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At least 1,063 records · Page 59Linked to original sources
PubMed2003

Expression of photoreceptor-associated molecules during human fetal eye development.

PURPOSE: A characteristic feature of the human retina is the early differentiation of foveal cells followed by a central to peripheral wave of maturation. This can obscure the true onset of differentiation when regions other that the fovea are sampled, or when methods based on whole retina or whole eye tissue are employed, such as reverse transcription-polymerase chain technique (RT-PCR). In order to assess the suitability of RT-PCR based approaches during human retinal development and to gain insight into the developmental progression of photoreceptor differentiation and maturation in the human, we analyzed the expression of several photoreceptor-associated genes by immunocytochemical labeling (ICC) of the foveal region as well as by RT-PCR of total RNA from whole fetal eyes from different developmental stages. METHODS: Expression of phosphodiesterase beta (PDEB), interphotoreceptor binding protein (IRBP), tubby-like protein (TULP), short wavelength specific (S) opsin, long and medium wavelength specific (L/M) opsin, rod opsin and the transcription factors Crx and Nrl were assessed by RT-PCR from total RNA prepared from snap frozen intact human fetal eyes ranging from fetal week 9 (Fwk 9) to Fwk 18. ICC labeling was performed in a large number of eyes within an age group for IRBP, TULP, Nrl, S opsin, L/M opsin and rod opsin on frozen sections that included the fovea centralis. RESULTS: All ICC markers appeared first in or around the fovea. We detected PDEB and Crx expression as early as Fwk 10, by RT-PCR. TULP and IRBP were first observed with ICC in a small number of foveal cones at Fwk 9, although the first transcripts were not detected until Fwk 12. Nrl-positive nuclei appeared around the fovea by Fwk 11 and S opsin-positive cones by Fwk 12. L/M opsin-positive cones and rod opsin-positive rods were first detected between Fwk 15-16. In general, ICC labeling in the fovea was present for most genes up to 2 weeks before the corresponding transcripts could be successfully amplified by RT-PCR from whole eye tissue. CONCLUSIONS: Our results indicate that in order to pinpoint exactly when and where a molecule appears, ICC labeling of the fovea is a more reliable indicator. RT-PCR was prone to underestimate the exact onset of expression of the molecules tested, yet it faithfully recapitulated the sequence in which they appeared. In addition, our data show that in the human fetal retina, Crx and Nrl are both expressed when the first rod photoreceptors are being generated. This agrees well with previous in vitro results suggesting a synergistic action of both proteins during differentiation of human rod photoreceptors.

Biomarkers↗
PubMed1997

Difference in hepatic metallothionein content in Antarctic red-blooded and haemoglobinless fish: undetectable metallothionein levels in haemoglobinless fish is accompanied by accumulation of untranslated metallothionein mRNA.

Icefish (family Channichthyidae, suborder Nothothenioidei) are a group of Antarctic fish that have evolved unique phenotypes in order to adapt to the environment in which they live. Besides the lack of haemoglobin and the drastic reduction in the number of erythrocyte-like cells, another striking feature of the icefish is that their liver is devoid of metallothionein. These cysteine-rich heavy-metal-binding proteins are usually present in large amounts in a large variety of organisms, from bacteria to mammals. Despite the failure to detect appreciable levels of metallothionein in icefish liver, a cDNA encoding metallothionein was produced from total RNA by reverse transcriptase PCR. The icefish metallothionein showed high percentage identity with metallothionein from Trematomus bernachii, a red-blooded Antarctic fish in which a normal content of hepatic metallothionein was found. Steady-state mRNA levels were assessed in fish liver by high-stringency hybridization of the metallothionein probe with total RNA. The results showed that icefish livers retain large amounts of untranslated metallothionein mRNA. The stability of the icefish transcript might be correlated with the lack of specific motifs in the untranslated 3' ends of mRNA.

Adaptation, Physiological↗
PubMed2003

Identification of a high-affinity phosphate transporter gene in a prasinophyte alga, Tetraselmis chui, and its expression under nutrient limitation.

