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The morphology and biochemistry of nanostructures provide evidence for synthesis and signaling functions in human cerebrospinal fluid.

Harrington MG, Fonteh AN, Oborina E, Liao P, Cowan RP, McComb G, Chavez JN, Rush J, Biringer RG, Hühmer AF - Cerebrospinal Fluid Res (2009)

Bottom Line: Nanostructure fractions had a unique composition compared to CSF supernatant, richer in omega-3 and phosphoinositide lipids, active prostanoid enzymes, and fibronectin.Unique morphology and biochemistry features of abundant and discrete membrane-bound CSF nanostructures are described.Prostaglandin H synthase activity, essential for prostanoid production and previously unknown in CSF, is localized to nanospheres.

View Article: PubMed Central - HTML - PubMed

Affiliation: Molecular Neurology, Huntington Medical Research Institutes, Pasadena, CA, 91101 USA. mghworks@hmri.org.

ABSTRACT

Background: Cerebrospinal fluid (CSF) contacts many brain regions and may mediate humoral signaling distinct from synaptic neurotransmission. However, synthesis and transport mechanisms for such signaling are not defined. The purpose of this study was to investigate whether human CSF contains discrete structures that may enable the regulation of humoral transmission.

Methods: Lumbar CSF was collected prospectively from 17 participants: with no neurological or psychiatric disease, with Alzheimer's disease, multiple sclerosis, or migraine; and ventricular CSF from two cognitively healthy participants with long-standing shunts for congenital hydrocephalus. Cell-free CSF was subjected to ultracentrifugation to yield supernatants and pellets that were examined by transmission electron microscopy, shotgun protein sequencing, electrophoresis, western blotting, lipid analysis, enzymatic activity assay, and immuno-electron microscopy.

Results: Over 3,600 CSF proteins were identified from repeated shotgun sequencing of cell-free CSF from two individuals with Alzheimer's disease: 25% of these proteins are normally present in membranes. Abundant nanometer-scaled structures were observed in ultracentrifuged pellets of CSF from all 16 participants examined. The most common structures included synaptic vesicle and exosome components in 30-200 nm spheres and irregular blobs. Much less abundant nanostructures were present that derived from cellular debris. Nanostructure fractions had a unique composition compared to CSF supernatant, richer in omega-3 and phosphoinositide lipids, active prostanoid enzymes, and fibronectin.

Conclusion: Unique morphology and biochemistry features of abundant and discrete membrane-bound CSF nanostructures are described. Prostaglandin H synthase activity, essential for prostanoid production and previously unknown in CSF, is localized to nanospheres. Considering CSF bulk flow and its circulatory dynamics, we propose that these nanostructures provide signaling mechanisms via volume transmission within the nervous system that are for slower, more diffuse, and of longer duration than synaptic transmission.

No MeSH data available.


Related in: MedlinePlus

TEM of ultrastructures from P3 fractions, representative of 16 samples. A-F: abundant nanospheres; D-F: including large dense core vesicles; G: nanoblobs (upward arrows) and nanostrands (downward arrow); H and J: nanodebris resembles structures previously reported from ventricle walls. Scale bars 100 nm.
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Figure 4: TEM of ultrastructures from P3 fractions, representative of 16 samples. A-F: abundant nanospheres; D-F: including large dense core vesicles; G: nanoblobs (upward arrows) and nanostrands (downward arrow); H and J: nanodebris resembles structures previously reported from ventricle walls. Scale bars 100 nm.

Mentions: P3s from all 16 subjects had abundant, negatively stained structures (Figure 4) that were almost absent from S3. There was no difference in the observed structures when we prepared S3/P3 fractions freshly from two participants (sample #s 12 & 13, Table 1) as compared to preparations from their S1 samples that had been stored at -80°C for 12 months. The most common structure was roughly spherical with a mean diameter of 50 nm, ranging between 30-200 nm (Figure 4A-F). We estimated the number of nanospheres between 106 and 109 per mL of CSF, and their morphology was similar to that of synaptic vesicles and exosomes. Some spherical forms were more electron-dense (Figure 4D-F), similar in appearance to LDCVs [25].


