Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anionic microdomains within the aortic smooth muscle cell (SMC) surface glycocalyx represent a potential barrier to the endocytosis of anionic plasma proteins. Cultured SMCs exposed briefly to cationized ferritin (CF) exhibit ultrastructural aggregations of surface anionic sites resulting in intervening areas essentially devoid of anionic charge. Preincubation of cultured aortic medial SMCs with 0.2 mg/ml CF for 1 minute at 37 C resulted in a 4-fold increase in binding and a 13-fold increase in internalization of 125I-human serum albumin (125I-HSA) relative to cells pretreated with native ferritin. When both the CF preincubation and the endocytosis were performed at 4 C, the influence of CF was abolished. Studies at 4 C indicated that CF pretreatment of SMC at 37 C induced high affinity (Kd = 1.5 nM) saturable 125I-HSA binding, in addition to low-affinity nonsaturable binding. These results were further confirmed by binding competition studies using increasing concentrations of unlabeled HSA. In contrast, low-density lipoprotein, a large anionic molecule, failed to compete with 125I-HSA for binding sites on CF-pretreated SMCs at either 4 or 37 C. Pulse-chase studies at 37 C indicated that 20-30% of internalized 125I-HSA was degraded, and 40-50% exocytosed within 24 hours in CF-treated cells. CF pretreatment of the SMCs did not significantly enhance the uptake of 14C-sucrose as a measure of fluid-phase endocytosis at 30 and 60 minutes. The results of these studies emphasize the potentially important regulatory roles of cell-surface anionic charge distribution and cationic molecules in cellular endocytosis.
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PMID:Stimulation of albumin endocytosis by cationized ferritin in cultured aortic smooth muscle cells. 407 18

We have suggested that renal tubular synthesis of C3 and its activation in the cortical interstitium is a mechanism for the progression of glomerulonephritis to interstitial injury. To test this hypothesis, immune complex glomerulonephritis was induced in C57BL/6 mice by intraperitoneal injections of horse spleen apoferritin and lipopolysaccharide (HSA/LPS). When compared to wild-type (WT) animals, C3 knockout (C3KO) mice had glomerular changes that were identical. Morphometric analysis of the cortical interstitium, however, showed marked differences. WT mice had more interstitial inflammation, edema, and tubular atrophy, when compared to C3KO mice. At the end of the experiment, WT animals also had significantly more proteinuria than did C3KOs. These experiments provide further evidence of a role of locally synthesized complement in the progression of glomerular disease.
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PMID:C3 is central to the interstitial component of experimental immune complex glomerulonephritis. 1587 25

Skeletal demineralization is a frequent accompaniment of chronic renal disease and is likely multifactorial. We studied the role of inflammation in stimulating bone resorption in a rat model of glomerulonephritis (GN). Three-week-old Sprague-Dawley rats received either saline (n = 8) or horse spleen apoferritin and lipopolysaccharide (HSA/LPS, n = 8) by intraperitoneal injection, for 6 weeks; afterward, they were observed for either an additional 3 weeks (9 weeks total; n = 4 from each group) or 14 weeks (20 weeks total; n = 4 from each group). Kidneys were analyzed by histomorphometry, and blood and urine samples were obtained to assess bone resorption. Whole-body and isolated femur Dual-Energy X-ray Absorptiometry (DEXA) scans were performed at the end of each study. HSA/LPS-treated animals developed a proliferative GN by 9 weeks, which is associated with proteinuria but no change in renal function. Between 9 and 20 weeks, there was evidence of an increasing interstitial inflammation (1381 +/- 67 interstitial cells/mm(2) at 9 weeks and 1818 +/- 28 interstitial cells/mm(2) at 20 weeks.) There was also evidence of bone resorbing activity as assessed by experimental/control (E/C) < 1.0 at 9 (E/C plasma = 0.66 +/- 0.05) and 20 (E/C plasma = 0.52 +/- 0.04) weeks. Parathyroid hormone (PTH) levels were normal at all time points, and no differences in bone mineral density were found. This model produces not only an immune glomerular/tubular injury, but also a stimulus for bone resorption that is related to objective measures of inflammation severity. The bone resorption is not caused by renal insufficiency, hyperparathyroidism, or steroid therapy. This model will prove useful in other studies of the role of renal inflammation in skeletal disorders.
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PMID:Nonparathyroid hormone-mediated calcium resorption in a rat model of immune glomerulonephritis. 1613 56

