Publications by authors named "Esma Karkeni"
Article Synopsis
- Cytomegalovirus (CMV) infection can harm newborns, leading to the need for effective treatments to combat both viral and immune damage.
- Research in a mouse model shows that cellular prion protein (PrP) helps regulate T cell immunity, with PrP-null mice demonstrating better control over CMV through stronger CD8 T cell responses.
- The study identifies that CMV increases PrP levels via ADAM10, which hinders T cell responses in neonates, and confirms similar downregulation of PrP in human CMV-infected cells, emphasizing the findings' relevance to human health.
Several inflammatory markers such as cytokines, chemokines, and microRNAs (miRNAs) are well known to be induced during obesity and are strongly linked to their comorbidities. Among many others factors, the micronutrient status is suspected to reduce obesity-associated inflammation via blunting inflammatory signalling pathways. This is notably the case for active forms of vitamin A (all-trans retinoic acid ATRA) and vitamin D (1,25(OH)D) as previously shown.
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- Long-term multilineage hematopoietic donor chimerism is a rare occurrence in patients receiving solid organ transplants, particularly those from lymphoid-rich organs like the intestine or liver.
- Unlike other organs, there has been no evidence of kidney-resident hematopoietic stem cells in mammals, but new findings suggest they may exist.
- A case study of a pediatric kidney transplant recipient indicates that these kidney-derived stem cells can reside in bone marrow long-term, ultimately replacing the host's stem cells and achieving full donor chimerism in blood lineages.
Article Synopsis
- - Propolis extracts show promise as nutraceuticals for managing obesity and related health issues, but their effectiveness varies based on the plant sources used by bees.
- - In a study with high-fat-fed mice, poplar propolis extract powder (PPEP) significantly reduced body weight gain and improved glucose levels, while other propolis extracts (BPEP and DPEP) did not yield beneficial effects.
- - PPEP influenced adipose tissue gene expression by promoting lipid breakdown and inhibiting inflammation, potentially due to its unique polyphenol content that activates antioxidant genes.
Article Synopsis
- Obesity is linked to lower levels of vitamin D (25(OH)D), but the mechanisms behind this relationship are not well understood, particularly the initial factors that could explain it.
- * A study on male mice showed that a short-term high-fat (HF) diet resulted in increased body fat and lower free 25(OH)D levels, with changes in liver and kidney gene expression related to vitamin D metabolism.
- * The findings suggest that a high-fat diet may trigger changes in vitamin D metabolism, potentially indicating long-term storage of vitamin D in fat tissue and contributing to obesity-related metabolic issues.
Article Synopsis
- * In a study, male mice on a high-fat diet given a propolis extract experienced less weight gain, lower body fat, and improved blood sugar levels.
- * The extract boosts genes related to fat breakdown and energy production while reducing inflammation, potentially targeting the Nrf2 pathway as a mechanism of action.
Article Synopsis
- This study investigated how physical exercise affects blood vessel growth in fat tissue after weight loss in mice with diet-induced obesity, focusing on a specific molecular pathway.
- Results showed that exercise counteracts the normal inhibitory factors on blood vessel growth in fat tissue, leading to improved fat tissue health and insulin sensitivity in obese mice.
- The findings suggest that exercise has therapeutic potential for treating obesity-related health issues and provides insights for developing targeted treatments in humans.
Article Synopsis
- * Vitamin D treatment decreases breast cancer growth and boosts the activity of CD8+ T cells in the tumors, suggesting a potential role in enhancing immune response against cancer.
- * However, in environments with a high-fat diet, vitamin D's positive effects on breast cancer growth and CD8+ T cell infiltration are diminished, highlighting how diet can influence cancer progression and treatment efficacy.
Article Synopsis
- A study examines the biological functions of the less-studied (5Z)-lycopene isomer compared to the more common all-trans (all-E)-lycopene, especially in human adipocytes (fat cells).
- Both isomers were found to influence the same gene expression profiles and biological pathways, particularly through activating peroxisome proliferator-activated receptor (PPAR) signaling.
- The study concludes that lycopene isomers have similar effects in reducing inflammation and improving glucose uptake in adipocytes, suggesting potential benefits in preventing obesity-related disorders.
Article Synopsis
- The study investigated how nine specific microRNAs found in microparticles affect inflammation and vascular function in women with obesity during an 8-week aerobic exercise program.
- It compared sedentary women with normal weight and women with obesity, finding that the latter had higher cardiovascular risks and different microRNA profiles.
- Results showed that exercise led to reduced BMI and inflammation in both groups, improved vascular responses for healthy women, and increased levels of circulating microparticles, suggesting a potential for identifying microRNA biomarkers in cardiovascular disease.
Diet induced obesity modifies vitamin D metabolism and adipose tissue storage in mice.
