Purification of Emu IgY for Therapeutic and Diagnostic Use Based on Monoclonal Secondary Antibodies Specific to Emu IgY.

The emu is the second largest ratite; thus, their sera and egg yolks, obtained after immunization, could provide therapeutic and diagnostically important immunoglobulins with improved production efficiency. Reliable purification tools are required to establish a pipeline for supplying practical emu-derived antibodies, the majority of which belongs to the immunoglobulin Y (IgY) class. Therefore, we generated a monoclonal secondary antibody specific to emu IgY. Initially, we immunized an emu with bovine serum albumin multiply haptenized with 2,4-dinitrophenyl (DNP) groups. Polyclonal emu anti-DNP antibodies were partially purified using conventional precipitation method and used as antigen for immunizing a BALB/c mouse. Splenocytes were fused with myeloma cells and a hybridoma clone secreting a desirable secondary antibody (mAb#2-16) was established. The secondary antibody bound specifically to emu-derived IgY, distinguishing IgYs from chicken, duck, ostrich, quail, and turkey, as well as human IgGs. Affinity columns immobilizing the mAb#2-16 antibodies enabled purification of emu IgY fractions from sera and egg yolks via simple protocols, with which we succeeded in producing IgYs specific to the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) spike protein with a practical binding ability. We expect that the presented purification method, and the secondary antibody produced in this study, will facilitate the utilization of emus as a novel source of therapeutic and diagnostic antibodies.

Anti-MuSK Antibody-positive Myasthenia Gravis Successfully Treated with Outpatient Periodic Weekly Blood Purification Therapy.

A 37-year-old man with anti-muscle-specific tyrosine kinase (MuSK) antibody-positive myasthenia gravis (MG) presented with subacute progressive dysphagia and muscle weakness of the neck and bilateral upper extremities. Conventional immune-suppressive treatments and high-dose intravenous immunoglobulin were ineffective. He then displayed repeated exacerbations and remissions over the course of two years, despite two to four sessions of plasma exchange (PE) every two months. The patient was successfully treated with outpatient periodic weekly blood purification therapy with alternative PE and double-filtration plasmapheresis using an internal shunt. This case report suggests the benefits of blood purification therapy with an internal shunt against anti-MuSK antibody-positive MG.

An ocular form of myasthenia gravis with a high titer of anti-MuSK antibodies during a long-term follow-up.

We herein report a case of ocular myasthenia gravis (MG) that was highly positive for anti-muscle-specific tyrosine kinase (MuSK) antibodies. The examined patient exhibited bilateral ptosis and lateral gaze palsy without any generalized symptoms and was diagnosed with ocular MG with anti-MuSK antibodies. She responded to treatment with prednisolone and immunosuppressants and experienced only ocular symptoms for four years and eight months after onset. Ocular MG with anti-MuSK antibodies lasting for a long term has rarely been described. Our findings suggest that it may be reasonable to test for the presence of anti-MuSK antibodies in patients who present with external ophthalmoplegia.

The effect of dopamine agonists: the expression of GDNF, NGF, and BDNF in cultured mouse astrocytes.

In Parkinson's disease, cell death is selectively induced in mesencephalic nigral dopaminergic neurons. At present, no disease modifying therapy or radical treatment has been found for this disease. Some dopamine agonists may have a neuroprotective action in cultured cells and animal models. In the present study, we examined stimulating effects of a non-ergoline D(2) dopamine agonist, ropinirole, on synthesis/secretion of neurotrophic factors, including NGF, BDNF, and GDNF, in cultured mouse astrocytes. These effects were compared with those of ergoline dopamine agonists, SKF-38393, a D(1) agonist, bromocriptine, D(2) agonist, and apomorphine, D(1)/D(2) agonist. Ropinirole elevated GDNF levels to 4-fold, and NGF levels to 6.3-fold, compared with the control group. Of the dopamine agonists examined, ropinirole produced and secreted more GDNF than a 1.8-fold greater amount of apomorphine, a lesser amount of bromocriptine, or a 2.8-fold greater amount of SKF-38393, which served as the control group.