A high-affinity phosphate transporter gene, TcPHO, was isolated from a growth-dependent subtracted cDNA library of the marine unicellular alga Tetraselmis chui. The full-length cDNA of TcPHO obtained by 5' and 3' rapid amplification of cDNA ends was 1,993 bp long and encoded an open reading frame consisting of 610 amino acids. The deduced amino acid sequence of TcPHO exhibited 51.6 and 49.8% similarity to the amino acid sequences of PHO89 from Saccharomyces cerevisiae and PHO4 from Neurospora crassa, respectively. In addition, hydrophobicity and secondary structure analyses revealed 12 conserved transmembrane domains that were the same as those found in PHO89 and PHO4. The expression of TcPHO mRNA was dependent on phosphate availability. With a low-phosphate treatment, the TcPHO mRNA concentration increased sharply to 2.72 fmol micro g of total RNA(-1) from day 1 to day 2 and remained at this high level from days 2 to 4. Furthermore, rescue treatment with either phosphate or p-nitrophenyl phosphate effectively inhibited TcPHO mRNA expression. In contrast, TcPHO mRNA expression stayed at a low level (range, 0.25 to 0.28 fmol micro g of total RNA(-1)) under low-nitrate conditions. The expression pattern suggests that TcPHO can be used as a molecular probe for monitoring phosphorus stress in T. chui.

Algal Proteins↗
PubMed1997

Transient upregulation of IGF-I gene expression in brown adipose tissue of cold-exposed rats.

The possible involvement of locally produced insulin-like growth factor I (IGF-I) in the cold-induced hyperplasia of interscapular brown adipose tissue (BAT) was investigated in 2-, 4-, and 7-day cold-exposed (CE, 4 degrees C) rats by measuring BAT IGF-I expression at a time when extensive BAT cell proliferation occurs. By comparison with thermoneutral (25 degrees C) controls, plasma IGF-I decreased in CE rats despite an increased food intake, whereas BAT IGF-I peptide increased markedly to peak after 4 days at 4 degrees C. The ratio of class 1 to class 2 IGF-I mRNA was much higher in BAT than in liver. BAT IGF-I mRNA levels per unit weight total RNA doubled after 2 days at 4 degrees C but decreased thereafter to the level in controls. Upregulation of BAT IGF-I mRNA also occurred in CE rats with a food intake restricted to the level of controls. The transient cold-induced upregulation of BAT IGF-I (per unit weight total RNA) suggests that IGF-I plays a role in the early cold-induced BAT hyperplasia that occurs in vivo.

Adipose Tissue, Brown↗
PubMed1996

Determination of apolipoprotein mRNA levels by ribonuclease protection assay.

The ribonuclease protection assay procedure described enables the relative quantitation of either single mRNAs or multiple mRNA species simultaneously in a sample of total RNA and demonstrates its applicability to two systems of relevance to the study of apolipoproteins, namely, liver tissue and liver-derived cell lines in culture. The main requirements of the method are the availability of cDNA cloned into a vector that directs the transcription of antisense RNA for the preparation of radioactive probes, and choice of suitable restriction endonuclease sites for linearizing the cDNA so that the final protected products of the various mRNA species are sufficiently different in size to allow their separation. For moderately abundant apolipoprotein mRNAs in rat liver, the method is sensitive down to 1 microgram total RNA. Other experimental sources of RNA or the assay of less abundant mRNA species may require a larger amount of starting material. These aspects of the assay need to be determined for each probe/ tissue system to be studied. The need for adjustments to the specific radioactivity of the probes will depend on the relative abundance of the target mRNA molecules and can be readily determined empirically. The rationale for varying the specific radioactivities to facilitate multiple assays as suggested here is both simple and effective. A preliminary assay provides information on the relative levels of the mRNA species of interest, and the step of preparing, in parallel, a sample of unlabeled antisense RNA provides the means for quantitative dilution of specific radioactivity of the 32P-labeled RNA probe where required.

Animals↗
PubMed1996

Expression of biglycan, decorin and fibromodulin in the hypertrophic phase of experimental osteoarthritis.

This study sought to assess the relative levels of the mRNAs of the core proteins of the small proteoglycans (PGs) biglycan, decorin and fibromodulin in the hypertrophic phase of the early osteoarthritis (OA) that follows joint injury. Experimental OA was induced in eight dogs by transection of the anterior cruciate ligament. Articular cartilage was harvested from each joint, the total RNA was extracted and the concentration of DNA in the cartilage was measured. The relative levels of mRNA for biglycan, decorin and fibromodulin were assessed by northern blot analyses. An increase in cartilage mass with no increase in DNA concentration confirmed that the joints were in the hypertrophic phase that follows joint injury. The total RNA per microgram of DNA was increased 2.5 times. Compared with control cartilage, the mRNA levels in osteoarthritic cartilage, when normalized to the concentration of DNA, were increased 3.9 times for biglycan, 1.2 times for decorin and 2.4 times for fibromodulin. Because these small PGs affect collagen fibrillogenesis in vitro, their discoordinate metabolism may contribute to the abnormal collagen formation and deposition that occurs in OA and to the ultimate failure of the articular cartilage.

