Parvalbumin overexpression alters immune-mediated increases in intracellular calcium, and delays disease onset in a transgenic model of familial amyotrophic lateral sclerosis.

Intracellular calcium is increased in vulnerable spinal motoneurons in immune-mediated as well as transgenic models of amyotrophic lateral sclerosis (ALS). To determine whether intracellular calcium levels are influenced by the calcium-binding protein parvalbumin, we developed transgenic mice overexpressing parvalbumin in spinal motoneurons. ALS immunoglobulins increased intracellular calcium and spontaneous transmitter release at motoneuron terminals in control animals, but not in parvalbumin overexpressing transgenic mice. Parvalbumin transgenic mice interbred with mutant SOD1 (mSOD1) transgenic mice, an animal model of familial ALS, had significantly reduced motoneuron loss, and had delayed disease onset (17%) and prolonged survival (11%) when compared with mice with only the mSOD1 transgene. These results affirm the importance of the calcium binding protein parvalbumin in altering calcium homeostasis in motoneurons. The increased motoneuron parvalbumin can significantly attenuate the immune-mediated increases in calcium and to a lesser extent compensate for the mSOD1-mediated 'toxic-gain-of-function' in transgenic mice.

Immune reactivity in a mouse model of familial ALS correlates with disease progression.

OBJECTIVE: The cause of motor neuron death in ALS is incompletely understood. This study aims to define the potential involvement of nonneuronal immune-inflammatory factors in the destruction of motor neurons in mutant superoxide dismutase-1 (SOD1) transgenic mice as a model of ALS. BACKGROUND: The presence of activated microglia, IgG and its receptor for Fc portion (FcgammaRI), and T lymphocytes in the spinal cord of both patients with ALS and experimental animal models of motor neuron disease strongly suggests that immune-inflammatory factors may be actively involved in the disease process. METHODS: The expression of immune-inflammatory factors was followed in both human mutant (G93A) SOD1 transgenic mice and human wild-type SOD1 transgenic mice, at different ages (40, 80, and 120 days). Fixed, frozen, free-floating sections of the lumbar spinal cord were stained with antibodies against CD11b, IgG, FcgammaRI, intercellular adhesion molecule-1 (ICAM-1), CD3, and glial fibrillary acidic protein. RESULTS: The earliest change observed was the upregulation of ICAM-1 in the ventral lumbar spinal cord of 40-day-old mutant SOD1 mice. IgG and FcgammaRI reactivities were detected on motor neurons as early as 40 days and on microglial cells at later stages. Microglial activation was first evident in the ventral horn at 80 days, whereas reactive astrocytes and T cells became most prominent in 120-day-old mutant SOD1 mice. CONCLUSION: The upregulation of proinflammatory factors during early presymptomatic stages as well as the expansion of immune activation as disease progresses in mutant SOD1 transgenic mice suggest that immune-inflammatory mechanisms could contribute to disease progression.

Laparoscopic ureteral reconstruction with small intestinal submucosa.

PURPOSE: To evaluate the feasibility of laparoscopic ureteral reconstruction with small intestinal submucosa (SIS) in the pig ureter. MATERIALS AND METHODS: Eight female pigs weighing between 25 and 30 kg were enrolled. After anesthesia was administered, a double-pigtail stent was inserted, the animals were moved to a lateral decubitus position, pneumoperitoneum was established, and three 10-mm ports were positioned. The ureter was opened longitudinally for 7 cm, and two thirds of the periphery of the upper third of the left ureter was excised. The SIS was anastomosed to the upper and distal ureteral segments with chromic 4-0 sutures. The double-pigtail stent was removed 6 weeks after the initial procedure, and retrograde pyelography was performed a week later to confirm the viability of the pelvicaliceal system. RESULTS: The average duration of the procedures was 210 minutes (range 125-250 minutes). All animals survived the entire follow-up period of 7 weeks. Retrograde pyelography revealed a patent ureteral lumen, and no obstructive phenomena were observed. Histologically, the SIS-regenerated ureteral segments were remarkably similar to normal porcine ureters and were indistinguishable from neighboring tissue. CONCLUSION: Laparoscopic ureteral reconstruction with SIS proved to be effective and technically feasible. The SIS seems to be an effective biodegradable scaffold, facilitating regeneration of host tissue.

Primary synovial sarcoma of the kidney: a case report with literature review.

