control-conjugates

Aquino NSS, Campideli-Santana AC, Antunes LM, Araújo-Lopes R, da Costa Silva KS, Costa Henriques P, de Oliveira Gusmão D, Bernuci MP, Szawka RE, dos Reis AM (2023) Partial loss of KNDy neurons in prenatally androgen treated female rats alters the LH secretion and ovarian morphology in a model of polycystic ovary syndrome. J Endocrine Society 7(S1):bvad114.1215. doi: 10.1210/jendso/bvad114.1215

Objective: To examine the impact of partial loss of KNDy neurons in prenatally androgen-treated female rats on luteinizing hormone (LH) secretion and ovarian morphology, as a model of polycystic ovary syndrome (PCOS).

Summary: The study found that the ablation of KNDy neurons resulted in increased LH pulse amplitude and mean LH levels without affecting pulse frequency, and partially restored the number of primordial follicles, suggesting KNDy neurons’ role in modulating LH release and ovarian reserve in PCOS.

Usage: Intra-ARC stereotaxic injections of the neurokinin-3 receptor agonist conjugated with Saporin (NKB-SAP, IT-63) to induce the lesion of KNDy neurons. Blank-SAP (IT-21) was used as a control.

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

Goodman RL, Moore AM, Onslow K, Hileman SM, Hardy SL, Bowdridge EC, Walters BA, Agus S, Griesgraber MJ, Aerts EG, Lehman MN, Coolen LM (2023) Lesions of kndy and kiss1r neurons in the arcuate nucleus produce different effects on lh pulse patterns in female sheep. Endocrinology 164(11):bqad148. doi: 10.1210/endocr/bqad148 PMID: 37776515

Objective: To test the functional role of ovine KNDy neurons in pulse generation and identify the roles of nearby Kiss1 receptor (Kiss1R)-containing cells.

Summary: Injection of NK3-SAP (NKB-SAP) ablated over 90% of the KNDy cells, Kiss-SAP lesioned about two-thirds of the Kiss1R population. This led to a significant decrease in LH pulse amplitude and altering LH pulse patterns. NK3-SAP increased the interpulse interval without affecting the regularity of LH pulses, whereas Kiss-SAP disrupted their regular hourly occurrence but not the interpulse interval. The findings suggest that KNDy neurons are critical for GnRH pulse generation in ewes, while ARC Kiss1R cells support the amplitude and regularity of these pulses, possibly as part of a positive feedback loop involving GABA or glutamate.

Usage: Saporin conjugates were injected into the arcuate nucleus. Kiss-SAP (kisspeptin54-SAP) was diluted to 700 ng/μL in PBS immediately before use. In preliminary work to test the effectiveness of Kiss-SAP, a single unilateral injection (1 μL of 700 ng/μL) of this conjugate was made in the preoptic area of 3 ewes. The contralateral side was used as control and either received no injections or Blank-SAP (1 μL of 700 ng/μL) (IT-21).

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

Harris RBS (2023) Low dose peripheral leptin infusion produces selective activation of ventromedial hypothalamic and hindbrain STAT3. Am J Physiol Endocrinol Metab doi: 10.1152/ajpendo.00083.2023 PMID: 37285599

Objective: To show that the deletion of leptin-receptor expressing cells in the ventromedial hypothalamus (VMH) has no effect on basal body weight or body fat mass, but greatly attenuates the inhibition of food intake.

Summary: This study evaluates leptin’s impact on hypothalamic pSTAT3 in leptin-infused versus injected rats. High-dose leptin suppressed food intake and reduced weight and fat mass without affecting energy metrics, with pSTAT3 increases observed in the VMH only during intake suppression and in the nucleus of the solitary tract over both short and extended periods. These results highlight the role of VMH and hindbrain receptors in mediating leptin’s effects on food intake and metabolic changes.

Usage: Leptin-SAP is referenced in Seamon et al 2019: Male Sprague-Dawley rats received bilateral VMH 75 nl injections of 260 ng/microliter of Leptin-SAP (IT-47) or Blank-Saporin (IT-21).

