Overexpression of LH3 reduces the incidence of hypertensive intracerebral hemorrhage in mice.

Hypertensive intracerebral hemorrhage (ICH) is a devastating cerebrovascular disease with no effective treatment. Lysyl hydroxylase 3 (LH3) is essential for collagen IV intermolecular crosslinking and stabilization. Deficiency in LH3 affects the assembly and secretion of collagen IV and basement membrane (BM) integrity of vessels. Here, we investigated whether LH3 has significant implications for disease progression and therapeutic intervention. Spontaneous hypertensive ICH of mice was induced by angiotensin II and L-NAME treatment. The adeno-associated virus was delivered into brain by stereotactic injection to knockdown or overexpress LH3. We found LH3 levels were reduced in human patients with ICH and gradually decreased in mice before ICH. LH3 knockdown increased the incidence of hypertensive ICH in mice. The incidence, number, and size of ICHs in mice were markedly reduced by LH3 overexpression. RNA-seq revealed that LH3 overexpression significantly reversed the profound alterations in gene transcriptional profiles of cerebral vessels. LH3 overexpression was sufficient to enhance BM integrity, inhibit matrix metalloproteinase activity, attenuate microglial activation and leukocyte infiltration, and reduce VSMC apoptosis before ICH. These results indicate that LH3 overexpression attenuates susceptibility to hypertensive ICH. We emphasize that LH3 modulation may serve as a viable approach for future investigations of ICH prevention.