We describe a case of primary renal synovial sarcoma (SS) in a 48-year-old man. The patient presented with hematuria and was found to have a large tumor in his left kidney on computed tomography scan. Histology revealed a highly cellular spindle cell neoplasm with minimal pleomorphism. The major differential diagnoses included leiomyosarcoma, hemangiopericytoma, and SS. The presence of focal areas with a biphasic pattern, uniformly positive immunostain for bcl-2, focally positive immunostains for epithelial membrane antigen and cytokeratin, and negative immunostains for CD-34, smooth muscle actin and S-100 established the diagnosis. This was subsequently confirmed by molecular testing for t(X;18) translocation. Since the existence of primary SS in the kidney was first suggested in 1999, to the best of our knowledge a total of 19 cases including the present case have been reported to date. Although primary renal SS is rare, these findings indicate that it should be included in the differential diagnosis of spindle cell tumors of the kidney.

Management of malignant extrinsic compression of the ureter by simultaneous placement of two ipsilateral ureteral stents.

BACKGROUND AND PURPOSE: Extrinsic ureteral obstruction caused by various malignancies often necessitates urinary diversion. The use of single ureteral stents as a form of urinary diversion results in a high failure rate, while the use of two ipsilateral stents has shown promising results. We report our experience using the latter technique. PATIENTS AND METHODS: Between 1996 and 2001, four male and three female patients with a mean age of 65 years (range 37-95 years) who had extrinsic compression of the ureters underwent single stent management to relieve obstruction. Ureteral obstruction was secondary to prostate cancer (N = 3), cervical cancer (2), non-Hodgkin's lymphoma (1), and transitional-cell cancer of the bladder and ureter (1). After failure of such management, two 7F stents or a combination of 8F/6F double-J ureteral stents were placed. The stents were changed every 4 to 6 months. Follow-up included serial renal ultrasound scans and serum creatinine measurements. RESULTS: Ureteral stricture length ranged from 2 to 4 cm. Insertion of two double-J ureteral stents in a single ureter was successful in all cases. During the mean follow-up of 16 months (range 1-38 months), the ureteral stents were tolerated by all patients, without significant discomfort. Marked improvement of hydronephrosis and alleviation of flank pain was noted in all patients. Three patients have died at 1 to 3 months. Renal function improved, with a mean decline in the serum creatinine concentration from 3.2 mg/dL to 1.48 mg/dL in the five patients tested. CONCLUSION: Simultaneous placement of two double-J ureteral stents for the management of ureteral obstruction secondary to a malignancy is a safe and effective technique.

Radical prostatectomy versus brachytherapy for early-stage prostate cancer.

BACKGROUND AND PURPOSE: The considerations in choosing a treatment for prostate cancer are potential for cure, acute toxicity, long-term morbidity, quality of life, and direct and indirect costs. The classic options are radical prostatectomy, external-beam radiation, and watchful waiting. During the last decade, technological advances have fostered another: brachytherapy. METHODS: This article compares brachytherapy and radical prostatectomy in terms of cancer control, complications, and cost using series from medical centers that have pioneered and advocated particular procedures. RESULTS: In the surgical series from Johns Hopkins, the 7-year success rate (no PSA >0.2 ng/mL) of anatomic radical prostatectomy was 97.8% in patients with stage T(2c) or lower disease and a Gleason score of < or =6. In the brachytherapy series from Seattle, the 7-year success rate (PSA < or =0.5 ng/mL) was 79%. Postoperatively, 68% of the patients who were potent preoperatively maintained erectile function, and 92% were fully continent. Urethral toxicity is slightly more common in patients treated by brachytherapy, but in the authors' series, no patient remained incontinent after 6 months. Some patients became impotent during follow-up. The cost of brachytherapy ($16,200) is less than that of ($27,000), although the difference may be reduced by the use of neoadjuvant hormonal therapy with the former. CONCLUSION: Patients receiving brachytherapy appear to have a slightly higher rate of disease progression. The side effects generally are acceptable and may be less severe than those of surgery. Further follow-up data are needed to define the roles of these two treatments for early-stage prostate cancer.

Cloacal exstrophy: a unified management plan.

