Biology subjects

Kononenko, N.

Publications and source records attributed to Kononenko, N..

5 recordsLinked to original sources

bioRxiv2025

Gene Therapy for Efficient Suppression of T-Type Channels in Treating Diabetic Neuropathy

Painful diabetic neuropathy (PDN), a chronic and often incurable syndrome, is one of the most common and unpleasant complications of diabetes. Effective clinical interventions for PDN are very limited and already developed approaches are characterized by lack of molecular or cellular target specificity and a short duration of therapeutic effects. Numerous investigations causally link upregulation of the Cav3.2 T-type Ca2+ channels in peripheral nociceptive neurons to painful symptoms of PDN. Here we suggest an approach to alleviate these symptoms based on implementation of virus-mediated cell-specific delivery of vectors expressing small hairpin RNAs (shRNAs). Processed by Dicer into specific small interfering RNA (siRNA), they would suppress the expression of T-type Ca2+ channels. In order to experimentally validate this approach, we have initially confirmed the ability of designed Dicer-substrate small interfering RNAs (DsiRNAs) to suppress expression of T-type channels in neurons of primary hippocampal and dorsal root ganglia (DRG) cultures. Target sequences of the effectively interfering DsiRNA were then used to design shRNAs and the coding sequences of shRNAs were cloned into the vector pAAV under U6 promotor. This plasmid was also proved to be effective in interference with expression of the T-type channels in the rat cultured DRG neurons. The expression cassette of this plasmid will be packed into AAV6 particles with tropism to unmyelinated fibers to suppress T-type channel expression in nociceptive DRG neurons and to alleviate painful symptoms of PDN.

neuroscience↗

bioRxiv2025

Nutrient stress activates Rab5b-mediated autophagy to remodel the synaptic proteome

Synaptic proteostasis is crucial for maintaining neuronal function and plasticity, yet how synapses adapt to metabolic stress remains poorly understood. Here, we show that nutrient deprivation, particularly serum withdrawal, induces robust autophagy-dependent remodeling of the synaptic proteome, while mTORC1 inhibition has more limited effects. Nutrient stress rapidly activates autophagy both globally and at synapses, with synaptic autophagy peaking within 1-2 hours of serum withdrawal. Mechanistically, we uncover that the LC3 lipidation complex (ATG5-ATG12-ATG16L1) is recruited to synapses via Rab5b-positive endosomes in a dynein-dependent manner. Live imaging reveals enhanced Rab5b-ATG16L1 co-trafficking and increased ATG5 mobility upon serum withdrawal, supporting a model of spatiotemporally controlled autophagy precursor delivery to synaptic compartments. Functionally, nutrient deprivation acutely dampens neuronal excitability in vitro, while a two-week fasting-mimicking diet in vivo triggers synaptic proteome remodeling that overlaps with starvation-induced autophagy cargo. In contrast, restriction of mTORC1-activating amino acids fails to induce comparable synaptic changes, suggesting that synaptic autophagy is regulated by nutrient signals beyond mTORC1. Our findings define a Rab5b-mediated trafficking mechanism that couples nutrient sensing to localized synaptic degradation, providing new insight into how neurons preserve proteostasis under metabolic challenge.

neuroscience↗

bioRxiv2025

The capability of plant-bacteria consortia to reduce the genotoxicity of unsymmetrical dimethylhydrazine in the environment

Unsymmetrical dimethylhydrazine (UDMH) despite its proven high toxicity continues to be used in rocket technology and some other areas of human activity. In this work, the ability of plant-bacteria consortia to reduce the genotoxicity of UDMH incomplete oxidation products was investigated. Genotoxicity was assessed using a specific lux-biosensor Escherichia coli MG1655 pAlkA-lux sensitive to DNA alkylation in cell. For microbiological biodegradation, the Bacillus subtilis KK1112 strain was obtained by the isolation from soil with a subsequent selection for resistance to high UDMH concentrations (more than 5000 MAC). Its ability to biodegrade UDMH was shown by observing the reduction of DNA alkylation of the KK1112-treated UDMH. The ability of KK1112 cells to act in a bacterial-plant consortium with following fodder halo-phytes was studied: Bromus inermis Leyss, Medicago varia Mart. and Phleum pratense L. A synergistic reduction in the alkylating properties of UDMH oxidation products was observed under the combined use of bacteria and plant seedlings. The greatest effect was obtained when bacteria was used in combination with B. inermis. It was shown that KK1112 cells accelerate the seedlings development and mitigate the growth inhibition that occurs during incubation with UDMH. The obtained results indicate that it is optimal to introduce the bacterium KK1112 in combination with B. inermis plants for soils in arid climate zones during reclamation after UDMH exposure.

ecology↗

bioRxiv2024

Endocytic adaptor AP-2 maintains Purkinje cell function by balancing cerebellar parallel and climbing fiber synapses

The selective loss of cerebellar Purkinje cells is a hallmark of various neurodegenerative movement disorders, yet the precise mechanism driving their degeneration remains enigmatic. Here, we show that the endocytic adaptor protein complex 2 (AP-2) is essential for the survival of Purkinje cells. Employing a multidisciplinary approach encompassing mouse genetics, viral tracing, ex vivo calcium imaging, and kinematic analysis, we demonstrate that mice lacking the {micro}-subunit of AP-2 in cerebellar Purkinje cells exhibit early-onset ataxia associated with progressive Purkinje cell degeneration. Importantly, we uncover that synaptic input dysfunctions, characterized by a predominance of parallel fiber (PF) over climbing fiber (CF) synapses, precede Purkinje cell loss. Mechanistically, we find that AP-2 localizes to Purkinje cell dendrites, where it interacts with the PF synapse-enriched protein GRID2IP. The loss of AP-2 results in proteasome-dependent degradation of GRID2IP and accumulation of the glutamate {delta}2 receptor (GLUR{delta}2) in distal Purkinje cell dendrites, leading to an excess of PF synapses while CF synapses are drastically reduced. The overrepresentation of PF synaptic input induces Purkinje cell hyperexcitation, which can be alleviated by enhancing synaptic glutamate clearance using the antibiotic ceftriaxone. Our findings demonstrate the critical role of AP-2 in preventing motor gait dysfunctions by regulating GRID2IP levels in Purkinje cells, thereby preserving the equilibrium of PF and CF synaptic inputs in a cell-autonomous manner.

neuroscience↗

bioRxiv2022

Autophagy regulates neuronal excitability by controlling cAMP/Protein Kinase A signaling

Autophagy provides nutrients during starvation and eliminates detrimental cellular components. However, accumulating evidence indicates that autophagy is not merely a housekeeping process. Here, we show that the protein AuTophaGy 5 (ATG5) functions in neurons to regulate the cAMP-dependent protein kinase A (PKA)-mediated phosphorylation of a synapse-confined proteome. This function of ATG5 is independent of bulk turnover of synaptic proteins and requires the targeting of PKA inhibitory R1 subunits to autophagosomes. Neuronal loss of ATG5 causes synaptic accumulation of PKA R1, which sequesters the PKA catalytic subunit and diminishes the cAMP/PKA-dependent phosphorylation of postsynaptic cytoskeletal proteins mediating AMPAR trafficking. Glutamatergic neurons-confined ATG5 deletion augments AMPAR-dependent excitatory neurotransmission and causes the appearance of spontaneous recurrent seizures in mice. Our findings identify a novel role of autophagy in regulating PKA signaling at glutamatergic synapses and suggest the PKA as a target for restoration of synaptic function in neurodegenerative conditions with autophagy dysfunction.

neuroscience↗