The Role of Creatine in the Development and Activation of Immune Responses.

The use of dietary supplements has become increasingly common over the past 20 years. Whereas supplements were formerly used mainly by elite athletes, age and fitness status no longer dictates who uses these substances. Indeed, many nutritional supplements are recommended by health care professionals to their patients.

Creatinine downregulates TNF-α in macrophage and T cell lines.

Creatinine is the breakdown product of creatine, a key participant in the generation of ATP and is traditionally considered to be a biologically inert waste product. Based on our earlier work, we analyzed the effects of creatinine hydrochloride on the expression of tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine, in a human T cell line, as well as human and mouse macrophage cell lines. Exposing cells to creatinine hydrochloride significantly reduced TNF-α mRNA and protein levels compared to control-treated cultures in all cell lines tested.

Serum amyloid A1 (SAA1) protein in human colostrum.

Proteins of the serum amyloid A (SAA) family have been remarkably conserved in evolution. Their biologic function(s) are not fully defined but they are likely to be a part of primordial host defense. We have detected a ∼ 12-kDa protein reacting with antibodies against serum amyloid A (SAA) in human colostrum by western blotting.

Beyond muscles: The untapped potential of creatine.

Creatine is widely used by both elite and recreational athletes as an ergogenic aid to enhance anaerobic exercise performance. Older individuals also use creatine to prevent sarcopenia and, accordingly, may have therapeutic benefits for muscle wasting diseases. Although the effect of creatine on the musculoskeletal system has been extensively studied, less attention has been paid to its potential effects on other physiological systems.

Effect of creatine, creatinine, and creatine ethyl ester on TLR expression in macrophages.

Despite the widespread availability and use of dietary supplements, minimal work has been performed to assess the potential dangers many of these supplements may have on the host's well-being, in particular the host's ability to respond to infection. One supplement extensively used by both adolescents and adults is creatine. Using Real-time PCR, we examined the impact of short-term exposure of a mouse macrophage cell line (RAW 264.

Evaluation of colostrum-derived human mammary-associated serum amyloid A3 (M-SAA3) protein and peptide derivatives for the prevention of enteric infection: in vitro and in murine models of intestinal disease.

In vitro experiments confirmed that a 10-mer peptide derived from human mammary-associated serum amyloid A3 (M-SAA3) protected intestinal epithelial cells from enteropathogenic Escherichia coli (EPEC) adherence. The entire 42-mer human M-SAA3 protein was even more effective, reducing EPEC binding by 72% relative to untreated cells (P<0.05), compared with 25% and 57% reductions for the human 10-mer and Lactobacillus GG, respectively.

Robust expression of a bioactive mammalian protein in Chlamydomonas chloroplast.

We have engineered the chloroplast of eukaryotic algae to produce a number of recombinant proteins, including human monoclonal antibodies, but, to date, have achieved expression to only 0.5% of total protein. Here, we show that, by engineering the mammalian coding region of bovine mammary-associated serum amyloid (M-SAA) as a direct replacement for the chloroplast psbA coding region, we can achieve expression of recombinant protein above 5% of total protein.

Bovine serum amyloid A3 gene structure and promoter analysis: induced transcriptional expression by bacterial components and the hormone prolactin.

Regulation of the bovine Saa3 promoter in response to signaling molecules associated with lactation or bacterial infection was assessed using a luciferase reporter system. Although the liver is the primary site for the production of acute phase proteins, typically serum amyloid A1 (SAA1) and serum amyloid A2 (SAA2), analysis of the differential expression of serum amyloid A3 (SAA3) by mammary epithelial cells is limited. Gram-negative bacterial lipopolysaccharide (LPS) and the Gram-positive bacterial lipoteichoic acid (LTA) substantially upregulated transcriptional expression driven by the Saa3 promoter in bovine mammary epithelial cells by 18.

Staphylococcus aureus lipotechoic acid induces differential expression of bovine serum amyloid A3 (SAA3) by mammary epithelial cells: Implications for early diagnosis of mastitis.

Mastitis is one of the most costly diseases of agriculturally important animals and is a common problem for lactating cows. Current methods used to detect clinical and especially subclinical mastitis are either inadequate or problematic. Pathogens such as the gram-positive bacterium Staphylococcus aureus or the gram-negative bacterium Escherichia coli typically cause mastitis.

Differential expression and secretion of bovine serum amyloid A3 (SAA3) by mammary epithelial cells stimulated with prolactin or lipopolysaccharide.

Serum amyloid A (SAA) proteins were originally identified as prominent acute phase serum reactants synthesized predominately by hepatocytes in response to infection, inflammation and trauma. In this study, we report the differential expression and secretion of serum amyloid A3 (SAA3) by bovine mammary epithelial cells following stimulation with either prolactin (PRL) or lipopolysaccharide (LPS). Reverse transcription-polymerase chain reaction analysis of PRL or LPS induced bovine mammary epithelial cells resulted in the detection of only the mammary-derived Saa3 (M-Saa3) transcript.

Induction of human mammary-associated serum amyloid A3 expression by prolactin or lipopolysaccharide.

In most mammalian species, serum amyloid A isoform 3 (SAA3) appears to be the predominant SAA isoform expressed extrahepatically. However, human SAA3 gene expression has not been detected previously and, therefore, this gene was referred to as a pseudogene. We report for the first time the transcriptional expression of human SAA3.

The conserved TFLK motif of mammary-associated serum amyloid A3 is responsible for up-regulation of intestinal MUC3 mucin expression in vitro.

In various mammalian species, an isoform of serum amyloid A is secreted at high concentrations into colostrum. A conserved four-amino-acid motif (TFLK) is contained within the first eight N-terminal amino acid residues of this mammary-associated serum amyloid A isoform 3 (M-SAA3). Peptides derived from the bovine N-terminal amino acid sequence of M-SAA3 were produced and added to cell culture medium of HT29 cells to study the effects on intestinal mucin gene expression.

Human serum amyloid A3 peptide enhances intestinal MUC3 expression and inhibits EPEC adherence.

We previously determined that the N-terminal region of bovine mammary-associated serum amyloid A3 (M-SAA3) increased intestinal mucin MUC3 levels in HT29 human intestinal cells by approximately 2.5-fold, relative to untreated cells. This study shows that the human M-SAA3 N-terminal peptide further enhances MUC3 transcript levels by approximately 4.