J Steroid Biochem Mol Biol
January 2019
Article Synopsis
- Low levels of vitamin D, specifically 25-hydroxyvitamin D (25(OH)D), are linked to obesity, suggesting obesity may lower vitamin D levels.
- In a study with male mice on high-fat diets, researchers found changes in vitamin D metabolism, including a temporary increase in total 25(OH)D but a consistent decrease in free 25(OH)D after a prolonged high-fat diet.
- Increased 25(OH)D was found in adipose tissue, correlating with changes in specific enzymes, indicating that a high-fat diet may disrupt vitamin D metabolism and contribute to lower free 25(OH)D levels associated with obesity.
It is well established that the active form of vitamin D (i.e., 1,25-dihydroxyvitamin D [1,25(OH)2D]) regulates the expression of genes involved in its own metabolism and transport in the kidney and possibly in the liver.
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- Several studies indicate that high lycopene or tomato product intake is linked to a reduced risk of metabolic diseases, prompting this study to assess their effects on obesity-related issues.
- Male mice were divided into groups to receive different diets (control, high fat, and high fat with lycopene or tomato powder), and results showed that both supplements significantly improved markers related to fat accumulation and reduced inflammation without affecting overall body weight.
- The findings suggest that both lycopene and tomato powder could offer similar health benefits, making them valuable in nutritional strategies to combat obesity-related disorders.
Article Synopsis
- ATRA, a metabolite of Vitamin A, was found to reduce inflammation in adipose tissues of humans and mice, impacting body weight regulation and obesity-related inflammation.
- In human adipocytes, ATRA decreased the expression of 17 chemokines and limited the movement of macrophages, while similar effects were confirmed in a mouse model treated with ATRA.
- The anti-inflammatory benefits of ATRA were linked to decreased activation of the NF-κB pathway, suggesting its potential as a preventive nutritional strategy against obesity and related health issues.
Article Synopsis
- - Vitamin D (VD) helps reduce inflammation in fat tissue, which is linked to obesity-related chronic diseases, by lowering inflammation markers and immune cell infiltration.
- - The study found that VD prevents the upregulation of specific microRNAs (miR-146a, miR-150, and miR-155) triggered by inflammation in human fat cells, with similar effects seen in mice.
- - VD’s regulation of these microRNAs is linked to its ability to inhibit NF-κB signaling, a pathway involved in inflammation, suggesting a potential new mechanism for how VD may influence metabolic inflammation.
Article Synopsis
- Adiponectin, a protein produced by fat cells, plays a key role in reducing diabetes, inflammation, and heart disease, but its production decreases with a long-term high-fat diet.
- A study on mice showed that both high-fat and high-vitamin A diets lead to decreased adiponectin levels and increased activation of certain signaling pathways related to vitamin A.
- The research revealed that increased expression of a specific enzyme (ALDH1A1) and certain vitamin A receptor interactions contributed to the reduced adiponectin production in the adipose tissue of mice on these diets.
Article Synopsis
- Obesity leads to changes in adipose tissue that promote inflammation and related health issues, with microRNAs, particularly miR-155, playing a key regulatory role.
- The study found that miR-155 levels were increased in TNFα-treated adipocytes and showed a strong correlation with body mass index and inflammation markers in obese individuals.
- The research suggests that miR-155 contributes to a pro-inflammatory feedback loop in adipose tissue via the NF-κB pathway, potentially worsening inflammation in adipocytes.
Article Synopsis
- - Cross-sectional studies suggest that there is a negative correlation between vitamin D levels in the body and obesity, implying that lower vitamin D may be linked to higher obesity rates.
- - Research on animal models indicates that vitamin D affects fat tissue and cell biology, which could mean that insufficient vitamin D might contribute to obesity and related health issues like inflammation and insulin resistance.
- - While some prospective studies hint that vitamin D could help prevent obesity, overall clinical and genetic studies show mixed results, indicating that more research is needed to clarify the relationship between vitamin D and obesity.
Article Synopsis
- Vitamin D (VD) has immunoregulatory effects that reduce inflammation in fat cells and limit macrophage infiltration, which is important in the context of obesity-related inflammation.
- A study confirmed that 1,25 dihydroxy-VD decreased the expression of various chemokines and inhibited macrophage migration, showing considerable effects on inflammation markers in both lab and live animal models.
- The findings suggest that VD plays a significant role in regulating inflammation in adipose tissue by reducing proinflammatory cytokines and chemokines, improving our understanding of its potential benefits for obesity-related health issues.
Article Synopsis
- There is a connection between vitamin D levels and the prevalence of obesity and type 2 diabetes, but the exact causality is not clear yet.
- A study was conducted using mice to investigate if vitamin D3 supplementation could prevent obesity caused by a high-fat diet.
- The results indicated that vitamin D3 helped limit weight gain and improved blood sugar control, likely by enhancing fat oxidation and boosting energy expenditure, suggesting its potential role in preventing obesity and metabolic issues.