Related Products: Leptin-SAP (Cat. #IT-47), Blank-SAP (Cat. #IT-21)

See Also:

• Seamon M et al. Leptin receptor-expressing neurons in ventromedial nucleus of the hypothalamus contribute to weight loss caused by fourth ventricle leptin infusions. Am J Physiol Endocrinol Metab 317(4):E586-E596, 2019.

Chen CH, Tsai TC, Wu YJ, Hsu KS (2023) Gastric vagal afferent signaling to the basolateral amygdala mediates anxiety-like behaviors in experimental colitis mice. JCI Insight e161874. doi: 10.1172/jci.insight.161874 PMID: 37200091

Objective: This study aimed to characterize gut-to-brain signaling and brain circuitry responsible for anxiety-like behaviors in a mouse model of inflammatory bowel disease.

Summary: The researchers found that mice with experimental colitis induced by dextran sulfate sodium administration displayed increased anxiety-like behaviors, which were prevented by cutting the vagus nerve connecting the gut to the brain. Further experiments showed that silencing brain cells in the locus coeruleus that project to the basolateral amygdala reduced anxiety behaviors in the colitis mice.

Usage: CCK-SAP (250 ng/µl) or Blank-SAP (250 ng/µl) were unilaterally or bilaterally injected to rostral (0.5 µl) and caudal (0.5 µl) parts of the nodose ganglia using a beveled injection pipette controlled by a microprocessor-controlled injector at the speed of 50 nl/sec.

Related Products: CCK-SAP (Cat. #IT-31), Blank-SAP (Cat. #IT-21)

Hoffman S, Alvares D, Adeli K (2022) GLP-1 attenuates intestinal fat absorption and chylomicron production via vagal afferent nerves originating in the portal vein. Mol Metab 65:101590. doi: 10.1016/j.molmet.2022.101590 PMID: 36067913

Objective: To examine the effect of vagal GLP-1 signaling on intestinal fat absorption and lipoprotein production.

Summary: Selective deafferentation of GLP-1R-containing nodose neurons with GLP-1R (Exenatide)-SAP caused significant increases in postprandial (but not fasting) plasma TG, plasma cholesterol, and TRL TG following an olive oil gavage. Over a 2-week period, increased food consumption and elevated liver lipids were also observed.

Usage: GLP-1R-SAP or Blank-SAP was administered to Syrian golden hamsters (bilateral nodose ganglia; 1 µg/1 µl).

Related Products: Ex4-SAP (GLP-1-SAP) (Cat. #IT-90), Blank-SAP (Cat. #IT-21)

Zhou XA, Ngiam G, Qian L, Sankorrakul K, Coulson EJ, Chuang KH (2022) The basal forebrain volume reduction detected by MRI does not necessarily link with the cholinergic neuronal loss in the Alzheimer’s disease mouse model. Neurobiol Aging 117:24-32. doi: 10.1016/j.neurobiolaging.2022.03.017 PMID: 35640461

Objective: Assess basal forebrain (BF) cholinergic neuron number by histological counts and compare with the volume measurements from an in vivo MRI Alzheimer’s disease (AD) mouse model.

Summary: Degeneration of cholinergic neurons in the BF contributes to cognitive impairment in AD. A decrease of BF volume measured by structural MRI is thought to represent loss of cholinergic neurons. As there are various types of neurons in the BF, whether this MRI measurement actually reflects the change of cholinergic neurons has not been verified. To test whether specific loss of cholinergic neurons results in BF reduction, the authors ablated cholinergic neurons in the Medial septum.

Usage: Lesions were made via injections of mu-p75-SAP (0.5 mg/ml) or control Rabbit-IgG-SAP (0.5 mg/mL) into ten-week-old female C57Bl/6J mice. However, there was no detectable change in MRI volume between lesioned and unlesioned mice. The results indicate that although loss of cholinergic neurons within the BF likely contribute to volume loss, this change in volume cannot be taken as a direct biomarker of cholinergic neuron number.