Animals↗
PubMed2001

High stability of mRNAs postmortem and protocols for their assessment by RT-PCR.

Measurement of gene expression is a major area of brain research. We report on the remarkable postmortem stability of a selection of brain mRNAs in both fresh and frozen brain tissue. We describe techniques for extracting total RNA, synthesizing cDNAs from the mRNAs, amplifying specific cDNAs by the polymerase chain reaction technique, and quantitating the products. We chose five genes to study: the housekeeping gene cyclophilin; the complement components C3 and C4; the microtubule associated protein-2 (MAP-2); and the strongly inducible cyclooxygenase COX-2. We found little deterioration in total RNA or in any of the mRNAs in postmortem tissue up to 96 h. When tissue was frozen, stored at -70 degrees C for 15 years and then thawed, there was no evidence of deterioration from storage, but there was gradual deterioration post thawing. All the mRNAs were stable for 1-2 h at 4 degrees C following thawing. Cyclophilin, C3 and C4 mRNAs were still stable after 8 h, MAP-2 and COX-2 mRNAs showed significant deterioration between 2 and 4 h, and COX-2 mRNA showed drastic deterioration between 4 and 8 h. The data give no indication of rapid postmortem degeneration of RNA. Reliable mRNA values may be obtained from postmortem brain with long autolysis times provided the tissue has been kept in the cold, and from frozen tissues for 1-2 h after thawing.

Alzheimer Disease↗
PubMed1985

Control of insulin gene expression in pancreatic beta-cells and in an insulin-producing cell line, RIN-5F cells. I. Effects of glucose and cyclic AMP on the transcription of insulin mRNA.

To define the mechanism whereby glucose regulates islet insulin mRNA content, insulin gene transcription rates were determined in islets labeled with [3H]uridine at low (3.3) or high (17 mM) glucose. Glucose stimulated the transcription of total RNA almost 2-fold and insulin mRNA 5.6-fold. Addition of dibutyryl cAMP to islets in vitro could partially mimic the effect of glucose on insulin gene-specific transcription. In the insulin-producing RIN-5F cell line, glucose did not affect transcription, while cholera toxin acted as a secretagogue and increased total RNA and insulin gene-specific transcription as well. We conclude that glucose exerts a specific stimulatory effect on the transcription of the insulin gene(s) in normal islets and that this effect may be mediated in part by cAMP.

Animals↗
PubMed1989

Expression of two actin genes during larval development in the sea urchin Strongylocentrotus purpuratus.

We report the first measurements of cell number, total RNA, and transcript accumulations for two actin genes during larval development of the sea urchin Strongylocentrotus purpuratus. At 5 weeks of feeding, when development of laboratory-raised larvae is completed, the cell number has increased about 100-fold with respect to the pluteus-stage embryo to about 150,000 +/- 50,000, and the total RNA has increased 46-fold to about 130 ng per larva. The transcripts of the Cylla cytoskeletal actin gene, which is expressed in adult tissues, continue to accumulate throughout larval development. A contrasting pattern of transcript accumulation is observed for Cyllla, a different cytoskeletal actin gene that in the embryo is expressed only in aboral ectoderm. These transcripts increase in number early in larval development, when the larval epidermis is differentiating, and then decline in quantity. It is known that at metamorphosis the larval epidermis is largely histolyzed and that the Cyllla gene is not expressed in the juvenile or adult.

Actins↗
PubMed2002

Real-time PCR provides evidence for thyrotropin receptor mRNA expression in orbital as well as in extraorbital tissues.

