Molecular mechanisms of disturbed thermoregulation exemplified by Crisponi syndrome

• Applicant: Professor Dr. Frank Rutsch
• Subject Area: Pediatric and Adolescent Medicine
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 411699220

• Final Report Year: 2023

Final Report Abstract

Despite intensive research, thermoregulatory disorders in humans are poorly understood. Individuals with Crisponi syndrome develop episodes of hyperthermia after birth and coldinduced sweating in adolescence. Crisponi syndrome is caused by pathogenic variants in cytokine receptor like factor 1 (CRLF1) or cardiotrophin like cytokine factor 1 (CLCF1). In addition to mutations in CRLF1 or CLCF1, we identified three pathogenic variants in the kelch domain of kelch like family member 7 (KLHL7). These pathogenic variants are associated with a Crisponi-like phenotype. Previously, we identified a link between CRLF1 secretion and the severity of the Crisponi phenotype. We also demonstrated increased noradrenaline levels in plasma samples of adolescent Crisponi individuals after exposure to cold. In our preliminary work for this proposal, we were able to show that loss of function of Crlf1 in mouse embryos is associated with altered expression of tyrosine hydroxylase (TH) and dopamine betahydroxylase (DBH), both key enzymes in noradrenaline synthesis. As part of this DFG project, we successfully established a cell culture model for Crisponi syndrome. We generated induced pluripotent stem cells from fibroblasts of Crisponi patients, which we subsequently differentiated into human neurons of the central nervous system. In these neurons, as in Crlf1 knockout embryos, we detected an increased expression of TH and DBH. Since thermoregulation is controlled by sympathetic neurons, we additionally differentiated the induced stem cells into human sympathetic neurons (hsN) of the peripheral nervous system. In hsN, loss of function of CRLF1 or CLCF1 is also associated with increased expression of TH and DBH and subsequently with increased noradrenaline content. The question why mutations in KLHL7 lead to a Crisponi-like phenotype was also a aim of this proposal. We were able to verify for the first time a correlation between KLHL7 dysfunction and altered noradrenaline metabolism. HsN carrying the KLHL7 pathogenic variants exhibit increased expression of TH and DBH. Although hsN do not show increased intracellular noradrenaline levels, we detected increased secretion of noradrenaline into the cell culture medium. Why KLHL7 dysfunction is associated with increased expression of TH and DBH has not yet been elucidated and is the subject of current investigations.

Publications

• Crisponi/cold‐induced sweating syndrome: Differential diagnosis, pathogenesis and treatment concepts. Clinical Genetics, 97(1), 209-221.
  Buers, Insa; Persico, Ivana; Schöning, Lara; Nitschke, Yvonne; Di Rocco, Maja; Loi, Angela; Sahi, Puneet Kaur; Utine, Gulen Eda; Bayraktar‐Tanyeri, Bilge; Zampino, Giuseppe; Crisponi, Giangiorgio; Rutsch, Frank & Crisponi, Laura
  
• Exome sequencing in Crisponi/cold‐induced sweating syndrome–like individuals reveals unpredicted alternative diagnoses. Clinical Genetics, 95(5), 607-614.
  Angius, Andrea; Uva, Paolo; Oppo, Manuela; Buers, Insa; Persico, Ivana; Onano, Stefano; Cuccuru, Gianmauro; Van Allen Margot, I.; Hulait, Gurdip; Aubertin, Gudrun; Muntoni, Francesco; Fry, Andrew E.; Annerén, Göran; Stattin, Eva‐Lena; Palomares‐Bralo, María; Santos‐Simarro, Fernando; Cucca, Francesco; Crisponi, Giangiorgio; Rutsch, Frank & Crisponi, Laura
  
• Crisponi syndrome/cold-induced sweating syndrome type 2: Reprogramming of CS/CISS2 individual derived fibroblasts into three clones of one iPSC line. Stem Cell Research, 46, 101855.
  Buers, Insa; Schöning, Lara; Tomas, Loges Niki; Nitschke, Yvonne; Höben, Inga Marlena; Röpke, Albrecht; Crisponi, Laura; Omran, Heymut & Rutsch, Frank
  
• Generation of induced pluripotent stem cell lines from a Crisponi/Cold induced sweating syndrome type 1 individual. Stem Cell Research, 46, 101820.
  Schöning, Lara; Loges, Niki Tomas; Nitschke, Yvonne; Höben, Inga Marlena; Röpke, Albrecht; Crisponi, Laura; Omran, Heymut; Rutsch, Frank & Buers, Insa
  
• CRLF1 and CLCF1 in Development, Health and Disease. International Journal of Molecular Sciences, 23(2), 992.
  Crisponi, Laura; Buers, Insa & Rutsch, Frank
  
• Molecular mechanisms of thermoregulatory defects in Crisponi Syndrome. (Vortrag) Crisponi Patiententreffen, Cagliari, Italien, November 2022
  Insa Buers & Frank Rutsch