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P H Patterson

Publications and source records attributed to P H Patterson.

At least 19 recordsLinked to original sources
PubMed1995

Differential regulation of motor neuron survival and choline acetyltransferase expression following axotomy.

Although it is well known that motor neuron survival following axotomy is enhanced with maturation, the ability of surviving neurons to express the cholinergic enzyme choline acetyltransferase (ChAT) following axotomy has not ben closely examined. Moreover, the utility of the facial nucleus in studies of motoneuron response to injury and to trophic factors, coupled with the increasing importance of the mouse in gene targeting, compelled us to investigate the age dependence of neuronal survival and ChAT expression in the mouse facial nucleus following axotomy. We cut the facial nerve at postnatal day (P) 4, 7, 14, 21, and 28 or in the adult and used Nissl staining and ChAT immunocytochemistry to quantitate survival and ChAT expression, respectively, following 1, 2, or 3 weeks' survival at each age. We confirm in this model that the rate and extent of motor neuron death following axotomy is reduced with increasing maturity. The surviving neurons maintain a high ChAT content through P21; however, axotomy from P28 through adulthood results in a striking reduction in ChAT immunoreactivity. That is, although axotomy at P21 results in 61% motor neuron survival, with virtually all of the surviving neurons being ChAT positive, axotomy in the adult results in 72% survival but only 9% of the neurons are ChAT positive. Thus, surviving motor neurons in the adult animals are only weakly cholinergic. These results indicate that a change in the regulation of ChAT expression occurs following P21 so that cell survival and enzyme levels are uncoupled. We suggest that the putative factor or factors that enhances motor neuron survival in maturity is not capable of maintaining ChAT expression.

Aging↗
PubMed1995

Adrenal chromaffin cells transdifferentiate in response to basic fibroblast growth factor and show directed outgrowth to a nerve growth factor source in vivo.

Chromaffin cells exposed to basic fibroblast growth factor (bFGF) in vitro express characteristics of sympathetic neurons, extend neurites, and become dependent on nerve growth factor (NGF) for survival. We explored whether the growth factor responsiveness of chromaffin cells could be exploited to enhance the transdifferentiation, neurite outgrowth and functional efficacy of chromaffin cells implanted into rats with unilateral 6-hydroxydopamine lesions. Cografts of neonatal chromaffin cells and fibroblasts genetically modified to produce bFGF were placed into the dopamine-depleted striatum of adult rats. Either control-transfected or NGF-producing fibroblasts were then transplanted 1 mm distal to the cograft. Chromaffin cells transdifferentiated under the influence of bFGF, as indicated by the growth of neurites and the expression of neuron-specific proteins. Distal grafts of NGF-producing fibroblasts successfully induced chromaffin neurites to traverse through the host parenchyma to the NGF source. In the absence of NGF fibroblast grafts, neither neurite extension nor good, long-term survival of the chromaffin-derived neurons was observed. Assessments of apomorphine-induced rotational behavior 2- and 4-weeks postgrafting revealed no behavior improvements in any of the groups. These results indicate that localized sources of growth factors are effective in inducing the transdifferentiation of grafted chromaffin cells as well as the extension of chromaffin-derived neurites into the host parenchyma. Such chromaffin cell-derived neurons are, however, functionally ineffective in this rat model of Parkinson's disease. Whether the lack of behavioral improvement reflected the tropic growth of neurites to an inappropriate striatal region or the noradrenergic nature of the chromaffin cell-derived neurons remains to be clarified. Nonetheless, these results caution that promoting transdifferentiation and neurite extension from engrafted chromaffin cells may not be sufficient to achieve desired functional effects of such grafts.

Adrenal Medulla↗
PubMed1995

CD9 plays a role in Schwann cell migration in vitro.

