Parkinson’s disease (PD) is a common neurodegenerative disease that lacks therapies to prevent progressive neurodegeneration. Impaired energy metabolism and reduced ATP levels are common features of PD. Previous studies revealed that terazosin (TZ) enhances the activity of phosphoglycerate kinase 1 (PGK1), thereby stimulating glycolysis and increasing cellular ATP levels. Therefore, we asked whether enhancement of PGK1 activity would change the course of PD. In toxin-induced and genetic PD models in mice, rats, flies, and induced pluripotent stem cells, TZ increased brain ATP levels and slowed or prevented neuron loss. The drug increased dopamine levels and partially restored motor function. Because TZ is prescribed clinically, we also interrogated 2 distinct human databases. We found slower disease progression, decreased PD-related complications, and a reduced frequency of PD diagnoses in individuals taking TZ and related drugs. These findings suggest that enhancing PGK1 activity and increasing glycolysis may slow neurodegeneration in PD.

Although many animal species sense gravity for spatial orientation, the molecular bases remain uncertain. Therefore, we studied Drosophila melanogaster , which possess an inherent upward movement against gravity-negative geotaxis. Negative geotaxis requires Johnston's organ, a mechanosensory structure located in the antenna that also detects near-field sound. Because channels of the transient receptor potential (TRP) superfamily can contribute to mechanosensory signaling, we asked whether they are important for negative geotaxis. We identified distinct expression patterns for 5 TRP genes; the TRPV genes nanchung and inactive were present in most Johnston's organ neurons, the TRPN gene nompC and the TRPA gene painless were localized to 2 subpopulations of neurons, and the TRPA gene pyrexia was expressed in cap cells that may interact with the neurons. Likewise, mutating specific TRP genes produced distinct phenotypes, disrupting negative geotaxis ( painless and pyrexia ), hearing ( nompC ), or both ( nanchung and inactive ). Our genetic, physiological and behavioral data indicate that the sensory component of negative geotaxis involves multiple TRP genes. The results also distinguish between different mechanosensory modalities and set the stage for understanding how TRP channels contribute to mechanosensation.

The α1-adrenergic receptor antagonist terazosin protects flies and mammalian cells from stress and apoptosis through direct activation of the glycolytic enzyme phosphoglycerate kinase 1, which interacts with Hsp90 to promote ATP consumption. Drugs that can protect against organ damage are urgently needed, especially for diseases such as sepsis and brain stroke. We discovered that terazosin (TZ), a widely marketed α1-adrenergic receptor antagonist, alleviated organ damage and improved survival in rodent models of stroke and sepsis. Through combined studies of enzymology and X-ray crystallography, we discovered that TZ binds a new target, phosphoglycerate kinase 1 (Pgk1), and activates its enzymatic activity, probably through 2,4-diamino-6,7-dimethoxyisoquinoline′s ability to promote ATP release from Pgk1. Mechanistically, the ATP generated from Pgk1 may enhance the chaperone activity of Hsp90, an ATPase known to associate with Pgk1. Upon activation, Hsp90 promotes multistress resistance. Our studies demonstrate that TZ has a new protein target, Pgk1, and reveal its corresponding biological effect. As a clinical drug, TZ may be quickly translated into treatments for diseases including stroke and sepsis.

The Drosophila tracheal system and mammalian airways are branching networks of tubular epithelia that deliver oxygen to the organism. In mammals, the epithelial Na ⁺ channel (ENaC) helps clear liquid from airways at the time of birth and removes liquid from the airspaces in adults. We tested the hypothesis that related Drosophila degenerin (DEG)/ENaC family members might play a similar role in the fly. Among 16 Drosophila DEG/ENaC genes, called pickpocket (PPK) genes, we found 9 expressed in the tracheal system. By in situ hybridization, expression appeared in late-stage embryos after tracheal tube formation, with individual PPK genes showing distinct temporal and spatial expression patterns as development progressed. Promoters for several PPK genes drove reporter gene expression in the larval and adult tracheal systems. Adding the DEG/ENaC channel blocker amiloride to the medium inhibited liquid clearance from the trachea of first instar larvae. Moreover, when RNA interference was used to silence PPK4 and PPK11, larvae failed to clear tracheal liquid. These data suggest substantial molecular diversity of DEG/ENaC channel expression in the Drosophila tracheal system where the PPK proteins likely play a role in Na ⁺ absorption. Extensive similarities between Drosophila and mammalian airways offer opportunities for genetic studies that may decipher further the structure and function of DEG/ENaC proteins and development of the airways.

Classification of apoptosis and necrosis by morphological difference has been widely used for decades. However, this method has been seriously doubt in recent years, mainly due to lack of functional and biochemical evidence to interpret the morphology changes. To address these questions, we devised genetic manipulations in Drosophila to study pyknosis, a process of nuclear shrinkage and chromatin condensation occurred in apoptosis and necrosis. By following the progression of necrotic pyknosis, we surprisingly observed a transient state of chromatin detachment from the nuclear envelope (NE), followed with the NE completely collapsed onto chromatin. This phenomenon leads us to discover that phosphorylation of barrier-to-autointegration factor (BAF) mediates this initial separation of NE from chromatin. Functionally, inhibition of BAF phosphorylation suppressed the necrosis in both Drosophila and human cells, suggesting necrotic pyknosis is conserved in the propagation of necrosis. In contrast, apoptotic pyknosis did not show a detached state of chromatin from NE and inhibition of BAF phosphorylation had no effect on apoptotic pyknosis and apoptosis. Our research provides the first genetic evidence supporting morphological classification of apoptosis and necrosis by pyknosis.