References

Kato J, O’Donnell RT, Abuhay M, Tuscano JM (2012) Efficacy and toxicity of a CD22-targeted antibody-saporin conjugate in a xenograft model of non-Hodgkin’s lymphoma. Oncoimmunology 1(9):1469-1475. doi: 10.4161/onci.21815

Summary: CD22 is a B-cell-specific antigen found on many B-cell malignancies. It is not expressed by stem cell precursors, and is rapidly internalized when bound by an antibody. In this work, the authors use a custom conjugate of anti-CD22 (mAb HB22.7) and saporin in a cytotoxicity assay on non-Hodgkin’s lymphoma cell lines, as well as in a mouse tumor model. The dosing for the tumor model was 1 mg conjugate per kg of animal. Mouse IgG-SAP (Cat. #IT-18) was used as a control. The results indicate that CD22 is a potential therapeutic target for cancer therapy.

Related Products: Mouse IgG-SAP (Cat. #IT-18), Custom Conjugates

Mittelman-Smith MA, Williams H, Krajewski-Hall SJ, McMullen NT, Rance NE (2012) Role for kisspeptin/neurokinin B/dynorphin (KNDy) neurons in cutaneous vasodilatation and the estrogen modulation of body temperature. Proc Natl Acad Sci U S A 109(48):19846-19851. doi: 10.1073/pnas.1211517109

Summary: Menopause is marked by estrogen withdrawal, and also by hot flushes. Given the fact that hypothalamic levels of kisspeptin/neurokinin B/dynorphin (KNDy) neurons are significantly altered in menopause, the authors investigated whether these neurons are involved in the generation of flushes. Rats received bilateral injections of NK3-SAP (Cat. #IT-63) into the arcuate nucleus – a total of 40 ng. Blank-SAP (Cat. #IT-21) was used as control. The data indicate that KNDy neurons promote cutaneous vasodilation, and play a role in 17β-estradiol modulation of body temperature, supporting the hypothesis that these neurons could play a role in the generation of hot flushes.

Related Products: NKB-SAP (Cat. #IT-63), Blank-SAP (Cat. #IT-21)

Kerbler GM, Hamlin AS, Pannek K, Kurniawan ND, Keller MD, Rose SE, Coulson EJ (2013) Diffusion-weighted magnetic resonance imaging detection of basal forebrain cholinergic degeneration in a mouse model. Neuroimage 66C:133-141. doi: 10.1016/j.neuroimage.2012.10.075

Summary: The authors examined the effectiveness of diffusion MRI using diffusion tensor imaging (DTI) and probabilistic tractography in detecting cholinergic loss in a mouse model. Mice received bilateral 0.2-μg icv injections of mu p75-SAP (Cat. #IT-16). Rabbit IgG-SAP (Cat. #IT-35) was used as control. The animals were then examined using DTI. The data indicate that DTI is a valid technique for assessment of cholinergic loss in septo-hippocampal tracts as a result of Alzheimer’s disease.

Related Products: mu p75-SAP (Cat. #IT-16), Rabbit IgG-SAP (Cat. #IT-35)

Tuscano JM, Kato J, Pearson D, Xiong C, Newell L, Ma Y, Gandara DR, O’Donnell RT (2012) CD22 antigen is broadly expressed on lung cancer cells and is a target for antibody-based therapy. Cancer Res 72(21):5556-5565. doi: 10.1158/0008-5472.CAN-12-0173

Summary: The median overall survival of patients with advanced, unresectable, non-small cell lung cancer is 9-12 mos. A potential therapeutic target is CD22, a protein expressed on lung cancer cells. The authors examined the use of the monoclonal antibody HB22.7 as an antitumor agent. To assess internalization of the antibody, it was first incubated with 10 μg/ml Mab-ZAP (Cat. #IT-04) then applied to two different cancer cell lines in culture. Analysis of cell viability demonstrated that CD22 internalized when bound by the antibody-toxin complex, suggesting that targeting CD22 has therapeutic potential.

