Improvement of Growth Retardation and Related Immunodeficiency by Dietary Intervention with Crackers Containing Animal Source Ingredients in Malnourished Rats

Hidden hunger is a risk factor for many health problems, including stunting, which is one of the globally prevalent signs of malnutrition. Stunting can be reduced through feeding on animal source foods. In our study, some animal source foods (egg, butter, yoghurt, and white cheese) in addition to other nutritious ingredients (wheat flour, minced fresh carrot, wheat germ, yeast, and iodine salt) were used to prepare four samples of crackers, with different taste (cumin, paprika, tomato, and cheese). The dough from all ingredients was prepared, flattened, cut then baked to prepare the crackers. These crackers were organoleptically and physically evaluated. Antioxidant activity, total phenolic content (TPC) and total flavonoid contents of the crackers’ samples were determined. The cumin-flavored crackers (the highest in TPC, flavonoids, and antioxidant activity) was evaluated for its macro-and micronutrients and studied in malnourished rats. Two groups of rats (each of 12) were fed on a balanced diet and a protein-deficient diet, respectively for 3 weeks. Six rats from each group were sacrificed and the remaining rats were fed on a balanced diet and diet supplemented with the cumin-flavored crackers, respectively for 5 weeks. The cumin-flavored crackers (100 g) contained 15.64 g protein, 231.00 mg calcium, 4.00 mg zinc, 83.75 µg iodine, arginine (16.53 mg/g protein), and lysine (19.30 mg/g protein). Malnutrition, immunodeficiency (as evidenced by a drop in cluster of differentiation 4 (CD4), cluster of differentiation 8 (CD8) and CD4/CD8 ratio), and stunting (as evidenced by a decrease in rat length, femur length, and insulin growth factor-1) were all observed in rats fed a protein-deficient diet for 3 weeks. Also, femur calcium and magnesium decreased in the malnourished rats. The dietary intervention with the cumin-flavored crackers reversed the reduction in aforementioned parameters in the malnourished rats. The cumin-flavored crackers may improve growth retardation and related immunodeficiency in previously malnourished rats.

IP3-mediated Ca2+ signals regulate larval to pupal transition under nutrient stress through the H3K36 methyltransferase Set2

ABSTRACT Persistent loss of dietary protein usually signals a shutdown of key metabolic pathways. In Drosophila larvae that have reached a ‘critical weight’ and can pupariate to form viable adults, such a metabolic shutdown would needlessly lead to death. Inositol 1,4,5-trisphosphate-mediated calcium (IP3/Ca2+) release in some interneurons (vGlutVGN6341) allows Drosophila larvae to pupariate on a protein-deficient diet by partially circumventing this shutdown through upregulation of neuropeptide signaling and the expression of ecdysone synthesis genes. Here, we show that IP3/Ca2+ signals in vGlutVGN6341 neurons drive expression of Set2, a gene encoding Drosophila Histone 3 Lysine 36 methyltransferase. Furthermore, Set2 expression is required for larvae to pupariate in the absence of dietary protein. IP3/Ca2+ signal-driven Set2 expression upregulates key Ca2+-signaling genes through a novel positive-feedback loop. Transcriptomic studies, coupled with analysis of existing ChIP-seq datasets, identified genes from larval and pupal stages that normally exhibit robust H3K36 trimethyl marks on their gene bodies and concomitantly undergo stronger downregulation by knockdown of either the intracellular Ca2+ release channel IP3R or Set2. IP3/Ca2+ signals thus regulate gene expression through Set2-mediated H3K36 marks on select neuronal genes for the larval to pupal transition.