[Effects of acetylcholinesterase inhibitors on patients with MuSK antibody positive myasthenia gravis].

In order to clarify the clinical characteristics and effects of acetylcholinesterase inhibitors of patients with generalized myasthenia gravis with antibodies to muscle specific kinase (MuSK), we investigated seven patients with MuSK antibodies and eleven patients without both antibodies of acetylcholine receptor and MuSK. All patients with MuSK antibodies showed bulbar symptoms, which frequency was significantly higher compared to those in patients without double antibodies. The frequency of positive result of Tensilon test was significantly lower in patients with MuSK antibodies than in those without double antibodies. In response to intravenous edrophonium chloride, MuSK positive patients showed adverse reactions in a small dosage of edrophonium chloride, less than 5 mg, such as fasciculation on facial muscles and stuffy sensation of throat. The adverse responses to a small dosage of intravenous edrophonium chloride injection is useful information to distinguish patients with seronegative generalized MG, whether they have MuSK antibodies or not. When acetylcholinesterase inhibitors medication is tried to patients with MuSK antibodies, if necessary, a small dosage of inhibitors should be used to avoid cholinergic hypersensitivity.

Serum brain-derived neurotrophic factor in patients with type 2 diabetes mellitus: Relationship to glucose metabolism and biomarkers of insulin resistance.

OBJECTIVES: The aims of this study were to measure serum levels of brain-derived neurotrophic factor (BDNF) in patients with type 2 diabetes mellitus (T2DM) and to investigate the association of these BDNF levels with biomarkers of glucose metabolism and insulin resistance. DESIGN AND METHODS: We studied 112 patients with T2DM and 80 age- and gender-matched control subjects. RESULTS: Serum BDNF levels were significantly lower in patients with T2DM compared to control subjects (15.5+/-5.2 ng/mL vs. 20.0+/-7.3 ng/mL, P<0.01). In patients with T2DM, BDNF levels were significantly higher in females than in males (P<0.01). In the female patients, BDNF was positively related to immunoreactive insulin (IRI) (rho=0.458, P<0.05) and HOMA-R (rho=0.444, P<0.05). Stepwise multiple regression analysis showed a significant relationship between BDNF and IRI (F=5.294, P<0.05) in female patients with diabetes. CONCLUSIONS: These findings suggest that BDNF may contribute to glucose metabolism.

Heterogeneity of immunopathological features of AChR/MuSK autoantibody-negative myasthenia gravis.

We compared B cells and germinal centers in thymus from myasthenia gravis (MG) patients either with anti-acetylcholine receptor (AChR) autoantibodies or with neither anti-muscle-specific tyrosine kinase (MuSK) nor anti-AChR (seronegative MG: SN-MG). The numbers and frequencies of total and germinal center B cells varied in the SN-MG thymi, some of which were normal/atrophic. Others were clearly hyperplastic, their B cell parameters overlapping with those in AChR-positive MG, which implicates the thymus in pathogenesis. Indeed, some SN-MG patients apparently benefited from thymectomy, which should be considered a management option.

Anti-alkaline phosphatase antibody positive myasthenia gravis.

Anti-alkaline phosphatase antibody (AP Ab) was specific in 9% of 249 anti-acetylcholine receptor (AChR) Ab-positive myasthenia gravis (MG) (SPMG) patients but not in patients with AChR Ab-negative MG (SNMG), other neurological and immunological diseases, or healthy volunteers. No cross-reactivity and no significant titer correlation were found between AP Ab and AChR Ab. We confirmed immunologically by radioimmunoassay and western blot analysis the presence of antibodies directed against AP. AP Ab-positive SPMG patients were characterized clinically as having female predominance and a more severe form of generalized MG than AP Ab-negative SPMG patients, and about half required artificial ventilation at maximum severity. AP Ab's pathogenic role in MG is yet unclarified, but our findings show AP to be a novel antigen among the various autoantigens present in MG patients and in whom AP Ab may modify clinical symptoms.