To identify molecules that regulate Schwann cell migration, we have generated a panel of monoclonal antibodies against Schwann cell surface antigens that modulate Schwann cell migration in in vitro bioassays. One of these antibodies, SMRA1, recognizes a 26 kDa Schwann cell surface membrane protein identified here as CD9. SMRA1 enhances Schwann cell migration on two biologically relevant substrates: living axons of cultured dorsal root ganglion neurons, and cryostat sections of sciatic nerve. This CD9-induced regulation of Schwann cell motility is correlated with a rise in cytosolic calcium and enhanced tyrosine phosphorylation of several Schwann cell proteins. These results, together with the findings of Hadjiargyrou and Patterson (1994), implicate CD9 as an important regulator of Schwann cell behavior in peripheral nerve.

Animals↗
PubMed1995

FORSE-1: a positionally regulated epitope in the developing rat central nervous system.

We designed a protocol to identify cell surface molecules expressed in restricted spatial patterns in the developing central nervous system (CNS) that might be regulated by regionally restricted transcription factors. The immunogen was a membrane fraction from NT2/D1 embryocarcinoma cells that were induced to differentiate into neurons and upregulate Hox gene expression in response to retinoic acid. One monoclonal antibody (mAb), FORSE-1, specifically labels the rostral rat CNS from the earliest stages. Staining is observed in the rostral but not caudal neural folds of the embryo prior to neural tube closure. Staining is enriched in the forebrain as compared to the rest of the CNS, until E18. Between E11.5 and E13.5, only certain areas of the telencephalon and diencephalon are labeled. Later, up to E17.5, FORSE-1 labeling is specifically restricted to the telencephalon, where a correlation with mitotic activity is apparent: the ventricular zone labels with FORSE-1, while the cortical plate is negative. The staining of the neuroepithelium is intensified by acetone fixation, which also reveals, between E11.5 and E13.5, a dorsoventrally restricted, FORSE-1-positive region of the spinal cord. After E18, the entire CNS is labeled, through adulthood. The mAb labels the surfaces of dissociated, living cells. Other, non-CNS areas of FORSE-1 labeling are nasal and otic placodes, nasal epithelium, nasal glands, and early (E9.5-10.5) endoderm. mAb FORSE-1 recognizes an epitope present on both a high-molecular-weight (> 200 kDa) proteoglycan from embryonic and early postnatal brain, and on a 80 kDa doublet that is restricted to the CNS in the adult. These findings suggest the FORSE-1 antigen as a candidate cell surface molecule for mediating regional specification from the earliest stages of CNS development.

Acetone↗
PubMed1995

CD9, a major platelet cell surface glycoprotein, is a ROCA antigen and is expressed in the nervous system.

We previously generated a monoclonal antibody (mAb), ROCA1, which binds preferentially to rostral versus caudal sympathetic ganglia and intercostal nerves. Two other mAbs, ROCA2 and B2C11, bind to the same structures but not in rostrocaudal gradients. All three mAbs recognize a 26 kDa cell surface protein. Amino acid sequence data obtained from the affinity purified 26 kDa protein showed some homology with human CD9, a tetraspan protein implicated in intercellular signaling in hematopoietic cells. Using the PCR, we obtained cDNA clones representing the entire rat CD9 coding sequence from sciatic nerve and sympathetic ganglia. ROCA1, ROCA2, and B2C11 each immunoprecipitate a 26 kDa protein from CHO cells stably transfected with one of the clones, demonstrating that the ROCA cell surface antigen is indeed rat CD9. We find that CD9 mRNA is widely expressed, with particularly high levels present in a number of neural tissues. In situ hybridization demonstrates that peripheral neurons and Schwann cells, as well as adrenal chromaffin cells express CD9 mRNA. Consistent with immunoblot analyses showing that, unlike the ROCA1 epitope, the 26 kDa protein is not expressed in a rostrocaudal gradient, we find similar levels of rat CD9 mRNA in rostral and caudal intercostal nerves. In developing postnatal rat sciatic nerve, CD9 mRNA levels are coordinately regulated with the expression of myelin genes. These results provide another example of a cell surface protein expressed by both hematopoietic and neural cells, and suggest a role for CD9 in intercellular signaling in the nervous system.