IP3/Ca2+ signals regulate larval to pupal transition under nutrient stress through the H3K36 methyltransferase dSET2

Persistent loss of dietary protein usually signals a shutdown of key metabolic pathways. In Drosophila larvae, that have crossed “critical weight” and can pupariate to form viable adults, such a metabolic shut-down would needlessly lead to death. IP3/Ca2+ signals in certain interneurons (vGlutVGN6341) allow Drosophila larvae to pupariate on a protein-deficient diet by partially circumventing this shutdown through upregulation of neuropeptide signaling and the expression of ecdysone synthesis genes. Here we show that IP3/Ca2+ signals in vGlutVGN6341 neurons drive expression of dSET2, a Drosophila Histone 3 Lysine 36 methyltransferase. Further, dSET2 expression is required for larvae to pupariate in the absence of dietary protein. IP3/Ca2+ signal-driven dSET2 expression upregulates key Ca2+ signaling genes through a novel positive feedback loop. Transcriptomic studies coupled with analysis of existing ChIP-seq datasets identified genes from larval and pupal stages, that normally exhibit robust H3K36 trimethyl marks on their gene bodies and concomitantly undergo stronger downregulation by knockdown of either an intracellular Ca2+ release channel the IP3R or dSET2. IP3/Ca2+ signals thus regulate gene expression through dSET2 mediated H3K36 marks on select neuronal genes for the larval to pupal transition.

Dietary nitrate metabolism and enteric methane mitigation in sheep consuming a protein-deficient diet

It was hypothesised that the inclusion of nitrate (NO3–) or cysteamine hydrochloride (CSH) in a protein deficient diet (4.8% crude protein; CP) would improve the productivity of sheep while reducing enteric methane (CH4) emissions. A complete randomised designed experiment was conducted with yearling Merino sheep (n = 24) consuming a protein-deficient wheaten chaff control diet (CON) alone or supplemented with 1.8% nitrate (NO3–; DM basis), 0.098% urea (Ur, DM basis) or 80 mg cysteamine hydrochloride/kg liveweight (CSH). Feed intake, CH4 emissions, volatile fatty acids (VFA), digesta kinetics and NO3–, nitrite (NO2–) and urea concentrations in plasma, saliva and urine samples were measured. There was no dietary effect on animal performance or digesta kinetics (P > 0.05), but adding NO3– to the CON diet reduced methane yield (MY) by 26% (P = 0.01). Nitrate supplementation increased blood MetHb, plasma NO3– and NO2– concentrations (P < 0.05), but there was no indication of NO2– toxicity. Overall, salivary NO3– concentration was greater than plasma NO3– (P < 0.05), indicating that NO3– was concentrated into saliva. Our results confirm the role of NO3– as an effective additive to reduce CH4 emissions, even in a highly protein-deficient diet and as a source of additional nitrogen (N) for microbial protein synthesis via N-recycling into saliva and the gut. The role of CSH as an additive in low quality diets for improving animal performance and reducing CH4 emissions is still unclear.

Iberian pig adaptation to acorn consumption: I. Net portal appearance of metabolites

Most valuable cured products from Iberian pigs come from pure bred animals raised for a final grazing-fattening period where pigs eat mainly acorns, a low protein energy rich fruit. This is a nutritional challenge for animals fed equilibrated diets from weaning. The aim of the study was to determine net portal appearance (NPA) of metabolites in gilts fed acorns and evaluate adaptational changes after one week of feeding. Two sampling periods were carried out (after one day and after one week of acorn feeding) with six gilts (34 kg average BW) set up with three catheters: in carotid artery and portal vein for blood sampling, and ileal vein for para-aminohippuric acid (PAH) infusion to measure portal plasma flow (PPF). Pigs were fed at 2.5 × ME for maintenance a standard diet in two portions, at 09:00 (0.25) and 15:00 h (the remaining 0.75). On the day prior to the first sampling period, pigs were fed 2.4 kg of oak acorns. After feeding 0.25 of ration a 6 h serial blood collection was initiated. Following an identical protocol, a second sampling session was performed 1 week later. Adaptation to acorn consumption decreased NPA of ammonia (47%,P < 0.001). Although there was a transfer of urea from the gastrointestinal tract to the circulation in both sampling periods, no differences in NPA of urea was found (P > 0.05). NPA of glucose was not influenced by sampling period (P > 0.05), but NPA of lactate was greatly increased (231%,P < 0.001). There was a negative NPA of albumin although adaptation to acorn feeding did not alter it. Although NPA of triglycerides and cholesterol were unchanged, a subtle increase in arterial and portal cholesterol was noticed (9.6%,P < 0.01). Pigs fed a protein deficient diet for one week adapted decreasing NPA of ammonia for saving metabolic energy as less ammonia would become available for conversion to urea.