Related Products: Mab-ZAP (Cat. #IT-04)

Vetrivelan R, Fuller PM, Yokota S, Lu J, Saper CB (2012) Metabolic effects of chronic sleep restriction in rats. Sleep 35(11):1511-1520. doi: 10.5665/sleep.2200

Summary: In order to investigate whether there is a correlation between sleep and weight the authors administered 200 nl of a 0.1% solution of orexin-SAP (Cat. #IT-20) to the ventrolateral preoptic area of rats. Although the lesioned animals slept less than the controls, weight gain was slower than controls.

Related Products: Orexin-B-SAP (Cat. #IT-20)

Rossi CA, Lehmkuhle MJ, Dudek FE (2012) Evidence that focal hippocampal interneuron loss disrupts theta- and gamma- band activity. Neuroscience 2012 Abstracts 918.06. Society for Neuroscience, New Orleans, LA.

Summary: Hippocampal theta (6-12 Hz) and gamma (40-100 Hz) activity are oscillatory local field potentials (LFPs) that are thought to play a critical role in the encoding and storage of new information. GABA-ergic interneurons are hypothetically involved in the generation and pacing of these oscillatory patterns of activity. The current study aimed to directly test the hypothesis that interneurons are responsible for local gamma and theta generation in the dorsal CA1 region of the hippocampus in mice. Selective focal interneuron lesions were made by intrahippocampal injection of the targeted neurotoxin SSP-Saporin into dorsal CA1 in the hippocampus of GAD67-GFP transgenic mice. Chronic recording electrodes were also implanted in the lesion area. LFPs were monitored continuously, along with video recordings of the subjects, for a period of several weeks. LFP recordings were analyzed over 24-hour periods for the occurrence of theta- and gamma-band activity. Analysis of LFP data revealed attenuation of both local theta and gamma activity in SSP-saporin-injected animals compared to controls. These results suggest a direct role of GABA-ergic interneurons in the generation of local rhythmic activity in these two frequency bands, and, by extension, an important role in learning and memory processes.

Related Products: SSP-SAP (Cat. #IT-11)

Ljubojevic V, Botly L, De Rosa E (2012) Cholinergic contributions to learned attentional suppression in the rat with touchscreens. Neuroscience 2012 Abstracts 729.13. Society for Neuroscience, New Orleans, LA.

Summary: One of the tasks of the attentional system is to filter environmental input according to its behavioral relevance. The neuromodulator acetylcholine (ACh) is thought to play a role in this process because of its ability to boost the signal-to-noise ratio of incoming sensory information. Cholinergic innervation of the attentional system has been shown to be necessary for successful selection of behaviorally-relevant stimuli (signal). However, it is not yet clear if ACh also plays a part in the attentional suppression of behaviorally-irrelevant information (noise). Thus, we examined the effect of cortical cholinergic deafferentation on attentional suppression in rats. To measure attentional suppression, we used a rat analog of the learning-to-ignore (LI) task originally designed for human participants (Dixon et al., 2009). The paradigm consisted of three stages of training (Prime1, Prime2, Probe; 10 sessions per stage), each of which involved stages of visual simultaneous discriminations between two stimuli. In both Prime conditions, individuals learned to respond to target stimuli (A+ and then C+ respectively), while ignoring the same distractor stimulus (B-). During Probe, the previously ignored stimulus became the target (B+) and a novel stimulus (D-) was introduced as a distractor. Eighteen male Long-Evans rats were trained to perform the touchscreen-based LI task. Like the human data, a behavioral decrement (lower accuracy) was observed during the Probe phase of the LI task when compared to Prime 1 and 2, which suggests that the ignored distractor stimulus was suppressed during Prime. We hypothesized that administration of the ACh-specific immunotoxin, 192 IgG-saporin, into the nucleus basalis magnocellularis (NBM) would lead to better performance during Probe condition relative to controls. Accordingly, the rats were subjected to either cholinergic immunotoxic (SAP, N=10) or sham lesion surgery (SHAM, N=8). After 2 weeks of post-surgical recovery, the rats were tested on the LI task with a new stimulus set. The two groups performed comparably during Prime1 and 2, with both SAP and SHAM rats successfully learning the discriminations. As predicted, during Probe SAP rats exhibited significantly less behavioral decrement than controls. Histological analysis revealed that the lesion was chemically and anatomically specific to cholinergic cells in the NBM. This counterintuitive finding suggests that the improved performance during Probe, due to reduced ACh input to the neocortex, was due to inefficient attentional suppression of the behaviorally-irrelevant stimulus.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Ortiz-Barajas O, Ramos-Rodriguez J, Berrocoso E, Garcia Alloza M (2012) Limited effect of serotonergic denervation on beta-amyloid and cognitive impairment in APPswe/PS1dE9 mice. Neuroscience 2012 Abstracts 751.12. Society for Neuroscience, New Orleans, LA.