[Titer of anti-muscle-specific receptor tyrosine kinase (MuSK) antibody correlated with symptomatic improvement in response to corticosteroid therapy in a patient with anti-MuSK antibody-positive myasthenia gravis: a case report].

A 54-year-old woman was admitted to our hospital because of diplopia, dysphagia, dropped head, and muscle weakness with easy fatigability. A neurological examination showed bilateral ptosis, ocular motility disorder, dysphagia, and weakness of the neck extensor muscles. Edrophonium and repetitive nerve stimulation tests of the thenar muscles showed positive results. The serum titer of anti-acetylcholine receptor antibody was negative. A thymoma was not detected in her chest CT. Finally, she was diagnosed with anti-MuSK antibody-positive myasthenia gravis based on the high serum titer of anti-MuSK antibody (239 nmol/l). Her symptoms improved after administration of prednisolone. However, the symptoms were aggravated when the prednisolone dosage was reduced, and the titer of anti-MuSK antibody rose at the same time. We evaluated the possible association between changes in the severity of her clinical symptoms and the titer of the antibody during prednisolone therapy. It was revealed that the titer of the antibody was correlated to the severity of clinical symptoms expressed by a QMG (Quantitative Myasthenia Gravis) score. These findings indicate that monitoring the titer of anti-MuSK antibody can be useful for assessing disease activity as well as decision making during treatment.

[A case of anti-MuSK antibody-positive myasthenia gravis with dropped head as the initial presenting symptom].

A 53-year-old woman was admitted to our hospital because of dropped head. Neurological examination showed no abnormality except for weakness of the neck extensor muscles. Her symptoms worsened in the evening, requiring her to support her head by placing her hand against her chin. Edrophonium and repetitive stimulation tests gave negative results, and anti-acetylcholine receptor antibodies were not detected. She had no thymoma. However, she was found to have a high serum titer of anti-MuSK antibody (37.3 nM). She was diagnosed as having myasthenia gravis (MG) and treatment with pyridostigmine was started. However, this had to be withdrawn because of fasciculation as an adverse effect. She was therefore treated with prednisolone, and this resulted in marked improvement. The initial presenting symptom in this case was dropped head, and there were none of the results of laboratory or electrophysiological examinations that are usually typical of MG. MG was eventually diagnosed by measurement of anti-MuSK antibody. The present case suggests that a patient presenting with dropped head without any obvious cause needs to be studied for the presence of anti-MuSK antibody.

Resistin concentrations in murine adipose tissue and serum measured by a new enzyme immunoassay.

OBJECTIVE: In an attempt to clarify the conflicting data on resistin mRNA expression and protein analysis by western blotting in adipose tissue and serum, we developed a sensitive enzyme-linked immunosorbent assay (ELISA) for direct measurement of mouse resistin. RESEARCH METHODS AND PROCEDURES: We developed polyclonal antibodies directed to the N (21 to 40) and C (79 to 91) termini of mouse resistin. Then, affinity-purified anti-C-terminal resistin immunoglobin G (IgG) was biotinylated. ELISA was based on the sandwiching of antigen between antibody IgG coated on polystyrene plates and biotinylated antibody IgG. The bound biotinylated antibody was quantified with streptavidin-linked horseradish peroxidase. RESULTS: New ELISA can measure a concentration as low as 0.5 ng/mL of recombinant mouse resistin and is sensitive and specific enough to measure resistin protein in various adipose tissues and in sera. In normal mice, decreases in resistin concentrations in both white adipose tissue and serum were age dependent during 6 to 24 weeks of development. Resistin concentrations were significantly higher in omental adipose tissue in comparison with perirenal and abdominal adipose tissues and were 2- to 5-fold higher in females than males during the growth period. ob/ob mice had significantly lower resistin concentrations than the control mice in both sera and the white adipose tissues, particularly in the omental fat. The treatment by testosterone, but not progesterone or beta-estradiol, in cultured adipocytes reduces resistin protein levels in a dose-dependent manner. DISCUSSION: New sensitive ELISA for mouse resistin clarified that the resistin concentrations in normal mice were markedly elevated in the omental adipose depots as compared with the perirenal and abdominal adipocyte depots and significantly elevated compared with adipose tissues in genetically obese mice.

