**5. Conclusions**

Our data showed that, in PBMCs of MS patients, oxidative stress is associated with increased level of PHB2 and stabilization of OMA1. We propose that the alteration of PHB2, OMA1, and OPA1 is involved in the apoptosis resistance. We hypothesize involvement of specific proteolytic processing of OPA1 in lymphocytes of MS patients. Other investigations will be needed to define the mechanisms at the bases of this deregulations and the possible proteases involved in the characteristic processing of OPA1 in MS samples. The specific OPA1 electrophoretic profile and an increased level of PHB2 in MS patients could also be taken in account to assess disease activity. Understanding of the molecular mechanisms underlying these deregulations could shed light on new therapeutic interventions.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2227-9059/8/4/85/s1.

**Author Contributions:** Conceptualization, A.S. and D.D.R.; methodology, A.S. and D.D.R.; software, A.S. and D.D.R.; validation, A.S. and D.D.R.; formal analysis, A.S. and D.D.R.; resources, M.R., P.L., D.P., M.T.; data curation, A.S., D.D.R., A.F., S.R., M.R., D.P.; writing—original draft preparation, A.S. and D.D.R.; writing—review and editing, A.S., D.D.R., M.T., A.F., S.R., M.R., D.P.; supervision, A.S. and D.D.R.; project administration, A.S. and D.D.R.; funding acquisition, A.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by University of Bari to Anna Signorile, project title "Regolazione dei sistemi redox e bioenergetici cellulari in condizioni fisio-patologiche".

**Conflicts of Interest:** The authors declare no conflict of interest.
