Pandala N, De Melo Haefeli L, Lang M, Stone EM, Mullins RF, Tucker BA, Han IC (2025) Development of a targeted choroidal injury model for the study of retinal degenerations and therapeutic cell replacement. bioRxiv 2025.07.29.667466. doi: 10.1101/2025.07.29.667466
Summary: The choroid is a vascular structure that provides nutrients to the photoreceptors by diffusion as well as removal of waste from the outer retina, essentially enabling proper retinal function. Loss of the choroid is a crucial pathophysiologic step in a wide range of retinal diseases. However a current limitation in developing choroidal cell replacement is the lack of a reliable injury model to allow study of transplantation strategies. Existing models rely on either ablative injury to the choroid with laser photocoagulation, but can damage unintended structures, or systemic sodium iodate administration, which causes diffuse, progressive choroidal injury. Authors were able to show suprachoroidal injection of anti-CD38 and anti-CD105 saporin conjugates resulted in targeted, localized, and non-progressive choroidal injury in rats. Immunotoxin-based models of targeted choroidal injury may be useful for understanding pathways of retinal degeneration and facilitating development of therapies for diseases involving choroidal cell loss.
Lee H, Hor CC, Horwitz LR, Xiong A, Su XY, Soden DR, Yang S, Cai W, Zhang W, Li C, Radcliff C, Dinh A, Fung TLR, Rovcanin I, Pipe KP, Xu XZS, Duan B (2025) A dedicated skin-to-brain circuit for cool sensation in mice. Nat Commun 16(1):6731. doi: 10.1038/s41467-025-61562-y PMID: 40721582
Objective: To investigate the functional contributions of specific spinal dorsal horn neuron subtypes to cold and pain sensation using targeted ablation and optogenetic tools.
Summary: The study identifies Calb1+ spinal neurons as essential mediators of cool sensation in mice. Behavioral and physiological responses following targeted ablation reveal distinct sensory processing roles for various neuronal subtypes.
Usage: Bombesin-SAP (IT-40), or control conjugate Blank-SAP (IT-21), was administered intrathecally at a dose of 400 ng in 10 μL sterile saline to ablate GRPR+ spinal neurons and assess their role in sensory behavior.
Nazmuddin M, Stammes MA, Klink PC, Vernes MK, Bakker J, Langermans JAM, van Laar T, Philippens IHCHM (2025) Stereotactic lesioning of cholinergic cells by injection of ME20.4 Saporin in the nucleus basalis of Meynert in a rhesus monkey (Macaca mulatta). J Neuropathol Exp Neurol nlaf081. doi: 10.1093/jnen/nlaf081 PMID: 40673943
Objective: To describe a procedure to inject ME20.4-SAP, an immunotoxin that specifically binds to and depletes cholinergic neurons stereotactically into the nucleus basalis of Meynert (NBM) of a rhesus monkey (Macaca mulatta).
Summary: A digital non-human primate brain atlas was co-registered to the brain of the monkey. A custom-designed cranial chamber was also implanted to the skull to guide the injection. The effects of the ME20.4-SAP injections were evaluated in vivo with PET-CT using [18F]-FEOBV as a radiotracer. This approach yielded reliable spatial accuracy and successful delivery of ME20.4-SAP into the NBM. This saporin-mediated selective destruction of cholinergic neurons in the NBM, using MRI-guidance and a cranial chamber, offers a promising method to study the pathophysiology of NBM degeneration and possible therapeutic interventions.
Usage: The first dose was chosen based on previous NBM lesioning works in common marmosets where infusing 1.4 μg ME20.4-SAP (Cat. #IT-15, in a concentration of 0.20 μg/μl) into each side of the NBM produced partial NBM depletion. At the second injection session, 5 μg ME20.4-SAP (in 0.5 μg/μl solution) was administered into each NBM side.
