Low protein

About: Low protein is a research topic. Over the lifetime, 8139 publications have been published within this topic receiving 213225 citations.

Single Molecule Protein Detection with Attomolar Sensitivity Using Droplet Digital Enzyme-Linked Immunosorbent Assay

Abstract: Many proteins are present at low concentrations in biological samples, and therefore, techniques for ultrasensitive protein detection are necessary To overcome challenges with sensitivity, the digital enzyme-linked immunosorbent assay (ELISA) was developed, which is 1000× more sensitive than conventional ELISA and allows sub-femtomolar protein detection However, this sensitivity is still not sufficient to measure many proteins in various biological samples, thereby limiting our ability to detect and discover biomarkers To overcome this limitation, we developed droplet digital ELISA (ddELISA), a simple approach for detecting low protein levels using digital ELISA and droplet microfluidics ddELISA achieves maximal sensitivity by improving the sampling efficiency and counting more target molecules ddELISA can detect proteins in the low attomolar range and is up to 25-fold more sensitive than digital ELISA using Single Molecule Arrays (Simoa), the current gold standard tool for ultrasensitive protein detection Using ddELISA, we measured the LINE1/ORF1 protein, a potential cancer biomarker that has not been previously measured in serum Additionally, due to the simplicity of our device design, ddELISA is promising for point-of-care applications Thus, ddELISA will facilitate the discovery of biomarkers that have never been measured before for various clinical applications

A Low Carbohydrate, High Protein Diet Slows Tumor Growth and Prevents Cancer Initiation

Abstract: Since cancer cells depend on glucose more than normal cells, we compared the effects of low carbohydrate (CHO) diets to a Western diet on the growth rate of tumors in mice. To avoid caloric restriction-induced effects, we designed the low CHO diets isocaloric with the Western diet by increasing protein rather than fat levels because of the reported tumor-promoting effects of high fat and the immune-stimulating effects of high protein. We found that both murine and human carcinomas grew slower in mice on diets containing low amylose CHO and high protein compared with a Western diet characterized by relatively high CHO and low protein. There was no weight difference between the tumor-bearing mice on the low CHO or Western diets. Additionally, the low CHO-fed mice exhibited lower blood glucose, insulin, and lactate levels. Additive antitumor effects with the low CHO diets were observed with the mTOR inhibitor CCI-779 and especially with the COX-2 inhibitor Celebrex, a potent anti-inflammatory drug. Strikingly, in a genetically engineered mouse model of HER-2/neu-induced mammary cancer, tumor penetrance in mice on a Western diet was nearly 50% by the age of 1 year whereas no tumors were detected in mice on the low CHO diet. This difference was associated with weight gains in mice on the Western diet not observed in mice on the low CHO diet. Moreover, whereas only 1 mouse on the Western diet achieved a normal life span, due to cancer-associated deaths, more than 50% of the mice on the low CHO diet reached or exceeded the normal life span. Taken together, our findings offer a compelling preclinical illustration of the ability of a low CHO diet in not only restricting weight gain but also cancer development and progression.

Mechanisms of thermogenesis induced by low protein diets

Abstract: Weanling (22-day-old) rats fed a low protein (8% casein) diet consumed the same amount of energy as controls (22% casein diet), but intake corrected for body size (kJ/kg0.75) was increased in the former group. Weight gain and the efficiency of gain (g gain/MJ) were markedly reduced in low protein fed rats. Resting oxygen consumption (VO2) was elevated by 15% in the low protein group but this difference was completely abolished by beta-adrenergic blockade with propranolol. Interscapular brown adipose tissue (BAT) mass, protein content, mitochondrial yield and GDP binding were increased in low protein fed rats but mitochondrial alpha-glycophosphate shuttle activity of BAT was unaltered, although shuttle activity was elevated in liver mitochondria. Plasma triiodothyronine levels were increased by 64% in the low protein group, whereas insulin levels were markedly reduced in spite of normal blood glucose levels. Resting VO2 and BAT mass were also increased in older (55-day-old) rats fed the low protein diet, but the changes were smaller than in weanling rats. These data suggest that the decreased metabolic efficiency seen in rats fed protein deficient diets involves sympathetic activation of BAT, and is therefore similar to the thermogenic responses seen in cold adapted and cafeteria-fed animals.