Outstanding user reported satisfaction for light emitting diodes under-eye rejuvenation.

The under-eye region is an area of significant cosmetic concern. Photobiomodulation (PBM) has emerged as an effective, safe, inexpensive, and convenient treatment for skin rejuvenation. Herein, we aim to evaluate the safety and efficacy of a LED under-eye device for under-eye rejuvenation, as measured by objective and patient reported outcomes. Eleven participants self-administered treatment using a commercially available LED device emitting red (633 nm) and near infrared (830 nm) light for six weeks. Standardized photographs and questionnaires were administered at baseline and six weeks. Photographic digital analysis indicated an improvement in under-eye wrinkles at six weeks compared to baseline, with a reduction in wrinkle score from 20.05 to 19.72. However, this finding was not statistically significant. Participants self-reported consistent improvements in under-eye wrinkles, texture, dark circles, bags, pigmentation, and erythema. All participants reported a high degree of comfortability, ease of use, and satisfaction with the eye device. The participants noted no moderate or severe adverse events and few reports of transient expected outcomes such as mild erythema. The participants' self-reported improvements and high user satisfaction, and the device's favorable safety profile, highlights the benefits of at-home LED devices for under-eye rejuvenation. Future randomized controlled trials with larger sample sizes could further establish the safety and efficacy of at-home LED under-eye treatments.

Fibroblast growth factor homologous factors serve as a molecular rheostat in tuning arrhythmogenic cardiac late sodium current.

Voltage-gated sodium (Nav1.5) channels support the genesis and brisk spatial propagation of action potentials in the heart. Disruption of NaV1.5 inactivation results in a small persistent Na influx known as late Na current (I Na,L), which has emerged as a common pathogenic mechanism in both congenital and acquired cardiac arrhythmogenic syndromes. Here, using low-noise multi-channel recordings in heterologous systems, LQTS3 patient-derived iPSCs cardiomyocytes, and mouse ventricular myocytes, we demonstrate that the intracellular fibroblast growth factor homologous factors (FHF1-4) tune pathogenic I Na,L in an isoform-specific manner. This scheme suggests a complex orchestration of I Na,L in cardiomyocytes that may contribute to variable disease expressivity of NaV1.5 channelopathies. We further leverage these observations to engineer a peptide-inhibitor of I Na,L with a higher efficacy as compared to a well-established small-molecule inhibitor. Overall, these findings lend insights into molecular mechanisms underlying FHF regulation of I Na,L in pathophysiology and outline potential therapeutic avenues.

Probing ion channel macromolecular interactions using fluorescence resonance energy transfer.

Ion channels are macromolecular complexes whose functions are exquisitely tuned by interacting proteins. Fluorescence resonance energy transfer (FRET) is a powerful methodology that is adept at quantifying ion channel protein-protein interactions in living cells. For FRET experiments, the interacting partners are tagged with appropriate donor and acceptor fluorescent proteins. If the fluorescently-labeled molecules are in close proximity, then photoexcitation of the donor results in non-radiative energy transfer to the acceptor, and subsequent fluorescence emission of the acceptor. The stoichiometry of ion channel interactions and their relative binding affinities can be deduced by quantifying both the FRET efficiency and the total number of donors and acceptors in a given cell. In this chapter, we discuss general considerations for FRET analysis of biological interactions, various strategies for estimating FRET efficiencies, and detailed protocols for construction of binding curves and determination of stoichiometry. We focus on implementation of FRET assays using a flow cytometer given its amenability for high-throughput data acquisition, enhanced accessibility, and robust analysis. This versatile methodology permits mechanistic dissection of dynamic changes in ion channel interactions.