Noble EE, Harris RBS (2025) Leptin in the VMH contributes to the initial overconsumption of palatable diets by rats. Am J Physiol Endocrinol Metab 329(1):E1-E17. doi: 10.1152/ajpendo.00090.2025 PMID: 40418155
Objective: To determine whether leptin receptor–expressing neurons in the ventromedial hypothalamus (VMH) contribute to the initial overconsumption of a high-fat diet in rats.
Summary: Ablation of VMH leptin receptor–expressing neurons using Leptin-SAP prevented the early hyperphagic response to a high-fat diet in male rats but had no long-term impact on energy intake, body weight, or glucose clearance. These findings suggest VMH leptin signaling plays a key role in initiating, but not maintaining, diet-induced hyperphagia.
Usage: Leptin-SAP (IT-47) was stereotaxically injected into the VMH of male and female rats (20 ng in 80 nL) to ablate leptin receptor–expressing neurons. This targeted lesion confirmed the role of VMH leptin signaling in mediating early-phase overeating in response to a high-fat diet.
Szysiak N, Kosior-Korzecka U, longo V, Patkowski K, Greguła-Kania M, Nowakiewicz A, Bochniarz M,Junkuszew A (2025) Influence of neurokinin b, dynorphin a and kisspeptin-10 on in vitro gonadotropin secretion by anterior pituitary cells isolated from pubescent ewes. J Vet Res doi: 10.2478/jvetres-2025-0003
Objective: The aim of the study was to analyze the direct effect of the hypothalamic neuropeptides kisspeptin-10, neurokinin B, and dynorphin A on gonadotropin secretion by pituitary cells isolated from pubescent ewes.
Summary: Puberty is a multifactorial and complex process in animal development and in the case of livestock, timely attainment of sexual maturity contributes to increased reproductive efficiency, which leads to higher profitability. Studies revealed that kisspeptin, neurokinin B and dynorphin neuropeptides, collectively referred to as KNDy neuropeptides, are recognized as the key neuropeptides produced and secreted by the arcuate nucleus of the hypothalamus (ARC), and involved in the endocrine regulation of the onset of puberty. They all play roles in the endocrine regulation of the hypothalamic-pituitary-ovarian (HPO) axis in puberty. Kisspeptin-10, NKB and Dyn A had a direct impact on gonadotropin secretion by ovine pituitary cells. However, a detailed explanation of their role in gonadotropin secretion by the anterior pituitary gland in sheep and their impact on the regulation of the HPO axis during sexual maturation or in the pathomechanism of delayed puberty requires further studies.
Usage: Prepubertal ewes received 1 μL (0.7 μg) of NKB-SAP (NK3-SAP) [IT-63] or Blank-SAP (IT-21) injections aimed at the arcuate (ARC) nucleus to ablate neurons expressing NK3R.
Kim P, Kumar V, Garner N, Jayasingh O, Roman G, Walters S, Vo T, Nguyen Q, Bowles J, Woodruff T, Inder W, Hunt J, Heyde I, Oster H, Rawashdeh O (2025) A systemic clock brake: Period1 stabilizes the circadian network under environmental stress. bioRxiv 2025.06.12.659230. doi: 10.1101/2025.06.12.659230
Objective: To investigate the role of the core circadian clock gene Period1 (Per1) in regulating light-induced circadian realignment and systemic physiological stability across central and peripheral tissues.
Summary: Per1-deficient mice showed accelerated behavioral, hormonal, and metabolic re-entrainment to shifted light-dark cycles, highlighting Per1’s role as a buffer that stabilizes circadian responses. Despite faster adaptation, Per1 deletion compromised SCN network coherence and increased peripheral metabolic phase instability.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N38) at a 1:2000 dilution to quantify ipRGCs in the retina and confirm that Per1-deficiency did not affect melanopsin-positive cell abundance.
