Paclitaxel induced polyneuropathy can be detected with the Catwalk method.

<p>(A) A typical Catwalk run; the animal crosses from right to left. Paws are automatically detected and labeled by the program, in this example right hind paw (RH) and the left forepaw. Examples of gait parameters for the right hind paw are displayed at the bottom of the graph in respect to the step cycle. (B) Animals treated with paclitaxel develop distinct gait alterations compared to vehicle controls. The swing phase (squares, long dashed line) increases, while the stance phase (open triangles, dotted line) and the duty cycle (circles, solid line) decreases. Duty cycle expresses the stance phase as a percentage of the entire step cycle (stand + swing). (C) The print area of the hind paws is also significantly reduced in neuropathic animals. (D) The duty cycle of the hind paws shows a small correlation with the mechanical withdrawal threshold of the animals. Similar results are obtained for the correlation of the (E) hind paw stance phase duration with the caudal nerve SNAP. Solid lines in (D-E) signify linear regression lines, while medium dashed lines depict the 95% prediction interval. * p<0.05; *** p<0.001; both compared to the control group at the same time point (One-way ANOVA).</p

Dose-dense paclitaxel treatment induces a sensory polyneuropathy in mice.

<p>(A) Schedule of paclitaxel treatment and behavioral as well as electrophysiological testing. Animals received paclitaxel at a dose of 20 mg paclitaxel/kg BW three times per week over four weeks with a cumulative dose of 240 mg/kg BW. (B) Paclitaxel treated animals gained less weight than controls, but their weight quickly normalized after the last injection. (C) Motor coordination in the rotarod test was comparable in paclitaxel and vehicle injected animals. (D) Paclitaxel treated animals developed mechanical allodynia with a significantly reduced mechanical withdrawal threshold of the hind paws as well as a (E) predominantly axonal neuropathy with a diminished sensory nerve action potential amplitude (SNAP) of the caudal nerve. (F) Alterations of the caudal nerve SNAP showed a strong positive correlation with the mechanical withdrawal threshold (dashed line depicts the 95% prediction interval). *** p<0.001 compared to the control group at the same time point (One-way ANOVA).</p

DataSheet1_Induced pluripotent stem cell-derived brain organoids as potential human model system for chemotherapy induced CNS toxicity.DOCX

Neurotoxic phenomena are among the most common side effects of cytotoxic agents. The development of chemotherapy-induced polyneuropathy (CIPN) is a well-recognized adverse reaction in the peripheral nervous system, while changes of cognitive functions (post-chemotherapy cognitive impairment (PCCI)) are more diffuse and have only recently drawn scientific interest. PCCI in patients most often displays as short-term memory loss, reduced multitasking ability or deficits in language. Not least, due to a lack of preclinical human model systems, the underlying molecular mechanisms are poorly understood, and treatments are missing. We thus investigated whether induced pluripotent stem cell (iPSC)-derived brain organoids can serve as a human model system for the study of chemotherapy induced central nervous system toxicity. We robustly generated mature brain organoids from iPSC-derived neuronal precursor cells (NPC), which showed a typical composition with 1) dividing NPCs forming ventricle like structures 2) matured neurons and 3) supporting glial cells closer to the surface. Furthermore, upon stimulation the brain organoids showed functional signaling. When exposed to increasing concentrations of paclitaxel, a frequently used chemotherapy drug, we observed time dependent neurotoxicity with an EC50 of 153 nM, comparable to a published murine model system. Histological analysis after paclitaxel exposure demonstrated dose dependent apoptosis induction and reduced proliferation in the organoids with further Western blot analyses indicating the degradation of neuronal calcium sensor one protein (NCS-1) and activation of Caspase-3. We could also provide evidence that paclitaxel treatment negatively affects the pool of neuronal and astrocyte precursor cells as well as mature neurons. In summary our data suggests that human iPSC derived brain organoids are a promising preclinical model system to investigate molecular mechanisms underlying PCCI and to develop novel prevention and treatment strategies.</p