BACKGROUND/PURPOSE: The belief that patients with cloacal exstrophy have a short and therefore useless colon is all too common. Frequently, the colon is used for urinary or vaginal reconstruction, and the possibility of a pull-through is lost. In the authors' experience, the use of a unified management plan allowed most patients to undergo pull-through and avoid a permanent stoma. METHODS: Twenty-five patients were treated for cloacal exstrophy in the authors' institution from 1985 through 1999. In all patients, bladder closure, omphalocele repair, and creation of a colostomy were performed at birth. All available colon, no matter how small, was incorporated into the fecal stream. After at least 1 year, patients were assessed for the ability to form solid stool through their stoma. Normal colonic length, capacity to form solid stool, or success with a bowel management regimen through the stoma were considered indications for pull-through. Genitourinary reconstruction was contingent on the colorectal plan. RESULTS: Colonic length ranged from normal in 12 patients, 40 to 70 cm in 3 patients, 10 to 30 cm in 4 patients, and less than 10 cm in 2 patients. All 25 patients underwent pull-through. Three are totally continent, 4 are continent with occasional soiling, 11 remain clean with a bowel management regimen, and 4 are too young to assess. One patient was clean, but now refuses bowel management. Two early patients, both with less than 10 cm of colon, now have ileostomies. CONCLUSIONS: During neonatal repair, a colostomy should be formed incorporating all pieces of colon, no matter how small. With time, most patients will be able to form solid stool, and a pull-through should be undertaken if that ability exists. Decisions regarding genitourinary reconstruction should be made only after the gastrointestinal plan is established to achieve the optimal use of available bowel.

Ultrastructural evidence of calcium involvement in experimental autoimmune gray matter disease.

Experimental studies have suggested that increased calcium and inappropriate calcium handling by motoneurons might have a significant role in motoneuron degeneration. To further define the involvement of calcium in motoneuron loss we used the oxalate-pyroantimonate technique for calcium fixation and monitored the ultrastructural distribution of calcium in spinal motoneurons in experimental autoimmune gray matter disease (EAGMD). In cervical and hypoglossal motoneurons from animals with relatively preserved upper extremity and bulbar function, increased calcium precipitates were present in the cytoplasm as well as in mitochondria, endoplasmic reticulum and Golgi complex without significant morphologic alterations. In surviving lumbar motoneurons of animals with hindlimb paralysis, however, there was massive morphological destruction of intracellular organelles but no significant accumulation of calcium precipitates. These findings suggest that altered calcium homeostasis is involved in motoneuron immune-mediated injury with increased calcium precipitates early in the disease process and decreased to absent calcium precipitates later in the pathogenesis of motoneuron injury.

Experimental destruction of substantia nigra initiated by Parkinson disease immunoglobulins.

BACKGROUND: Increased levels of free radicals and oxidative stress may contribute to the pathogenesis of substantia nigra (SN) injury in Parkinson disease (PD), but the initiating etiologic factors remain undefined in most cases. OBJECTIVE: To determine the potential importance of immune mechanisms in triggering or amplifying neuronal injury, we assayed serum samples from patients with PD to determine the ability of IgG to initiate relatively specific SN injury in vivo. METHODS: IgG purified from the serum of 5 patients with PD and 10 disease control (DC) patients was injected into the right side of the SN in adult rats. Coronal sections were cut from the whole brain at the level of the stereotaxic injections, stained for tyrosine hydroxylase and with cresyl violet, and cellular profiles were counted in identical brain regions at the injection and contralateral sides. The ratio of cell profile counts of the corresponding injected and uninjected regions was used as an internal standard. RESULTS: Four weeks following injection of IgG, a 50% decrease in tyrosine hydroxylase-positive cellular profiles was noted on the injected sides compared with the contralateral sides of the same animals. Similarly, applied DC IgG caused only an 18% decrease. Cresyl violet staining revealed a 35% decrease in neuronal profiles of PD IgG injected into the SN pars compacta compared with the contralateral uninjected side, whereas DC IgG caused a minimal 10% decrease. Even at 4 weeks after the PD IgG injections, perivascular inflammation and significant microglial infiltration were present near injured SN pars compacta neurons. No cytotoxic effects of PD IgG were noted in choline acetyltransferase-positive neurons after stereotaxic injections into the medial septal region. Absorption of PD IgG with mesencephalic membranes and protein A agarose gel beads removed cytotoxicity, while absorption with liver membranes did not change the cytotoxicity. CONCLUSIONS: Our data suggest that PD IgG can initiate a relatively specific inflammatory destruction of SN pars compacta neurons in vivo and demonstrate the potential relevance of immune mechanisms in PD.

Intracellular calcium parallels motoneuron degeneration in SOD-1 mutant mice.