Aging↗
PubMed1995

An anti-CD9 monoclonal antibody promotes adhesion and induces proliferation of Schwann cells in vitro.

We have recently found that CD9, a cell surface glycoprotein involved in intercellular signaling in hematopoietic cells, is also expressed by neurons and glia in the peripheral nervous system. Antibody perturbation experiments were conducted to examine the function of CD9 in neural cells. Three anti-CD9 monoclonal antibodies (mAbs) (ROCA1, ROCA2, B2C11) were tested for their ability to promote adhesion of several Schwann cell lines (S-16, RN22, JS1), primary Schwann cells and PC12 cells. Only B2C11 promotes adhesion in all cells tested. Although ROCA2 immunolabels living cells strongly, it had no effect on the adhesion of any of these cells. In addition, ROCA1 and several positive-staining, control mAbs also had no effect. Another mAb, 192-IgG, directed against the low affinity NGF receptor, also promotes the adhesion of S-16, PC12, and primary Schwann cells. In addition to adhesion, contact of S-16 Schwann cells with B2C11 specifically induces morphological changes and robust proliferation. None of the other mAbs, including 192-IgG, induce proliferation of S-16 cells. These results provide evidence that CD9 may be involved in signaling, activation and growth regulation of cells in the nervous system.

Animals↗
PubMed1995

Enhanced survival and neuronal differentiation of adrenal chromaffin cells cografted into the striatum with NGF-producing fibroblasts.

Although adrenal medullary chromaffin cells have been used extensively for intracerebral grafting, their survival has generally been poor. Improved survival of the implanted cells has been achieved by exposing the chromaffin cells to NGF in vivo. Culture studies have shown, however, that chromaffin cells are converted into sympathetic neurons when NGF is included in the medium. The degree to which such a transdifferentiation may occur in vivo has not been determined. We assessed the effects of cografting chromaffin cells with primary fibroblasts genetically engineered to express NGF. Chromaffin cells from 10 d old rats were implanted with NGF-producing or beta-galactosidase-producing primary fibroblasts (control fibroblasts) into the striatum of 6-hydroxydopamine treated adult rats of the same strain. Eight weeks postgrafting, chromaffin cells cografted with NGF-producing fibroblasts displayed many of the features of mature sympathetic neurons such as large somata, long processes, transmitter vesicles similar to those found in neurons, and positive immunolabeling for the neuronal markers neurofilament, MAP2 and SCG10. Chromaffin-derived neuron number was also significantly enhanced in the presence of NGF-producing fibroblasts. While control fibroblasts were also found to increase chromaffin cell number above that of chromaffin cells grafted alone, the control fibroblasts did not induce neuronal transdifferentiation. These results demonstrate that chromaffin cells cografted with NGF-producing fibroblasts undergo transdifferentiation in vivo and express many characteristics of mature sympathetic neurons. The consequences of this transdifferentiation on the long term survival and function of the transplanted cells in vivo remain to be clarified.

Adrenal Glands↗
PubMed1995

Regionalization of the developing forebrain: a comparison of FORSE-1, Dlx-2, and BF-1.

The FORSE-1 monoclonal antibody (mAb) was generated using a strategy designed to produce mAbs against neuronal cell surface antigens that might be regulated by regionally restricted transcription factors in the developing CNS. To determine whether FORSE-1 has a labeling pattern similar to that of known transcription factors, the expression of BF-1 and Dlx-2 was examined by in situ hybridization on sections serial to those labeled with FORSE-1. We find a striking overlap between BF-1 and FORSE-1 in the telencephalon; both are expressed in the lateral but not the medial walls of the telencephalon, and the boundaries of expression are apparently identical. FORSE-1 staining is detected prior to BF-1 expression in the neural tube, however. FORSE-1 and Dlx-2 have very different patterns of expression in the forebrain, suggesting that regulation by Dlx-2 cannot by itself explain the distribution of FORSE-1. However, they share some sharp boundaries in the diencephalon. In addition, FORSE-1 identifies some previously unknown boundaries in the developing forebrain. These results indicate that a new cell surface marker can be used to subdivide the embryonic telencephalon and diencephalon into regions smaller than previously described, providing necessary complexity to the developmental patterning in the forebrain.