The morphology and biochemistry of nanostructures provide evidence for synthesis and signaling functions in human cerebrospinal fluid.

Harrington MG, Fonteh AN, Oborina E, Liao P, Cowan RP, McComb G, Chavez JN, Rush J, Biringer RG, Hühmer AF - Cerebrospinal Fluid Res (2009)

TEM of ultrastructures from P3 fractions, representative of 16 samples. A-F: abundant nanospheres; D-F: including large dense core vesicles; G: nanoblobs (upward arrows) and nanostrands (downward arrow); H and J: nanodebris resembles structures previously reported from ventricle walls. Scale bars 100 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2746175&req=5

Figure 4: TEM of ultrastructures from P3 fractions, representative of 16 samples. A-F: abundant nanospheres; D-F: including large dense core vesicles; G: nanoblobs (upward arrows) and nanostrands (downward arrow); H and J: nanodebris resembles structures previously reported from ventricle walls. Scale bars 100 nm.
Mentions: P3s from all 16 subjects had abundant, negatively stained structures (Figure 4) that were almost absent from S3. There was no difference in the observed structures when we prepared S3/P3 fractions freshly from two participants (sample #s 12 & 13, Table 1) as compared to preparations from their S1 samples that had been stored at -80°C for 12 months. The most common structure was roughly spherical with a mean diameter of 50 nm, ranging between 30-200 nm (Figure 4A-F). We estimated the number of nanospheres between 106 and 109 per mL of CSF, and their morphology was similar to that of synaptic vesicles and exosomes. Some spherical forms were more electron-dense (Figure 4D-F), similar in appearance to LDCVs [25].

Bottom Line: Nanostructure fractions had a unique composition compared to CSF supernatant, richer in omega-3 and phosphoinositide lipids, active prostanoid enzymes, and fibronectin.Unique morphology and biochemistry features of abundant and discrete membrane-bound CSF nanostructures are described.Prostaglandin H synthase activity, essential for prostanoid production and previously unknown in CSF, is localized to nanospheres.

View Article: PubMed Central - HTML - PubMed

Affiliation: Molecular Neurology, Huntington Medical Research Institutes, Pasadena, CA, 91101 USA. mghworks@hmri.org.

ABSTRACT

Background: Cerebrospinal fluid (CSF) contacts many brain regions and may mediate humoral signaling distinct from synaptic neurotransmission. However, synthesis and transport mechanisms for such signaling are not defined. The purpose of this study was to investigate whether human CSF contains discrete structures that may enable the regulation of humoral transmission.

Methods: Lumbar CSF was collected prospectively from 17 participants: with no neurological or psychiatric disease, with Alzheimer's disease, multiple sclerosis, or migraine; and ventricular CSF from two cognitively healthy participants with long-standing shunts for congenital hydrocephalus. Cell-free CSF was subjected to ultracentrifugation to yield supernatants and pellets that were examined by transmission electron microscopy, shotgun protein sequencing, electrophoresis, western blotting, lipid analysis, enzymatic activity assay, and immuno-electron microscopy.

Results: Over 3,600 CSF proteins were identified from repeated shotgun sequencing of cell-free CSF from two individuals with Alzheimer's disease: 25% of these proteins are normally present in membranes. Abundant nanometer-scaled structures were observed in ultracentrifuged pellets of CSF from all 16 participants examined. The most common structures included synaptic vesicle and exosome components in 30-200 nm spheres and irregular blobs. Much less abundant nanostructures were present that derived from cellular debris. Nanostructure fractions had a unique composition compared to CSF supernatant, richer in omega-3 and phosphoinositide lipids, active prostanoid enzymes, and fibronectin.

Conclusion: Unique morphology and biochemistry features of abundant and discrete membrane-bound CSF nanostructures are described. Prostaglandin H synthase activity, essential for prostanoid production and previously unknown in CSF, is localized to nanospheres. Considering CSF bulk flow and its circulatory dynamics, we propose that these nanostructures provide signaling mechanisms via volume transmission within the nervous system that are for slower, more diffuse, and of longer duration than synaptic transmission.

No MeSH data available.


Related in: MedlinePlus