxiv2026

Plant Molecules Protect Against Inflammatory Bowel Disease by Restoring Gut Microbiota-Immune Homeostasis and Suppressing Pro-inflammatory Markers

Inflammatory bowel disease (IBD) is associated with chronic intestinal inflammation and gut microbial dysbiosis, yet effective microbiome-targeted therapeutics remain limited. Here, we investigated the anti-inflammatory and microbiome-modulating activities of metabolites isolated from Garcinia brassii, an endemic species of the Australian Wet Tropics. Five compounds, including a new natural product named garcitine, were isolated and structurally characterised. In human immune cells, garcinol and garcinia biflavonoid 1 significantly suppressed lipopolysaccharide-induced production of IL-1{beta}, IL-6, and TNF without detectable cytotoxicity, while parvifoliol F selectively inhibited IL-1{beta} release. Therapeutic efficacy was further evaluated in a TNBS-induced murine colitis model, where garcinia biflavonoid 1 and parvifoliol F significantly reduced colonic inflammation and improved histopathological outcomes. 16S rRNA sequencing demonstrated that both compounds restored gut microbial homeostasis by reversing colitis-associated dysbiosis and reducing inflammation-associated microbial signatures. Functional pathway prediction further suggested suppression of pro-inflammatory microbial metabolic pathways following treatment. Together, these findings demonstrate that Garcinia-derived metabolites alleviate experimental colitis through coordinated immunomodulatory and microbiome-reprogramming mechanisms and identify garcinia biflavonoid 1 and parvifoliol F as promising candidates for microbiome-targeted IBD therapeutics.

immunology↗

bioRxiv2026

Population-specific drivers of reproductive phenology in a widespread large carnivore, the gray wolf

Animals often rely on cues from the environment to time reproduction with optimal conditions. However, for most species, which environmental cues are used and how their use varies across a species distribution remains poorly understood. The gray wolf (Canis lupus) is found across a broad latitudinal range (12{degrees}N to 83{degrees}N) and diverse natural habitats, making them an ideal study species to explore these questions. Using 1,261 estimated birth dates of wild and captive wolves across their global range, we investigated how environmental variables influence reproductive phenology in this widespread large carnivore. Birth dates for wild wolves ranged from November 22nd for Indian wolves (18{degrees}N) to June 15th for Arctic wolves (80{degrees}N). The best predictor of timing of birth was increasing daylength during the mating season, followed by precipitation variability during the year. The timing of birth in captive wolves was highly similar to wild wolves at same latitudes, suggesting they use similar environmental cues to time reproduction. Near the equator where photoperiod is more stable, wolves remained seasonal and likely use climatic cues to time reproduction. Our work reveals populations may use different environmental cues to time reproduction, a characteristic that likely facilitates adaptation to diverse environments.

ecology↗

bioRxiv2024

Divergent effects of 3-nitrooxypropanol on enteric methane emissions in Holstein and Brown Swiss cows, and its lack of synergy with Acacia mearnsii tannin extract

The objectives of this study were to investigate the combined effects of 3-nitrooxypropanol (3-NOP) and Acacia mearnsii tannin extract (TAN), and their interactions with dairy cattle breed [Brown Swiss (BS) vs. Holstein Friesian (HF)], on lactational performance, and enteric methane (CH4) emissions. Sixteen multiparous mid-lactation cows, including 8 BS and 8 HF cows were used in a split-plot design, with breed as the main plot. Cows within each subplot were arranged in a replicated 4 x 4 Latin Square design with a 2 x 2 factorial arrangement of treatments across four 24-d periods. The experimental diets were: 1) CON (basal total mixed ration), 2) 3-NOP (60 mg/kg DM), 3) TAN (3% of DM), and 4) 3-NOP + TAN. Spot samples of urine, feces, and gas emissions (via GreenFeed) were collected at the end of each period 8 times over 3 days. No 3-NOP x TAN x Breed interactions were observed for DM intake (DMI), milk production, or enteric gas emissions, except for CH4 yield (g/kg DMI) and CO2 production. Breed influenced DMI, milk production, and component yields, with HF cows consuming 3.7 kg/d more DMI, producing 9.3 kg/d more milk, and achieving greater feed efficiency and higher milk component yields than BS cows. Milk yield and energy-corrected milk (ECM) tended to increase in HF but tended to decrease in BS cows by 3-NOP. Cows fed TAN had 1 kg/d lower DMI with the tendency for 3-NOP x TAN showed greater reduction when TAN was fed alone, but milk yield, ECM, and feed efficiency remained unchanged. Cows fed TAN exhibited 18% lower milk urea nitrogen (N) concentration and 23.0% lower urinary N but 36.7% greater fecal N excretions as a percentage of daily N intake. A 3-NOP x Breed interaction was observed in CH4 production (g/d), with a 21.7% reduction in HF, and a 13.0% reduction in BS. Similarly, there were 3-NOP x Breed tendencies in CH4 yield and intensity (g/kg ECM), with reductions in HF cows of 21.8% and 23.4%, respectively, compared to 11.0% and 10.8% in BS cows. In conclusion, there were no synergistic or additive effects between 3-NOP and TAN on enteric CH4 mitigation. The enteric CH4 emission mitigating effect of 3-NOP was more pronounced in HF cows than in BS cows. Further research is needed to understand breed-specific responses and to optimize CH4 mitigation strategies for inclusion in national greenhouse gas inventories. ImplicationsThis study demonstrated that the feed additive 3-nitrooxypropanol reduces enteric methane emissions in dairy cows, with a greater reduction observed in Holsteins (22%) compared to Brown Swiss (13%) cows. While combining 3-NOP with Acacia mearnsii tannin extract did not further reduce methane. Feeding Acacia mearnsii extract decreased nitrogen excretion, potentially reducing environmental nitrogen pollution from manure. Neither additive substantially impacted milk production; however, 3-nitrooxypropanol tended to increase milk yield in Holsteins while reducing it in Brown Swiss. Overall, this study suggests that enteric methane mitigation efficacy of dietary strategies for different cattle breeds should be further investigated.

animal behavior and cognition↗

bioRxiv2023

Single-cell RNA-seq reveals TCR clonal expansion and a high frequency of transcriptionally distinct double-negative T cells in NOD mice

T cells primarily drive the autoimmune destruction of pancreatic beta cells in Type 1 diabetes (T1D). However, the profound yet uncharacterized diversity of the T cell populations in vivo has hindered obtaining a clear picture of the T cell changes that occur longitudinally during T1D onset. This study aimed to identify T cell clonal expansion and distinct transcriptomic signatures associated with T1D progression in Non-Obese Diabetic (NOD) mice. Here we profiled the transcriptome and T cell receptor (TCR) repertoire of T cells at single-cell resolution from longitudinally collected peripheral blood and pancreatic islets of NOD mice using single-cell RNA sequencing technology. Surprisingly, we detected a considerable high frequency of islet-matching T cell clones in the peripheral circulation and blood-matching T cell clones in the islets. Our analysis showed that transcriptional signatures of the T cells are associated with the matching status of the T cells, suggesting potential future applications as a marker for early prediction of diabetes onset using peripheral T cells. In addition, we discovered a high frequency of transcriptionally distinct double negative (DN) T cells that might arise from naive and effector backgrounds through the loss of CD4 or CD8 in a yet unknown biological pathway. This study provides a single-cell level transcriptome and TCR repertoire atlas of T cells in NOD mice and opens the door for more research into the causes of type 1 diabetes and inflammatory autoimmune disease using mouse models.

immunology↗