Transgenic mice with Cu,Zn superoxide dismutase (SOD-1) mutations provide a unique model to examine altered Ca homeostasis in selectively vulnerable and resistant motoneurons. In degenerating spinal motoneurons of G93 A SOD-1 mice, developing vacuoles were filled with calcium, while calcium was gradually depleted from the cytoplasm and intact mitochondria. In oculomotor neurons, no degenerative changes, vacuolization, or increased calcium were noted. Motor axon terminals of interosseus muscle gradually degenerated and intracellular calcium was depleted. Oculomotor terminals of mutant SOD-1 mice were smaller and exhibited no degenerative changes, but did exhibit unique membrane-enclosed organelles containing calcium. Spinal motoneurons of SOD-1 mice were shown to have fewer calcium binding proteins, such as parvalbumin, compared with oculomotor neurons. These data suggest that the SOD-1 mutation is associated with impaired calcium homeostasis in motoneurons in vivo, with increased likelihood of degeneration associated with higher levels of intracellular calcium and lower to absent levels of calbindin-D28K and/or parvalbumin, and decreased likelihood of degeneration associated with minimally changed calcium and ample calbindin-D28K and/or parvalbumin.

1Alpha, 25 dihydroxyvitamin D3-dependent up-regulation of calcium-binding proteins in motoneuron cells.

Our understanding of selective neuronal vulnerability as well as etiopathogenesis of sporadic neurodegenerative diseases is extremely limited. In ALS, altered calcium homeostasis appears to contribute significantly to selective neuronal injury. Further in ALS, the absence of calcium binding proteins (calbindin-D28K, parvalbumin, and calretinin) correlates with selective vulnerability and cell loss. In motoneuron cell culture models an ALS IgG-triggered and calcium-mediated destruction can be reversed by increased expression of calbindin-D28K following retroviral infection with calbindin-D28K cDNA. To increase calcium binding protein expression in motoneurons in vitro and in vivo, we have employed vitamin D3. Forty-eight hr treatment of differentiated VSC 4.1 cells with 0.1-30 nM 1,25 dihydroxyvitamin D3 induced a two-fold increase in the immunoreactivity for calbindin-D28K and parvalbumin. Injection of 80-120 ng, 1,25 dihydroxyvitamin D3 in the cerebral ventricles of adult rats also induced positive immunoreactivity for calcium binding proteins in ventral motoneurons which are completely devoid of such reactivity in the adult stage. These data suggest that analogs of 1,25 dihydroxyvitamin D3 may be useful tools in enhancing the expression of calcium binding proteins in the motor system and may have possible therapeutic value in neurodegenerative disease.

Amyotrophic lateral sclerosis immunoglobulins increase intracellular calcium in a motoneuron cell line.

A hybrid motoneuron cell line (VSC4.1) was used as a model system to study the relationship between alterations in intracellular calcium and subsequent cell death induced by immunoglobulin fractions purified from sera of patients with ALS. Using fluo-3 fluorescence imaging, immunoglobulins from 8 of 10 patients with ALS were found to induce transient increases in intracellular calcium ([Ca2+]i) in differentiated VSC4.1 cells. These transient [Ca2+]i increases required extracellular calcium entry through voltage-gated calcium channels sensitive to synthetic FTX and to high concentrations (>1 microM) of omega-agatoxin IVa. The incidence of transient [Ca2+]i increases induced by ALS immunoglobulins correlated with the extent of cytotoxicity induced by the same ALS immunoglobulins in parallel cultures of VSC4.1 cells. Furthermore, manipulations which blocked transient [Ca2+]i increases (addition of synthetic FTX or omega-agatoxin IVa) also inhibited the cytotoxic effects of ALS immunoglobulins. No transient calcium increases were observed in VSC4.1 cells following addition of immunoglobulins from 7 neurologic disease control patients. However, transient [Ca2+]i increases were observed following addition of immunoglobulins from 4 of 5 patients with myasthenia gravis (MG). The [Ca2+]i changes induced by MG immunoglobulins were not blocked by s-FTX, suggesting that they result from a different mechanism than those induced by ALS immunoglobulins. These results suggest that immunoglobulins from patients with ALS can induce transient increases in intracellular calcium in a motoneuron cell line, which may represent early events in the cascade of processes leading to injury and death of susceptible cells.

Autoimmunity and ALS.

