Kisspeptin in reproduction

Although the functions of kisspeptin originally were believed to be restricted to metastasis suppression, a novel role for this protein was discovered in 2003. Loss-of-function mutations in its receptor, GPR54, were found to cause absence of puberty and hypogonadotropic hypogonadism in humans. Mice with targeted deletions of GPR54 also have a hypogonadotropic phenotype, confirming the important role of this ligand-receptor family in the control of puberty and reproductive function. Since these discoveries, the peptide products of the KISS1 gene have been shown to be powerful stimulators of the gonadotropic axis. This review examines the role of kisspeptins and GPR54 in reproductive function.     

Transplanted human cones incorporate into the retina and function in a murine cone degeneration model

Once human photoreceptors die, they do not regenerate, thus, photoreceptor transplantation has emerged as a potential treatment approach for blinding diseases. Improvements in transplant organization, donor cell maturation, and synaptic connectivity to the host will be critical in advancing this technology for use in clinical practice. Unlike the unstructured grafts of prior cell-suspension transplantations into end-stage degeneration models, we describe the extensive incorporation of induced pluripotent stem cell (iPSC) retinal organoid–derived human photoreceptors into mice with cone dysfunction. This incorporative phenotype was validated in both cone-only as well as pan-photoreceptor transplantations. Rather than forming a glial barrier, Müller cells extended throughout the graft, even forming a series of adherens junctions between mouse and human cells, reminiscent of an outer limiting membrane. Donor-host interaction appeared to promote polarization as well as the development of morphological features critical for light detection, namely the formation of inner and well-stacked outer segments oriented toward the retinal pigment epithelium. Putative synapse formation and graft function were evident at both structural and electrophysiological levels. Overall, these results show that human photoreceptors interacted readily with a partially degenerated retina. Moreover, incorporation into the host retina appeared to be beneficial to graft maturation, polarization, and function.     

The Ultra-Processed Food Content of School Meals and Packed Lunches in the United Kingdom

British children have the highest levels of ultra-processed food (UPF) consumption in Europe. Schools are posited as a positive setting for impacting dietary intake, but the level of UPFs consumed in schools is currently unknown. This study determined the UPF content of school food in the UK. We conducted a pooled cross-sectional analysis of primary (4–11 years, n = 1895) and secondary schoolchildren (11–18 years, n = 1408) from the UK’s National Diet and Nutrition Survey (2008–2017). Multivariable quantile regression models determined the association between meal-type (school meal or packed lunch) and lunchtime UPF intake (NOVA food classification system). We showed that on average, UPF intake was high in both primary (72.6% total lunch Kcal) and secondary schoolchildren (77.8% total lunch Kcal). Higher UPF intakes were observed in packed lunch consumers, secondary schoolchildren, and those in lower income households. This study highlights the need for a renewed focus on school food. Better guidance and policies that consider levels of industrial processing in food served in schools are needed to ensure the dual benefit of encouraging school meal uptake and equitably improving children’s diets.     

Ceramide changes in abdominal subcutaneous and visceral adipose tissue among diabetic and nondiabetic patients

BackgroundThis study profiles ceramides extracted from visceral and subcutaneous adipose tissue of human subjects by liquid chromatography‐mass spectrometry to determine a correlation with status of diabetes and gender.MethodsSamples of visceral and abdominal wall subcutaneous adipose tissue (n = 36 and n = 31, respectively) were taken during laparoscopic surgery from 36 patients (14 nondiabetic, 22 diabetic and prediabetic) undergoing bariatric surgery with a body mass index (BMI) >35 kg/m² with ≥1 existing comorbidity or BMI ≥40 kg/m². Sphingolipids were extracted and analyzed using liquid chromatography‐mass spectrometry.ResultsAfter logarithm 2 conversion, paired analysis of visceral to subcutaneous tissue showed differential accumulation of Cer(d18:1/16:0), Cer(d18:1/18:0), and Cer(d18:1/24:1) in visceral tissue of prediabetic/diabetic female subjects, but not in males. Within‐tissue analysis showed higher mean levels of ceramide species linked to insulin resistance, such as Cer(d18:1/18:0) and Cer(d18:1/16:0), in visceral tissue of prediabetic/diabetic patients compared with nondiabetic subjects and higher content of Cer(d18:1/14:0) in subcutaneous tissue of insulin‐resistant female patients compared with prediabetic/diabetic males. Statistically significant differences in mean levels of ceramide species between insulin‐resistant African American and insulin‐resistant Caucasian patients were not evident in visceral or subcutaneous tissue.ConclusionsAnalysis of ceramides is important for developing a better understanding of biological processes underlying type 2 diabetes, metabolic syndrome, and obesity. Knowledge of the accumulated ceramides/dihydroceramides may reflect on the prelipolytic state that leads the lipotoxic phase of insulin resistance and may shed light on the predisposition to insulin resistance by gender.     

Food Sales and Adult Weight Status: Results of a Cross-Sectional Study in England

Ecological studies often use supermarket location as a proxy measure of the food environment. In this study, we used data on sales at a leading mainstream supermarket chain to explore how area-level supermarket use is associated with overweight and obesity in English adults. Sales data were aggregated to local authority level and joined to a national dataset describing self-reported height and weight and fruit and vegetable consumption. Regression models showed a modest association between higher levels of unhealthy food sales relative to health food sales and increased odds of being overweight and obese. Although effect sizes were small, they persisted after adjustment for area-level deprivation. Supermarket sales data provide additional understanding in the study of food environments and their impact on increasing weight status. Future health policies should consider using ‘big data’ combined with other research methods to address the increasing consumption of unhealthy and highly processed foods.     

Antioxidant,cytotoxic, and anti-venom activity of Alstonia parvifolia Merr. Bark

Objective: To evaluate antioxidant, cytotoxic, and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr. Methods: Gas chromatography-mass spec...