Summary: Alzheimer’s Disease (AD) is a neurodegenerative disease characterized by progressive cognitive and memory impairment. Amyloid-beta (Aβ) deposition, as senile plaques (SP), seems to play a key role in the development and progression of the illness. Moreover SP tend to accumulate in cortex and hippocampus, relevant areas in learning and memory. On the other hand neuronal loss is the pathological feature that best correlates with duration and severity of the illness and at present animal available animal models hardly reproduce the complexity of the disease. We have previously seen that selective cortical and hipocampal cholinergic denervation, using murine p-75 saporin, may worsen cognitive abilities in APPswe/PS1dE9 mice as well as increase SP deposition in denervated areas. In the present work we lesioned 7 months old APPswe/PS1dE9 mice with 1 µl of 5,7-dyhidroxytiptamine (0.16 µg/µl) injected in the raphe nucleus (RN). In order to guarantee selective removal of cortical and hipocampal serotonergic inervation, and protect noardernergic and dopaminergic neurons, animals were i.p. injected with desipramine and nomifensine before surgery. We observed a clear reduction of tryptophan hydroxilase staining in the RN. In the Morris water maze test we observed learning and memory impairment in APPswe/Ps1dE9 mice, without a synergistic effect of the serotonergic lesion. When we assessed SP deposition we did not observe a significant increase of SP in cortex or hipocampus 14 days after the lesion, as we observed after selective cholinergic denervation. Altogether our data suggest that cognitive impairment and induced SP depositioin observed after cholinergic denervation is not achieved when serotonergic system is affected, supporting a selective effect mediated by different neurotransmitter systems. Acknowledgements: MG-A: RYC-2008-02333, ISCIII-Subdirección General de Evaluación y Fomento de la Investigación (PS09/00969), Fundación Dr. Eugenio Rodriguez Pascual, Junta Andalucia Excelencia (CTS-7847).

Related Products: mu p75-SAP (Cat. #IT-16)

Ostock CY, Lindenbach D, Jaunarajs KL, Dupre KB, Goldenberg A, Bhide NS, Bishop C (2012) Noradrenergic denervation by DBH saporin reduces behavioral responsivity to L-DOPA in the hemi-parkinsonian rat. Neuroscience 2012 Abstracts 758.06. Society for Neuroscience, New Orleans, LA.