Animals↗
PubMed1994

Major changes in the expression of the mRNAs for cholinergic differentiation factor/leukemia inhibitory factor and its receptor after injury to adult peripheral nerves and ganglia.

The neuropoietic cytokine cholinergic differentiation factor/leukemia inhibitory factor (CDF/LIF) acts as a trophic factor, enhancing neuronal survival, and as a differentiation factor, altering neuronal gene expression. There is also evidence that its plays a role in the response of adult neural tissue to injury. We have examined this possibility further in rats by analyzing changes in the levels of mRNAs for CDF/LIF and its two receptor subunits in response to peripheral nerve damage in culture and in vivo. Using a quantitative RNase protection assay, we find that CDF/LIF mRNA increases dramatically (176-fold) in adult, but not neonatal, sympathetic ganglia and in adult dorsal root ganglia and sciatic nerve after organ culture for 24 hr. This mRNA is clearly detectable by in situ hybridization only in the nonneuronal cells of these structures. When the sciatic nerve is transected in vivo, CDF/LIF mRNA increases significantly in the regions immediately proximal and distal to the lesion site. The mRNA for the ligand binding subunit of the CDF/LIF receptor complex decreases somewhat upon culture and nerve section. The dramatic rise in CDF/LIF mRNA after nerve injury is further evidence that this cytokine is involved in the response to damage, a function that overlaps with its postulated role in wounding or infection in several nonneural tissues.

Animals↗
PubMed1994

Neuropoietic cytokines and activin A differentially regulate the phenotype of cultured sympathetic neurons.

A number of cytokines sharing limited sequence homology have been grouped as a family because of partially overlapping biological activities, receptor subunit promiscuity, and the prediction of a shared secondary structure. Since several of these cytokines regulate gene expression and cell number in the nervous and hematopoietic systems, this specific group is termed the neuropoietic cytokine family. Using a reverse transcription-polymerase chain reaction-based assay system for monitoring the expression of multiple phenotypic markers in cultured sympathetic neurons, we present further evidence that, in addition to cholinergic differentiation factor/leukemia inhibitory factor and ciliary neurotrophic factor, oncostatin M, growth promoting activity, interleukin 6, and interleukin 11 belong in this family. In addition, one member of the transforming growth factor beta superfamily, activin A, shares a selective overlap with the neuropoietic family in the spectrum of neuropeptides that it induces in sympathetic neurons. The particular neuropeptides induced by activin A, however, demonstrate that the activity of this cytokine is distinct from that of the neuropoietic family. Twenty-six other cytokines and growth factors were without detectable activity in this assay.

Activins↗
PubMed1994

The molecular basis of retinotectal topography.

Over 50 years have passed since Roger Sperry formulated a simple model of how visual space, as seen by the retina, can be projected onto the brain in a two-dimensional, topographic map during development. Sperry posited a set of two orthogonal gradients in the retina that gives each cell a positional identity. He further suggested that these molecules could be used to match up with complementary gradients in the target field of the retinal projection, the tectum. While some investigators hold that the existence of such molecules may not be necessary to establish retinotectal maps, recent work has identified several cell surface proteins whose distributions are of the type predicted by Sperry. An unexpected twist comes from culture assays demonstrating that inhibitory activities on tectal membranes can guide the growth of processes from retinal neurons. Moreover, the expression patterns of several enzymes and three transcription factors suggest that these proteins are candidates for regulatory agents in the determination of cell position in the retina. In addition, results from perturbation experiments support the candidacy of two of the enzymes, and a new mutant screen has uncovered several as yet unidentified genes that are required for establishment of the proper retinotectal map. A number of these results were presented at a recent meeting on neurospecificity held in Cargese, Corsica and sponsored by NATO and NSF.

