Crystalline-like Inclusions Research Articles

Skeletal Muscle-Restricted Expression of Human SOD1 in Transgenic Mice Causes a Fatal ALS-Like Syndrome.

Amyotrophic lateral sclerosis (ALS) is a fatal heterogeneous neurodegenerative disease that causes motor neuron (MN) loss and skeletal muscle paralysis. It is uncertain whether this degeneration of MNs is triggered intrinsically and is autonomous, or if the disease initiating mechanisms are extrinsic to MNs. We hypothesized that skeletal muscle is a primary site of pathogenesis in ALS that triggers MN degeneration. Some inherited forms of ALS are caused by mutations in the superoxide dismutase-1 (SOD1) gene, that encodes an antioxidant protein, so we created transgenic (tg) mice expressing wild-type-, G37R-, and G93A-human SOD1 gene variants only in skeletal muscle. Presence of human SOD1 (hSOD1) protein in skeletal muscle was verified by western blotting, enzyme activity gels, and immunofluorescence in myofibers and satellite cells. These tg mice developed limb weakness and paresis with motor deficits, limb and chest muscle wasting, diaphragm atrophy, and age-related fatal disease with a lifespan shortening of 10–16%. Brown and white adipose tissue also became wasted. Myofibers of tg mice developed crystalline-like inclusions, individualized sarcomere destruction, mitochondriopathy with vesiculation, DNA damage, and activated p53. Satellite cells became apoptotic. The diaphragm developed severe loss of neuromuscular junction presynaptic and postsynaptic integrity, including decreased innervation, loss of synaptophysin, nitration of synaptophysin, and loss of nicotinic acetylcholine receptor and scaffold protein rapsyn. Co-immunoprecipitation identified hSOD1 interaction with rapsyn. Spinal cords of tg mice developed gross atrophy. Spinal MNs formed cytoplasmic and nuclear inclusions, axonopathy, mitochondriopathy, accumulated DNA damage, activated p53 and cleaved caspase-3, and died. Tg mice had a 40–50% loss of MNs. This work shows that hSOD1 in skeletal muscle is a driver of pathogenesis in ALS, that involves myofiber and satellite cell toxicity, and apparent muscle-adipose tissue disease relationships. It also identifies a non-autonomous mechanism for MN degeneration explaining their selective vulnerability as likely a form of target-deprivation retrograde neurodegeneration.

Peripheral Nervous System Involvement in Late-Onset Cobalamin C Disease?

Background: Cobalamin C (cblC) has a fundamental role in both central and peripheral nervous system function at any age. Neurologic manifestations may be the earliest and often the only manifestation of hereditary or acquired cblC defect. Peripheral neuropathy remains a classical but underdiagnosed complication of cblC defect, especially in late-onset cblC disease caused by mutations in the methylmalonic aciduria type C and homocysteinemia (MMACHC) gene. So the clinical, electrophysiological, and pathological characteristics of late-onset cblC disease are not well-known.Methods: A retrospective study of patients with late-onset cblC disease was conducted at our hospital on a 3-year period. The neuropathy was confirmed by the nerve conduction study. Sural biopsies were performed in 2 patients.Results: Eight patients were identified, with a mean onset age of 16.25 ± 6.07 years. All patients had methylmalonic aciduria, homocysteinemia, compound heterozygous MMACHC gene mutations were detected in all patients, and 7/8 patients with c.482G>A mutation. One patient concomitant with homozygote c.665C>T mutation in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. All patients showed limb weakness and cognitive impairment. Five patients had possible sensorimotor axonal polyneuropathy predominantly in the distal lower limbs. Sural biopsies showed loss of myelinated and unmyelinated fibers. Electro microscopy revealed crystalline-like inclusions bodies in Schwann cells and axonal degeneration.Conclusion: Late-onset cblC disease had possible heterogeneous group of distal axonal neuropathy. c.482G>A mutation is a hot spot mutation in late-onset cblC disease.

Morphological study of bovine pregnant corpus luteum cells.

The bovine pregnant corpus luteum was examined morphologically, to clarify the appearance and properties of the intramitochondrial bodies (IMB) in mitochondria of the large luteum cell (LLC). The incidence and diameter of the IMB (200-900 nm) showed a tendency to increase with the advance of pregnancy. Histochemically, the IMB reacted positively with protein, and immunohistochemically, they reacted IMB with 11 alpha-hydroxyprogesterone-1-11 succinyl-bovine serum albumin (P-BSA). The IMB seemed to combine with protein, and these granules did not undergo exocytosis. The cytoplasm of LLC contained another type of small electron-dense granules that were 150-200 nm in diameter, had an orifice for secretion, and reacted with relaxin. Small luteum cells (SLC) revealed crystalline-like inclusions. It is suggested that these inclusion cells participate in the synthesis of steroids.