We present the synthesis and structure of various protein nanotubes comprised of an alternate layer-by-layer (LbL) assembly using a polycation as an electrostatic glue. The nanotubes were fabricated by sequential LbL depositions of positively charged polycations and negatively charged proteins into a porous polycarbonate (PC) membrane, followed by release of the cylindrical core by quick dissolution of the template with CH(2)Cl(2). This procedure provides a variety of protein nanotubes without interlayer cross-linking. The three-cycle depositions of poly-L-arginine (PLA) and human serum albumin (HSA, M(w)=66.5 kDa) into the porous PC template (pore diameter, D(p)=400 nm) yielded well-defined (PLA/HSA)(3) nanotubes with an outer diameter of 419+/-29 nm and a wall thickness of 46+/-8 nm, revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. The outer diameter of the tubules can be controlled by the pore size of the template (200-800 nm), whereas the wall thickness is always constant, independent of the D(p) value. The (PEI/HSA)(3) (PEI: polyethylenimine) nanotubes showed a slightly thin wall of 39+/-5 nm. CD spectra of the multilayered (PEI/HSA)(n) film on a flat quartz plate suggested that the secondary structure of HSA between the polycations was almost the same as that in aqueous solution. The three-cycle LbL depositions of PLA and ferritin (M(w)=460 kDa) or myoglobin (Mb, M(w)=1.7 kDa) into the porous PC membrane also gave cylindrical hollow structures. The wall thickness of the (PLA/ferritin)(3) and (PLA/Mb)(3) nanotubes were 55+/-5 nm and 31+/-4 nm; it depends on the globular size of the protein (ferritin>HSA>Mb). The individual ferritin molecule was clearly seen in the tubular walls by SEM and TEM measurements.
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PMID:Protein nanotubes comprised of an alternate layer-by-layer assembly using a polycation as an electrostatic glue. 1881 57

Abnormal scarring results from the expression and composition of extracellular matrix molecules. The transcription and translation of collagens I and III, fibronectin, laminin, periostin, and tenascin are all increased in raised dermal scar tissue. However, human keloid development is not fully defined. In this study, we identified proteins expressed differentially between normal skin and keloid scar tissues and examined their function in keloid formation using fibroblasts. Skin specimens from normal volunteers and patients with keloids were obtained by skin biopsy. Whole proteins were isolated by two-dimensional electrophoresis, and differentially expressed proteins were identified by matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry. Protein function was determined by proliferation assay using annexin A2-overexpressing keloid fibroblasts. The expression of 11 protein spots was altered by at least 1.5-fold in patients with keloids than in normal volunteers. Of these proteins, annexin A2, a pre-serum amyloid P component, serum albumin precursor, and tryptase-I, were down-regulated in keloid tissue compared to normal skin. Collagen alpha 1(V) chain precursor, collagen alpha 1(I) chain precursor, ferritin light subunit, alpha 1(III) collagen, 6-phosphogluconolactonase, and calponin 2 were up-regulated. Diminished expression of annexin A2 was confirmed by immunoblotting and immunohistochemistry. Treatment with the recombinant human epidermal growth factor increased proliferation of keloid fibroblasts, which was more inhibited in annexin A2-overexpressing fibroblasts than in non-transfected control cells. These results imply that annexin A2 may participate in keloid formation by inhibiting keloid fibroblast proliferation. Therefore, it is concluded that annexin A2 may be a valuable therapeutic target for keloid lesions.
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PMID:Annexin A2 participates in human skin keloid formation by inhibiting fibroblast proliferation. 2440 84

Occupational asthma (OA) is a complex disease that is often hard to diagnose due to difficulties in detecting relevant exposure, along with inherent differences in disease susceptibility. Numerous studies have attempted to identify relevant biological and genetic markers for OA and to devise tools capable of detecting exposure to the causative agent. Immunological markers, including skin prick test reactivity and specific IgE and IgG antibodies can be used to detect high-molecular-weight allergens in cases of baker's asthma. For OA induced by low-molecular-weight agents, such as isocyanate, potential biomarkers include serum-specific IgE and IgG antibodies to isocyanate-HSA conjugate and IgG to cytokeratin 19 and transglutaminase-2. For protein-based markers, ferritin/transferrin and vitamin D-binding protein levels have been suggested for isocyanate-OA. Genetic markers of susceptibility to isocyanate-OA include human leukocyte antigen and CTNNA3. Further investigations will be needed to identify better biomarkers for OA, which may be used to inform clinical decision.
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PMID:Biological and genetic markers in occupational asthma. 2543 Sep 50