Animals↗
PubMed1994

Energy metabolism in isolated chick (Gallus domesticus) gastrocnemius and tilapia (Tilapia mossambica) epaxial muscle at various temperatures in vitro.

Muscle respiration experiments on inhibitor dosage (experiment 1), muscle preparation (tendons removed vs. unstretched vs. stretched muscles; chick muscle only; experiment 2) and media temperature (26.5, 32, 37, 42 degrees C; experiment 3) were conducted on chick (Gallus domesticus) gastrocnemius and tilapia (Tilapia mossambica) epaxial muscle in vitro. Experiment 1: The dosage of cycloheximide and ouabain required for maximum inhibition of protein synthesis and Na+,K+ ATPase, respectively, in chick and tilapia muscle was approximately 6 x 10(-5) M. Experiment 2: Removing the tendons of chick muscle decreased (% inhibition, P = 0.05) cycloheximide-sensitive respiration compared to stretched and unstretched muscles (tendons intact). However, muscle preparation had little influence on ouabain-sensitive respiration. Experiment 3: Cycloheximide-sensitive respiration tended to increase (microliter O2/mg DNA.hr, P = 0.054) with media temperature in tilapia muscle. Chick muscle was less responsive in this respect. Ouabain-sensitive respiration increased at lower temperature in chick muscle (% inhibition, cubic relationship, P = 0.001) and at higher temperature in tilapia muscle (% inhibition, quadratic relationship, P = 0.0002).

Animals↗
PubMed1994

Depolarization differentially regulates the effects of bone morphogenetic protein (BMP)-2, BMP-6, and activin A on sympathetic neuronal phenotype.

As a first step in defining the role of the transforming growth factor-beta (TGF-beta) superfamily in the development of the sympathetic nervous system, we analyzed effects of several members of this family on neuronal gene expression in dissociated cell culture using a reverse transcription-polymerase chain reaction method. We found that, in addition to activin A, bone morphogenetic protein (BMP)-2 and BMP-6 also induce mRNAs for distinct sets of neuropeptides and neurotransmitter synthetic enzymes in sympathetic neurons. TGF-beta 1 and TGF-beta 3 are, however, without detectable effect in this assay. Surprisingly, we find that the patterns of neuropeptide genes induced by activin A, BMP-2, and BMP-6 are each affected differently by neuronal depolarization. Depolarization can either promote or block the effects of different cytokines on the same neuropeptide gene, and depolarization can either promote or block the effects of a given cytokine on different neuropeptide genes. This evidence suggests that neuronal activity may be a key mediator of cytokine modulation of neuronal gene expression.

Activins↗
PubMed1994

Intratracheal injection of LPS and cytokines. V. LPS induces expression of LIF and LIF inhibits acute inflammation.

Lipopolysaccharide (LPS) injected into the trachea of rats was found to induce the secretion of leukemia inhibitory factor (LIF) into bronchoalveolar lavage (BAL) fluid with a maximum expression of LIF after 2-12 h. The acute pulmonary neutrophilic inflammation caused by the intratracheal injection of bacterial endotoxin (LPS) could be inhibited by the intratracheal coinjection of recombinant LIF. Compared with intratracheal injection of LPS alone, intratracheal coinjection of LIF and LPS decreases the number of BAL neutrophils obtained 6 h later by approximately 50% (P < 0.0001). LIF decreased the amount of the proinflammatory cytokine tumor necrosis factor (TNF), but not the amount of the anti-inflammatory cytokine interleukin (IL)-6, in the BAL fluid of LPS-injected rats. Similarly, intravenous LIF was found to decrease TNF expression, but increase IL-6 expression, in the serum of rats receiving intravenous LPS. Intravenous LIF, even in the absence of LPS, was found to cause IL-6 expression. In conclusion, intratracheal LPS initiates the secretion of endogenous LIF into the alveolar space where LIF may contribute to the downregulation of LPS-initiated acute neutrophilic inflammation by downregulating expression of TNF. LIF may down-regulate LPS-initiated TNF expression at least in part indirectly by upregulating expression of IL-6, a cytokine known to downregulate LPS-initiated TNF expression.