Zhu M, Wu Y, Gao H, Qi F, Zhang X, Ran Y (2025) Differential regulation of mTOR activity in retinal ganglion cells underlies their distinct susceptibility to ischemia/reperfusion. Commun Biol 8(1):911. doi: 10.1038/s42003-025-08314-2 PMID: 40500296
Objective: To explore why intrinsically photosensitive retinal ganglion cells (ipRGCs) are more resistant to ischemia/reperfusion (I/R) injury than other RGC subtypes and to examine the role of mTOR signaling in this differential vulnerability.
Summary: ipRGCs exhibited higher mTOR activity and greater resistance to I/R injury compared to other RGCs. Rapamycin had cell-type–specific effects: it protected non-ipRGCs by increasing mTOR activity but suppressed mTOR in ipRGCs unless light was removed, revealing that light conditions critically influence mTOR-mediated neuroprotection.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N39) at a 1:2000 dilution to identify and quantify ipRGCs in retinal whole-mounts following ischemic injury.
Ren X, Wang Y, Zhang Y (2025) Targeted depletion of dysfunctional hematopoietic stem cells mitigates myeloid-biased differentiation in aged mice. Cell Discov 11:56. doi: 10.1038/s41421-025-00810-3 PMID: 40490480
Objective: To develop and evaluate a targeted strategy for depleting dysfunctional, myeloid-biased CD150-high hematopoietic stem cells (HSCs) in aged mice to restore balanced hematopoiesis and mitigate aging-related blood disorders.
Summary: The study used an antibody-toxin conjugate to selectively eliminate CD150-high HSCs, improving lymphoid-to-myeloid ratios, reducing platelet hyperproduction, and restoring hematopoietic balance in aged mice. Treatment preserved functional CD150-low HSCs and showed minimal off-target or systemic toxicity.
Usage: Streptavidin-ZAP (IT-27) was combined with a biotinylated anti-CD150 antibody to generate Anti-CD150-SAP (IT-103). This conjugate was used at doses of 1–2 mg/kg in vivo and as low as 0.01 nM in vitro to specifically deplete CD150-high HSCs while sparing CD150-low populations.
Movahed AY, Bagheri R, Savatier P, Šarić T, Moradi S (2025) Elimination of tumorigenic pluripotent stem cells from their differentiated cell therapy products: An important step toward ensuring safe cell therapy. Stem Cell Reports 102543. doi: 10.1016/j.stemcr.2025.102543 PMID: 40541178
Objective: To review and evaluate current strategies for eliminating tumorigenic pluripotent stem cells (PSCs) from differentiated cell therapy products to improve the safety of PSC-based regenerative therapies.
Summary: Residual undifferentiated PSCs pose a tumorigenic risk in cell therapies. This review outlines genetic, antibody, toxin, and small molecule strategies for selectively removing PSCs, emphasizing the need for efficient, selective methods to ensure safety in regenerative medicine.
Usage: References a previous study that used Fab-ZAP to eliminate pluripotent stem cells by targeting specific surface markers, demonstrating its application as a targeted immunotoxin for PSC depletion.
Son S, Beaudoin DL, Hassan AR, Akpo MS, Ichinose T, Garrett AM (2025) A characterization of mouse retinal ganglion cell types labeled with AAV tools. bioRxiv 2025.06.02.657062. doi: 10.1101/2025.06.02.657062
Objective: To characterize the cell-type specificity and functional diversity of retinal ganglion cells (RGCs) labeled by AAV vectors carrying synthetic promoters ProA13 and ProA27 in the mouse retina.
Summary: ProA13 and ProA27 AAV vectors selectively labeled molecularly and morphologically distinct subsets of RGCs, including melanopsin-positive ipRGC subtypes. ProA27 labeled a broader diversity of ipRGCs (M1–M4), while ProA13 primarily labeled M1 cells, enabling analysis of their structural, functional, and projection differences.
Usage: Melanopsin (OPN4) was detected using Anti-Melanopsin (AB-N38) at a 1:5000 dilution to identify and classify ipRGCs in AAV-labeled retinas.