Significant evidence has accrued suggesting that antibodies to voltage-gated calcium channel are observed in at least some patients with sporadic ALS (SALS) and that such antibodies alter the function of these ion channels in vitro and in vivo. Further, passive transfer of these immunoglobulin-containing fractions into mice produces changes at the neuromuscular junction that are very similar to changes observed in patients with SALS. These changes reflect local alterations in intracellular Ca2+ homeostasis and, in animal models, may also evidence early changes of motoneuron injury, such as Golgi apparatus swelling and fragmentation. Although not yet documented to induce motoneuron death in vivo, SALS immunoglobulins induce Ca(2+)-dependent apoptosis in a differentiated motoneuron hybrid cell line via a mechanism that involves oxidative injury. SALS immunoglobulin-mediated apoptosis in these cells is regulated by the presence of the same calcium-binding proteins that may modulate selective motoneuron vulnerability in SALS.

Expression of calbindin-D28K in motoneuron hybrid cells after retroviral infection with calbindin-D28K cDNA prevents amyotrophic lateral sclerosis IgG-mediated cytotoxicity.

Calbindin-D28K and/or parvalbumin appear to influence the selective vulnerability of motoneurons in amyotrophic lateral sclerosis (ALS). Their immunoreactivity is undetectable in motoneurons readily damaged in human ALS, and in differentiated motoneuron hybrid cells [ventral spinal cord (VSC 4.1 cells)] that undergo calcium-dependent apoptotic cell death in the presence of ALS immunoglobulins. To provide additional evidence for the role of calcium-binding proteins in motoneuron vulnerability, VSC 4.1 cells were infected with a retrovirus carrying calbindin-D28K cDNA under the control of the promoter of the phosphoglycerate kinase gene. Differentiated calbindin-D28K cDNA-infected cells expressed high calbindin-D28K and demonstrated increased resistance to ALS IgG-mediated toxicity. Treatment with calbindin-D28K antisense oligodeoxynucleotides, which significantly decreased calbindin-D28K expression, rendered these cells vulnerable again to ALS IgG toxicity.

Apoptosis induced by beta-N-oxalylamino-L-alanine on a motoneuron hybrid cell line.

It has been suggested that beta-N-oxalylamino-L-alanine, a non-protein amino acid present in the Lathyrus Sativus seeds, may play a role in the etiopathogenesis of neurolathyrism, a toxic form of motor neuron disease clinically characterized by a severe spastic paraparesis. In order to investigate the mechanisms of beta-N-oxalylamino-L-alanine-mediated cell death, we studied the effect of this neurotoxin as well as other excitatory amino acids agonists on the growth and survival of motoneuron hybrid ventral spinal cord 4.1 cells. beta-N-oxalylamino-L-alanine was toxic to ventral spinal cord 4.1 cells in a concentration-dependent fashion (0.5-10 mM). Among the excitatory amino acids tested, only glutamate (1-10 mM), quisqualate (1 mM) and, with less extent, beta-N-methylamino-L-alanine (10 mM) induced a significant reduction of cell survival. The effect of Lathyrus Sativus neurotoxin was a slow process, becoming apparent only after 24-48 h of incubation. Interestingly, a mathematical analysis applied to the time course and dose curve of beta-N-oxalylamino-L-alanine toxicity suggested that even for very low concentrations of the amino acid it is theoretically possible to predict a time-dependent effect. The cell death was not blocked by antagonists of N-methyl-D-aspartate or non-N-methyl-D-aspartate receptors; aurintricarboxylic acid and alpha-tocopherol gave a partial protection; cysteine (1 mM) prevented the toxic effect of both Lathyrus Sativus neurotoxin and glutamate as well as quisqualate. Morphologically, in the presence of either beta-N-oxalylamino-L-alanine, glutamate or quisqualate, ventral spinal cord 4.1 cells showed apoptotic features also confirmed by ISEL technique and agarose gel electrophoresis of genomic DNA. Thus, our results suggest that in ventral spinal cord 4.1 motoneuron hybrid cells, in the absence of functional synaptic excitatory amino acid receptors, beta-N-oxalylamino-L-alanine induces cell degeneration through an apoptotic mechanism, possibly mediated by a block of cystine/glutamate Xc antiporter.

Cell death induced by beta-amyloid 1-40 in MES 23.5 hybrid clone: the role of nitric oxide and NMDA-gated channel activation leading to apoptosis.