OBJECTIVE: The TSH receptor (TSHr) expressed on thyroid follicular cells is the autoantigen involved in the pathogenesis of Graves' hyperthyroidism. Whether this receptor is expressed in extrathyroidal tissues, and whether it participates directly in the pathogenesis of thyroid-associated ophthalmopathy (TAO) is unclear. DESIGN: The aim of the present study was to measure TSHr mRNA in retro-orbital tissues, retro-orbital adipose tissue, extraocular muscle, and skin from patients with TAO and in several tissues from patients not affected by thyroid diseases using RT-PCR and real-time PCR. METHODS: Total RNA was isolated from tissue specimens, reverse transcribed, and amplified using specific primers for the extracellular portion and a part of a 1.3 kbp variant form of the TSHr gene. Determination of TSHr mRNA levels using real-time PCR was also performed by the TaqMan system; to normalize for differences in the amount of total RNA added to the reaction, amplification of beta-actin gene was performed as an endogenous control. RESULTS: A single-round RT-PCR amplification using specific primers for the extracellular portion of the TSHr gene demonstrated an amplification product of 1.2 kbp in the thyroid, but not in all other tissues. A second-round RT-PCR amplification using the same primers and starting from the previous amplification product demonstrated a band of the size expected for the TSHr gene in all tissue specimens analyzed irrespective of their origin. Similar results were obtained using primers specific for a part of the variant form of 1.3 kbp of the TSHr gene. The amount of TSHr mRNA measured by real-time PCR with the TaqMan probe and expressed as TSHr/beta-actin ratio was similar in the tissues from TAO patients with respect to the tissues from subjects not affected by thyroid diseases. CONCLUSIONS: We measured TSHr mRNA in tissues from patients with TAO using the very sensitive and quantitative method of real-time PCR. The level of transcription was similar to that measured in extraorbital tissues from patients who were not affected by thyroid diseases. These data suggest an illegitimate TSHr mRNA transcription in all the tissues examined apart from thyroid.

Adipose Tissue↗
PubMed1993

Changes in ribosomal protein and ribosomal RNA synthesis during rat intestinal differentiation.

Subtraction hybridization studies, used to identify genes involved in the control of enterocyte proliferation and/or differentiation, allowed detection of a clone shown to have homologies with rat, chicken, and human acidic ribosomal phosphoprotein P1. Since increases in P1 transcript have been associated with intestinal malignancy, we explored the relationship of P1 and other ribosomal proteins to normal intestinal proliferation and differentiation. Male rats were used to prepare enterocytes as isolated cell fractions representative of the crypt to villus axis of differentiation. Total RNA was extracted from pooled cell fractions and evaluated for mRNA and rRNA steady-state levels. Nuclei were prepared from isolated enterocytes, and nuclear runoff studies were performed to estimate rates of nascent transcription. The P1 complementary DNA from the crypt cell library detected a mRNA of 650 base pairs which showed approximately 8-fold greater steady-state levels in crypt than in villus cells. Similar crypt specificity was also noted for mRNAs coding for elongation factor EF-12 and for ribosomal proteins P0, P1, and S6 (using clones from Y-L. Chan and I. G. Wool). In contrast, 28S rRNA steady-state levels did not differ between villus and crypt, indicating that ribosomal content had remained constant. In situ hybridization studies confirmed the predominant crypt localization of P1 mRNA. Nascent transcription rate studies showed that the proportion of newly synthesized P1 mRNA to total RNA was the same for the villus and crypt, suggesting that the lower content of villus P1 mRNA may be due to increased degradation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

Detection of cancer cells in peripheral blood of breast cancer patients using reverse transcription-polymerase chain reaction for epidermal growth factor receptor.

The epidermal growth factor receptor (EGFR) has been reported to be expressed in high levels in primary breast cancer by immunohistochemistry. In the present study, a reverse transcription (RT)-PCR assay using EGFR primers was developed and evaluated for the detection of circulating micrometastases in the blood of breast cancer patients. Total RNA was extracted from breast cancer cell lines and from the blood of 23 control individuals and 37 breast cancer patients. After reverse transcription, outer and nested primers for EGFR were used for cDNA amplification. RNA integrity was confirmed with parallel RT-PCR amplification using beta2-microglobulin primers. PCR products were electrophoresed on agarose gels containing ethidium bromide and visualized by UV photography. Southern blotting was used to confirm EGFR specificity. The nested EGFR RT-PCR assay was capable of detecting a lower limit of 100 fg of total RNA from the A431 cell line. EGFR RNA was identified from the blood of 4 of 18 (22%) metastatic breast cancer patients, 0 of 6 locally recurrent breast cancer patients, 0 of 13 adjuvant breast cancer patients, and 0 of 23 controls (P = 0.03, metastatic versus control). The 18 metastatic breast cancer patients all had progressive disease at the time of blood sampling. The identity of the four EGFR-positive bands was confirmed by Southern blotting. The presence of RT-PCR positivity for EGFR was not a treatment-related phenomenon, because three of the four EGFR-positive patients were not receiving treatment at the time of blood collection. RT-PCR for EGFR is a sensitive and specific method for the detection of circulating micrometastases in a proportion of patients with metastatic breast cancer.