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

Madrid LI, Bandhavkar S, Hafey K, Jimenez-Martin J, Milne M, Coulson EJ, Jhaveri DJ (2022) Stimulation of the muscarinic receptor M4 activates quiescent neural precursor cells and ameliorates medial septum cholinergic lesion-induced impairments in adult hippocampal neurogenesis. bioRxiv 2022.08.25.505357. doi: 10.1101/2022.08.25.505357

Objective: To investigate the contribution of basal forebrain medial septum (MS) and diagonal band of Broca (DBB) cholinergic neurons that innervate the hippocampus and the identity of the cholinergic receptor(s) that regulate the production and maturation of new neurons.

Summary: This work reveals stage-specific roles of cholinergic signaling in regulating functionally relevant adult hippocampal neurogenesis.

Usage: Medial septum cholinergic lesion was achieved by infusion of mu p75-SAP (0.4 µg/µl). Rabbit IgG-SAP (0.4 µg/µl) was used as control.

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

Krieger JP, Asker M, Van der Velden P, Börchers S, Richard JE, Maric I, Longo F, Singh A, De Larigue G, Skibicka KP (2022) Neural pathway for gut feelings: vagal interoceptive feedback from the gastrointestinal tract is a critical modulator of anxiety-like behavior. Biological Psychiatry in press. doi: 10.1016/j.biopsych.2022.04.020

Objective: To determine how the sensing of gastrointestinal state affects anxiety.

Summary: Vagal sensory signals from the gastrointestinal tract are critical for baseline and feeding-induced tuning of anxiety via the central amygdala in rats. The article results suggest vagal gut-brain signaling as a target to normalize interoception in anxiety.

Usage: 1.5 ul of CCK-SAP or Blank-SAP were delivered into each nodose ganglion at 250 ng/ul.

Related Products: CCK-SAP (Cat. #IT-31), Blank-SAP (Cat. #IT-21)

Nguyen KL, Lamerand SR, Deshpande RP, Taylor BK (2021) Featured Article: Selective ablation of IB4+ primary afferent neurons reduces mechanical and cold hyperalgesia in an EAE mouse model of multiple sclerosis. Targeting Trends 22

Related Products: IB4-SAP (Cat. #IT-10), Blank-SAP (Cat. #IT-21)

Read the featured article in Targeting Trends.

See Also:

• Nguyen KL et al. Contribution of small diameter non-peptidergic primary afferent neurons to central neuropathic pain in a new, more clinically relevant mouse model of multiple sclerosis. Neuroscience 2021 Abstracts P377/07, 2021. Society for Neuroscience, Virtual

Ancheta LR, Shramm PA, Bouajram R, Higgins D, Lappi DA (2022) Saporin as a commercial reagent: its uses and unexpected impacts in the biological sciences-tools from the plant kingdom. Toxins (Basel) 14(3):184. doi: 10.3390/toxins14030184 PMID: 35324681

Summary: Saporin is a ribosome-inactivating protein that can cause inhibition of protein synthesis and causes cell death when delivered inside a cell. Development of commercial Saporin results in a technology termed ‘molecular surgery’, with Saporin as the scalpel. Its low toxicity (it has no efficient method of cell entry) and sturdy structure make Saporin a safe and simple molecule for many purposes. The most popular applications use experimental molecules that deliver Saporin via an add-on targeting molecule. These add-ons come in several forms: peptides, protein ligands, antibodies, even DNA fragments that mimic cell-binding ligands. Cells that do not express the targeted cell surface marker will not be affected. This review will highlight some newer efforts and discuss significant and unexpected impacts on science that molecular surgery has yielded over the last almost four decades. There are remarkable changes in fields such as the Neurosciences with models for Alzheimer’s Disease and epilepsy, and game-changing effects in the study of pain and itch. Many other uses are also discussed to record the wide-reaching impact of Saporin in research and drug development.

Read complete article.