Acute Disease↗
PubMed1994

Feeding value of poultry by-products extruded with cassava, barley, and wheat middlings for broiler chicks: the effect of ensiling poultry by-products as a preservation method prior to extrusion.

In one experiment, six treatment diets including two levels of cassava meal, barley, or wheat middlings extruded with poultry by-products (PBP; a 3:1 ratio of broiler offal and condemned carcasses) were compared with a corn and soybean meal control diet for broiler performance from 1 d to 3 wk of age. No treatment differences in body weight (P > .05) were observed, and all chicks averaged 166, 421, and 788 g at 1, 2, and 3 wk of age, respectively. Weight gain and feed consumption were not affected by the experimental diets (P < .05). Birds fed the control diet had better overall feed conversion (1.24) than birds fed the diet containing 20% extruded barley and PBP (1.37) (P < .05). Feeding PBP extruded with cassava (10 and 20%) or barley (10%) resulted in equal broiler performance at less cost than birds fed the control diet. In a second experiment, 10% sucrose was mixed with PBP by weight and ensiled for 7 d at ambient temperatures in an anaerobic vessel. Diets containing cassava extruded with fresh and ensiled PBP (FR-PBP and EN-PBP, respectively) were compared with control diets (CON) for broilers to 6 wk of age. No differences in body weight were observed by 6 wk. Feed conversion of the CON birds was poorer than the birds fed the FR-PBP (P < .05). Chilled carcass yield was better for the CON compared with the EN-PBP treatment; however, dietary treatment had no effect on the percentage breast meat, thigh, drumstick, wing, or cage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1994

Comparison of freeze-dried and extruded Spirulina platensis as yolk pigmenting agents.

Experiment 1 was an 8-wk study with Japanese quail fed 0, .5, 1.0, 2.0, and 4.0% of freeze-dried spirulina or the dry equivalent of fresh spirulina extruded with corn. Experiment 2 was a 16-wk repeat of Experiment 1 using levels of 0, .25, .5, 1.0, and 2.0% spirulina. In the third experiment, corn, barley, and cassava were extruded with fresh spirulina equal to 1% of the dried product, and each feedstuff fed with 1% freeze-dried spirulina. Four replicates of five quail were assigned to each treatment. Yolk color increased with increasing dietary levels of spirulina in Experiment 1. There also was a consistent increase in yolk color with freeze-dried spirulina compared with the extruded spirulina. This pattern was also seen in Experiment 2. In addition, eggs from quail fed the extruded corn control diet had markedly lower yolk scores than those from quail fed the untreated corn control diet. The mean Roche yolk color score of eggs from quail fed corn, barley, or cassava extruded with spirulina was 5.91, 3.55, and 6.70, respectively. These values were respectively 1.41, 1.89, and 4.06 units greater than the corresponding control values.

Animals↗
PubMed1993

A modified method for obtaining large amounts of high titer polyclonal ascites fluid.

When limited amounts of antigens are available, it is often difficult to obtain large quantities of polyclonal antisera. Although antisera can be raised in small rodents, yields are usually small. To circumvent these problems, we have designed a modified method for generating polyclonal ascites fluid (AF). Using the appropriate strain of mice and adjuvant, we generated high serum titers by injection of 1-100 micrograms of protein. Following i.p. injection of compatible sarcoma cells, 13-19 ml of high titer (1:1000-1:20,000), polyclonal ascites fluid were obtained from each mouse. Similar results were obtained using nine different antigens.

Adjuvants, Immunologic↗