Summary: Dopamine (DA) replacement therapy with L-DOPA remains the most effective treatment for Parkinson’s disease (PD), but prolonged use frequently leads to deleterious side effects including involuntary choreic and dystonic movements known as L-DOPA induced dyskinesias (LID). It has been well established that DA loss in PD is accompanied by concomitant noradrenergic (NE) denervation of the locus coeruleus (LC); however, the contribution of NE loss to LID remains controversial and is often overlooked in traditional animal models of PD. Previous work from our lab demonstrated that rats with NE depletion induced by the selective NE neurotoxin DA beta hydroxylase saporin (DBH saporin) display reduced behavioral sensitivity to L-DOPA. The current investigation sought to further characterize the utility of DBH saporin lesions in a rodent model of PD by employing immunohistological techniques to correlate NE cell loss with behavioral outcome. Male Spraque-Dawley rats received unilateral 6-OHDA lesions of the medial forebrain bundle with intraventricular injections of either vehicle or DBH saporin. A number of well characterized behavioral tests were employed to determine lesion effects and L-DOPA responsiveness including: the abnormal involuntary movements scale for rodent dyskinesia, the forepaw adjusting steps (FAS) test as a metric of L-DOPA’s anti-parkinsonian efficacy, and locomotor chambers to observe motor performance. Sensitivity of primed animals to different doses of L-DOPA (0-12 mg/kg) and DA agonists SKF81297 (0., 0.08, 0.8 mg/kg) and Quinpirole (0, 0.05, 0.5 mg/kg) was assessed. Reduced behavioral responsiveness was associated with reductions in tyrosine hydroxylase positive cells within the LC of DBH saporin lesioned animals. Results indicate that NE denervation reduced anti-parkinsonian efficacy of L-DOPA on the FAS test. In primed rats, LC NE loss attenuated dyskinetic responses to L-DOPA and the DA agonist SKF81297. Taken together, these results indicate that DBH saporin lesions not only mimick the NE loss seen in idiopathic PD, but also reveal an underexplored contribution of the NE system to the manifestation of PD symptoms and LID.

Related Products: Anti-DBH-SAP (Cat. #IT-03)

Biggs LM, Simonton AR, Meredith M (2012) Intercalated nucleus modulates chemosensory processing in medial amygdala. Neuroscience 2012 Abstracts 781.07. Society for Neuroscience, New Orleans, LA.

Summary: The vomeronasal organ is necessary for interpretation by naive rodents (hamsters, mice) of many chemosensory signals. Information is relayed to medial amygdala (Me) via the accessory olfactory bulbs. FRA (Fos related antigen) responses in Me to chemosensory cues suggest this area is important for categorization of cues based on biological relevance to the animal. Anterior Me (MeA) is activated by all chemosensory cues (conspecific and heterospecific). Posterior Me (MeP) activates for conspecific and biologically relevant heterospecific stimuli only. Other heterospecific stimuli suppress MeP, apparently via GABA inhibition, while the adjacent medial-caudal intercalated nucleus (m-ICNc) is activated. Intercalated nuclei (ICNs) are groups of GABAergic cells between amygdala main-divisions. Those adjacent to basolateral and central amygdala (BLA, CeA) are known to mediate BLA, CeA responses via GABA inhibition, modulated by inhibitory DA-D1 receptors on ICN cells. We hypothesize that m-ICNc modulates MeP in a similar manner, as suggested by FRAs data, but this has not yet been tested directly. In hamsters, we show a hyperpolarization of MeP cells and suppression of ongoing spiking in whole-cell slice electrophysiology using in-slice stimulation of m-ICNc. The effect of dopamine and other modulators on this functional relationship is under study with agonists and antagonists. ICN, but not Me, cells carry mu-opioid receptors (MORs). In mice, we use Dermorphin-Saporin, a toxin that selectively destroys MOR+ neurons, to lesion m-ICNc to assess its role in chemosensory responses in MeP. Also in mice, a specific MUP protein in male urine (mMU) facilitates learning of a male’s chemosensory signature by females. We have quantified Me response to high and low molecular weight (HMW, LMW) fractions (LMW lacks protein) and whole mMU using FRAs immediate early gene expression. Preliminary results show no significant difference between HMW, LMW, or whole mMU in Me, however within the BLA (involved in volatile odor learning), there are significant differences in activity between stimuli in females without post-weaning exposure to male urine and no prior exposure to adult male urine.

Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12)