Vincent Caiozzo, Ph.D
Professor in Residence
From a clinical perspective, the Ilizarov technique is used to lengthen long
bones and salvaging limb length following traumatic injuries. While previous
studies have exclusively focused upon issues related to bone, very little
is known about the response of skeletal muscle, connective tissue, nerve,
or vessels to distraction. The ability to lengthen bone using the Ilizarov
technique is thought to be limited by the soft tissues adjacent to the bone
defect. As a result of constant bone lengthening, skeletal muscles are also
under constant stretch.
Currently, it is not known what effect bone lengthening has
on the contractile, biochemical, and molecular properties of
skeletal muscle. As a result, we have developed a rodent Ilizarov
model that simulates that used in humans. Our current interests
are to examine the adaptability of the flexors and extensors
of a joint to constant stretch. By developing an understanding
of the adaptation of skeletal muscle to the Ilizarov technique,
more optimal methods of bone lengthening should be developed.
Dr. Caiozzo’s current research interests are focused on
3 key aspects of skeletal muscle: i) the mechanistic role of
contractile and regulatory proteins
in muscle mechanics; ii) the mechanistic basis of muscle plasticity; and iii)
the application of the first two pursuits to clinically relevant pathologies.
Regarding the first area, previous studies conducted in his
laboratory have focused upon the relationship between myosin
isoforms and maximal shortening velocity. Current studies are
directed at a more complete understanding of the role of myosin
using whole muscle, single motor unit, and single fiber studies.
Using the novel work loop technique, he has been able to develop
a model that describes the role of activation and relaxation
processes in limiting the mechanical work produced by skeletal
muscle during repetitive contractions.
These studies have shown that relaxation plays a major role
in limiting the amount of mechanical work that can be produced
by skeletal muscle, and that relaxation is length and strain
dependent. Future studies with single fibers will specifically
focus upon the role of myosin, troponin-C , and the sarcoplasmic
reticulum in the relaxation process by using caged chelators
of calcium that are activated by laser flash photolysis.
Dr. Caiozzo is also involved with the UC Irvine Space Cycle.
Dr. Caiozzo received his undergraduate degree from California State University,
Long Beach and his Master of Science in Kinesiology from UCLA. He completed
his doctorate degree in cell biology at the University of California, Irvine.
Dr. Caiozzo frequently serves on study sections at NIH. This
past year Dr. Caiozzo was a member of the NIH NCRR Site Visit
Team, and participated in the development of the 5-year strategic
plan for the NIH NCAM. Dr. Caiozzo also currently serves as the
Associate Team Leader for the Physical Fitness, Nutrition, and
Rehabilitation Team of NASA’s National Space Biology Research
Institute. Also, he is the Chair of the Molecular and Cellular
Regulatory Mechanisms Interest Group of the American College
of Sports Medicine.
Dr. Caiozzo serves on a number of University and College of
Medicine Committees. Dr. Caiozzo is a member of the Irvine Academic
Senate. Additionally, he is a member of the GCRC Advisory Committee,
and is the Chair of the GCRC Executive Advisory Committee. Dr.
Caiozzo also serves on the Mentor Committee in the College of
Medicine. Dr. Caiozzo’s primary academic appointment is
in the Department of Orthopaedics, and he holds joint appointments
with the Departments of Physiology and Biophysics, Otolaryngology,
and Community and Environment Medicine.
Cell Biology, UC Irvine