Biomarkers, Tumor↗
PubMed1988

Ethanol-induced inhibition of liver cell function: I. Effect of ethanol on hormone stimulated hepatocyte DNA synthesis and the role of ethanol metabolism.

We have studied a short term effect (96 hr) of ethanol on hormone-stimulated DNA synthesis in a primary rat hepatocyte culture system. Studies were also performed with respect to total RNA and protein synthesis as well as albumin secretion measured by a solid-phase radioimmunoassay. We found that ethanol, when added to cultured hepatocytes, resulted in a substantial reduction in hormone-stimulated hepatocyte DNA synthesis and this effect was concentration dependent and occurred in serum-free medium. Ethanol also had an inhibitory effect on total RNA synthesis but protein synthesis and albumin secretion remained essentially unchanged. We determined that hepatocytes exposed to ethanol during the first 24 hr of culture were the most susceptible to inhibition of DNA synthesis. During the first 24 hr, alcohol dehydrogenase (ADH) activity was present in the cells at higher levels than at 48 and 72 hr. In human hepatoma cell lines and differentiated primary and secondary chick fibroblasts, no ADH activity was demonstrable; such cells were not inhibited by 100 mM ethanol additions and DNA synthesis rates were similar to untreated cultures. Other alcohols found to be metabolized by hepatocyte ADH were inhibitory towards hormone-stimulated DNA synthesis whereas those with less metabolism had little effect. Hepatocytes treated with 4-methylpyrazole, an inhibitor of ADH, were partially protected from ethanol effects. Taken together our results are consistent with the hypothesis that a major physiological effect of ethanol on the hepatocyte is a direct impairment of DNA synthesis and that alcohol metabolism is required.

Alcohol Dehydrogenase↗
PubMedDate not supplied

[Identification of the mRNA of the nucleocapsid proteins of pathogenic arenaviruses].

Total RNA from cells infected with Machupo and Lassa viruses as well as individual sedimentation classes of these RNAs were translated in the cell-free protein-synthesizing system from rabbit reticulocytes. The translation products were precipitated either with anti-Machupo immune gamma-globulin or monoclonal antibodies to nucleocapsid protein (NP) of Lassa virus. Both total RNA and RNA fraction with the sedimentation coefficient 15-16S promoted the synthesis of protein which comigrated in gel with NP protein of purified virions. It is concluded that monocistron mRNA for NP protein of arenaviruses has the sedimentation coefficient 15-16 S.

Animals↗
PubMed1996

Tissue distribution and quantitation of a gene expressing a 64-kDa antigen associated with thyroid-associated ophthalmopathy.

We have developed a competitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the quantitation of 1D mRNA, which encodes a 64-kDa protein associated with thyroid-associated ophthalmopathy, in preparations of total RNA from a variety of human tissues. This competitive RT-PCR assay is based on coamplification of competing 1D cDNA internal control template (pGEM-1D') and target cDNA template. 1D-specific mRNA was quantified in 10 human tissues. The level of 1D transcript expression in these tissues decreased in the following order: thyroid (5 pg/mg total RNA) > eye muscle (3.2 pg/mg) > skeletal muscle (2.4 pg/mg) > ovary (2 pg/mg) > cerebellum (0.4 pg/mg), kidney (0.33 pg/mg), pancreas (0.27 pg/mg), spleen (0.22 pg/mg), and thymus (0.19 pg/microgram) > retina (0.016 pg/mg). Graves' disease may be a multisystem autoimmune disorder of the connective tissue and skeletal muscle (and thyroid) that is mainly localized in the orbit and skin. One mechanism for this localization may be increased expression of target autoantigens, of which the 64-kDa protein 1D is a candidate, in the involved tissues. The higher expression of the 1D molecule in thyroid and eye supports this hypothesis.

Animals↗
PubMed1994

Expression of mRNA for matrix gamma-carboxyglutamic acid protein during progression of atherosclerosis in aortae of Watanabe heritable hyperlipidemic rabbits.