Dynamic features of luteal secretory granules: ultrastructural changes during the course of pregnancy in the cow.

The ultrastructure of large and small cells from corpora lutea of pregnant cows (days 45-280) were evaluated by electron microscopy. The distinguishing features of small cells (10-15 micron in diameter) included stacks of rough endoplasmic reticulum, whorls of smooth endoplasmic reticulum, elongated mitochondria containing crystalline-like inclusions, and cytoplasmic lipid droplets. The large cells (20-50 micron in diameter) contained numerous mitochondria packed tightly together (no elongated structures), an abundance of smooth endoplasmic reticulum (no whorls), and a large number of membrane-bound secretory granules (150-300 nm in diameter). These granules appeared to be packaged in the Golgi, accumulated at a paranuclear region, and migrated as a group to the cell membrane where they were exocytosed. These granules were first observed on day 45 and increased in number to reach a peak around day 200. Lipid droplets became a common cytoplasmic inclusion in the large cells during the third trimester of pregnancy. In addition, during this stage, an electron-dense substance began to accumulate in the mitochondria to such an extent as to occlude the cristae. These mitochondria looked like large (500-1800 nm) membrane-bound granules; however, they did not undergo exocytosis. Their appearance in large cells during the last 3 months of pregnancy may reflect a change in steroid metabolism. Thus, there are two morphologically distinct cell types throughout pregnancy in the cow. The large cell containing the secretory granules underwent what appeared to be a progressive state of apparent deterioration with advancing pregnancy. The morphology of the small cell did not undergo such a dynamic change. No morphological evidence was observed that would support a transition state between the two cell types.

The presence of hepatic intramitochondrial crystalline inclusions in polybrominated biphenyl-treated mice.

Electron microscopic study of livers from mice fed 167 ppm polybrominated biphenyl (PBB) revealed mitochondrial abnormalities which consisted of both alterations in size and the formation of crystalline-like inclusions within the mitochondrial matrix. These inclusions appeared as parallel arrays of rods and were found in elongated mitochondria which contained few cristae. The findings are briefly described and the possible significance of such inclusions in relation to mitochondrial aberrations are discussed.

Changes in the adrenal cortex of the rat after chronic administration of the steroidogenic inhibitor U-8113

In concert with studies of the effects of various pharmacologic inhibitors of corticosteroidogenesis on adrenocortical morphology, U-8113, an analog of amphenone B, was administered daily to Sprague-Dawley rats for 7, 14, 21 or 30 day. The primary morphological responses involved increases in adrenal weight, width of zona fasciculata, width of zona reticularis, intracellular lipids, mitochondrial size, mitochondrial vacuolation and crystalline-like inclusions, small coated vesicles, lysosomes, autophagic vacuoles and cholesterol ester clefts. In particular, the increases in lysosomes, coated vesicles and autophagic vacuoles containing morphologically altered mitochondria were considered reflective of mechanisms designed to maintain cellular integrity amidst functional impairment. Lipid analysis revealed marked increases in cholesterol esters and phospholipids, supportive of morphological observations. When permitted a 14 day recovery period following either 14 or 30 days of inhibitor therapy, most fine structural alterations and lipid derangements were diminished, and the cells approximated normal parameters.

Cuticle formation in parasitic nematodes: Ultrastructure of molting and the effects of actinomycin-D

The ultrastructure of cuticle formation and the effect of actinomycin-D on cuticle formation were examined in the second molt of Nippostrongylus brasiliensis . At the end of the first molt the rough endoplasmic reticulum of the hypodermis (epidermis) had narrow cisternae. As cuticle formation began the RER cisternae dilated and accumulated a fibrous material. These large fibrous material-containing vesicles then decreased and by the time cuticle deposition was completed they had disappeared. Actinomycin-D prevented the proliferation of RER and the formation of fibrous material-containing vesicles. Actinomycin-D induced several ultrastructural alterations in the hypodermis, the most prominent of which were large crystalline-like inclusions. Other alterations involved the configuration of RER and structure of nucleoli. These morphological aspects of cuticle formation were correlated to the molecular events that control molting.

Ultrastructural effects of griseofulvin on the myxomycete Physarum polycephalum. Inhibition of mitosis and the production of microtubule crystals.

The antifungal antibiotic griseofulvin inhibits the growth of the myxomycetePhysarum polycephalum. Mitosis in the microplasmodium is inhibited by griseofulvin. Griseofulvin treated microplasmodia show many ultrastructural abnormalities. Nuclei of such micro-plasmodia are extremely large, often up to 30 μm in diameter and are presumably polyploid. Griseofulvin induces the formation of crystalline-like inclusions of microtubules in the nucleoplasm. Organization of the plasmodial surface is also affected by griseofulvin. Griseofulvin treated plasmodia show blebbing of the peripheral cytoplasm.