The actin cytoskeleton mediates mechanical coupling between cells and their tissue microenvironments. The architecture and composition of actin networks are modulated by force, but it is unclear how interactions between actin filaments (F-actin) and associated proteins are mechanically regulated. Here, we employ both optical trapping and biochemical reconstitution with myosin motor proteins to show single piconewton forces applied solely to F-actin enhance binding by the human version of the essential cell-cell adhesion protein αE-catenin, but not its homolog vinculin. Cryo-electron microscopy structures of both proteins bound to F-actin reveal unique rearrangements that facilitate their flexible C-termini refolding to engage distinct interfaces. Truncating α-catenin's C-terminus eliminates force-activated F-actin binding, and addition of this motif to vinculin confers force-activated binding, demonstrating that α-catenin's C-terminus is a modular detector of F-actin tension. Our studies establish that piconewton force on F-actin can enhance partner binding, which we propose mechanically regulates cellular adhesion through a-catenin.

Background and purposeCardiovascular diseases and dementia are two major diseases in the elderly. Atherosclerosis is associated with future vascular events and cognitive impairment. The PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE) study is a population-based prospective cohort study with comprehensive evaluation of multiterritorial artery stenosis and plaque using advanced vascular imaging techniques and prospective collection of vascular events and cognitive assessments.MethodsBetween May 2017 and September 2019, the PRECISE study enrolled 3067 community-dwelling adults with ages between 50 and 75 years cluster sampled from six villages and four communities of Lishui city in China. Data are collected in face-to-face interviews at baseline, 2-year and 4-year follow-up visits. Brain MRI including high-resolution sequences for intracranial and carotidal arteries and CT angiography for thoracoabdominal arteries were performed at baseline and will be rescanned after 4 years. Cardiovascular/cerebrovascular events and cognitive assessment will be prospectively collected after the enrollment. Blood and urine samples were collected and biomarkers were tested at baseline.ResultsA total of 3067 subjects were enrolled, among which 53.5% were female with an average age of 61.2±6.7 years. Among them, 2.8%, 8.1%, 43.1% and 21.6% had a history of stroke, coronary heart diseases, hypertension and diabetes mellitus, respectively.ConclusionsThe PRECISE study is a population-based prospective cohort study with comprehensive evaluation of atherosclerotic stenosis and plaque using advanced vascular imaging techniques. Data from this cohort provide us an opportunity to precisely evaluate polyvascular atherosclerosis and its association with future vascular events and cognitive impairment.Trial registration numberClinicalTrials.gov Registry (NCT03178448).

. Hypertension alters GABA receptor-mediated inhibition of neurons in the nucleus of the solitary tract. Am J Physiol Regul Integr Comp Physiol 285: R1276-R1286, 2003 10.1152/ajpregu. 00255.2003.-Previous studies have demonstrated that microinjection of baclofen, a GABA B receptor agonist, into the nucleus of the solitary tract (NTS) results in an enhanced pressor response in hypertensive (HT) rats compared with normotensive (NT) rats, suggesting a possible alteration in the responses of neurons in this area to activation of GABA B receptors. The following studies were designed to determine whether HT alters the sensitivity of neurons in the NTS to GABA receptor agonists. Sham-operated NT and unilateral nephrectomized, renal-wrap HT Sprague-Dawley rats were anesthetized, and the responses of NTS neurons receiving aortic nerve (AN) afferent inputs to iontophoretic application of GABA, the GABA A receptor agonist muscimol, and the GABA B agonist baclofen were examined. The AN input was classified as monosynaptic (MSN) if the cell responded to each of two stimuli separated by 5 ms with an action potential. If the cell did not respond, the input was considered polysynaptic (PSN). In MSNs, inhibition of AN-evoked discharge by GABA was not altered in 1 wk of HT but was reduced in 4 wk of HT, whereas in PSNs, sensitivity to GABA was reduced at 1 and 4 wk of HT. In HT rats, inhibition of AN-evoked discharge by baclofen was enhanced in MSNs, but not in PSNs, after 1 and 4 wk of HT, whereas inhibition by muscimol was reduced in MSNs and PSNs at 1 and 4 wk of HT. Changes in sensitivity to muscimol and baclofen within MSNs were the same whether the MSN received a slowly or a rapidly conducted AN afferent input. The results demonstrate that early in HT the sensitivity of NTS neurons to inhibitory amino acids is altered and that these changes are maintained for Ն4 wk. The alterations are dependent on the subtype of GABA receptor being activated and whether the neuron receives a mono-or polysynaptic baroreceptor afferent input. (12), and GABA B receptors are metabotropic, G protein-coupled receptors that mediate presynaptic and postsynaptic inhibition by reductions in calcium conductance or increases in potassium conductance, respectively (8). Activation of GABA A receptors on NTS neurons results in chloride-dependent membrane hyperpolarization and inhibition of baroreceptor-evoked discharge (10,19). Activation of GABA B receptors can evoke presynaptic and/or postsynaptic inhibition of NTS neurons (1, 19) and inhibit baroreceptor-evoked discharge in NTS neurons (19).The sensitivity of NTS neurons to the selective GABA A agonist muscimol was the same whether the neuron received a monosynaptic or a polysynaptic aortic nerve (AN) input (19). In contrast, NTS neurons receiving a monosynaptic AN input were much less sensitive to the inhibitory effects of the GABA B agonist baclofen than were NTS neurons receiving a polysynaptic AN input (19). An in vitro study reported that presynaptic inhibition of monosynaptic tractus inputs t...