In an effort to characterize mRNAs that are highly expressed during atherosclerosis, we employed differential hybridization screening of a cDNA library constructed from total RNA derived from the aorta of Watanabe heritable hyperlipidemic (WHHL) rabbits. Characterizing the cDNAs for mRNAs that are present in large amounts in WHHL rabbit aortae, we identified a positive clone encoding matrix gamma-carboxyglutamic acid protein (MGP). The primary structure of rabbit MGP was deduced from nucleotide sequence analysis of the cDNA. Northern blot analysis of total RNA prepared from aortae of WHHL and normal rabbits of various ages indicated that the expression of MGP mRNA increased in proportion to the progression of atherosclerosis in WHHL rabbits. Analysis of MGP mRNA by in situ hybridization revealed that a significant amount of MGP mRNA is accumulated in atherosclerotic lesions of WHHL rabbits, suggesting that the expression of MGP mRNA is correlated with the progression of atherosclerosis.

Amino Acid Sequence↗
PubMed2006

[Screen of inflammatory genes regulated by heat shock factor 1 and corroboration with SOCS3 gene].

OBJECTIVE: To screen the inflammatory mediators genes regulated by HSF1, and explore the mechanism of downstream genes regulated by HSF1. METHODS: HSF-/- and HSF1+/+ mice were injected with 15 mg/kg LPS intraperitoneally (ip), respectively, and were treated as previous after HSR. The total RNA of lung tissues were extracted and filtrated by SuperArray gene Microarry. The promoter of candidate genes were analyzed by transcription element search software to search for heat shock element (HSE). Select the suppressor of cytokine signaling 3 (SOCS3) with HSE. Macrophage cells were stimulated with 400 ng/mL LPS, and were treated as previous after HSR, then the total RNA was extracted respectively. RT-PCR and northern blot assay were performed to detect the expression levels of SOCS3 mRNA. RESULTS: Fifteen genes were repressed by HSF1, including 9 genes with complete HSE. Eleven genes were accelerated by HSF1 possibly, including 8 genes with complete HSE. The promoter of SOCS3 gene contained one complete HSE. LPS stimulation obviously increased the levels of SOCS3 mRNA in macrophages of RAW264.7 mice, which was inhibited by HSR and over-expression of HSF1. CONCLUSION: HSR or HSF1 inhibits LPS induced expression of SOCS3 mRNA; HSF1 might inhibit LPS-induced expression of SOCS3 mRNA by binding to HSE in the promoter of SOCS3 gene.

Animals↗
PubMed2006

Serotonin receptor subtype mRNA expression in human ocular tissues, determined by RT-PCR.

PURPOSE: To determine the relative density and tissue localization of mRNAs for serotonin (5-hydroxytryptamine; 5HT) receptor subtypes in human ocular tissues and correlate with their possible functions in the eye. METHODS: Total RNA was extracted from human ocular tissues samples from multiple donors and transcribed into cDNA. An optimized reverse transcriptase polymerase chain reaction (RT-PCR) procedure was then used to amplify the signals using primers designed against human 5HT receptor cDNAs. The PCR products were analyzed by gel electrophoresis and confirmed by endonuclease digestion. RESULTS: Variable amounts of total RNA were extracted from different tissues with the least amount from ciliary epithelium and most amount from retina. 5HT2 receptor subtype mRNAs were the most abundant with 5HT2A and 5HT2B being the most predominant in the retina, ciliary body, ciliary epithelium, choroid, conjunctiva, and iris. Ciliary body, choroid, and conjunctiva were most enriched in 5HT3 receptor mRNA, with relatively lower levels in the iris. 5HT4 receptor mRNA was most enriched in the retina, ciliary body, choroid, conjunctiva, and somewhat detectable in the iris. 5HT5 receptor mRNA was abundant in the retina, ciliary body, and iris. 5HT6 receptor mRNA was the least abundant of all subtypes studied and could only be detected in the iris. 5HT7 receptor mRNA was enriched in the ciliary body, choroid, conjunctiva, and iris, with much lower levels in the retina and ciliary epithelium. Optic nerve tissue of 1-2 donors exhibited the presence of 5HT2B, 5HT5, and 5HT7 receptor mRNAs. Data for human trabecular meshwork cells indicated a high density of mRNAs for 5HT2A and 5HT2B, with much lower levels of 5HT2C, 5HT5, and 5HT7 receptor mRNAs. CONCLUSIONS: Human ocular tissues differentially expressed mRNAs for the various 5HT receptor subtypes. These studies suggest a diverse range of possible physiological and pharmacological functions of 5HT receptors in these human ocular tissues.

Eye↗