The molecular events associated with beta-amyloid-induced neuronal injury remain incompletely characterized. Using a substantia nigra/neuroblastoma hybrid cell line (MES 23.5) synthetic beta-amyloid 1-40 induced a time and dose-dependent apoptotic cell death which was characterized by cell shrinkage and fragmentation of DNA, and was inhibited by aurintricarboxylic acid (ATA), and cycloheximide (CHX). Following beta-amyloid 1-40 treatment, cyclic GMP, an index of NO synthesis, was increased in MES 23.5 cells. The NO scavenger hemoglobin, as well as the NO synthase inhibitors NG-monomethyl-L-arginine acetate (L-NMMA) and L-N5-(1-iminoethyl)ornithine hydrochloride (L-NI0) attenuated such increases. These same inhibitors and scavengers also significantly prevented cytotoxicity. beta-Amyloid also induced an early and transient increase in intracellular calcium as monitored with laser scanning confocal microscopy and Fluo-3 imaging. These induced calcium transients could be significantly blocked by the N-methyl-D-aspartic acid (NMDA) receptor antagonist MK-801. Pretreatment with MK-801 or removal of extracellular Ca2+ also reduced beta-amyloid-induced NO production and neurotoxicity. Furthermore, beta-amyloid neurotoxicity was greatly enhanced in the absence of Mg2+ or in the presence of glutamate or NMDA. These data suggest that beta-amyloid can lead to apoptotic cell death through a NO mediated process possibly triggered by Ca2+ entry through activated NMDA-gated channels.

The role of immune processes in amyotrophic lateral sclerosis pathogenesis.

Despite many efforts, the etiopathogenesis of ALS remains unknown. During the last decade evidence for an autoimmune involvement in motoneuron degeneration and death has remarkably increased. Multiple reports have documented significant expression of proteins associated with immune function in affected areas of ALS patients. Two animal models of immune-mediated motoneuron destruction have been developed that closely resemble clinical, electrophysiological and morphological features of human ALS. Inflammatory foci within the spinal cord, and IgG at the neuromuscular junction as well as within upper and lower motoneurons found in the animal models support the role of autoimmune mechanisms of motoneuron destruction in this model. IgG from ALS patients and from the animal models can passively transfer physiological changes at the neuromuscular junction in mice. That ALS IgG interact with calcium channels and induce an alteration of their function is now electrophysiologically and biochemically evident. Furthermore, it has been documented that motoneurons may be selectively vulnerable since they have a deficient calcium buffering capacity. Although further research efforts are necessary to elucidate the interaction of the ALS antibodies with the calcium channel function and how defective calcium handling by the motoneurons is important in their degeneration, the current data strongly suggest the involvement of autoimmune mechanisms in ALS etiopathogenesis.

Tomaculous neuropathy with unusual clinical aspects.

Tomaculous neuropathy represents the morphological substrate of the recurrent familial neuropathy with liability to pressure palsies. Some ultrastructural changes characterizing the tomaculous neuropathy can occur as incidental aspects in other different neuropathies. Few tomaculous neuropathy cases with clinical aspect of chronic polyneuropathy without paretic episodes have been mentioned in the literature. In the present work, we report four cases who offered the morphological surprise of a true tomaculous neuropathy with 15-37% of the teased fibres bearing tomaculae sized: 55-106 microns/20-23 microns, on the background of a demyelinating neuropathy with 25-56% of the teased fibres showing segmental de- or remyelination. The clinical and electrophysiological diagnoses of these 4 patients were: HSMN type I (2 cases), HSMN type VIII (polyneuropathy associated with a cerebello-extrapyramidal syndrome -1 case), and a neurogenic scapuloperoneal syndrome (1 case). The specificity of the tomaculous neuropathy is discussed.

Amyotrophic lateral sclerosis immunoglobulins increase Ca2+ currents in a motoneuron cell line.

The sporadic form of amyotrophic lateral sclerosis (ALS) is an idiopathic and eventually lethal disorder causing progressive degeneration of cortical and spinal motoneurons. Recent studies have shown that the majority of patients with sporadic ALS have serum antibodies that bind to purified L-type voltage-gated calcium channels and that antibody titer correlates with the rate of disease progression. Furthermore, antibodies purified from ALS patient sera have been found to alter the physiologic function of voltage-gated calcium channels in nonmotoneuron cell types. Using whole-cell patch-clamp techniques, immunoglobulins purified from sera of 5 of 6 patients with sporadic ALS are now shown to increase calcium currents in a hybrid motoneuron cell line, VSC4.1. These calcium currents are blocked by the polyamine funnel-web spider toxin FTX, which has previously been shown to block Ca2+ currents and evoked transmitter release at mammalian motoneuron terminals. These data provide additional evidence linking ALS to an autoimmune process and suggest that antibody-induced increases in calcium entry through voltage-gated calcium channels may occur in motoneurons in this disease, with possible deleterious effects in susceptible neurons.