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AMP deaminase 1 (AMPD1) deficiency has been associated with premature muscle fatigue and reduced work capacity, but this finding has been inconsistent. Herein, we report that although AMPD1 knockdown in mouse skeletal muscle does not change maximal isometric force, it negatively impacts muscle function by slowing contraction and relaxation kinetics in EDL muscle but not SOL muscle. Furthermore, AMPD1 knockdown differentially affects the [AMP]/AMPK responses to fatiguing contractions in an intensity-dependent manner in EDL muscle.

Chronic migraine encephalalgia (CME) with concomitant temporomandibular disorder (TMD) is a serious illness with limited effective treatment options. This study explores the effectiveness of onabotulinumtoxinA (BtxA) as an adjunct therapeutic to TMJ arthroscopy in the relief of CME.A retrospective cohort study of patients receiving TMJ arthroscopy, with or without BtxA injections for CME, was conducted. Variables assessed include pain using a visual analog scale (VAS), maximal incisal opening (MIO), muscle soreness, and headache frequency and duration.Sixty patients (44 BtxA, 16 Control), consisting of 56 (93.3%) females, met inclusion criteria. A significant reduction in pain is reported with patients receiving BtxA (These results support the use of adjunctive BtxA treatment with arthroscopy for the treatment of CME in the context of TMD.

One strategy for treating cancer is to prevent metastatic spread. Matrix metalloproteinase are considered potential targets for cancer therapy because of their role in degrading the extracellular matrix and fostering tumor progression. In some cancer models, the small molecule 1,2,3,4,6-Penta-O-galloyl-β-d-glucose (PGG) exhibited inhibitory properties against matrix metalloproteinase (MMP) related metastatic activity. This study explored whether PPG may limit the potential for metastatic spread in oral squamous cell carcinoma. This study used Cal-27 cells, a cell line derived from a squamous cell carcinoma line of human tongue origin, and antibodies for MMP-1, -2, -3, -9, -13, MT1-MMP signal transducers and activators of transcription 3 (Stat3), and pStat3. Cells were treated with PGG at different concentrations to evaluate MMP and Stat3 activation. Expansion assays were performed using Matrigel matrixes to measure Cal-27 invasiveness in the presence of PGG. PGG decreased the expression of MMP-2, -9 and -13 in the Cal-27 cell line, decreased phosphorylation of Stat3 and reduced gene expression of MMP-2, -9 and -13. As observed in Matrigel expansion assays, PGG limited the invasiveness of Cal-27 cells in a dose-dependent manner. PPG is a small molecule inhibitor with the potential to reduce the expression of the matrix metalloproteinases and to limit the invasiveness of the squamous cell carcinoma line, Cal-27. By controlling the expression of molecules responsible for metastasis, PPG may offer a new therapeutic option for treating oral squamous cell carcinoma.

Labile plasma iron (LPI) is redox active, exchangeable iron that catalyzes the formation of reactive oxygen species. Serum transferrin binds iron in a non-exchangeable form and delivers iron to cells. In several inflammatory diseases serum LPI increases but the reason LPI forms is unknown. This work evaluates possible pathways leading to LPI and examines potential mediators of apo transferrin iron loading to prevent LPI. Previously phosphate was shown to inhibit iron loading into apo transferrin by competitively binding free Fe3+. The reaction of Fe3+ with phosphate produced a soluble ferric phosphate complex. In this study we evaluate iron loading into transferrin under physiologically relevant phosphate conditions to evaluate the roles of citrate and albumin in mediating iron delivery into apo transferrin. We report that preformed Fe3+-citrate was loaded into apo transferrin and was not inhibited by phosphate. A competition study evaluated reactions when Fe3+ was added to a solution with citrate, phosphate and apo transferrin. The results showed citrate marginally improved the delivery of Fe3+ to apo transferrin. Studies adding Fe3+ to a solution with phosphate, albumin and apo transferrin showed that albumin improved Fe3+ loading into apo transferrin. The most efficient Fe3+ loading into apo transferrin in a phosphate solution occurred when both citrate and albumin were present at physiological concentrations. Citrate and albumin overcame phosphate inhibition and loaded apo transferrin equal to the control of Fe3+ added to apo transferrin. Our results suggest a physiologically important role for albumin and citrate for apo transferrin iron loading.