Effect of atorvastatin on in vitro expression of resistin in adipocytes and monocytes/macrophages and effect of atorvastatin treatment on serum resistin levels in patients with type 2 diabetes.

Resistin is a novel cysteine-rich protein that plays a role in the development of insulin resistance and atherosclerosis. HMG-CoA reductase inhibitors (statins) possess anti-inflammatory properties that are independent of their lipid-lowering action. The aims of this study were to investigate the effect of atorvastatin on expression of resistin in vitro and to determine the effect of 6 months of treatment with atorvastatin on serum levels of resistin in patients with type 2 diabetes. 3T3-L1 adipocytes and human monocytes/macrophages and preadipocytes were incubated with 1 and 10 micromol/l atorvastatin for 24 and 48 h, followed by measurement of resistin mRNA by the quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Serum resistin concentration in the patients with type 2 diabetes was measured at baseline and after 6 months of atorvastatin treatment (10 mg/day). qRT-PCR analysis revealed that atorvastatin decreased resistin mRNA expression in a dose- and time-dependent manner. Serum resistin concentration tended to decrease after 6 months of atorvastatin treatment, although this decrease did not reach statistical significance. In conclusion, the findings of our in vitro study contribute to the growing volume of evidence on the anti-inflammatory and anti-atherosclerotic effects of statins, and led us to suggest that statins may control inflammatory responses by inhibiting expression of resistin mRNA. It is necessary to confirm the findings of our in vitro study by an appropriately designed large-scale clinical study.

Production of NGF, BDNF and GDNF in mouse astrocyte cultures is strongly enhanced by a cerebral vasodilator, ifenprodil.

Ifenprodil, a non-competitive NMDA-receptor antagonist, has been shown to exhibit marked cytoprotective activities in animal models for focal ischemia and Parkinson's disease. To test the hypothesis that the cytoprotective effect is due to the release of neurotrophic factors (NTFs), we examined the effects of ifenprodil on the NTF contents in mouse astrocyte cultures. The results revealed that ifenprodil strongly enhanced the production of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) in these cultures. The ifenprodil-induced NGF secretion was found to be partially mediated by the activation of protein kinase C (PKC) and p42/p44 mitogen-activated protein (MAP) kinase cascade pathways. These findings suggest that the cytoprotective effects of ifenprodil are probably attributed to enhanced secretion of these NTFs from astrocytes.

Cabergoline stimulates synthesis and secretion of nerve growth factor, brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor by mouse astrocytes in primary culture.

Neuroprotection is the primary concern in patients with newly diagnosed Parkinson's disease. The D2/weak D1 dopamine agonist cabergoline elicits neuroprotection by antioxidation and scavenging free radicals, and may protect neurons by up-regulating endogenous neurotrophic factors synthesis in the brain. In primary cultured mouse astrocytes, cabergoline 37 micromol/l immediately elevated concentrations of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor (GDNF) in culture medium, reaching 9.9-, 2.6- and 30-fold, respectively, of control levels at 16 h. Relative mRNA levels were 3.0-, 1.5- and 1.9-fold, respectively, of controls at 3 h. These effects may be mediated partly by the dopamine D2 receptor. Cabergoline may be a good candidate for an inducer of GDNF, which may have neuroprotective and neurorestorative properties in dopaminergic nigral neurons.