In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.

[EX Q]: The localization and synthesis of basic fibroblast growth factor (bFGF) in the rat carotid artery were investigated at times of chronic smooth muscle cell proliferation. Immunocytochemical staining showed the presence of bFGF in the uninjured arterial wall, and after balloon injury, this cellular staining was decreased. Western and northern blot analyses likewise showed that the amount of bFGF protein and mRNA decreased after injury. A neutralizing antibody to bFGF was administered 4 and 5 days after injury and was found to have no effect on intimal smooth muscle cell proliferation. These data suggest that an increase in the expression of bFGF is not necessary for chronic smooth muscle cell proliferation observed after balloon catheter injury and that bFGF is not the major mitogen responsible for intimal smooth muscle cell proliferation.
[EX A]: Intimal smooth muscle cell proliferation after balloon catheter injury. The role of basic fibroblast growth factor.

[EX Q]: DNA polymerase lambda (pol) is a recently identified DNA polymerase whose cellular function remains elusive. Here we show, that pol participates at the molecular level in a chromosomal context, in the repair of DNA double strand breaks (DSB) via non-homologous end joining (NHEJ) in mammalian cells. The expression of a catalytically inactive form of pol (polDN) decreases the frequency of NHEJ events in response to I-Sce-I-induced DSB whereas inactivated forms of its homologues pol and pol do not. Only events requiring DNA end processing before ligation are affected; this defect is associated with large deletions arising in the vicinity of the induced DSB. Furthermore, polDN-expressing cells exhibit increased sensitization and genomic instability in response to ionizing radiation similar to that of NHEJ-defective cells. Our data support a requirement for pol in repairing a subset of DSB in genomic DNA, thereby contributing to the maintenance of genetic stability mediated by the NHEJ pathway.
[EX A]: The DNA polymerase is required for the repair of non-compatible DNA double strand breaks by NHEJ in mammalian cells

[EX Q]: Nerve growth factor (NGF) is a potent survival and axon growth factor for neuronal populations in the peripheral nervous system. Although the mechanisms by which target-derived NGF influences survival of innervating neurons have been extensively investigated, its regulation of axonal growth and target innervation are just being elucidated. Here, we identify Wnt5a, a member of the Wnt family of secreted growth factors, as a key downstream effector of NGF in mediating axonal branching and growth in developing sympathetic neurons. Wnt5a is robustly expressed in sympathetic neurons when their axons are innervating NGF-expressing targets. NGF:TrkA signaling enhances neuronal expression of Wnt5a. Wnt5a rapidly induces axon branching while it has a long-term effect on promoting axon extension. Loss of Wnt5a function revealed that it is necessary for NGF-dependent axonal branching and growth, but not survival, in vitro. Furthermore, Wnt5a(-/-) mice display reduced innervation of NGF-expressing target tissues, and a subsequent increase in neuronal apoptosis, in vivo. Wnt5a functions in developing sympathetic neurons by locally activating protein kinase C in axons. Together, our findings define a novel regulatory pathway in which Wnt5a, expressed in sympathetic neurons in response to target-derived NGF, regulates innervation of peripheral targets.
[EX A]:
Wnt5a mediates nerve growth factor-dependent axonal branching and growth in developing sympathetic neurons.