The recombinant Chlorobium tepidum ferritin (rCtFtn) is able to oxidize iron using ferroxidase activity but its ferroxidase activity is intermediate between the H-chain human ferritin and the L-chain human ferritin. The rCtFtn has an unusual C-terminal region composed of 12 histidine residues, as well as aspartate and glutamate residues. These residues act as potential metal ion ligands, and the rCtFtn homology model predicts that this region projects inside the protein cage. The rCtFtn also lacks a conserved Tyr residue in position 19. In order to know if those differences are responsible for the altered ferroxidase properties of rCtFtn, we introduced by site-directed mutagenesis a stop codon at position 166 and a Tyr residue replaced Ala19 in the gene of rCtFtn (rCtFtn 166). The rCtFtn166 keeps the canonical sequence considered important for the activity of this family of proteins. Therefore, we expected that rCtFtn 166 would possess similar properties to those described for this protein family. The rCtFtn 166 is able to bind, oxidize and store iron; and its activity is inhibit by Zn(II) as was described for other ferritins. However, the rCtFtn 166 possesses a decrease ferroxidase activity and protein stability compared with the wild type rCtFtn. The analysis of the Ala19Tyr rCtFtn shows that this change does not affect the kinetic of iron oxidation. Therefore, these results indicate that the C-terminal regions have an important role in the activity of the ferroxidase center and the stability of rCtFtn.

Iron-containing ferritin has been used for light harvesting and as a photocatalyst. In this study, we test the hypothesis that changing the iron mineral core composition can alter the light harvesting and photocatalytic properties of ferritin, by co-depositing iron in the presence of halides or oxo-anions. This caused the anions to be incorporated into the iron mineral. We report that some of these new iron minerals possess different band gaps than the original ferrihydrite within ferritin. We found an increase in band gap of up to 0.288 eV or a decrease by as much as 0.104 eV, depending on the type of anion and amount of anions incorporated into the ferrihydrite mineral.

Hepcidin is a small cysteine-rich signaling peptide that regulates blood serum iron concentrations [1–4]. Patients with chronic inflammation are known to have elevated levels of hepcidin in their blood and urine and often suffer from anemia as a result [5–10]. Measuring and quantifying the amount of active hepcidin in blood and urine can help to determine the cause and severity of the anemia thereby helping physicians determine the correct course of treatment [11–16]. We have developed a simple technique to isolate, chemically modify, and concentrate hepcidin from blood and urine coupled to high-pressure liquid chromatography mass spectrometry that can accurately and reproducibly measure and quantify the active hormone.

In chronic kidney diseases, NTBI can occur even when total iron levels in serum are low and transferrin is not saturated. We postulated that elevated serum phosphate concentrations, present in CKD patients, might disrupt Fe 3 + loading into apo-transferrin by forming Fe(III)–phosphate species. We report that phosphate competes with apo-transferrin for Fe 3 + by forming a soluble Fe(III)–phosphate complex. Once formed, the Fe(III)–phosphate complex is not a substrate for donating Fe 3 + to apo-transferrin. Phosphate (1–10 mM) does not chelate Fe(III) from diferric transferrin under the conditions examined. Complexed forms of Fe 3 + , such as iron nitrilotriacetic acid (Fe 3 + -NTA), and Fe(III)–citrate are not susceptible to this phosphate complexation reaction and efficiently deliver Fe 3 + to apo-transferrin in the presence of phosphate. This reaction suggests that citrate might play an important role in protecting against Fe(III), phosphate interactions in vivo . In contrast to the reactions of Fe 3 + and phosphate, the addition of Fe 2 + to a solution of apo-transferrin and phosphate lead to rapid oxidation and deposition of Fe 3 + into apo-transferrin. These in vitro data suggest that, in principle, elevated phosphate concentrations can influence the ability of apo-transferrin to bind iron, depending on the oxidation state of the iron.