Hung LY, Alves ND, Del Colle A, Talati A, Najjar SA, Bouchard V, Gillet V, Tong Y, Huang Z, Browning KN, Hua J, Liu Y, Woodruff JO, Juarez D, Medina M, Posner J, Tonello R, Yalcinkaya N, Israelyan N, Ringel R, Yang L, Leong KW, Yang M, Sze JY, Savidge T, Gingrich J, Shulman RJ, Gershon MD, Ouellet A, Takser L, Ansorge MS, Margolis KG (2025) Intestinal epithelial serotonin as a novel target for treating disorders of gut-brain interaction and mood. Gastroenterology 168(4):754-768. doi: 10.1053/j.gastro.2024.11.012 PMID: 39672518
Objective: To investigate how intestinal epithelial serotonin influences mood and gastrointestinal function, and to identify gut-targeted therapies for mood disorders and disorders of gut-brain interaction (DGBI).
Summary: Selective deletion of the serotonin transporter (SERT) from the intestinal epithelium reduced anxiety- and depression-like behaviors in mice without affecting gut motility or cognition. These effects were dependent on afferent vagal signaling. Conversely, depleting intestinal serotonin increased anxiety. A human birth cohort study linked in utero SSRI/SNRI exposure to a higher risk of functional constipation, supporting a gut-brain role in DGBI.
Usage: CCK-SAP (IT-31) was bilaterally injected into the nodose ganglia, and after one week, tests of anxiety and depression were performed.
Griesgraber MJ, Coolen LM, Onslow KM, Corey JR, Rice RE, Aerts EG, Bowdridge EC, Hardy SL, Lehman MN, Goodman RL, Hileman SM (2025) Critical role of arcuate nucleus kisspeptin and Kiss1R in regulation of the ovine luteinizing hormone surge. J Neuroendocrinol e70010. doi: 10.1111/jne.70010 PMID: 40033679
Objective: To examine the functional role of arcuate nucleus (ARC) dynorphin-containing (KNDy) and kisspeptin (Kiss) 1R-containing neurons in ovine luteinizing hormone (LH) surge secretion via injection of saporin-ligand conjugates (SAP) to ablate these neural populations.
Summary: NKB-SAP injections significantly reduced the percentage of ARC Kiss1 (~65% decrease) cells compared to control animals, and a surge-like increase of LH was prevented in ewes with the greatest degree of Kiss1 cell ablation. Kiss-SAP injections had no effect on Kiss1 cell percentage or ARC Kiss1R cell number compared to controls. However, Kiss-SAP injections consistently and robustly decreased LH surge amplitude, with 80% of Kiss-SAP-treated ewes failing to generate a surge. These results support the conclusion that KNDy neurons contribute significantly to the ovine LH surge, while ARC Kiss1R neurons appear to be necessary for a functional surge to occur in sheep.
Usage: Saporin conjugates, NKB-SAP (IT-63) and Kisspeptin-SAP (IT-102) were injected at 700 ng/μL.
Objective: To determine if local reactivation of antigen-specific oral CD8+ TRM exacerbates ligature-induced periodontitis (LIP) in mice.
Summary: Topical application of virus-mimicking peptides during LIP increased alveolar bone loss, enhanced gingival and cervical lymph node inflammation, and upregulated gingival genes linked to innate immunity and cytotoxicity. Depleting CD103+ CD8+ TRM with αCD103-SAP prior to LIP prevented disease exacerbation, implicating these cells in periodontitis pathology.
Usage: Anti-CD103-SAP (IT-50) was administered in PBS at 5 μg (day -4), 2 μg (day 0), and 2 μg (day +4) relative to LIP induction.
Dib C, Queenan J, Willner H, Swartzrock L, Charlesworth C, Denis M, Davis J, Nakauchi H, Liu DR (2025) Combining hsc base-editing with anti-cd117 antibody conditioning to correct severe combined immunodeficiency disorder in a novel mouse model. Transplantation and Cellular Therapy 31(2):S253-S354. doi: 10.1016/j.jtct.2025.01.385
Objective: To test whether base-edited hematopoietic stem cells (HSPCs) combined with non-genotoxic antibody conditioning can correct severe combined immunodeficiency (SCID) in a novel Rag2 mutant mouse model.
Summary: Base-editing delivered via engineered virus-like particles successfully corrected Rag2 mutations in HSPCs, which restored lymphocyte development following transplantation. Conditioning with an Anti-CD117-Saporin conjugate enabled efficient engraftment without irradiation toxicity, demonstrating a safer strategy for SCID treatment.
Usage: Mice were conditioned with Anti-CD117-SAP (IT-83) at 1.5 mg/kg intravenously prior to transplantation of base-edited or wild-type HSPCs.
Prince C, Kumar D, Chambliss C, Okalava J, Malik S, Doering CB, Spencer HT, Archer D. Chandrakasan S (2025) Clinically relevant non-genotoxic conditioning with cd117 immunotoxin promotes robust donor chimerism and amelioration of sickle cell disease in a murine model. Transplantation and Cellular Therapy 31(2):S178. doi: 10.1016/j.jtct.2025.01.274
Objective: To investigate the efficacy of an Anti-CD117-Saporin conjugate as part of a non-genotoxic HCT strategy in a sickle cell disease (SCD) mouse model.
Summary: An Anti-CD117-SAP, combined with clinically relevant immunosuppression, achieved stable donor chimerism and corrected hematologic abnormalities in SCD mice. This conditioning regimen avoided transfusion requirements, graft-versus-host disease, and transplant-related mortality typical of TBI or busulfan-based approaches.
Usage: HbSS-Townes mice were conditioned with ATG and B cell depletion followed by Anti-CD117-SAP (IT-83, 0.75 µg/g) prior to HCT with HbAA-Townes donor marrow.
Objective: To uncover the role of a sparse but unusual population of genetically-distinct interneurons known as type-I nNOS neurons, using a novel pharmacological strategic to unilaterally ablate these neurons from the somatosensory cortex of mice.
Summary: Region-specific ablation produced changes in both neural activity and vascular dynamics, decreased power in the delta-band of the local field potential, reduced sustained vascular responses to prolonged sensory stimulation, and abolished the post-stimulus undershoot in cerebral blood volume. Coherence between the left and right somatosensory cortex gamma-band power envelope and blood volume at ultra-low frequencies was decreased, suggesting type-1 nNOS neurons integrate long-range coordination of brain signals. Authors also observed decreases in the amplitude of resting-state blood volume oscillations and decreased vasomotion following the ablation of type-I nNOS neurons.
Usage: Type-I nNOS neurons were selectively ablated with saporin conjugated to a substance P analog (SP-SAP, IT-07). Intracortical injection with 4 ng of either SAP conjugate or Blank-SAP (IT-21).
Dogrul BN, Dogrul BN, Machado Kopruszinski C, Dolatyari Eslami M, Watanabe M, Luo S, Moreira de Souza LH, Vizin RL, Yue X, Palmiter RD, Navratilova E, Porreca F (2025) Descending facilitation from rostral ventromedial medulla mu opioid receptor-expressing neurons is necessary for maintenance of sensory and affective dimensions of chronic neuropathic pain. Pain 166(1):153-159. doi: 10.1097/j.pain.0000000000003360 PMID: 39058958
Objective: To determine whether rostral ventromedial medulla (RVM) mu opioid receptor (MOR)–expressing neurons are required for the expression and maintenance of established neuropathic pain.
Summary: Using chemogenetic silencing of MOR-expressing neurons, the study showed that inhibition of RVM-MOR cells reversibly reduces tactile allodynia and the affective component of neuropathic pain, demonstrating that descending facilitation from these neurons sustains chronic pain. The authors reference earlier findings using Dermorphin-SAP to confirm that complete ablation of MOR-expressing RVM neurons prevents neuropathic pain development without affecting acute surgical pain.
Usage: Dermorphin-SAP (IT-12) was referenced from prior studies as a method for selective ablation of MOR-expressing RVM neurons that prevented mechanical allodynia following spinal nerve ligation.
Vringer M, Zhou J, Gool JK, Bijlenga D, Lammers GJ, Fronczek R, Schinkelshoek MS (2024) Recent insights into the pathophysiology of narcolepsy type 1. Sleep Med Rev 78:101993. doi: 10.1016/j.smrv.2024.101993 PMID: 39241492
Objective: To focus on recent insights into Narcolepsy type 1 (NT1) pathophysiology, discussing structural and functional changes, immune system involvement, genetic findings, and future perspectives for the pathophysiology and treatment options.
Summary: Narcolepsy type 1 (NT1) is one of the central disorders of the hypersomnolence and results from hypocretin (Hcrt, also nown as orexin) deficiency in the brain. The development of HcrtR2-specific or dual HcrtR1 and HcrtR2 agonists, has shown promising results in pre-clinical and clinical trials. These agonists can potentially become the first drugs to directly target the Hcrt system and replace the shortage of Hcrt in NT1.
Usage: Hcrt-2 conjugated to the ribosome-inactivating toxic protein saporin (Orexin-SAP, Cat #IT-20) eliminated up to 90% of Hcrt neurons but also caused significant loss of neighboring neuronal cells, such as Melanin-concentrating hormone (MCH) neurons.
Wang D, Wei SN, Zhang L, Lang ZC, Wang SN, Cheng B, Lu Y, Wang X, Wang W, Li FS, Zhang H (2024) Impaired basal forebrain cholinergic neuron gdnf signaling contributes to perioperative sleep deprivation–induced chronicity of postsurgical pain in mice through regulating cholinergic neuronal activity, apoptosis, and autophagy. CNS Nerusci Ther doi: 10.1111/cns.70147 PMID: 39639706
Objective: This study investigated the roles of lateral basal forebrain glial cell line–derived neurotrophic factor (GDNF). The authors researched GDNF and the associated signaling and cholinergic neuron activity, apoptosis, and autophagy dysfunction in sleep deprivation–induced increased risk of chronic postsurgical pain (CPSP) in mice.
Summary: Perioperative sleep deprivation promotes chronicity of postsurgical pain possibly through decreasing basal forebrain GDNF signaling and causing cholinergic neuronal apoptosis and autophagy dysfunction.
Usage: To ablate the basal forebrain cholinergic neurons, 0.4μg/μL of mu p75-SAP (IT-16) in 0.6μL phosphate-buffered saline was used 3 weeks before the Skin/Muscle Incision and Retraction modeling.
Lewis RD, Keilholz AN, Smith CL, Burd EA, Nichols NL (2024) Spinal TNF-α receptor 1 is differentially required for phrenic long-term facilitation (pLTF) over the course of motor neuron death in adult rats. Front Physiol 15 doi: 10.3389/fphys.2024.1488951 PMID: 39703667
Objective: To study the impact motor neuron death has on the output of surviving phrenic motor neurons as well as the compensatory mechanisms that are recruited.
Summary: Results revealed that TNFR1 expression was increased on phrenic motor neurons of 28d CTB-SAP rats, and that astrocytes were increased and exhibited reactive morphology in the phrenic motor nucleus of CTB-SAP rats. This work suggests that TNFR1 could be used as a potential therapeutic agent in CTB-SAP rats and patients with respiratory motor neuron disease.
Usage: Intrapleural injection of CTB-SAP (25μg dissolved in PBS) to target respiratory motor neurons.
